rename path ResourceOwner() to ProtectedResource()

small cleanup in paths, primarily splitting files
so that file contents are more clearly owned, which
should be a little better for readability and code
placement.

Also renames `ServicePrefix` to `BuildPrefix` in
anticipation of multi-service prefixes.

src/cli/backup/sharepoint_test.go

@@ -163,12 +163,11 @@ func (suite *SharePointUnitSuite) TestSharePointBackupCreateSelectors() {
 	)
 
 	table := []struct {
-		name            string
-		site            []string
-		weburl          []string
-		data            []string
-		expect          []string
-		expectScopesLen int
+		name   string
+		site   []string
+		weburl []string
+		data   []string
+		expect []string
 	}{
 		{
 			name:   "no sites or urls",
@@ -181,63 +180,54 @@ func (suite *SharePointUnitSuite) TestSharePointBackupCreateSelectors() {
 			expect: selectors.None(),
 		},
 		{
-			name:            "site wildcard",
-			site:            []string{flags.Wildcard},
-			expect:          bothIDs,
-			expectScopesLen: 2,
+			name:   "site wildcard",
+			site:   []string{flags.Wildcard},
+			expect: bothIDs,
 		},
 		{
-			name:            "url wildcard",
-			weburl:          []string{flags.Wildcard},
-			expect:          bothIDs,
-			expectScopesLen: 2,
+			name:   "url wildcard",
+			weburl: []string{flags.Wildcard},
+			expect: bothIDs,
 		},
 		{
-			name:            "sites",
-			site:            []string{id1, id2},
-			expect:          []string{id1, id2},
-			expectScopesLen: 2,
+			name:   "sites",
+			site:   []string{id1, id2},
+			expect: []string{id1, id2},
 		},
 		{
-			name:            "urls",
-			weburl:          []string{url1, url2},
-			expect:          []string{url1, url2},
-			expectScopesLen: 2,
+			name:   "urls",
+			weburl: []string{url1, url2},
+			expect: []string{url1, url2},
 		},
 		{
-			name:            "mix sites and urls",
-			site:            []string{id1},
-			weburl:          []string{url2},
-			expect:          []string{id1, url2},
-			expectScopesLen: 2,
+			name:   "mix sites and urls",
+			site:   []string{id1},
+			weburl: []string{url2},
+			expect: []string{id1, url2},
 		},
 		{
-			name:            "duplicate sites and urls",
-			site:            []string{id1, id2},
-			weburl:          []string{url1, url2},
-			expect:          []string{id1, id2, url1, url2},
-			expectScopesLen: 2,
+			name:   "duplicate sites and urls",
+			site:   []string{id1, id2},
+			weburl: []string{url1, url2},
+			expect: []string{id1, id2, url1, url2},
 		},
 		{
-			name:            "unnecessary site wildcard",
-			site:            []string{id1, flags.Wildcard},
-			weburl:          []string{url1, url2},
-			expect:          bothIDs,
-			expectScopesLen: 2,
+			name:   "unnecessary site wildcard",
+			site:   []string{id1, flags.Wildcard},
+			weburl: []string{url1, url2},
+			expect: bothIDs,
 		},
 		{
-			name:            "unnecessary url wildcard",
-			site:            []string{id1},
-			weburl:          []string{url1, flags.Wildcard},
-			expect:          bothIDs,
-			expectScopesLen: 2,
+			name:   "unnecessary url wildcard",
+			site:   []string{id1},
+			weburl: []string{url1, flags.Wildcard},
+			expect: bothIDs,
 		},
 		{
-			name:            "Pages",
-			site:            bothIDs,
-			data:            []string{dataPages},
-			expect:          bothIDs,
-			expectScopesLen: 1,
+			name:   "Pages",
+			site:   bothIDs,
+			data:   []string{dataPages},
+			expect: bothIDs,
 		},
 	}
 	for _, test := range table {
@@ -249,7 +239,7 @@ func (suite *SharePointUnitSuite) TestSharePointBackupCreateSelectors() {
 
 			sel, err := sharePointBackupCreateSelectors(ctx, ins, test.site, test.weburl, test.data)
 			require.NoError(t, err, clues.ToCore(err))
-			assert.ElementsMatch(t, test.expect, sel.DiscreteResourceOwners())
+			assert.ElementsMatch(t, test.expect, sel.ResourceOwners.Targets)
 		})
 	}
 }

src/internal/kopia/backup_bases.go

@@ -8,6 +8,7 @@ import (
 	"golang.org/x/exp/slices"
 
 	"github.com/alcionai/corso/src/internal/version"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/logger"
 )
 
@@ -25,7 +26,7 @@ type BackupBases interface {
 	MergeBackupBases(
 		ctx context.Context,
 		other BackupBases,
-		reasonToKey func(Reasoner) string,
+		reasonToKey func(identity.Reasoner) string,
 	) BackupBases
 }
 
@@ -131,7 +132,7 @@ func (bb *backupBases) ClearAssistBases() {
 func (bb *backupBases) MergeBackupBases(
 	ctx context.Context,
 	other BackupBases,
-	reasonToKey func(reason Reasoner) string,
+	reasonToKey func(reason identity.Reasoner) string,
 ) BackupBases {
 	if other == nil || (len(other.MergeBases()) == 0 && len(other.AssistBases()) == 0) {
 		return bb
@@ -165,7 +166,7 @@ func (bb *backupBases) MergeBackupBases(
 
 	// Calculate the set of mergeBases to pull from other into this one.
 	for _, m := range other.MergeBases() {
-		useReasons := []Reasoner{}
+		useReasons := []identity.Reasoner{}
 
 		for _, r := range m.Reasons {
 			k := reasonToKey(r)
@@ -216,7 +217,7 @@ func (bb *backupBases) MergeBackupBases(
 
 	// Add assistBases from other to this one as needed.
 	for _, m := range other.AssistBases() {
-		useReasons := []Reasoner{}
+		useReasons := []identity.Reasoner{}
 
 		// Assume that all complete manifests in assist overlap with MergeBases.
 		if len(m.IncompleteReason) == 0 {

src/internal/kopia/backup_bases_test.go

@@ -13,10 +13,11 @@ import (
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/internal/version"
 	"github.com/alcionai/corso/src/pkg/backup"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
-func makeManifest(id, incmpl, bID string, reasons ...Reasoner) ManifestEntry {
+func makeManifest(id, incmpl, bID string, reasons ...identity.Reasoner) ManifestEntry {
 	bIDKey, _ := makeTagKV(TagBackupID)
 
 	return ManifestEntry{
@@ -223,7 +224,7 @@ func (suite *BackupBasesUnitSuite) TestMergeBackupBases() {
 				ir = "checkpoint"
 			}
 
-			reasons := make([]Reasoner, 0, len(i.cat))
+			reasons := make([]identity.Reasoner, 0, len(i.cat))
 
 			for _, c := range i.cat {
 				reasons = append(reasons, NewReason("", ro, path.ExchangeService, c))
@@ -453,7 +454,7 @@ func (suite *BackupBasesUnitSuite) TestMergeBackupBases() {
 			got := bb.MergeBackupBases(
 				ctx,
 				other,
-				func(r Reasoner) string {
+				func(r identity.Reasoner) string {
 					return r.Service().String() + r.Category().String()
 				})
 			AssertBackupBasesEqual(t, expect, got)

src/internal/kopia/base_finder.go

@@ -12,6 +12,7 @@ import (
 	"github.com/alcionai/corso/src/internal/model"
 	"github.com/alcionai/corso/src/internal/operations/inject"
 	"github.com/alcionai/corso/src/pkg/backup"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
 )
@@ -29,23 +30,11 @@ const (
 	userTagPrefix = "tag:"
 )
 
-// TODO(ashmrtn): Move this into some inject package. Here to avoid import
-// cycles.
-type Reasoner interface {
-	Tenant() string
-	ProtectedResource() string
-	Service() path.ServiceType
-	Category() path.CategoryType
-	// SubtreePath returns the path prefix for data in existing backups that have
-	// parameters (tenant, protected resourced, etc) that match this Reasoner.
-	SubtreePath() (path.Path, error)
-}
-
 func NewReason(
 	tenant, resource string,
 	service path.ServiceType,
 	category path.CategoryType,
-) Reasoner {
+) identity.Reasoner {
 	return reason{
 		tenant:   tenant,
 		resource: resource,
@@ -81,7 +70,7 @@ func (r reason) Category() path.CategoryType {
 }
 
 func (r reason) SubtreePath() (path.Path, error) {
-	p, err := path.ServicePrefix(
+	p, err := path.BuildPrefix(
 		r.Tenant(),
 		r.ProtectedResource(),
 		r.Service(),
@@ -90,7 +79,7 @@ func (r reason) SubtreePath() (path.Path, error) {
 	return p, clues.Wrap(err, "building path").OrNil()
 }
 
-func tagKeys(r Reasoner) []string {
+func tagKeys(r identity.Reasoner) []string {
 	return []string{
 		r.ProtectedResource(),
 		serviceCatString(r.Service(), r.Category()),
@@ -98,13 +87,13 @@ func tagKeys(r Reasoner) []string {
 }
 
 // reasonKey returns the concatenation of the ProtectedResource, Service, and Category.
-func reasonKey(r Reasoner) string {
+func reasonKey(r identity.Reasoner) string {
 	return r.ProtectedResource() + r.Service().String() + r.Category().String()
 }
 
 type BackupEntry struct {
 	*backup.Backup
-	Reasons []Reasoner
+	Reasons []identity.Reasoner
 }
 
 type ManifestEntry struct {
@@ -116,7 +105,7 @@ type ManifestEntry struct {
 	// 1. backup user1 email,contacts -> B1
 	// 2. backup user1 contacts -> B2 (uses B1 as base)
 	// 3. backup user1 email,contacts,events (uses B1 for email, B2 for contacts)
-	Reasons []Reasoner
+	Reasons []identity.Reasoner
 }
 
 func (me ManifestEntry) GetTag(key string) (string, bool) {
@@ -212,7 +201,7 @@ func (b *baseFinder) getBackupModel(
 // most recent complete backup as the base.
 func (b *baseFinder) findBasesInSet(
 	ctx context.Context,
-	reason Reasoner,
+	reason identity.Reasoner,
 	metas []*manifest.EntryMetadata,
 ) (*BackupEntry, *ManifestEntry, []ManifestEntry, error) {
 	// Sort manifests by time so we can go through them sequentially. The code in
@@ -245,7 +234,7 @@ func (b *baseFinder) findBasesInSet(
 
 				kopiaAssistSnaps = append(kopiaAssistSnaps, ManifestEntry{
 					Manifest: man,
-					Reasons:  []Reasoner{reason},
+					Reasons:  []identity.Reasoner{reason},
 				})
 
 				logger.Ctx(ictx).Info("found incomplete backup")
@@ -266,7 +255,7 @@ func (b *baseFinder) findBasesInSet(
 
 				kopiaAssistSnaps = append(kopiaAssistSnaps, ManifestEntry{
 					Manifest: man,
-					Reasons:  []Reasoner{reason},
+					Reasons:  []identity.Reasoner{reason},
 				})
 
 				logger.Ctx(ictx).Info("found incomplete backup")
@@ -290,7 +279,7 @@ func (b *baseFinder) findBasesInSet(
 
 				kopiaAssistSnaps = append(kopiaAssistSnaps, ManifestEntry{
 					Manifest: man,
-					Reasons:  []Reasoner{reason},
+					Reasons:  []identity.Reasoner{reason},
 				})
 
 				logger.Ctx(ictx).Infow(
@@ -308,13 +297,13 @@ func (b *baseFinder) findBasesInSet(
 
 		me := ManifestEntry{
 			Manifest: man,
-			Reasons:  []Reasoner{reason},
+			Reasons:  []identity.Reasoner{reason},
 		}
 		kopiaAssistSnaps = append(kopiaAssistSnaps, me)
 
 		return &BackupEntry{
 			Backup:  bup,
-			Reasons: []Reasoner{reason},
+			Reasons: []identity.Reasoner{reason},
 		}, &me, kopiaAssistSnaps, nil
 	}
 
@@ -325,7 +314,7 @@ func (b *baseFinder) findBasesInSet(
 
 func (b *baseFinder) getBase(
 	ctx context.Context,
-	r Reasoner,
+	r identity.Reasoner,
 	tags map[string]string,
 ) (*BackupEntry, *ManifestEntry, []ManifestEntry, error) {
 	allTags := map[string]string{}
@@ -352,7 +341,7 @@ func (b *baseFinder) getBase(
 
 func (b *baseFinder) FindBases(
 	ctx context.Context,
-	reasons []Reasoner,
+	reasons []identity.Reasoner,
 	tags map[string]string,
 ) BackupBases {
 	var (

src/internal/kopia/base_finder_test.go

@@ -14,6 +14,7 @@ import (
 	"github.com/alcionai/corso/src/internal/model"
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/pkg/backup"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/path"
 )
 
@@ -39,7 +40,7 @@ var (
 	testUser2 = "user2"
 	testUser3 = "user3"
 
-	testAllUsersAllCats = []Reasoner{
+	testAllUsersAllCats = []identity.Reasoner{
 		// User1 email and events.
 		NewReason("", testUser1, path.ExchangeService, path.EmailCategory),
 		NewReason("", testUser1, path.ExchangeService, path.EventsCategory),
@@ -50,12 +51,12 @@ var (
 		NewReason("", testUser3, path.ExchangeService, path.EmailCategory),
 		NewReason("", testUser3, path.ExchangeService, path.EventsCategory),
 	}
-	testAllUsersMail = []Reasoner{
+	testAllUsersMail = []identity.Reasoner{
 		NewReason("", testUser1, path.ExchangeService, path.EmailCategory),
 		NewReason("", testUser2, path.ExchangeService, path.EmailCategory),
 		NewReason("", testUser3, path.ExchangeService, path.EmailCategory),
 	}
-	testUser1Mail = []Reasoner{
+	testUser1Mail = []identity.Reasoner{
 		NewReason("", testUser1, path.ExchangeService, path.EmailCategory),
 	}
 )
@@ -285,7 +286,7 @@ func (suite *BaseFinderUnitSuite) TestNoResult_NoBackupsOrSnapshots() {
 		sm: mockEmptySnapshotManager{},
 		bg: mockEmptyModelGetter{},
 	}
-	reasons := []Reasoner{
+	reasons := []identity.Reasoner{
 		NewReason("", "a-user", path.ExchangeService, path.EmailCategory),
 	}
 
@@ -304,7 +305,7 @@ func (suite *BaseFinderUnitSuite) TestNoResult_ErrorListingSnapshots() {
 		sm: &mockSnapshotManager{findErr: assert.AnError},
 		bg: mockEmptyModelGetter{},
 	}
-	reasons := []Reasoner{
+	reasons := []identity.Reasoner{
 		NewReason("", "a-user", path.ExchangeService, path.EmailCategory),
 	}
 
@@ -316,14 +317,14 @@ func (suite *BaseFinderUnitSuite) TestNoResult_ErrorListingSnapshots() {
 func (suite *BaseFinderUnitSuite) TestGetBases() {
 	table := []struct {
 		name         string
-		input        []Reasoner
+		input        []identity.Reasoner
 		manifestData []manifestInfo
 		// Use this to denote the Reasons a base backup or base manifest is
 		// selected. The int maps to the index of the backup or manifest in data.
-		expectedBaseReasons map[int][]Reasoner
+		expectedBaseReasons map[int][]identity.Reasoner
 		// Use this to denote the Reasons a kopia assised incrementals manifest is
 		// selected. The int maps to the index of the manifest in data.
-		expectedAssistManifestReasons map[int][]Reasoner
+		expectedAssistManifestReasons map[int][]identity.Reasoner
 		backupData                    []backupInfo
 	}{
 		{
@@ -349,10 +350,10 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser1,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				1: testUser1Mail,
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				1: testUser1Mail,
 			},
 			backupData: []backupInfo{
@@ -383,10 +384,10 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser1,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				1: testUser1Mail,
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 				1: testUser1Mail,
 			},
@@ -418,10 +419,10 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser1,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				1: testUser1Mail,
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 				1: testUser1Mail,
 			},
@@ -447,10 +448,10 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser3,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
 			backupData: []backupInfo{
@@ -474,10 +475,10 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser3,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				0: testAllUsersAllCats,
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				0: testAllUsersAllCats,
 			},
 			backupData: []backupInfo{
@@ -512,7 +513,7 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser3,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				0: {
 					NewReason("", testUser1, path.ExchangeService, path.EmailCategory),
 					NewReason("", testUser2, path.ExchangeService, path.EmailCategory),
@@ -524,7 +525,7 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					NewReason("", testUser3, path.ExchangeService, path.EventsCategory),
 				},
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				0: {
 					NewReason("", testUser1, path.ExchangeService, path.EmailCategory),
 					NewReason("", testUser2, path.ExchangeService, path.EmailCategory),
@@ -564,10 +565,10 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser1,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 				1: testUser1Mail,
 			},
@@ -600,10 +601,10 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser1,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				1: testUser1Mail,
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				1: testUser1Mail,
 			},
 			backupData: []backupInfo{
@@ -635,8 +636,8 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser1,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{},
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				1: testUser1Mail,
 			},
 			backupData: []backupInfo{
@@ -659,10 +660,10 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser1,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
 			backupData: []backupInfo{
@@ -694,10 +695,10 @@ func (suite *BaseFinderUnitSuite) TestGetBases() {
 					testUser1,
 				),
 			},
-			expectedBaseReasons: map[int][]Reasoner{
+			expectedBaseReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
-			expectedAssistManifestReasons: map[int][]Reasoner{
+			expectedAssistManifestReasons: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
 			backupData: []backupInfo{
@@ -764,17 +765,17 @@ func (suite *BaseFinderUnitSuite) TestFindBases_CustomTags() {
 
 	table := []struct {
 		name  string
-		input []Reasoner
+		input []identity.Reasoner
 		tags  map[string]string
 		// Use this to denote which manifests in data should be expected. Allows
 		// defining data in a table while not repeating things between data and
 		// expected.
-		expectedIdxs map[int][]Reasoner
+		expectedIdxs map[int][]identity.Reasoner
 	}{
 		{
 			name: "no tags specified",
 			tags: nil,
-			expectedIdxs: map[int][]Reasoner{
+			expectedIdxs: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
 		},
@@ -784,14 +785,14 @@ func (suite *BaseFinderUnitSuite) TestFindBases_CustomTags() {
 				"fnords": "",
 				"smarf":  "",
 			},
-			expectedIdxs: map[int][]Reasoner{
+			expectedIdxs: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
 		},
 		{
 			name: "subset of custom tags",
 			tags: map[string]string{"fnords": ""},
-			expectedIdxs: map[int][]Reasoner{
+			expectedIdxs: map[int][]identity.Reasoner{
 				0: testUser1Mail,
 			},
 		},
@@ -832,7 +833,7 @@ func checkManifestEntriesMatch(
 	t *testing.T,
 	retSnaps []ManifestEntry,
 	allExpected []manifestInfo,
-	expectedIdxsAndReasons map[int][]Reasoner,
+	expectedIdxsAndReasons map[int][]identity.Reasoner,
 ) {
 	// Check the proper snapshot manifests were returned.
 	expected := make([]*snapshot.Manifest, 0, len(expectedIdxsAndReasons))
@@ -848,7 +849,7 @@ func checkManifestEntriesMatch(
 	assert.ElementsMatch(t, expected, got)
 
 	// Check the reasons for selecting each manifest are correct.
-	expectedReasons := make(map[manifest.ID][]Reasoner, len(expectedIdxsAndReasons))
+	expectedReasons := make(map[manifest.ID][]identity.Reasoner, len(expectedIdxsAndReasons))
 	for idx, reasons := range expectedIdxsAndReasons {
 		expectedReasons[allExpected[idx].man.ID] = reasons
 	}
@@ -874,7 +875,7 @@ func checkBackupEntriesMatch(
 	t *testing.T,
 	retBups []BackupEntry,
 	allExpected []backupInfo,
-	expectedIdxsAndReasons map[int][]Reasoner,
+	expectedIdxsAndReasons map[int][]identity.Reasoner,
 ) {
 	// Check the proper snapshot manifests were returned.
 	expected := make([]*backup.Backup, 0, len(expectedIdxsAndReasons))
@@ -890,7 +891,7 @@ func checkBackupEntriesMatch(
 	assert.ElementsMatch(t, expected, got)
 
 	// Check the reasons for selecting each manifest are correct.
-	expectedReasons := make(map[model.StableID][]Reasoner, len(expectedIdxsAndReasons))
+	expectedReasons := make(map[model.StableID][]identity.Reasoner, len(expectedIdxsAndReasons))
 	for idx, reasons := range expectedIdxsAndReasons {
 		expectedReasons[allExpected[idx].b.ID] = reasons
 	}

src/internal/kopia/inject/inject.go

@@ -7,6 +7,7 @@ import (
 	"github.com/alcionai/corso/src/internal/data"
 	"github.com/alcionai/corso/src/internal/kopia"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 )
@@ -15,7 +16,7 @@ type (
 	BackupConsumer interface {
 		ConsumeBackupCollections(
 			ctx context.Context,
-			backupReasons []kopia.Reasoner,
+			backupReasons []identity.Reasoner,
 			bases kopia.BackupBases,
 			cs []data.BackupCollection,
 			pmr prefixmatcher.StringSetReader,
@@ -38,7 +39,7 @@ type (
 	BaseFinder interface {
 		FindBases(
 			ctx context.Context,
-			reasons []kopia.Reasoner,
+			reasons []identity.Reasoner,
 			tags map[string]string,
 		) kopia.BackupBases
 	}

src/internal/kopia/upload_test.go

@@ -24,6 +24,7 @@ import (
 	exchMock "github.com/alcionai/corso/src/internal/m365/exchange/mock"
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 )
@@ -951,7 +952,7 @@ func makeManifestEntry(
 	service path.ServiceType,
 	categories ...path.CategoryType,
 ) ManifestEntry {
-	var reasons []Reasoner
+	var reasons []identity.Reasoner
 
 	for _, c := range categories {
 		reasons = append(reasons, NewReason(tenant, resourceOwner, service, c))
@@ -2807,16 +2808,16 @@ func (suite *HierarchyBuilderUnitSuite) TestBuildDirectoryTreeSelectsMigrateSubt
 		migratedUser = "user_migrate"
 	)
 
-	oldPrefixPathEmail, err := path.ServicePrefix(testTenant, testUser, path.ExchangeService, path.EmailCategory)
+	oldPrefixPathEmail, err := path.BuildPrefix(testTenant, testUser, path.ExchangeService, path.EmailCategory)
 	require.NoError(t, err, clues.ToCore(err))
 
-	newPrefixPathEmail, err := path.ServicePrefix(testTenant, migratedUser, path.ExchangeService, path.EmailCategory)
+	newPrefixPathEmail, err := path.BuildPrefix(testTenant, migratedUser, path.ExchangeService, path.EmailCategory)
 	require.NoError(t, err, clues.ToCore(err))
 
-	oldPrefixPathCont, err := path.ServicePrefix(testTenant, testUser, path.ExchangeService, path.ContactsCategory)
+	oldPrefixPathCont, err := path.BuildPrefix(testTenant, testUser, path.ExchangeService, path.ContactsCategory)
 	require.NoError(t, err, clues.ToCore(err))
 
-	newPrefixPathCont, err := path.ServicePrefix(testTenant, migratedUser, path.ExchangeService, path.ContactsCategory)
+	newPrefixPathCont, err := path.BuildPrefix(testTenant, migratedUser, path.ExchangeService, path.ContactsCategory)
 	require.NoError(t, err, clues.ToCore(err))
 
 	var (

src/internal/kopia/wrapper.go

@@ -23,6 +23,7 @@ import (
 	"github.com/alcionai/corso/src/internal/operations/inject"
 	"github.com/alcionai/corso/src/internal/stats"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/control/repository"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
@@ -137,7 +138,7 @@ func (w *Wrapper) Close(ctx context.Context) error {
 // complete backup of all data.
 func (w Wrapper) ConsumeBackupCollections(
 	ctx context.Context,
-	backupReasons []Reasoner,
+	backupReasons []identity.Reasoner,
 	bases BackupBases,
 	collections []data.BackupCollection,
 	globalExcludeSet prefixmatcher.StringSetReader,

src/internal/kopia/wrapper_test.go

@@ -29,6 +29,7 @@ import (
 	"github.com/alcionai/corso/src/internal/m365/onedrive/metadata"
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/control/repository"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
@@ -800,16 +801,16 @@ func (suite *KopiaIntegrationSuite) TestBackupCollections() {
 		"brunhilda": "",
 	}
 
-	reasons := []Reasoner{
+	reasons := []identity.Reasoner{
 		NewReason(
 			testTenant,
-			suite.storePath1.ResourceOwner(),
+			suite.storePath1.ProtectedResource(),
 			suite.storePath1.Service(),
 			suite.storePath1.Category(),
 		),
 		NewReason(
 			testTenant,
-			suite.storePath2.ResourceOwner(),
+			suite.storePath2.ProtectedResource(),
 			suite.storePath2.Service(),
 			suite.storePath2.Category(),
 		),
@@ -1072,10 +1073,10 @@ func (suite *KopiaIntegrationSuite) TestBackupCollections_NoDetailsForMeta() {
 		"brunhilda": "",
 	}
 
-	reasons := []Reasoner{
+	reasons := []identity.Reasoner{
 		NewReason(
 			testTenant,
-			storePath.ResourceOwner(),
+			storePath.ProtectedResource(),
 			storePath.Service(),
 			storePath.Category()),
 	}
@@ -1267,7 +1268,7 @@ func (suite *KopiaIntegrationSuite) TestRestoreAfterCompressionChange() {
 
 	stats, _, _, err := w.ConsumeBackupCollections(
 		ctx,
-		[]Reasoner{r},
+		[]identity.Reasoner{r},
 		nil,
 		[]data.BackupCollection{dc1, dc2},
 		nil,
@@ -1385,7 +1386,7 @@ func (suite *KopiaIntegrationSuite) TestBackupCollections_ReaderError() {
 
 	stats, deets, _, err := suite.w.ConsumeBackupCollections(
 		suite.ctx,
-		[]Reasoner{r},
+		[]identity.Reasoner{r},
 		nil,
 		collections,
 		nil,
@@ -1618,7 +1619,7 @@ func (suite *KopiaSimpleRepoIntegrationSuite) SetupTest() {
 
 	stats, deets, _, err := suite.w.ConsumeBackupCollections(
 		suite.ctx,
-		[]Reasoner{r},
+		[]identity.Reasoner{r},
 		nil,
 		collections,
 		nil,
@@ -1745,11 +1746,11 @@ func (suite *KopiaSimpleRepoIntegrationSuite) TestBackupExcludeItem() {
 
 			stats, _, _, err := suite.w.ConsumeBackupCollections(
 				suite.ctx,
-				[]Reasoner{r},
+				[]identity.Reasoner{r},
 				NewMockBackupBases().WithMergeBases(
 					ManifestEntry{
 						Manifest: man,
-						Reasons:  []Reasoner{r},
+						Reasons:  []identity.Reasoner{r},
 					},
 				),
 				test.cols(),

src/internal/m365/graph/collections.go

@@ -79,7 +79,7 @@ func BaseCollections(
 	for cat := range categories {
 		ictx := clues.Add(ctx, "base_service", service, "base_category", cat)
 
-		full, err := path.ServicePrefix(tenant, rOwner, service, cat)
+		full, err := path.BuildPrefix(tenant, rOwner, service, cat)
 		if err != nil {
 			// Shouldn't happen.
 			err = clues.Wrap(err, "making path").WithClues(ictx)

src/internal/m365/graph/collections_test.go

@@ -24,10 +24,10 @@ func (suite *CollectionsUnitSuite) TestNewPrefixCollection() {
 	serv := path.OneDriveService
 	cat := path.FilesCategory
 
-	p1, err := path.ServicePrefix("t", "ro1", serv, cat)
+	p1, err := path.BuildPrefix("t", "ro1", serv, cat)
 	require.NoError(t, err, clues.ToCore(err))
 
-	p2, err := path.ServicePrefix("t", "ro2", serv, cat)
+	p2, err := path.BuildPrefix("t", "ro2", serv, cat)
 	require.NoError(t, err, clues.ToCore(err))
 
 	items, err := path.Build("t", "ro", serv, cat, true, "fld", "itm")

src/internal/m365/groups/restore.go

@@ -57,7 +57,7 @@ func ConsumeRestoreCollections(
 			ictx     = clues.Add(ctx,
 				"category", category,
 				"restore_location", clues.Hide(rcc.RestoreConfig.Location),
-				"protected_resource", clues.Hide(dc.FullPath().ResourceOwner()),
+				"protected_resource", clues.Hide(dc.FullPath().ProtectedResource()),
 				"full_path", dc.FullPath())
 		)
 

src/internal/m365/helper_test.go

@@ -942,7 +942,7 @@ func checkHasCollections(
 
 		p, err := loc.ToDataLayerPath(
 			fp.Tenant(),
-			fp.ResourceOwner(),
+			fp.ProtectedResource(),
 			fp.Service(),
 			fp.Category(),
 			false)

src/internal/m365/onedrive/backup.go

@@ -108,7 +108,7 @@ func migrationCollections(
 
 	// unlike exchange, which enumerates all folders on every
 	// backup, onedrive needs to force the owner PN -> ID migration
-	mc, err := path.ServicePrefix(
+	mc, err := path.BuildPrefix(
 		tenant,
 		bpc.ProtectedResource.ID(),
 		path.OneDriveService,
@@ -117,7 +117,7 @@ func migrationCollections(
 		return nil, clues.Wrap(err, "creating user id migration path")
 	}
 
-	mpc, err := path.ServicePrefix(
+	mpc, err := path.BuildPrefix(
 		tenant,
 		bpc.ProtectedResource.Name(),
 		path.OneDriveService,

src/internal/m365/onedrive_test.go

@@ -50,7 +50,7 @@ func mustGetDefaultDriveID(
 	ctx context.Context, //revive:disable-line:context-as-argument
 	ac api.Client,
 	service path.ServiceType,
-	resourceOwner string,
+	protectedResource string,
 ) string {
 	var (
 		err error
@@ -59,9 +59,9 @@ func mustGetDefaultDriveID(
 
 	switch service {
 	case path.OneDriveService:
-		d, err = ac.Users().GetDefaultDrive(ctx, resourceOwner)
+		d, err = ac.Users().GetDefaultDrive(ctx, protectedResource)
 	case path.SharePointService:
-		d, err = ac.Sites().GetDefaultDrive(ctx, resourceOwner)
+		d, err = ac.Sites().GetDefaultDrive(ctx, protectedResource)
 	default:
 		assert.FailNowf(t, "unknown service type %s", service.String())
 	}
@@ -86,10 +86,10 @@ type suiteInfo interface {
 	PrimaryUser() (string, string)
 	SecondaryUser() (string, string)
 	TertiaryUser() (string, string)
-	// ResourceOwner returns the resource owner to run the backup/restore
+	// ProtectedResource returns the resource owner to run the backup/restore
 	// with. This can be different from the values used for permissions and it can
 	// also be a site.
-	ResourceOwner() string
+	ProtectedResource() string
 	Service() path.ServiceType
 	Resource() resource.Category
 }
@@ -100,23 +100,23 @@ type oneDriveSuite interface {
 }
 
 type suiteInfoImpl struct {
-	ac               api.Client
-	controller       *Controller
-	resourceOwner    string
-	resourceCategory resource.Category
-	secondaryUser    string
-	secondaryUserID  string
-	service          path.ServiceType
-	tertiaryUser     string
-	tertiaryUserID   string
-	user             string
-	userID           string
+	ac                api.Client
+	controller        *Controller
+	protectedResource string
+	resourceCategory  resource.Category
+	secondaryUser     string
+	secondaryUserID   string
+	service           path.ServiceType
+	tertiaryUser      string
+	tertiaryUserID    string
+	user              string
+	userID            string
 }
 
 func NewSuiteInfoImpl(
 	t *testing.T,
 	ctx context.Context, //revive:disable-line:context-as-argument
-	resourceOwner string,
+	protectedResource string,
 	service path.ServiceType,
 ) suiteInfoImpl {
 	rsc := resource.Users
@@ -127,14 +127,14 @@ func NewSuiteInfoImpl(
 	ctrl := newController(ctx, t, rsc, path.OneDriveService)
 
 	return suiteInfoImpl{
-		ac:               ctrl.AC,
-		controller:       ctrl,
-		resourceOwner:    resourceOwner,
-		resourceCategory: rsc,
-		secondaryUser:    tconfig.SecondaryM365UserID(t),
-		service:          service,
-		tertiaryUser:     tconfig.TertiaryM365UserID(t),
-		user:             tconfig.M365UserID(t),
+		ac:                ctrl.AC,
+		controller:        ctrl,
+		protectedResource: protectedResource,
+		resourceCategory:  rsc,
+		secondaryUser:     tconfig.SecondaryM365UserID(t),
+		service:           service,
+		tertiaryUser:      tconfig.TertiaryM365UserID(t),
+		user:              tconfig.M365UserID(t),
 	}
 }
 
@@ -158,8 +158,8 @@ func (si suiteInfoImpl) TertiaryUser() (string, string) {
 	return si.tertiaryUser, si.tertiaryUserID
 }
 
-func (si suiteInfoImpl) ResourceOwner() string {
-	return si.resourceOwner
+func (si suiteInfoImpl) ProtectedResource() string {
+	return si.protectedResource
 }
 
 func (si suiteInfoImpl) Service() path.ServiceType {
@@ -388,7 +388,7 @@ func testRestoreAndBackupMultipleFilesAndFoldersNoPermissions(
 		ctx,
 		suite.APIClient(),
 		suite.Service(),
-		suite.ResourceOwner())
+		suite.ProtectedResource())
 
 	rootPath := []string{
 		odConsts.DrivesPathDir,
@@ -526,7 +526,7 @@ func testRestoreAndBackupMultipleFilesAndFoldersNoPermissions(
 				t,
 				testData,
 				suite.Tenant(),
-				[]string{suite.ResourceOwner()},
+				[]string{suite.ProtectedResource()},
 				control.DefaultOptions(),
 				restoreCfg)
 		})
@@ -547,7 +547,7 @@ func testPermissionsRestoreAndBackup(suite oneDriveSuite, startVersion int) {
 		ctx,
 		suite.APIClient(),
 		suite.Service(),
-		suite.ResourceOwner())
+		suite.ProtectedResource())
 
 	fileName2 := "test-file2.txt"
 	folderCName := "folder-c"
@@ -775,7 +775,7 @@ func testPermissionsRestoreAndBackup(suite oneDriveSuite, startVersion int) {
 				t,
 				testData,
 				suite.Tenant(),
-				[]string{suite.ResourceOwner()},
+				[]string{suite.ProtectedResource()},
 				control.DefaultOptions(),
 				restoreCfg)
 		})
@@ -796,7 +796,7 @@ func testRestoreNoPermissionsAndBackup(suite oneDriveSuite, startVersion int) {
 		ctx,
 		suite.APIClient(),
 		suite.Service(),
-		suite.ResourceOwner())
+		suite.ProtectedResource())
 
 	inputCols := []stub.ColInfo{
 		{
@@ -867,7 +867,7 @@ func testRestoreNoPermissionsAndBackup(suite oneDriveSuite, startVersion int) {
 				t,
 				testData,
 				suite.Tenant(),
-				[]string{suite.ResourceOwner()},
+				[]string{suite.ProtectedResource()},
 				control.DefaultOptions(),
 				restoreCfg)
 		})
@@ -891,7 +891,7 @@ func testPermissionsInheritanceRestoreAndBackup(suite oneDriveSuite, startVersio
 		ctx,
 		suite.APIClient(),
 		suite.Service(),
-		suite.ResourceOwner())
+		suite.ProtectedResource())
 
 	folderAName := "custom"
 	folderBName := "inherited"
@@ -1072,7 +1072,7 @@ func testPermissionsInheritanceRestoreAndBackup(suite oneDriveSuite, startVersio
 				t,
 				testData,
 				suite.Tenant(),
-				[]string{suite.ResourceOwner()},
+				[]string{suite.ProtectedResource()},
 				control.DefaultOptions(),
 				restoreCfg)
 		})
@@ -1094,7 +1094,7 @@ func testLinkSharesInheritanceRestoreAndBackup(suite oneDriveSuite, startVersion
 		ctx,
 		suite.APIClient(),
 		suite.Service(),
-		suite.ResourceOwner())
+		suite.ProtectedResource())
 
 	folderAName := "custom"
 	folderBName := "inherited"
@@ -1267,7 +1267,7 @@ func testLinkSharesInheritanceRestoreAndBackup(suite oneDriveSuite, startVersion
 				t,
 				testData,
 				suite.Tenant(),
-				[]string{suite.ResourceOwner()},
+				[]string{suite.ProtectedResource()},
 				control.DefaultOptions(),
 				restoreCfg)
 		})
@@ -1289,7 +1289,7 @@ func testRestoreFolderNamedFolderRegression(
 		ctx,
 		suite.APIClient(),
 		suite.Service(),
-		suite.ResourceOwner())
+		suite.ProtectedResource())
 
 	rootPath := []string{
 		odConsts.DrivesPathDir,
@@ -1383,7 +1383,7 @@ func testRestoreFolderNamedFolderRegression(
 				t,
 				testData,
 				suite.Tenant(),
-				[]string{suite.ResourceOwner()},
+				[]string{suite.ProtectedResource()},
 				control.DefaultOptions(),
 				restoreCfg)
 		})

src/internal/m365/sharepoint/collection.go

@@ -219,7 +219,7 @@ func (sc *Collection) retrieveLists(
 	lists, err := loadSiteLists(
 		ctx,
 		sc.client.Stable,
-		sc.fullPath.ResourceOwner(),
+		sc.fullPath.ProtectedResource(),
 		sc.jobs,
 		errs)
 	if err != nil {
@@ -282,14 +282,14 @@ func (sc *Collection) retrievePages(
 		return metrics, clues.New("beta service required").WithClues(ctx)
 	}
 
-	parent, err := as.GetByID(ctx, sc.fullPath.ResourceOwner())
+	parent, err := as.GetByID(ctx, sc.fullPath.ProtectedResource())
 	if err != nil {
 		return metrics, err
 	}
 
 	root := ptr.Val(parent.GetWebUrl())
 
-	pages, err := betaAPI.GetSitePages(ctx, betaService, sc.fullPath.ResourceOwner(), sc.jobs, errs)
+	pages, err := betaAPI.GetSitePages(ctx, betaService, sc.fullPath.ProtectedResource(), sc.jobs, errs)
 	if err != nil {
 		return metrics, err
 	}

src/internal/m365/sharepoint/restore.go

@@ -69,7 +69,7 @@ func ConsumeRestoreCollections(
 			ictx     = clues.Add(ctx,
 				"category", category,
 				"restore_location", clues.Hide(rcc.RestoreConfig.Location),
-				"resource_owner", clues.Hide(dc.FullPath().ResourceOwner()),
+				"resource_owner", clues.Hide(dc.FullPath().ProtectedResource()),
 				"full_path", dc.FullPath())
 		)
 
@@ -219,7 +219,7 @@ func RestoreListCollection(
 	var (
 		metrics   = support.CollectionMetrics{}
 		directory = dc.FullPath()
-		siteID    = directory.ResourceOwner()
+		siteID    = directory.ProtectedResource()
 		items     = dc.Items(ctx, errs)
 		el        = errs.Local()
 	)
@@ -292,7 +292,7 @@ func RestorePageCollection(
 	var (
 		metrics   = support.CollectionMetrics{}
 		directory = dc.FullPath()
-		siteID    = directory.ResourceOwner()
+		siteID    = directory.ProtectedResource()
 	)
 
 	trace.Log(ctx, "m365:sharepoint:restorePageCollection", directory.String())

src/internal/m365/stub/stub.go

@@ -183,7 +183,7 @@ func backupOutputPathFromRestore(
 
 	return path.Build(
 		inputPath.Tenant(),
-		inputPath.ResourceOwner(),
+		inputPath.ProtectedResource(),
 		inputPath.Service(),
 		inputPath.Category(),
 		false,

src/internal/operations/backup.go

@@ -26,6 +26,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/account"
 	"github.com/alcionai/corso/src/pkg/backup"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/count"
 	"github.com/alcionai/corso/src/pkg/fault"
@@ -276,11 +277,17 @@ func (op *BackupOperation) do(
 	detailsStore streamstore.Streamer,
 	backupID model.StableID,
 ) (*details.Builder, error) {
-	var (
-		reasons           = selectorToReasons(op.account.ID(), op.Selectors, false)
-		fallbackReasons   = makeFallbackReasons(op.account.ID(), op.Selectors)
-		lastBackupVersion = version.NoBackup
-	)
+	lastBackupVersion := version.NoBackup
+
+	reasons, err := op.Selectors.Reasons(op.account.ID(), false)
+	if err != nil {
+		return nil, clues.Wrap(err, "getting reasons")
+	}
+
+	fallbackReasons, err := makeFallbackReasons(op.account.ID(), op.Selectors)
+	if err != nil {
+		return nil, clues.Wrap(err, "getting fallback reasons")
+	}
 
 	logger.Ctx(ctx).With(
 		"control_options", op.Options,
@@ -367,13 +374,14 @@ func (op *BackupOperation) do(
 	return deets, nil
 }
 
-func makeFallbackReasons(tenant string, sel selectors.Selector) []kopia.Reasoner {
+func makeFallbackReasons(tenant string, sel selectors.Selector) ([]identity.Reasoner, error) {
 	if sel.PathService() != path.SharePointService &&
 		sel.DiscreteOwner != sel.DiscreteOwnerName {
-		return selectorToReasons(tenant, sel, true)
+		return sel.Reasons(tenant, true)
 	}
 
-	return nil
+	// return nil for fallback reasons since a nil value will no-op.
+	return nil, nil
 }
 
 // checker to see if conditions are correct for incremental backup behavior such as
@@ -415,41 +423,12 @@ func produceBackupDataCollections(
 // Consumer funcs
 // ---------------------------------------------------------------------------
 
-func selectorToReasons(
-	tenant string,
-	sel selectors.Selector,
-	useOwnerNameForID bool,
-) []kopia.Reasoner {
-	service := sel.PathService()
-	reasons := []kopia.Reasoner{}
-
-	pcs, err := sel.PathCategories()
-	if err != nil {
-		// This is technically safe, it's just that the resulting backup won't be
-		// usable as a base for future incremental backups.
-		return nil
-	}
-
-	owner := sel.DiscreteOwner
-	if useOwnerNameForID {
-		owner = sel.DiscreteOwnerName
-	}
-
-	for _, sl := range [][]path.CategoryType{pcs.Includes, pcs.Filters} {
-		for _, cat := range sl {
-			reasons = append(reasons, kopia.NewReason(tenant, owner, service, cat))
-		}
-	}
-
-	return reasons
-}
-
 // calls kopia to backup the collections of data
 func consumeBackupCollections(
 	ctx context.Context,
 	bc kinject.BackupConsumer,
 	tenantID string,
-	reasons []kopia.Reasoner,
+	reasons []identity.Reasoner,
 	bbs kopia.BackupBases,
 	cs []data.BackupCollection,
 	pmr prefixmatcher.StringSetReader,
@@ -501,9 +480,9 @@ func consumeBackupCollections(
 	return kopiaStats, deets, itemsSourcedFromBase, err
 }
 
-func matchesReason(reasons []kopia.Reasoner, p path.Path) bool {
+func matchesReason(reasons []identity.Reasoner, p path.Path) bool {
 	for _, reason := range reasons {
-		if p.ResourceOwner() == reason.ProtectedResource() &&
+		if p.ProtectedResource() == reason.ProtectedResource() &&
 			p.Service() == reason.Service() &&
 			p.Category() == reason.Category() {
 			return true

src/internal/operations/backup_test.go

@@ -27,6 +27,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/account"
 	"github.com/alcionai/corso/src/pkg/backup"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -107,7 +108,7 @@ func checkPaths(t *testing.T, expected, got []path.Path) {
 
 type mockBackupConsumer struct {
 	checkFunc func(
-		backupReasons []kopia.Reasoner,
+		backupReasons []identity.Reasoner,
 		bases kopia.BackupBases,
 		cs []data.BackupCollection,
 		tags map[string]string,
@@ -116,7 +117,7 @@ type mockBackupConsumer struct {
 
 func (mbu mockBackupConsumer) ConsumeBackupCollections(
 	ctx context.Context,
-	backupReasons []kopia.Reasoner,
+	backupReasons []identity.Reasoner,
 	bases kopia.BackupBases,
 	cs []data.BackupCollection,
 	excluded prefixmatcher.StringSetReader,
@@ -406,7 +407,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_ConsumeBackupDataCollections
 			path.ExchangeService,
 			path.ContactsCategory)
 
-		reasons = []kopia.Reasoner{
+		reasons = []identity.Reasoner{
 			emailReason,
 			contactsReason,
 		}
@@ -421,13 +422,13 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_ConsumeBackupDataCollections
 		bases = kopia.NewMockBackupBases().WithMergeBases(
 			kopia.ManifestEntry{
 				Manifest: manifest1,
-				Reasons: []kopia.Reasoner{
+				Reasons: []identity.Reasoner{
 					emailReason,
 				},
 			}).WithAssistBases(
 			kopia.ManifestEntry{
 				Manifest: manifest2,
-				Reasons: []kopia.Reasoner{
+				Reasons: []identity.Reasoner{
 					contactsReason,
 				},
 			})
@@ -441,7 +442,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_ConsumeBackupDataCollections
 
 	mbu := &mockBackupConsumer{
 		checkFunc: func(
-			backupReasons []kopia.Reasoner,
+			backupReasons []identity.Reasoner,
 			gotBases kopia.BackupBases,
 			cs []data.BackupCollection,
 			gotTags map[string]string,
@@ -537,12 +538,12 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 
 		pathReason1 = kopia.NewReason(
 			"",
-			itemPath1.ResourceOwner(),
+			itemPath1.ProtectedResource(),
 			itemPath1.Service(),
 			itemPath1.Category())
 		pathReason3 = kopia.NewReason(
 			"",
-			itemPath3.ResourceOwner(),
+			itemPath3.ProtectedResource(),
 			itemPath3.Service(),
 			itemPath3.Category())
 	)
@@ -590,7 +591,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 						},
 						DetailsID: "foo",
 					},
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
@@ -609,7 +610,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 			inputBackups: []kopia.BackupEntry{
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
@@ -636,13 +637,13 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 			inputBackups: []kopia.BackupEntry{
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
@@ -669,7 +670,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 			inputBackups: []kopia.BackupEntry{
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
@@ -684,7 +685,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 										[]string{
 											itemPath1.Tenant(),
 											itemPath1.Service().String(),
-											itemPath1.ResourceOwner(),
+											itemPath1.ProtectedResource(),
 											path.UnknownCategory.String(),
 										},
 										itemPath1.Folders()...,
@@ -713,7 +714,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 					[]string{
 						itemPath1.Tenant(),
 						path.OneDriveService.String(),
-						itemPath1.ResourceOwner(),
+						itemPath1.ProtectedResource(),
 						path.FilesCategory.String(),
 						"personal",
 						"item1",
@@ -728,7 +729,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 			inputBackups: []kopia.BackupEntry{
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
@@ -755,7 +756,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 			inputBackups: []kopia.BackupEntry{
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
@@ -785,7 +786,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 			inputBackups: []kopia.BackupEntry{
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
@@ -815,7 +816,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 			inputBackups: []kopia.BackupEntry{
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
@@ -846,7 +847,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 			inputBackups: []kopia.BackupEntry{
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
@@ -877,13 +878,13 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsItems
 			inputBackups: []kopia.BackupEntry{
 				{
 					Backup: &backup1,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason1,
 					},
 				},
 				{
 					Backup: &backup2,
-					Reasons: []kopia.Reasoner{
+					Reasons: []identity.Reasoner{
 						pathReason3,
 					},
 				},
@@ -972,7 +973,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsFolde
 
 		pathReason1 = kopia.NewReason(
 			"",
-			itemPath1.ResourceOwner(),
+			itemPath1.ProtectedResource(),
 			itemPath1.Service(),
 			itemPath1.Category())
 
@@ -983,7 +984,7 @@ func (suite *BackupOpUnitSuite) TestBackupOperation_MergeBackupDetails_AddsFolde
 				},
 				DetailsID: "did1",
 			},
-			Reasons: []kopia.Reasoner{
+			Reasons: []identity.Reasoner{
 				pathReason1,
 			},
 		}

src/internal/operations/manifests.go

@@ -10,6 +10,7 @@ import (
 	"github.com/alcionai/corso/src/internal/kopia"
 	"github.com/alcionai/corso/src/internal/kopia/inject"
 	"github.com/alcionai/corso/src/internal/m365/graph"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/logger"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -23,7 +24,7 @@ func produceManifestsAndMetadata(
 	ctx context.Context,
 	bf inject.BaseFinder,
 	rp inject.RestoreProducer,
-	reasons, fallbackReasons []kopia.Reasoner,
+	reasons, fallbackReasons []identity.Reasoner,
 	tenantID string,
 	getMetadata bool,
 ) (kopia.BackupBases, []data.RestoreCollection, bool, error) {
@@ -47,7 +48,7 @@ func produceManifestsAndMetadata(
 	bb = bb.MergeBackupBases(
 		ctx,
 		fbb,
-		func(r kopia.Reasoner) string {
+		func(r identity.Reasoner) string {
 			return r.Service().String() + r.Category().String()
 		})
 

src/internal/operations/manifests_test.go

@@ -15,6 +15,7 @@ import (
 	"github.com/alcionai/corso/src/internal/model"
 	"github.com/alcionai/corso/src/internal/tester"
 	"github.com/alcionai/corso/src/pkg/backup"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 )
@@ -47,7 +48,7 @@ type mockBackupFinder struct {
 
 func (bf *mockBackupFinder) FindBases(
 	_ context.Context,
-	reasons []kopia.Reasoner,
+	reasons []identity.Reasoner,
 	_ map[string]string,
 ) kopia.BackupBases {
 	if len(reasons) == 0 {
@@ -102,7 +103,7 @@ func (suite *OperationsManifestsUnitSuite) TestCollectMetadata() {
 	table := []struct {
 		name        string
 		manID       string
-		reasons     []kopia.Reasoner
+		reasons     []identity.Reasoner
 		fileNames   []string
 		expectPaths func(*testing.T, []string) []path.Path
 		expectErr   error
@@ -110,7 +111,7 @@ func (suite *OperationsManifestsUnitSuite) TestCollectMetadata() {
 		{
 			name:  "single reason, single file",
 			manID: "single single",
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason(tid, ro, path.ExchangeService, path.EmailCategory),
 			},
 			expectPaths: func(t *testing.T, files []string) []path.Path {
@@ -129,7 +130,7 @@ func (suite *OperationsManifestsUnitSuite) TestCollectMetadata() {
 		{
 			name:  "single reason, multiple files",
 			manID: "single multi",
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason(tid, ro, path.ExchangeService, path.EmailCategory),
 			},
 			expectPaths: func(t *testing.T, files []string) []path.Path {
@@ -148,7 +149,7 @@ func (suite *OperationsManifestsUnitSuite) TestCollectMetadata() {
 		{
 			name:  "multiple reasons, single file",
 			manID: "multi single",
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason(tid, ro, path.ExchangeService, path.EmailCategory),
 				kopia.NewReason(tid, ro, path.ExchangeService, path.ContactsCategory),
 			},
@@ -171,7 +172,7 @@ func (suite *OperationsManifestsUnitSuite) TestCollectMetadata() {
 		{
 			name:  "multiple reasons, multiple file",
 			manID: "multi multi",
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason(tid, ro, path.ExchangeService, path.EmailCategory),
 				kopia.NewReason(tid, ro, path.ExchangeService, path.ContactsCategory),
 			},
@@ -219,8 +220,8 @@ func buildReasons(
 	ro string,
 	service path.ServiceType,
 	cats ...path.CategoryType,
-) []kopia.Reasoner {
-	var reasons []kopia.Reasoner
+) []identity.Reasoner {
+	var reasons []identity.Reasoner
 
 	for _, cat := range cats {
 		reasons = append(
@@ -252,7 +253,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata() {
 		name        string
 		bf          *mockBackupFinder
 		rp          mockRestoreProducer
-		reasons     []kopia.Reasoner
+		reasons     []identity.Reasoner
 		getMeta     bool
 		assertErr   assert.ErrorAssertionFunc
 		assertB     assert.BoolAssertionFunc
@@ -263,7 +264,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata() {
 		{
 			name:       "don't get metadata, no mans",
 			rp:         mockRestoreProducer{},
-			reasons:    []kopia.Reasoner{},
+			reasons:    []identity.Reasoner{},
 			getMeta:    false,
 			assertErr:  assert.NoError,
 			assertB:    assert.False,
@@ -280,7 +281,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata() {
 				},
 			},
 			rp: mockRestoreProducer{},
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason("", ro, path.ExchangeService, path.EmailCategory),
 			},
 			getMeta:   false,
@@ -301,7 +302,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata() {
 				},
 			},
 			rp: mockRestoreProducer{},
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason("", ro, path.ExchangeService, path.EmailCategory),
 			},
 			getMeta:   true,
@@ -329,7 +330,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata() {
 					"id1": {data.NoFetchRestoreCollection{Collection: mockColl{id: "id1"}}},
 				},
 			},
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason("", ro, path.ExchangeService, path.EmailCategory),
 				kopia.NewReason("", ro, path.ExchangeService, path.ContactsCategory),
 			},
@@ -377,7 +378,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata() {
 					"id2": {data.NoFetchRestoreCollection{Collection: mockColl{id: "id2"}}},
 				},
 			},
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason("", ro, path.ExchangeService, path.EmailCategory),
 			},
 			getMeta:   true,
@@ -406,7 +407,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata() {
 					"id2": {data.NoFetchRestoreCollection{Collection: mockColl{id: "id2"}}},
 				},
 			},
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason("", ro, path.ExchangeService, path.EmailCategory),
 			},
 			getMeta:   true,
@@ -428,7 +429,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata() {
 				},
 			},
 			rp: mockRestoreProducer{err: assert.AnError},
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				kopia.NewReason("", ro, path.ExchangeService, path.EmailCategory),
 			},
 			getMeta:    true,
@@ -548,8 +549,8 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 		name            string
 		bf              *mockBackupFinder
 		rp              mockRestoreProducer
-		reasons         []kopia.Reasoner
-		fallbackReasons []kopia.Reasoner
+		reasons         []identity.Reasoner
+		fallbackReasons []identity.Reasoner
 		getMeta         bool
 		assertErr       assert.ErrorAssertionFunc
 		assertB         assert.BoolAssertionFunc
@@ -568,7 +569,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 				},
 			},
 			rp:              mockRestoreProducer{},
-			fallbackReasons: []kopia.Reasoner{fbEmailReason},
+			fallbackReasons: []identity.Reasoner{fbEmailReason},
 			getMeta:         false,
 			assertErr:       assert.NoError,
 			assertB:         assert.False,
@@ -593,7 +594,7 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 					"fb_id1": {data.NoFetchRestoreCollection{Collection: mockColl{id: "fb_id1"}}},
 				},
 			},
-			fallbackReasons: []kopia.Reasoner{fbEmailReason},
+			fallbackReasons: []identity.Reasoner{fbEmailReason},
 			getMeta:         true,
 			assertErr:       assert.NoError,
 			assertB:         assert.True,
@@ -624,8 +625,8 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 					"fb_id1": {data.NoFetchRestoreCollection{Collection: mockColl{id: "fb_id1"}}},
 				},
 			},
-			reasons:         []kopia.Reasoner{emailReason},
-			fallbackReasons: []kopia.Reasoner{fbEmailReason},
+			reasons:         []identity.Reasoner{emailReason},
+			fallbackReasons: []identity.Reasoner{fbEmailReason},
 			getMeta:         true,
 			assertErr:       assert.NoError,
 			assertB:         assert.True,
@@ -652,8 +653,8 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 					"fb_id2": {data.NoFetchRestoreCollection{Collection: mockColl{id: "fb_id2"}}},
 				},
 			},
-			reasons:         []kopia.Reasoner{emailReason},
-			fallbackReasons: []kopia.Reasoner{fbEmailReason},
+			reasons:         []identity.Reasoner{emailReason},
+			fallbackReasons: []identity.Reasoner{fbEmailReason},
 			getMeta:         true,
 			assertErr:       assert.NoError,
 			assertB:         assert.True,
@@ -688,8 +689,8 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 					"fb_id2": {data.NoFetchRestoreCollection{Collection: mockColl{id: "fb_id2"}}},
 				},
 			},
-			reasons:         []kopia.Reasoner{emailReason},
-			fallbackReasons: []kopia.Reasoner{fbEmailReason},
+			reasons:         []identity.Reasoner{emailReason},
+			fallbackReasons: []identity.Reasoner{fbEmailReason},
 			getMeta:         true,
 			assertErr:       assert.NoError,
 			assertB:         assert.True,
@@ -720,8 +721,8 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 					"fb_id1": {data.NoFetchRestoreCollection{Collection: mockColl{id: "fb_id1"}}},
 				},
 			},
-			reasons:         []kopia.Reasoner{emailReason},
-			fallbackReasons: []kopia.Reasoner{fbEmailReason},
+			reasons:         []identity.Reasoner{emailReason},
+			fallbackReasons: []identity.Reasoner{fbEmailReason},
 			getMeta:         true,
 			assertErr:       assert.NoError,
 			assertB:         assert.True,
@@ -752,8 +753,8 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 					"fb_id2": {data.NoFetchRestoreCollection{Collection: mockColl{id: "fb_id2"}}},
 				},
 			},
-			reasons:         []kopia.Reasoner{emailReason},
-			fallbackReasons: []kopia.Reasoner{fbEmailReason},
+			reasons:         []identity.Reasoner{emailReason},
+			fallbackReasons: []identity.Reasoner{fbEmailReason},
 			getMeta:         true,
 			assertErr:       assert.NoError,
 			assertB:         assert.True,
@@ -782,11 +783,11 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 					"fb_id1": {data.NoFetchRestoreCollection{Collection: mockColl{id: "fb_id1"}}},
 				},
 			},
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				emailReason,
 				kopia.NewReason("", ro, path.ExchangeService, path.ContactsCategory),
 			},
-			fallbackReasons: []kopia.Reasoner{
+			fallbackReasons: []identity.Reasoner{
 				fbEmailReason,
 				kopia.NewReason("", fbro, path.ExchangeService, path.ContactsCategory),
 			},
@@ -818,8 +819,8 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 					"fb_id1": {data.NoFetchRestoreCollection{Collection: mockColl{id: "fb_id1"}}},
 				},
 			},
-			reasons: []kopia.Reasoner{emailReason},
-			fallbackReasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{emailReason},
+			fallbackReasons: []identity.Reasoner{
 				kopia.NewReason("", fbro, path.ExchangeService, path.ContactsCategory),
 			},
 			getMeta:   true,
@@ -853,11 +854,11 @@ func (suite *OperationsManifestsUnitSuite) TestProduceManifestsAndMetadata_Fallb
 					"fb_id1": {data.NoFetchRestoreCollection{Collection: mockColl{id: "fb_id1"}}},
 				},
 			},
-			reasons: []kopia.Reasoner{
+			reasons: []identity.Reasoner{
 				emailReason,
 				kopia.NewReason("", ro, path.ExchangeService, path.ContactsCategory),
 			},
-			fallbackReasons: []kopia.Reasoner{
+			fallbackReasons: []identity.Reasoner{
 				fbEmailReason,
 				kopia.NewReason("", fbro, path.ExchangeService, path.ContactsCategory),
 			},

src/internal/operations/pathtransformer/restore_path_transformer.go

@@ -42,9 +42,9 @@ func locationRef(
 
 func basicLocationPath(repoRef path.Path, locRef *path.Builder) (path.Path, error) {
 	if len(locRef.Elements()) == 0 {
-		res, err := path.ServicePrefix(
+		res, err := path.BuildPrefix(
 			repoRef.Tenant(),
-			repoRef.ResourceOwner(),
+			repoRef.ProtectedResource(),
 			repoRef.Service(),
 			repoRef.Category())
 		if err != nil {
@@ -56,7 +56,7 @@ func basicLocationPath(repoRef path.Path, locRef *path.Builder) (path.Path, erro
 
 	return locRef.ToDataLayerPath(
 		repoRef.Tenant(),
-		repoRef.ResourceOwner(),
+		repoRef.ProtectedResource(),
 		repoRef.Service(),
 		repoRef.Category(),
 		false)

src/internal/operations/pathtransformer/restore_path_transformer_test.go

@@ -40,7 +40,7 @@ func (suite *RestorePathTransformerUnitSuite) TestGetPaths() {
 			Append(
 				repoRef.Tenant(),
 				repoRef.Service().String(),
-				repoRef.ResourceOwner(),
+				repoRef.ProtectedResource(),
 				repoRef.Category().String()).
 			Append(unescapedFolders...).
 			String()

src/internal/operations/test/exchange_test.go

@@ -347,7 +347,7 @@ func testExchangeContinuousBackups(suite *ExchangeBackupIntgSuite, toggles contr
 		// },
 	}
 
-	rrPfx, err := path.ServicePrefix(acct.ID(), uidn.ID(), service, path.EmailCategory)
+	rrPfx, err := path.BuildPrefix(acct.ID(), uidn.ID(), service, path.EmailCategory)
 	require.NoError(t, err, clues.ToCore(err))
 
 	// strip the category from the prefix; we primarily want the tenant and resource owner.

src/internal/operations/test/helper_test.go

@@ -32,6 +32,7 @@ import (
 	"github.com/alcionai/corso/src/pkg/account"
 	"github.com/alcionai/corso/src/pkg/backup"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/control"
 	"github.com/alcionai/corso/src/pkg/control/repository"
 	"github.com/alcionai/corso/src/pkg/count"
@@ -251,7 +252,7 @@ func checkBackupIsInManifests(
 			bf, err := kw.NewBaseFinder(sw)
 			require.NoError(t, err, clues.ToCore(err))
 
-			mans := bf.FindBases(ctx, []kopia.Reasoner{r}, tags)
+			mans := bf.FindBases(ctx, []identity.Reasoner{r}, tags)
 			for _, man := range mans.MergeBases() {
 				bID, ok := man.GetTag(kopia.TagBackupID)
 				if !assert.Truef(t, ok, "snapshot manifest %s missing backup ID tag", man.ID) {

src/internal/operations/test/onedrive_test.go

@@ -213,7 +213,7 @@ func runDriveIncrementalTest(
 		}
 	)
 
-	rrPfx, err := path.ServicePrefix(atid, roidn.ID(), service, category)
+	rrPfx, err := path.BuildPrefix(atid, roidn.ID(), service, category)
 	require.NoError(t, err, clues.ToCore(err))
 
 	// strip the category from the prefix; we primarily want the tenant and resource owner.

src/pkg/backup/details/testdata/testdata.go

@@ -104,7 +104,7 @@ func (p repoRefAndLocRef) locationAsRepoRef() path.Path {
 
 	res, err := tmp.ToDataLayerPath(
 		p.RR.Tenant(),
-		p.RR.ResourceOwner(),
+		p.RR.ProtectedResource(),
 		p.RR.Service(),
 		p.RR.Category(),
 		len(p.ItemLocation()) > 0)
@@ -133,7 +133,7 @@ func mustPathRep(ref string, isItem bool) repoRefAndLocRef {
 
 	rr, err := rrPB.ToDataLayerPath(
 		tmp.Tenant(),
-		tmp.ResourceOwner(),
+		tmp.ProtectedResource(),
 		tmp.Service(),
 		tmp.Category(),
 		isItem)

src/pkg/backup/identity/identity.go

@@ -0,0 +1,16 @@
+package identity
+
+import "github.com/alcionai/corso/src/pkg/path"
+
+// Reasoner describes the parts of the backup that make up its
+// data identity: the tenant, protected resources, services, and
+// categories which are held within the backup.
+type Reasoner interface {
+	Tenant() string
+	ProtectedResource() string
+	Service() path.ServiceType
+	Category() path.CategoryType
+	// SubtreePath returns the path prefix for data in existing backups that have
+	// parameters (tenant, protected resourced, etc) that match this Reasoner.
+	SubtreePath() (path.Path, error)
+}

src/pkg/path/builder.go

@@ -0,0 +1,379 @@
+package path
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"fmt"
+
+	"github.com/alcionai/clues"
+)
+
+// interface compliance required for handling PII
+var (
+	_ clues.Concealer = &Builder{}
+	_ fmt.Stringer    = &Builder{}
+)
+
+// Builder is a simple path representation that only tracks path elements. It
+// can join, escape, and unescape elements. Higher-level packages are expected
+// to wrap this struct to build resource-specific contexts (e.x. an
+// ExchangeMailPath).
+// Resource-specific paths allow access to more information like segments in the
+// path. Builders that are turned into resource paths later on do not need to
+// manually add prefixes for items that normally appear in the data layer (ex.
+// tenant ID, service, user ID, etc).
+type Builder struct {
+	// Unescaped version of elements.
+	elements Elements
+}
+
+// Append creates a copy of this Builder and adds the given elements them to the
+// end of the new Builder. Elements are added in the order they are passed.
+func (pb Builder) Append(elements ...string) *Builder {
+	res := &Builder{elements: make([]string, len(pb.elements))}
+	copy(res.elements, pb.elements)
+
+	// Unescaped elements can't fail validation.
+	//nolint:errcheck
+	res.appendElements(false, elements)
+
+	return res
+}
+
+func (pb *Builder) appendElements(escaped bool, elements []string) error {
+	for _, e := range elements {
+		if len(e) == 0 {
+			continue
+		}
+
+		tmp := e
+
+		if escaped {
+			tmp = TrimTrailingSlash(tmp)
+			// If tmp was just the path separator then it will be empty now.
+			if len(tmp) == 0 {
+				continue
+			}
+
+			if err := validateEscapedElement(tmp); err != nil {
+				return err
+			}
+
+			tmp = unescape(tmp)
+		}
+
+		pb.elements = append(pb.elements, tmp)
+	}
+
+	return nil
+}
+
+// UnescapeAndAppend creates a copy of this Builder and adds one or more already
+// escaped path elements to the end of the new Builder. Elements are added in
+// the order they are passed.
+func (pb Builder) UnescapeAndAppend(elements ...string) (*Builder, error) {
+	res := &Builder{elements: make([]string, 0, len(pb.elements))}
+	copy(res.elements, pb.elements)
+
+	if err := res.appendElements(true, elements); err != nil {
+		return nil, err
+	}
+
+	return res, nil
+}
+
+// SplitUnescapeAppend takes in an escaped string representing a directory
+// path, splits the string, and appends it to the current builder.
+func (pb Builder) SplitUnescapeAppend(s string) (*Builder, error) {
+	elems := Split(TrimTrailingSlash(s))
+
+	return pb.UnescapeAndAppend(elems...)
+}
+
+func (pb Builder) PopFront() *Builder {
+	if len(pb.elements) <= 1 {
+		return &Builder{}
+	}
+
+	elements := make([]string, len(pb.elements)-1)
+	copy(elements, pb.elements[1:])
+
+	return &Builder{
+		elements: elements,
+	}
+}
+
+// Dir removes the last element from the builder.
+func (pb Builder) Dir() *Builder {
+	if len(pb.elements) <= 1 {
+		return &Builder{}
+	}
+
+	return &Builder{
+		// Safe to use the same elements because Builders are immutable.
+		elements: pb.elements[:len(pb.elements)-1],
+	}
+}
+
+// HeadElem returns the first element in the Builder.
+func (pb Builder) HeadElem() string {
+	if len(pb.elements) == 0 {
+		return ""
+	}
+
+	return pb.elements[0]
+}
+
+// LastElem returns the last element in the Builder.
+func (pb Builder) LastElem() string {
+	if len(pb.elements) == 0 {
+		return ""
+	}
+
+	return pb.elements[len(pb.elements)-1]
+}
+
+// UpdateParent updates leading elements matching prev to be cur and returns
+// true if it was updated. If prev is not a prefix of this Builder changes
+// nothing and returns false. If either prev or cur is nil does nothing and
+// returns false.
+func (pb *Builder) UpdateParent(prev, cur *Builder) bool {
+	if prev == cur || prev == nil || cur == nil || len(prev.Elements()) > len(pb.Elements()) {
+		return false
+	}
+
+	parent := true
+
+	for i, e := range prev.Elements() {
+		if pb.elements[i] != e {
+			parent = false
+			break
+		}
+	}
+
+	if !parent {
+		return false
+	}
+
+	pb.elements = append(cur.Elements(), pb.elements[len(prev.Elements()):]...)
+
+	return true
+}
+
+// ShortRef produces a truncated hash of the builder that
+// acts as a unique identifier.
+func (pb Builder) ShortRef() string {
+	if len(pb.elements) == 0 {
+		return ""
+	}
+
+	data := bytes.Buffer{}
+
+	for _, element := range pb.elements {
+		data.WriteString(element)
+	}
+
+	sum := sha256.Sum256(data.Bytes())
+
+	// Some conversions to get the right number of characters in the output. This
+	// outputs hex, so we need to take the target number of characters and do the
+	// equivalent of (shortRefCharacters * 4) / 8. This is
+	// <number of bits represented> / <bits per byte> which gets us how many bytes
+	// to give to our format command.
+	numBytes := shortRefCharacters / 2
+
+	return fmt.Sprintf("%x", sum[:numBytes])
+}
+
+// Elements returns all the elements in the path. This is a temporary function
+// and will likely be updated to handle encoded elements instead of clear-text
+// elements in the future.
+func (pb Builder) Elements() Elements {
+	return append(Elements{}, pb.elements...)
+}
+
+// withPrefix creates a Builder prefixed with the parameter values, and
+// concatenated with the current builder elements.
+func (pb Builder) withPrefix(elements ...string) *Builder {
+	res := Builder{}.Append(elements...)
+	res.elements = append(res.elements, pb.elements...)
+
+	return res
+}
+
+// verifyPrefix ensures that the tenant and protectedResource are valid
+// values, and that the builder has some directory structure.
+func (pb Builder) verifyPrefix(tenant, protectedResource string) error {
+	if err := verifyInputValues(tenant, protectedResource); err != nil {
+		return err
+	}
+
+	if len(pb.elements) == 0 {
+		return clues.New("missing path beyond prefix")
+	}
+
+	return nil
+}
+
+// ---------------------------------------------------------------------------
+// Data Layer Path Transformers
+// ---------------------------------------------------------------------------
+
+func (pb Builder) ToStreamStorePath(
+	tenant, purpose string,
+	service ServiceType,
+	isItem bool,
+) (Path, error) {
+	if err := verifyInputValues(tenant, purpose); err != nil {
+		return nil, err
+	}
+
+	if isItem && len(pb.elements) == 0 {
+		return nil, clues.New("missing path beyond prefix")
+	}
+
+	metadataService := UnknownService
+
+	switch service {
+	case ExchangeService:
+		metadataService = ExchangeMetadataService
+	case OneDriveService:
+		metadataService = OneDriveMetadataService
+	case SharePointService:
+		metadataService = SharePointMetadataService
+	}
+
+	return &dataLayerResourcePath{
+		Builder: *pb.withPrefix(
+			tenant,
+			metadataService.String(),
+			purpose,
+			DetailsCategory.String()),
+		service:  metadataService,
+		category: DetailsCategory,
+		hasItem:  isItem,
+	}, nil
+}
+
+func (pb Builder) ToServiceCategoryMetadataPath(
+	tenant, user string,
+	service ServiceType,
+	category CategoryType,
+	isItem bool,
+) (Path, error) {
+	if err := ValidateServiceAndCategory(service, category); err != nil {
+		return nil, err
+	}
+
+	if err := verifyInputValues(tenant, user); err != nil {
+		return nil, err
+	}
+
+	if isItem && len(pb.elements) == 0 {
+		return nil, clues.New("missing path beyond prefix")
+	}
+
+	metadataService := UnknownService
+
+	switch service {
+	case ExchangeService:
+		metadataService = ExchangeMetadataService
+	case OneDriveService:
+		metadataService = OneDriveMetadataService
+	case SharePointService:
+		metadataService = SharePointMetadataService
+	}
+
+	return &dataLayerResourcePath{
+		Builder: *pb.withPrefix(
+			tenant,
+			metadataService.String(),
+			user,
+			category.String(),
+		),
+		service:  metadataService,
+		category: category,
+		hasItem:  isItem,
+	}, nil
+}
+
+func (pb Builder) ToDataLayerPath(
+	tenant, user string,
+	service ServiceType,
+	category CategoryType,
+	isItem bool,
+) (Path, error) {
+	if err := ValidateServiceAndCategory(service, category); err != nil {
+		return nil, err
+	}
+
+	if err := pb.verifyPrefix(tenant, user); err != nil {
+		return nil, err
+	}
+
+	return &dataLayerResourcePath{
+		Builder: *pb.withPrefix(
+			tenant,
+			service.String(),
+			user,
+			category.String()),
+		service:  service,
+		category: category,
+		hasItem:  isItem,
+	}, nil
+}
+
+func (pb Builder) ToDataLayerExchangePathForCategory(
+	tenant, user string,
+	category CategoryType,
+	isItem bool,
+) (Path, error) {
+	return pb.ToDataLayerPath(tenant, user, ExchangeService, category, isItem)
+}
+
+func (pb Builder) ToDataLayerOneDrivePath(
+	tenant, user string,
+	isItem bool,
+) (Path, error) {
+	return pb.ToDataLayerPath(tenant, user, OneDriveService, FilesCategory, isItem)
+}
+
+func (pb Builder) ToDataLayerSharePointPath(
+	tenant, site string,
+	category CategoryType,
+	isItem bool,
+) (Path, error) {
+	return pb.ToDataLayerPath(tenant, site, SharePointService, category, isItem)
+}
+
+// ---------------------------------------------------------------------------
+// Stringers and PII Concealer Compliance
+// ---------------------------------------------------------------------------
+
+// Conceal produces a concealed representation of the builder, suitable for
+// logging, storing in errors, and other output.
+func (pb Builder) Conceal() string {
+	return pb.elements.Conceal()
+}
+
+// Format produces a concealed representation of the builder, even when
+// used within a PrintF, suitable for logging, storing in errors,
+// and other output.
+func (pb Builder) Format(fs fmt.State, _ rune) {
+	fmt.Fprint(fs, pb.Conceal())
+}
+
+// String returns a string that contains all path elements joined together.
+// Elements of the path that need escaping are escaped.
+// The result is not concealed, and is not suitable for logging or structured
+// errors.
+func (pb Builder) String() string {
+	return pb.elements.String()
+}
+
+// PlainString returns an unescaped, unmodified string of the builder.
+// The result is not concealed, and is not suitable for logging or structured
+// errors.
+func (pb Builder) PlainString() string {
+	return pb.elements.PlainString()
+}

src/pkg/path/builder_test.go

@@ -0,0 +1,369 @@
+package path
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/alcionai/clues"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/stretchr/testify/suite"
+
+	"github.com/alcionai/corso/src/internal/tester"
+)
+
+type BuilderUnitSuite struct {
+	tester.Suite
+}
+
+func TestBuilderUnitSuite(t *testing.T) {
+	suite.Run(t, &BuilderUnitSuite{Suite: tester.NewUnitSuite(t)})
+}
+
+// set the clues hashing to mask for the span of this suite
+func (suite *BuilderUnitSuite) SetupSuite() {
+	clues.SetHasher(clues.HashCfg{HashAlg: clues.Flatmask})
+}
+
+// revert clues hashing to plaintext for all other tests
+func (suite *BuilderUnitSuite) TeardownSuite() {
+	clues.SetHasher(clues.NoHash())
+}
+
+func (suite *BuilderUnitSuite) TestAppend() {
+	table := append(append([]testData{}, genericCases...), basicUnescapedInputs...)
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			p := Builder{}.Append(test.input...)
+			assert.Equal(t, test.expectedString, p.String())
+		})
+	}
+}
+
+func (suite *BuilderUnitSuite) TestAppendItem() {
+	t := suite.T()
+
+	p, err := Build("t", "ro", ExchangeService, EmailCategory, false, "foo", "bar")
+	require.NoError(t, err, clues.ToCore(err))
+
+	pb := p.ToBuilder()
+	assert.Equal(t, pb.String(), p.String())
+
+	pb = pb.Append("qux")
+
+	p, err = p.AppendItem("qux")
+
+	require.NoError(t, err, clues.ToCore(err))
+	assert.Equal(t, pb.String(), p.String())
+
+	_, err = p.AppendItem("fnords")
+	require.Error(t, err, clues.ToCore(err))
+}
+
+func (suite *BuilderUnitSuite) TestUnescapeAndAppend() {
+	table := append(append([]testData{}, genericCases...), basicEscapedInputs...)
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			p, err := Builder{}.UnescapeAndAppend(test.input...)
+			require.NoError(t, err, clues.ToCore(err))
+
+			assert.Equal(t, test.expectedString, p.String())
+		})
+	}
+}
+
+func (suite *BuilderUnitSuite) TestEscapedFailure() {
+	target := "i_s"
+
+	for c := range charactersToEscape {
+		suite.Run(fmt.Sprintf("Unescaped-%c", c), func() {
+			tmp := strings.ReplaceAll(target, "_", string(c))
+
+			_, err := Builder{}.UnescapeAndAppend("this", tmp, "path")
+			assert.Errorf(suite.T(), err, "path with unescaped %s did not error", string(c))
+		})
+	}
+}
+
+func (suite *BuilderUnitSuite) TestBadEscapeSequenceErrors() {
+	target := `i\_s/a`
+	notEscapes := []rune{'a', 'b', '#', '%'}
+
+	for _, c := range notEscapes {
+		suite.Run(fmt.Sprintf("Escaped-%c", c), func() {
+			tmp := strings.ReplaceAll(target, "_", string(c))
+
+			_, err := Builder{}.UnescapeAndAppend("this", tmp, "path")
+			assert.Errorf(
+				suite.T(),
+				err,
+				"path with bad escape sequence %c%c did not error",
+				escapeCharacter,
+				c)
+		})
+	}
+}
+
+func (suite *BuilderUnitSuite) TestTrailingEscapeChar() {
+	base := []string{"this", "is", "a", "path"}
+
+	for i := 0; i < len(base); i++ {
+		suite.Run(fmt.Sprintf("Element%v", i), func() {
+			path := make([]string, len(base))
+			copy(path, base)
+			path[i] = path[i] + string(escapeCharacter)
+
+			_, err := Builder{}.UnescapeAndAppend(path...)
+			assert.Error(
+				suite.T(),
+				err,
+				"path with trailing escape character did not error")
+		})
+	}
+}
+
+func (suite *BuilderUnitSuite) TestElements() {
+	table := []struct {
+		name     string
+		input    []string
+		output   []string
+		pathFunc func(elements []string) (*Builder, error)
+	}{
+		{
+			name:   "SimpleEscapedPath",
+			input:  []string{"this", "is", "a", "path"},
+			output: []string{"this", "is", "a", "path"},
+			pathFunc: func(elements []string) (*Builder, error) {
+				return Builder{}.UnescapeAndAppend(elements...)
+			},
+		},
+		{
+			name:   "SimpleUnescapedPath",
+			input:  []string{"this", "is", "a", "path"},
+			output: []string{"this", "is", "a", "path"},
+			pathFunc: func(elements []string) (*Builder, error) {
+				return Builder{}.Append(elements...), nil
+			},
+		},
+		{
+			name:   "EscapedPath",
+			input:  []string{"this", `is\/`, "a", "path"},
+			output: []string{"this", "is/", "a", "path"},
+			pathFunc: func(elements []string) (*Builder, error) {
+				return Builder{}.UnescapeAndAppend(elements...)
+			},
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			p, err := test.pathFunc(test.input)
+			require.NoError(t, err, clues.ToCore(err))
+
+			assert.Equal(t, Elements(test.output), p.Elements())
+		})
+	}
+}
+
+func (suite *BuilderUnitSuite) TestPopFront() {
+	table := []struct {
+		name           string
+		base           *Builder
+		expectedString string
+	}{
+		{
+			name:           "Empty",
+			base:           &Builder{},
+			expectedString: "",
+		},
+		{
+			name:           "OneElement",
+			base:           Builder{}.Append("something"),
+			expectedString: "",
+		},
+		{
+			name:           "TwoElements",
+			base:           Builder{}.Append("something", "else"),
+			expectedString: "else",
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			assert.Equal(t, test.expectedString, test.base.PopFront().String())
+		})
+	}
+}
+
+func (suite *BuilderUnitSuite) TestShortRef() {
+	table := []struct {
+		name          string
+		inputElements []string
+		expectedLen   int
+	}{
+		{
+			name:          "PopulatedPath",
+			inputElements: []string{"this", "is", "a", "path"},
+			expectedLen:   shortRefCharacters,
+		},
+		{
+			name:          "EmptyPath",
+			inputElements: nil,
+			expectedLen:   0,
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			pb := Builder{}.Append(test.inputElements...)
+			ref := pb.ShortRef()
+			assert.Len(suite.T(), ref, test.expectedLen)
+		})
+	}
+}
+
+func (suite *BuilderUnitSuite) TestShortRefIsStable() {
+	t := suite.T()
+	pb := Builder{}.Append("this", "is", "a", "path")
+	prevRef := pb.ShortRef()
+	assert.Len(t, prevRef, shortRefCharacters)
+
+	for i := 0; i < 5; i++ {
+		ref := pb.ShortRef()
+		assert.Len(t, ref, shortRefCharacters)
+		assert.Equal(t, prevRef, ref, "ShortRef changed between calls")
+
+		prevRef = ref
+	}
+}
+
+func (suite *BuilderUnitSuite) TestShortRefIsUnique() {
+	pb1 := Builder{}.Append("this", "is", "a", "path")
+	pb2 := pb1.Append("also")
+
+	require.NotEqual(suite.T(), pb1, pb2)
+	assert.NotEqual(suite.T(), pb1.ShortRef(), pb2.ShortRef())
+}
+
+// TestShortRefUniqueWithEscaping tests that two paths that output the same
+// unescaped string but different escaped strings have different shortrefs. This
+// situation can occur when one path has embedded path separators while the
+// other does not but contains the same characters.
+func (suite *BuilderUnitSuite) TestShortRefUniqueWithEscaping() {
+	pb1 := Builder{}.Append(`this`, `is`, `a`, `path`)
+	pb2 := Builder{}.Append(`this`, `is/a`, `path`)
+
+	require.NotEqual(suite.T(), pb1, pb2)
+	assert.NotEqual(suite.T(), pb1.ShortRef(), pb2.ShortRef())
+}
+
+func (suite *BuilderUnitSuite) TestFolder() {
+	table := []struct {
+		name         string
+		p            func(t *testing.T) Path
+		escape       bool
+		expectFolder string
+		expectSplit  []string
+	}{
+		{
+			name: "clean path",
+			p: func(t *testing.T) Path {
+				p, err := Builder{}.
+					Append("a", "b", "c").
+					ToDataLayerExchangePathForCategory("t", "u", EmailCategory, false)
+				require.NoError(t, err, clues.ToCore(err))
+
+				return p
+			},
+			expectFolder: "a/b/c",
+			expectSplit:  []string{"a", "b", "c"},
+		},
+		{
+			name: "clean path escaped",
+			p: func(t *testing.T) Path {
+				p, err := Builder{}.
+					Append("a", "b", "c").
+					ToDataLayerExchangePathForCategory("t", "u", EmailCategory, false)
+				require.NoError(t, err, clues.ToCore(err))
+
+				return p
+			},
+			escape:       true,
+			expectFolder: "a/b/c",
+			expectSplit:  []string{"a", "b", "c"},
+		},
+		{
+			name: "escapable path",
+			p: func(t *testing.T) Path {
+				p, err := Builder{}.
+					Append("a/", "b", "c").
+					ToDataLayerExchangePathForCategory("t", "u", EmailCategory, false)
+				require.NoError(t, err, clues.ToCore(err))
+
+				return p
+			},
+			expectFolder: "a//b/c",
+			expectSplit:  []string{"a", "b", "c"},
+		},
+		{
+			name: "escapable path escaped",
+			p: func(t *testing.T) Path {
+				p, err := Builder{}.
+					Append("a/", "b", "c").
+					ToDataLayerExchangePathForCategory("t", "u", EmailCategory, false)
+				require.NoError(t, err, clues.ToCore(err))
+
+				return p
+			},
+			escape:       true,
+			expectFolder: "a\\//b/c",
+			expectSplit:  []string{"a\\/", "b", "c"},
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			p := test.p(t)
+			result := p.Folder(test.escape)
+			assert.Equal(t, test.expectFolder, result)
+			assert.Equal(t, test.expectSplit, Split(result))
+		})
+	}
+}
+
+func (suite *BuilderUnitSuite) TestPIIHandling() {
+	p, err := Build("t", "ro", ExchangeService, EventsCategory, true, "dir", "item")
+	require.NoError(suite.T(), err)
+
+	table := []struct {
+		name        string
+		p           Path
+		expect      string
+		expectPlain string
+	}{
+		{
+			name:        "standard path",
+			p:           p,
+			expect:      "***/exchange/***/events/***/***",
+			expectPlain: "t/exchange/ro/events/dir/item",
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			assert.Equal(t, test.expect, test.p.Conceal(), "conceal")
+			assert.Equal(t, test.expectPlain, test.p.String(), "string")
+			assert.Equal(t, test.expect, fmt.Sprintf("%s", test.p), "fmt %%s")
+			assert.Equal(t, test.expect, fmt.Sprintf("%+v", test.p), "fmt %%+v")
+			assert.Equal(t, test.expectPlain, test.p.PlainString(), "plain")
+		})
+	}
+}

src/pkg/path/category_type.go

@@ -0,0 +1,108 @@
+package path
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/alcionai/clues"
+)
+
+var ErrorUnknownCategory = clues.New("unknown category string")
+
+// CategoryType denotes what category of data the path corresponds to. The order
+// of the enums below can be changed, but the string representation of each enum
+// must remain the same or migration code needs to be added to handle changes to
+// the string format.
+type CategoryType int
+
+//go:generate stringer -type=CategoryType -linecomment
+const (
+	UnknownCategory   CategoryType = iota
+	EmailCategory                  // email
+	ContactsCategory               // contacts
+	EventsCategory                 // events
+	FilesCategory                  // files
+	ListsCategory                  // lists
+	LibrariesCategory              // libraries
+	PagesCategory                  // pages
+	DetailsCategory                // details
+)
+
+func ToCategoryType(category string) CategoryType {
+	cat := strings.ToLower(category)
+
+	switch cat {
+	case strings.ToLower(EmailCategory.String()):
+		return EmailCategory
+	case strings.ToLower(ContactsCategory.String()):
+		return ContactsCategory
+	case strings.ToLower(EventsCategory.String()):
+		return EventsCategory
+	case strings.ToLower(FilesCategory.String()):
+		return FilesCategory
+	case strings.ToLower(LibrariesCategory.String()):
+		return LibrariesCategory
+	case strings.ToLower(ListsCategory.String()):
+		return ListsCategory
+	case strings.ToLower(PagesCategory.String()):
+		return PagesCategory
+	case strings.ToLower(DetailsCategory.String()):
+		return DetailsCategory
+	default:
+		return UnknownCategory
+	}
+}
+
+// ---------------------------------------------------------------------------
+// Service-Category pairings
+// ---------------------------------------------------------------------------
+
+// serviceCategories is a mapping of all valid service/category pairs for
+// non-metadata paths.
+var serviceCategories = map[ServiceType]map[CategoryType]struct{}{
+	ExchangeService: {
+		EmailCategory:    {},
+		ContactsCategory: {},
+		EventsCategory:   {},
+	},
+	OneDriveService: {
+		FilesCategory: {},
+	},
+	SharePointService: {
+		LibrariesCategory: {},
+		ListsCategory:     {},
+		PagesCategory:     {},
+	},
+}
+
+func validateServiceAndCategoryStrings(s, c string) (ServiceType, CategoryType, error) {
+	service := toServiceType(s)
+	if service == UnknownService {
+		return UnknownService, UnknownCategory, clues.Stack(ErrorUnknownService).With("service", fmt.Sprintf("%q", s))
+	}
+
+	category := ToCategoryType(c)
+	if category == UnknownCategory {
+		return UnknownService, UnknownCategory, clues.Stack(ErrorUnknownService).With("category", fmt.Sprintf("%q", c))
+	}
+
+	if err := ValidateServiceAndCategory(service, category); err != nil {
+		return UnknownService, UnknownCategory, err
+	}
+
+	return service, category, nil
+}
+
+func ValidateServiceAndCategory(service ServiceType, category CategoryType) error {
+	cats, ok := serviceCategories[service]
+	if !ok {
+		return clues.New("unsupported service").With("service", fmt.Sprintf("%q", service))
+	}
+
+	if _, ok := cats[category]; !ok {
+		return clues.New("unknown service/category combination").
+			With("service", fmt.Sprintf("%q", service), "category", fmt.Sprintf("%q", category))
+	}
+
+	return nil
+}

src/pkg/path/drive.go

@@ -2,6 +2,7 @@ package path
 
 import "github.com/alcionai/clues"
 
+// TODO: Move this into m365/collection/drive
 // drivePath is used to represent path components
 // of an item within the drive i.e.
 // Given `drives/b!X_8Z2zuXpkKkXZsr7gThk9oJpuj0yXVGnK5_VjRRPK-q725SX_8ZQJgFDK8PlFxA/root:/Folder1/Folder2/file`

src/pkg/path/path.go

@@ -51,8 +51,6 @@
 package path
 
 import (
-	"bytes"
-	"crypto/sha256"
 	"fmt"
 	"strings"
 
@@ -84,7 +82,7 @@ type Path interface {
 	Service() ServiceType
 	Category() CategoryType
 	Tenant() string
-	ResourceOwner() string
+	ProtectedResource() string
 	Folder(escaped bool) string
 	Folders() Elements
 	Item() string
@@ -122,12 +120,6 @@ type Path interface {
 	fmt.Stringer
 }
 
-// interface compliance required for handling PII
-var (
-	_ clues.Concealer = &Builder{}
-	_ fmt.Stringer    = &Builder{}
-)
-
 // RestorePaths denotes the location to find an item in kopia and the path of
 // the collection to place the item in for restore.
 type RestorePaths struct {
@@ -135,186 +127,27 @@ type RestorePaths struct {
 	RestorePath Path
 }
 
-// Builder is a simple path representation that only tracks path elements. It
-// can join, escape, and unescape elements. Higher-level packages are expected
-// to wrap this struct to build resource-specific contexts (e.x. an
-// ExchangeMailPath).
-// Resource-specific paths allow access to more information like segments in the
-// path. Builders that are turned into resource paths later on do not need to
-// manually add prefixes for items that normally appear in the data layer (ex.
-// tenant ID, service, user ID, etc).
-type Builder struct {
-	// Unescaped version of elements.
-	elements Elements
+// ---------------------------------------------------------------------------
+// Exported Helpers
+// ---------------------------------------------------------------------------
+
+func Build(
+	tenant, protectedResource string,
+	service ServiceType,
+	category CategoryType,
+	hasItem bool,
+	elements ...string,
+) (Path, error) {
+	b := Builder{}.Append(elements...)
+
+	return b.ToDataLayerPath(
+		tenant, protectedResource,
+		service, category,
+		hasItem)
 }
 
-// Append creates a copy of this Builder and adds the given elements them to the
-// end of the new Builder. Elements are added in the order they are passed.
-func (pb Builder) Append(elements ...string) *Builder {
-	res := &Builder{elements: make([]string, len(pb.elements))}
-	copy(res.elements, pb.elements)
-
-	// Unescaped elements can't fail validation.
-	//nolint:errcheck
-	res.appendElements(false, elements)
-
-	return res
-}
-
-func (pb *Builder) appendElements(escaped bool, elements []string) error {
-	for _, e := range elements {
-		if len(e) == 0 {
-			continue
-		}
-
-		tmp := e
-
-		if escaped {
-			tmp = TrimTrailingSlash(tmp)
-			// If tmp was just the path separator then it will be empty now.
-			if len(tmp) == 0 {
-				continue
-			}
-
-			if err := validateEscapedElement(tmp); err != nil {
-				return err
-			}
-
-			tmp = unescape(tmp)
-		}
-
-		pb.elements = append(pb.elements, tmp)
-	}
-
-	return nil
-}
-
-// UnescapeAndAppend creates a copy of this Builder and adds one or more already
-// escaped path elements to the end of the new Builder. Elements are added in
-// the order they are passed.
-func (pb Builder) UnescapeAndAppend(elements ...string) (*Builder, error) {
-	res := &Builder{elements: make([]string, 0, len(pb.elements))}
-	copy(res.elements, pb.elements)
-
-	if err := res.appendElements(true, elements); err != nil {
-		return nil, err
-	}
-
-	return res, nil
-}
-
-// SplitUnescapeAppend takes in an escaped string representing a directory
-// path, splits the string, and appends it to the current builder.
-func (pb Builder) SplitUnescapeAppend(s string) (*Builder, error) {
-	elems := Split(TrimTrailingSlash(s))
-
-	return pb.UnescapeAndAppend(elems...)
-}
-
-func (pb Builder) PopFront() *Builder {
-	if len(pb.elements) <= 1 {
-		return &Builder{}
-	}
-
-	elements := make([]string, len(pb.elements)-1)
-	copy(elements, pb.elements[1:])
-
-	return &Builder{
-		elements: elements,
-	}
-}
-
-// Dir removes the last element from the builder.
-func (pb Builder) Dir() *Builder {
-	if len(pb.elements) <= 1 {
-		return &Builder{}
-	}
-
-	return &Builder{
-		// Safe to use the same elements because Builders are immutable.
-		elements: pb.elements[:len(pb.elements)-1],
-	}
-}
-
-// HeadElem returns the first element in the Builder.
-func (pb Builder) HeadElem() string {
-	if len(pb.elements) == 0 {
-		return ""
-	}
-
-	return pb.elements[0]
-}
-
-// LastElem returns the last element in the Builder.
-func (pb Builder) LastElem() string {
-	if len(pb.elements) == 0 {
-		return ""
-	}
-
-	return pb.elements[len(pb.elements)-1]
-}
-
-// UpdateParent updates leading elements matching prev to be cur and returns
-// true if it was updated. If prev is not a prefix of this Builder changes
-// nothing and returns false. If either prev or cur is nil does nothing and
-// returns false.
-func (pb *Builder) UpdateParent(prev, cur *Builder) bool {
-	if prev == cur || prev == nil || cur == nil || len(prev.Elements()) > len(pb.Elements()) {
-		return false
-	}
-
-	parent := true
-
-	for i, e := range prev.Elements() {
-		if pb.elements[i] != e {
-			parent = false
-			break
-		}
-	}
-
-	if !parent {
-		return false
-	}
-
-	pb.elements = append(cur.Elements(), pb.elements[len(prev.Elements()):]...)
-
-	return true
-}
-
-// ShortRef produces a truncated hash of the builder that
-// acts as a unique identifier.
-func (pb Builder) ShortRef() string {
-	if len(pb.elements) == 0 {
-		return ""
-	}
-
-	data := bytes.Buffer{}
-
-	for _, element := range pb.elements {
-		data.WriteString(element)
-	}
-
-	sum := sha256.Sum256(data.Bytes())
-
-	// Some conversions to get the right number of characters in the output. This
-	// outputs hex, so we need to take the target number of characters and do the
-	// equivalent of (shortRefCharacters * 4) / 8. This is
-	// <number of bits represented> / <bits per byte> which gets us how many bytes
-	// to give to our format command.
-	numBytes := shortRefCharacters / 2
-
-	return fmt.Sprintf("%x", sum[:numBytes])
-}
-
-// Elements returns all the elements in the path. This is a temporary function
-// and will likely be updated to handle encoded elements instead of clear-text
-// elements in the future.
-func (pb Builder) Elements() Elements {
-	return append(Elements{}, pb.elements...)
-}
-
-func ServicePrefix(
-	tenant, resourceOwner string,
+func BuildPrefix(
+	tenant, protectedResource string,
 	s ServiceType,
 	c CategoryType,
 ) (Path, error) {
@@ -324,209 +157,18 @@ func ServicePrefix(
 		return nil, err
 	}
 
-	if err := verifyInputValues(tenant, resourceOwner); err != nil {
+	if err := verifyInputValues(tenant, protectedResource); err != nil {
 		return nil, err
 	}
 
 	return &dataLayerResourcePath{
-		Builder:  *pb.withPrefix(tenant, s.String(), resourceOwner, c.String()),
+		Builder:  *pb.withPrefix(tenant, s.String(), protectedResource, c.String()),
 		service:  s,
 		category: c,
 		hasItem:  false,
 	}, nil
 }
 
-// withPrefix creates a Builder prefixed with the parameter values, and
-// concatenated with the current builder elements.
-func (pb Builder) withPrefix(elements ...string) *Builder {
-	res := Builder{}.Append(elements...)
-	res.elements = append(res.elements, pb.elements...)
-
-	return res
-}
-
-// ---------------------------------------------------------------------------
-// Data Layer Path Transformers
-// ---------------------------------------------------------------------------
-
-func (pb Builder) ToStreamStorePath(
-	tenant, purpose string,
-	service ServiceType,
-	isItem bool,
-) (Path, error) {
-	if err := verifyInputValues(tenant, purpose); err != nil {
-		return nil, err
-	}
-
-	if isItem && len(pb.elements) == 0 {
-		return nil, clues.New("missing path beyond prefix")
-	}
-
-	metadataService := UnknownService
-
-	switch service {
-	case ExchangeService:
-		metadataService = ExchangeMetadataService
-	case OneDriveService:
-		metadataService = OneDriveMetadataService
-	case SharePointService:
-		metadataService = SharePointMetadataService
-	}
-
-	return &dataLayerResourcePath{
-		Builder: *pb.withPrefix(
-			tenant,
-			metadataService.String(),
-			purpose,
-			DetailsCategory.String()),
-		service:  metadataService,
-		category: DetailsCategory,
-		hasItem:  isItem,
-	}, nil
-}
-
-func (pb Builder) ToServiceCategoryMetadataPath(
-	tenant, user string,
-	service ServiceType,
-	category CategoryType,
-	isItem bool,
-) (Path, error) {
-	if err := ValidateServiceAndCategory(service, category); err != nil {
-		return nil, err
-	}
-
-	if err := verifyInputValues(tenant, user); err != nil {
-		return nil, err
-	}
-
-	if isItem && len(pb.elements) == 0 {
-		return nil, clues.New("missing path beyond prefix")
-	}
-
-	metadataService := UnknownService
-
-	switch service {
-	case ExchangeService:
-		metadataService = ExchangeMetadataService
-	case OneDriveService:
-		metadataService = OneDriveMetadataService
-	case SharePointService:
-		metadataService = SharePointMetadataService
-	}
-
-	return &dataLayerResourcePath{
-		Builder: *pb.withPrefix(
-			tenant,
-			metadataService.String(),
-			user,
-			category.String(),
-		),
-		service:  metadataService,
-		category: category,
-		hasItem:  isItem,
-	}, nil
-}
-
-func (pb Builder) ToDataLayerPath(
-	tenant, user string,
-	service ServiceType,
-	category CategoryType,
-	isItem bool,
-) (Path, error) {
-	if err := ValidateServiceAndCategory(service, category); err != nil {
-		return nil, err
-	}
-
-	if err := pb.verifyPrefix(tenant, user); err != nil {
-		return nil, err
-	}
-
-	return &dataLayerResourcePath{
-		Builder: *pb.withPrefix(
-			tenant,
-			service.String(),
-			user,
-			category.String()),
-		service:  service,
-		category: category,
-		hasItem:  isItem,
-	}, nil
-}
-
-func (pb Builder) ToDataLayerExchangePathForCategory(
-	tenant, user string,
-	category CategoryType,
-	isItem bool,
-) (Path, error) {
-	return pb.ToDataLayerPath(tenant, user, ExchangeService, category, isItem)
-}
-
-func (pb Builder) ToDataLayerOneDrivePath(
-	tenant, user string,
-	isItem bool,
-) (Path, error) {
-	return pb.ToDataLayerPath(tenant, user, OneDriveService, FilesCategory, isItem)
-}
-
-func (pb Builder) ToDataLayerSharePointPath(
-	tenant, site string,
-	category CategoryType,
-	isItem bool,
-) (Path, error) {
-	return pb.ToDataLayerPath(tenant, site, SharePointService, category, isItem)
-}
-
-// ---------------------------------------------------------------------------
-// Stringers and PII Concealer Compliance
-// ---------------------------------------------------------------------------
-
-// Conceal produces a concealed representation of the builder, suitable for
-// logging, storing in errors, and other output.
-func (pb Builder) Conceal() string {
-	return pb.elements.Conceal()
-}
-
-// Format produces a concealed representation of the builder, even when
-// used within a PrintF, suitable for logging, storing in errors,
-// and other output.
-func (pb Builder) Format(fs fmt.State, _ rune) {
-	fmt.Fprint(fs, pb.Conceal())
-}
-
-// String returns a string that contains all path elements joined together.
-// Elements of the path that need escaping are escaped.
-// The result is not concealed, and is not suitable for logging or structured
-// errors.
-func (pb Builder) String() string {
-	return pb.elements.String()
-}
-
-// PlainString returns an unescaped, unmodified string of the builder.
-// The result is not concealed, and is not suitable for logging or structured
-// errors.
-func (pb Builder) PlainString() string {
-	return pb.elements.PlainString()
-}
-
-// ---------------------------------------------------------------------------
-// Exported Helpers
-// ---------------------------------------------------------------------------
-
-func Build(
-	tenant, resourceOwner string,
-	service ServiceType,
-	category CategoryType,
-	hasItem bool,
-	elements ...string,
-) (Path, error) {
-	b := Builder{}.Append(elements...)
-
-	return b.ToDataLayerPath(
-		tenant, resourceOwner,
-		service, category,
-		hasItem)
-}
-
 // FromDataLayerPath parses the escaped path p, validates the elements in p
 // match a resource-specific path format, and returns a Path struct for that
 // resource-specific type. If p does not match any resource-specific paths or
@@ -648,13 +290,13 @@ func Split(segment string) []string {
 // Unexported Helpers
 // ---------------------------------------------------------------------------
 
-func verifyInputValues(tenant, resourceOwner string) error {
+func verifyInputValues(tenant, protectedResource string) error {
 	if len(tenant) == 0 {
 		return clues.Stack(errMissingSegment, clues.New("tenant"))
 	}
 
-	if len(resourceOwner) == 0 {
-		return clues.Stack(errMissingSegment, clues.New("resourceOwner"))
+	if len(protectedResource) == 0 {
+		return clues.Stack(errMissingSegment, clues.New("protected resource"))
 	}
 
 	return nil
@@ -762,17 +404,3 @@ func join(elements []string) string {
 	// '\' according to the escaping rules.
 	return strings.Join(elements, string(PathSeparator))
 }
-
-// verifyPrefix ensures that the tenant and resourceOwner are valid
-// values, and that the builder has some directory structure.
-func (pb Builder) verifyPrefix(tenant, resourceOwner string) error {
-	if err := verifyInputValues(tenant, resourceOwner); err != nil {
-		return err
-	}
-
-	if len(pb.elements) == 0 {
-		return clues.New("missing path beyond prefix")
-	}
-
-	return nil
-}

src/pkg/path/path_test.go

@@ -2,7 +2,6 @@ package path
 
 import (
 	"fmt"
-	"strings"
 	"testing"
 
 	"github.com/alcionai/clues"
@@ -233,239 +232,7 @@ func (suite *PathUnitSuite) TeardownSuite() {
 	clues.SetHasher(clues.NoHash())
 }
 
-func (suite *PathUnitSuite) TestAppend() {
-	table := append(append([]testData{}, genericCases...), basicUnescapedInputs...)
-	for _, test := range table {
-		suite.Run(test.name, func() {
-			t := suite.T()
-
-			p := Builder{}.Append(test.input...)
-			assert.Equal(t, test.expectedString, p.String())
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestAppendItem() {
-	t := suite.T()
-
-	p, err := Build("t", "ro", ExchangeService, EmailCategory, false, "foo", "bar")
-	require.NoError(t, err, clues.ToCore(err))
-
-	pb := p.ToBuilder()
-	assert.Equal(t, pb.String(), p.String())
-
-	pb = pb.Append("qux")
-
-	p, err = p.AppendItem("qux")
-
-	require.NoError(t, err, clues.ToCore(err))
-	assert.Equal(t, pb.String(), p.String())
-
-	_, err = p.AppendItem("fnords")
-	require.Error(t, err, clues.ToCore(err))
-}
-
-func (suite *PathUnitSuite) TestUnescapeAndAppend() {
-	table := append(append([]testData{}, genericCases...), basicEscapedInputs...)
-	for _, test := range table {
-		suite.Run(test.name, func() {
-			t := suite.T()
-
-			p, err := Builder{}.UnescapeAndAppend(test.input...)
-			require.NoError(t, err, clues.ToCore(err))
-
-			assert.Equal(t, test.expectedString, p.String())
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestEscapedFailure() {
-	target := "i_s"
-
-	for c := range charactersToEscape {
-		suite.Run(fmt.Sprintf("Unescaped-%c", c), func() {
-			tmp := strings.ReplaceAll(target, "_", string(c))
-
-			_, err := Builder{}.UnescapeAndAppend("this", tmp, "path")
-			assert.Errorf(suite.T(), err, "path with unescaped %s did not error", string(c))
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestBadEscapeSequenceErrors() {
-	target := `i\_s/a`
-	notEscapes := []rune{'a', 'b', '#', '%'}
-
-	for _, c := range notEscapes {
-		suite.Run(fmt.Sprintf("Escaped-%c", c), func() {
-			tmp := strings.ReplaceAll(target, "_", string(c))
-
-			_, err := Builder{}.UnescapeAndAppend("this", tmp, "path")
-			assert.Errorf(
-				suite.T(),
-				err,
-				"path with bad escape sequence %c%c did not error",
-				escapeCharacter,
-				c)
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestTrailingEscapeChar() {
-	base := []string{"this", "is", "a", "path"}
-
-	for i := 0; i < len(base); i++ {
-		suite.Run(fmt.Sprintf("Element%v", i), func() {
-			path := make([]string, len(base))
-			copy(path, base)
-			path[i] = path[i] + string(escapeCharacter)
-
-			_, err := Builder{}.UnescapeAndAppend(path...)
-			assert.Error(
-				suite.T(),
-				err,
-				"path with trailing escape character did not error")
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestElements() {
-	table := []struct {
-		name     string
-		input    []string
-		output   []string
-		pathFunc func(elements []string) (*Builder, error)
-	}{
-		{
-			name:   "SimpleEscapedPath",
-			input:  []string{"this", "is", "a", "path"},
-			output: []string{"this", "is", "a", "path"},
-			pathFunc: func(elements []string) (*Builder, error) {
-				return Builder{}.UnescapeAndAppend(elements...)
-			},
-		},
-		{
-			name:   "SimpleUnescapedPath",
-			input:  []string{"this", "is", "a", "path"},
-			output: []string{"this", "is", "a", "path"},
-			pathFunc: func(elements []string) (*Builder, error) {
-				return Builder{}.Append(elements...), nil
-			},
-		},
-		{
-			name:   "EscapedPath",
-			input:  []string{"this", `is\/`, "a", "path"},
-			output: []string{"this", "is/", "a", "path"},
-			pathFunc: func(elements []string) (*Builder, error) {
-				return Builder{}.UnescapeAndAppend(elements...)
-			},
-		},
-	}
-	for _, test := range table {
-		suite.Run(test.name, func() {
-			t := suite.T()
-
-			p, err := test.pathFunc(test.input)
-			require.NoError(t, err, clues.ToCore(err))
-
-			assert.Equal(t, Elements(test.output), p.Elements())
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestPopFront() {
-	table := []struct {
-		name           string
-		base           *Builder
-		expectedString string
-	}{
-		{
-			name:           "Empty",
-			base:           &Builder{},
-			expectedString: "",
-		},
-		{
-			name:           "OneElement",
-			base:           Builder{}.Append("something"),
-			expectedString: "",
-		},
-		{
-			name:           "TwoElements",
-			base:           Builder{}.Append("something", "else"),
-			expectedString: "else",
-		},
-	}
-	for _, test := range table {
-		suite.Run(test.name, func() {
-			t := suite.T()
-
-			assert.Equal(t, test.expectedString, test.base.PopFront().String())
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestShortRef() {
-	table := []struct {
-		name          string
-		inputElements []string
-		expectedLen   int
-	}{
-		{
-			name:          "PopulatedPath",
-			inputElements: []string{"this", "is", "a", "path"},
-			expectedLen:   shortRefCharacters,
-		},
-		{
-			name:          "EmptyPath",
-			inputElements: nil,
-			expectedLen:   0,
-		},
-	}
-	for _, test := range table {
-		suite.Run(test.name, func() {
-			pb := Builder{}.Append(test.inputElements...)
-			ref := pb.ShortRef()
-			assert.Len(suite.T(), ref, test.expectedLen)
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestShortRefIsStable() {
-	t := suite.T()
-	pb := Builder{}.Append("this", "is", "a", "path")
-	prevRef := pb.ShortRef()
-	assert.Len(t, prevRef, shortRefCharacters)
-
-	for i := 0; i < 5; i++ {
-		ref := pb.ShortRef()
-		assert.Len(t, ref, shortRefCharacters)
-		assert.Equal(t, prevRef, ref, "ShortRef changed between calls")
-
-		prevRef = ref
-	}
-}
-
-func (suite *PathUnitSuite) TestShortRefIsUnique() {
-	pb1 := Builder{}.Append("this", "is", "a", "path")
-	pb2 := pb1.Append("also")
-
-	require.NotEqual(suite.T(), pb1, pb2)
-	assert.NotEqual(suite.T(), pb1.ShortRef(), pb2.ShortRef())
-}
-
-// TestShortRefUniqueWithEscaping tests that two paths that output the same
-// unescaped string but different escaped strings have different shortrefs. This
-// situation can occur when one path has embedded path separators while the
-// other does not but contains the same characters.
-func (suite *PathUnitSuite) TestShortRefUniqueWithEscaping() {
-	pb1 := Builder{}.Append(`this`, `is`, `a`, `path`)
-	pb2 := Builder{}.Append(`this`, `is/a`, `path`)
-
-	require.NotEqual(suite.T(), pb1, pb2)
-	assert.NotEqual(suite.T(), pb1.ShortRef(), pb2.ShortRef())
-}
-
-func (suite *PathUnitSuite) TestFromStringErrors() {
+func (suite *PathUnitSuite) TestFromDataLayerPathErrors() {
 	table := []struct {
 		name        string
 		escapedPath string
@@ -521,82 +288,7 @@ func (suite *PathUnitSuite) TestFromStringErrors() {
 	}
 }
 
-func (suite *PathUnitSuite) TestFolder() {
-	table := []struct {
-		name         string
-		p            func(t *testing.T) Path
-		escape       bool
-		expectFolder string
-		expectSplit  []string
-	}{
-		{
-			name: "clean path",
-			p: func(t *testing.T) Path {
-				p, err := Builder{}.
-					Append("a", "b", "c").
-					ToDataLayerExchangePathForCategory("t", "u", EmailCategory, false)
-				require.NoError(t, err, clues.ToCore(err))
-
-				return p
-			},
-			expectFolder: "a/b/c",
-			expectSplit:  []string{"a", "b", "c"},
-		},
-		{
-			name: "clean path escaped",
-			p: func(t *testing.T) Path {
-				p, err := Builder{}.
-					Append("a", "b", "c").
-					ToDataLayerExchangePathForCategory("t", "u", EmailCategory, false)
-				require.NoError(t, err, clues.ToCore(err))
-
-				return p
-			},
-			escape:       true,
-			expectFolder: "a/b/c",
-			expectSplit:  []string{"a", "b", "c"},
-		},
-		{
-			name: "escapable path",
-			p: func(t *testing.T) Path {
-				p, err := Builder{}.
-					Append("a/", "b", "c").
-					ToDataLayerExchangePathForCategory("t", "u", EmailCategory, false)
-				require.NoError(t, err, clues.ToCore(err))
-
-				return p
-			},
-			expectFolder: "a//b/c",
-			expectSplit:  []string{"a", "b", "c"},
-		},
-		{
-			name: "escapable path escaped",
-			p: func(t *testing.T) Path {
-				p, err := Builder{}.
-					Append("a/", "b", "c").
-					ToDataLayerExchangePathForCategory("t", "u", EmailCategory, false)
-				require.NoError(t, err, clues.ToCore(err))
-
-				return p
-			},
-			escape:       true,
-			expectFolder: "a\\//b/c",
-			expectSplit:  []string{"a\\/", "b", "c"},
-		},
-	}
-	for _, test := range table {
-		suite.Run(test.name, func() {
-			t := suite.T()
-
-			p := test.p(t)
-			result := p.Folder(test.escape)
-			assert.Equal(t, test.expectFolder, result)
-			assert.Equal(t, test.expectSplit, Split(result))
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestFromString() {
+func (suite *PathUnitSuite) TestFromDataLayerPath() {
 	const (
 		testTenant         = "tenant"
 		testUser           = "user"
@@ -715,7 +407,7 @@ func (suite *PathUnitSuite) TestFromString() {
 							assert.Equal(t, service, p.Service(), "service")
 							assert.Equal(t, cat, p.Category(), "category")
 							assert.Equal(t, testTenant, p.Tenant(), "tenant")
-							assert.Equal(t, testUser, p.ResourceOwner(), "resource owner")
+							assert.Equal(t, testUser, p.ProtectedResource(), "protected resource")
 
 							fld := p.Folder(false)
 							escfld := p.Folder(true)
@@ -740,43 +432,13 @@ func (suite *PathUnitSuite) TestFromString() {
 	}
 }
 
-func (suite *PathUnitSuite) TestPath_piiHandling() {
-	p, err := Build("t", "ro", ExchangeService, EventsCategory, true, "dir", "item")
-	require.NoError(suite.T(), err)
-
-	table := []struct {
-		name        string
-		p           Path
-		expect      string
-		expectPlain string
-	}{
-		{
-			name:        "standard path",
-			p:           p,
-			expect:      "***/exchange/***/events/***/***",
-			expectPlain: "t/exchange/ro/events/dir/item",
-		},
-	}
-	for _, test := range table {
-		suite.Run(test.name, func() {
-			t := suite.T()
-
-			assert.Equal(t, test.expect, test.p.Conceal(), "conceal")
-			assert.Equal(t, test.expectPlain, test.p.String(), "string")
-			assert.Equal(t, test.expect, fmt.Sprintf("%s", test.p), "fmt %%s")
-			assert.Equal(t, test.expect, fmt.Sprintf("%+v", test.p), "fmt %%+v")
-			assert.Equal(t, test.expectPlain, test.p.PlainString(), "plain")
-		})
-	}
-}
-
-func (suite *PathUnitSuite) TestToServicePrefix() {
+func (suite *PathUnitSuite) TestBuildPrefix() {
 	table := []struct {
 		name      string
 		service   ServiceType
 		category  CategoryType
 		tenant    string
-		owner     string
+		resource  string
 		expect    string
 		expectErr require.ErrorAssertionFunc
 	}{
@@ -785,7 +447,7 @@ func (suite *PathUnitSuite) TestToServicePrefix() {
 			service:   ExchangeService,
 			category:  ContactsCategory,
 			tenant:    "t",
-			owner:     "ro",
+			resource:  "ro",
 			expect:    join([]string{"t", ExchangeService.String(), "ro", ContactsCategory.String()}),
 			expectErr: require.NoError,
 		},
@@ -794,7 +456,7 @@ func (suite *PathUnitSuite) TestToServicePrefix() {
 			service:   ExchangeService,
 			category:  FilesCategory,
 			tenant:    "t",
-			owner:     "ro",
+			resource:  "ro",
 			expectErr: require.Error,
 		},
 		{
@@ -802,15 +464,15 @@ func (suite *PathUnitSuite) TestToServicePrefix() {
 			service:   ExchangeService,
 			category:  ContactsCategory,
 			tenant:    "",
-			owner:     "ro",
+			resource:  "ro",
 			expectErr: require.Error,
 		},
 		{
-			name:      "bad owner",
+			name:      "bad resource",
 			service:   ExchangeService,
 			category:  ContactsCategory,
 			tenant:    "t",
-			owner:     "",
+			resource:  "",
 			expectErr: require.Error,
 		},
 	}
@@ -818,7 +480,7 @@ func (suite *PathUnitSuite) TestToServicePrefix() {
 		suite.Run(test.name, func() {
 			t := suite.T()
 
-			r, err := ServicePrefix(test.tenant, test.owner, test.service, test.category)
+			r, err := BuildPrefix(test.tenant, test.resource, test.service, test.category)
 			test.expectErr(t, err, clues.ToCore(err))
 
 			if r == nil {

src/pkg/path/resource_path.go

@@ -1,161 +1,16 @@
 package path
 
 import (
-	"fmt"
-	"strings"
-
 	"github.com/alcionai/clues"
 )
 
-var ErrorUnknownService = clues.New("unknown service string")
-
-// ServiceType denotes what service the path corresponds to. Metadata services
-// are also included though they are only used for paths that house metadata for
-// Corso backups.
-//
-// Metadata services are not considered valid service types for resource paths
-// though they can be used for metadata paths.
-//
-// The order of the enums below can be changed, but the string representation of
-// each enum must remain the same or migration code needs to be added to handle
-// changes to the string format.
-type ServiceType int
-
-//go:generate stringer -type=ServiceType -linecomment
-const (
-	UnknownService            ServiceType = iota
-	ExchangeService                       // exchange
-	OneDriveService                       // onedrive
-	SharePointService                     // sharepoint
-	ExchangeMetadataService               // exchangeMetadata
-	OneDriveMetadataService               // onedriveMetadata
-	SharePointMetadataService             // sharepointMetadata
-)
-
-func toServiceType(service string) ServiceType {
-	s := strings.ToLower(service)
-
-	switch s {
-	case strings.ToLower(ExchangeService.String()):
-		return ExchangeService
-	case strings.ToLower(OneDriveService.String()):
-		return OneDriveService
-	case strings.ToLower(SharePointService.String()):
-		return SharePointService
-	case strings.ToLower(ExchangeMetadataService.String()):
-		return ExchangeMetadataService
-	case strings.ToLower(OneDriveMetadataService.String()):
-		return OneDriveMetadataService
-	case strings.ToLower(SharePointMetadataService.String()):
-		return SharePointMetadataService
-	default:
-		return UnknownService
-	}
-}
-
-var ErrorUnknownCategory = clues.New("unknown category string")
-
-// CategoryType denotes what category of data the path corresponds to. The order
-// of the enums below can be changed, but the string representation of each enum
-// must remain the same or migration code needs to be added to handle changes to
-// the string format.
-type CategoryType int
-
-//go:generate stringer -type=CategoryType -linecomment
-const (
-	UnknownCategory   CategoryType = iota
-	EmailCategory                  // email
-	ContactsCategory               // contacts
-	EventsCategory                 // events
-	FilesCategory                  // files
-	ListsCategory                  // lists
-	LibrariesCategory              // libraries
-	PagesCategory                  // pages
-	DetailsCategory                // details
-)
-
-func ToCategoryType(category string) CategoryType {
-	cat := strings.ToLower(category)
-
-	switch cat {
-	case strings.ToLower(EmailCategory.String()):
-		return EmailCategory
-	case strings.ToLower(ContactsCategory.String()):
-		return ContactsCategory
-	case strings.ToLower(EventsCategory.String()):
-		return EventsCategory
-	case strings.ToLower(FilesCategory.String()):
-		return FilesCategory
-	case strings.ToLower(LibrariesCategory.String()):
-		return LibrariesCategory
-	case strings.ToLower(ListsCategory.String()):
-		return ListsCategory
-	case strings.ToLower(PagesCategory.String()):
-		return PagesCategory
-	case strings.ToLower(DetailsCategory.String()):
-		return DetailsCategory
-	default:
-		return UnknownCategory
-	}
-}
-
-// serviceCategories is a mapping of all valid service/category pairs for
-// non-metadata paths.
-var serviceCategories = map[ServiceType]map[CategoryType]struct{}{
-	ExchangeService: {
-		EmailCategory:    {},
-		ContactsCategory: {},
-		EventsCategory:   {},
-	},
-	OneDriveService: {
-		FilesCategory: {},
-	},
-	SharePointService: {
-		LibrariesCategory: {},
-		ListsCategory:     {},
-		PagesCategory:     {},
-	},
-}
-
-func validateServiceAndCategoryStrings(s, c string) (ServiceType, CategoryType, error) {
-	service := toServiceType(s)
-	if service == UnknownService {
-		return UnknownService, UnknownCategory, clues.Stack(ErrorUnknownService).With("service", fmt.Sprintf("%q", s))
-	}
-
-	category := ToCategoryType(c)
-	if category == UnknownCategory {
-		return UnknownService, UnknownCategory, clues.Stack(ErrorUnknownService).With("category", fmt.Sprintf("%q", c))
-	}
-
-	if err := ValidateServiceAndCategory(service, category); err != nil {
-		return UnknownService, UnknownCategory, err
-	}
-
-	return service, category, nil
-}
-
-func ValidateServiceAndCategory(service ServiceType, category CategoryType) error {
-	cats, ok := serviceCategories[service]
-	if !ok {
-		return clues.New("unsupported service").With("service", fmt.Sprintf("%q", service))
-	}
-
-	if _, ok := cats[category]; !ok {
-		return clues.New("unknown service/category combination").
-			With("service", fmt.Sprintf("%q", service), "category", fmt.Sprintf("%q", category))
-	}
-
-	return nil
-}
-
 // dataLayerResourcePath allows callers to extract information from a
 // resource-specific path. This struct is unexported so that callers are
 // forced to use the pre-defined constructors, making it impossible to create a
 // dataLayerResourcePath with invalid service/category combinations.
 //
 // All dataLayerResourcePaths start with the same prefix:
-// <tenant ID>/<service>/<resource owner ID>/<category>
+// <tenant ID>/<service>/<protected resource ID>[/<subService>/<protected resource ID>]/<category>
 // which allows extracting high-level information from the path. The path
 // elements after this prefix represent zero or more folders and, if the path
 // refers to a file or item, an item ID. A valid dataLayerResourcePath must have
@@ -183,9 +38,9 @@ func (rp dataLayerResourcePath) Category() CategoryType {
 	return rp.category
 }
 
-// ResourceOwner returns the user ID or group ID embedded in the
+// ProtectedResource returns the resource ID embedded in the
 // dataLayerResourcePath.
-func (rp dataLayerResourcePath) ResourceOwner() string {
+func (rp dataLayerResourcePath) ProtectedResource() string {
 	return rp.Builder.elements[2]
 }
 

src/pkg/path/resource_path_test.go

@@ -37,7 +37,7 @@ var (
 			rest:   rest,
 		},
 		{
-			name:   "NoResourceOwner",
+			name:   "NoProtectedResource",
 			tenant: testTenant,
 			user:   "",
 			rest:   rest,
@@ -404,7 +404,7 @@ func (suite *DataLayerResourcePath) TestToExchangePathForCategory() {
 					assert.Equal(t, testTenant, p.Tenant())
 					assert.Equal(t, path.ExchangeService, p.Service())
 					assert.Equal(t, test.category, p.Category())
-					assert.Equal(t, testUser, p.ResourceOwner())
+					assert.Equal(t, testUser, p.ProtectedResource())
 					assert.Equal(t, strings.Join(m.expectedFolders, "/"), p.Folder(false))
 					assert.Equal(t, path.Elements(m.expectedFolders), p.Folders())
 					assert.Equal(t, m.expectedItem, p.Item())
@@ -471,12 +471,12 @@ func (suite *PopulatedDataLayerResourcePath) TestCategory() {
 	}
 }
 
-func (suite *PopulatedDataLayerResourcePath) TestResourceOwner() {
+func (suite *PopulatedDataLayerResourcePath) TestProtectedResource() {
 	for _, m := range modes {
 		suite.Run(m.name, func() {
 			t := suite.T()
 
-			assert.Equal(t, testUser, suite.paths[m.isItem].ResourceOwner())
+			assert.Equal(t, testUser, suite.paths[m.isItem].ProtectedResource())
 		})
 	}
 }

src/pkg/path/service_type.go

@@ -0,0 +1,53 @@
+package path
+
+import (
+	"strings"
+
+	"github.com/alcionai/clues"
+)
+
+var ErrorUnknownService = clues.New("unknown service string")
+
+// ServiceType denotes what service the path corresponds to. Metadata services
+// are also included though they are only used for paths that house metadata for
+// Corso backups.
+//
+// Metadata services are not considered valid service types for resource paths
+// though they can be used for metadata paths.
+//
+// The order of the enums below can be changed, but the string representation of
+// each enum must remain the same or migration code needs to be added to handle
+// changes to the string format.
+type ServiceType int
+
+//go:generate stringer -type=ServiceType -linecomment
+const (
+	UnknownService            ServiceType = iota
+	ExchangeService                       // exchange
+	OneDriveService                       // onedrive
+	SharePointService                     // sharepoint
+	ExchangeMetadataService               // exchangeMetadata
+	OneDriveMetadataService               // onedriveMetadata
+	SharePointMetadataService             // sharepointMetadata
+)
+
+func toServiceType(service string) ServiceType {
+	s := strings.ToLower(service)
+
+	switch s {
+	case strings.ToLower(ExchangeService.String()):
+		return ExchangeService
+	case strings.ToLower(OneDriveService.String()):
+		return OneDriveService
+	case strings.ToLower(SharePointService.String()):
+		return SharePointService
+	case strings.ToLower(ExchangeMetadataService.String()):
+		return ExchangeMetadataService
+	case strings.ToLower(OneDriveMetadataService.String()):
+		return OneDriveMetadataService
+	case strings.ToLower(SharePointMetadataService.String()):
+		return SharePointMetadataService
+	default:
+		return UnknownService
+	}
+}

src/pkg/repository/loadtest/repository_load_test.go

@@ -348,7 +348,7 @@ func ensureAllUsersInDetails(
 				continue
 			}
 
-			ro := p.ResourceOwner()
+			ro := p.ProtectedResource()
 			if !assert.NotEmpty(t, ro, "resource owner in path: "+rr) {
 				continue
 			}

src/pkg/selectors/exchange.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/alcionai/corso/src/internal/common/dttm"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/filters"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -43,6 +44,7 @@ type (
 var (
 	_ Reducer        = &ExchangeRestore{}
 	_ pathCategorier = &ExchangeRestore{}
+	_ reasoner       = &ExchangeRestore{}
 )
 
 // NewExchange produces a new Selector with the service set to ServiceExchange.
@@ -69,7 +71,7 @@ func (s Selector) ToExchangeBackup() (*ExchangeBackup, error) {
 }
 
 func (s ExchangeBackup) SplitByResourceOwner(users []string) []ExchangeBackup {
-	sels := splitByResourceOwner[ExchangeScope](s.Selector, users, ExchangeUser)
+	sels := splitByProtectedResource[ExchangeScope](s.Selector, users, ExchangeUser)
 
 	ss := make([]ExchangeBackup, 0, len(sels))
 	for _, sel := range sels {
@@ -103,7 +105,7 @@ func (s Selector) ToExchangeRestore() (*ExchangeRestore, error) {
 }
 
 func (sr ExchangeRestore) SplitByResourceOwner(users []string) []ExchangeRestore {
-	sels := splitByResourceOwner[ExchangeScope](sr.Selector, users, ExchangeUser)
+	sels := splitByProtectedResource[ExchangeScope](sr.Selector, users, ExchangeUser)
 
 	ss := make([]ExchangeRestore, 0, len(sels))
 	for _, sel := range sels {
@@ -122,6 +124,13 @@ func (s exchange) PathCategories() selectorPathCategories {
 	}
 }
 
+// Reasons returns a deduplicated set of the backup reasons produced
+// using the selector's discrete owner and each scopes' service and
+// category types.
+func (s exchange) Reasons(tenantID string, useOwnerNameForID bool) []identity.Reasoner {
+	return reasonsFor(s, tenantID, useOwnerNameForID)
+}
+
 // ---------------------------------------------------------------------------
 // Stringers and Concealers
 // ---------------------------------------------------------------------------

src/pkg/selectors/exchange_test.go

@@ -816,7 +816,7 @@ func (suite *ExchangeSelectorSuite) TestExchangeRestore_Reduce() {
 
 		joinedFldrs := strings.Join(newElems, "/")
 
-		return stubRepoRef(p.Service(), p.Category(), p.ResourceOwner(), joinedFldrs, p.Item())
+		return stubRepoRef(p.Service(), p.Category(), p.ProtectedResource(), joinedFldrs, p.Item())
 	}
 
 	makeDeets := func(refs ...path.Path) *details.Details {

src/pkg/selectors/groups.go

@@ -7,6 +7,7 @@ import (
 	"github.com/alcionai/clues"
 
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/path"
 )
@@ -40,6 +41,7 @@ type (
 var (
 	_ Reducer        = &GroupsRestore{}
 	_ pathCategorier = &GroupsRestore{}
+	_ reasoner       = &GroupsRestore{}
 )
 
 // NewGroupsBackup produces a new Selector with the service set to ServiceGroups.
@@ -66,7 +68,7 @@ func (s Selector) ToGroupsBackup() (*GroupsBackup, error) {
 }
 
 func (s GroupsBackup) SplitByResourceOwner(resources []string) []GroupsBackup {
-	sels := splitByResourceOwner[GroupsScope](s.Selector, resources, GroupsGroup)
+	sels := splitByProtectedResource[GroupsScope](s.Selector, resources, GroupsGroup)
 
 	ss := make([]GroupsBackup, 0, len(sels))
 	for _, sel := range sels {
@@ -100,7 +102,7 @@ func (s Selector) ToGroupsRestore() (*GroupsRestore, error) {
 }
 
 func (s GroupsRestore) SplitByResourceOwner(resources []string) []GroupsRestore {
-	sels := splitByResourceOwner[GroupsScope](s.Selector, resources, GroupsGroup)
+	sels := splitByProtectedResource[GroupsScope](s.Selector, resources, GroupsGroup)
 
 	ss := make([]GroupsRestore, 0, len(sels))
 	for _, sel := range sels {
@@ -119,6 +121,13 @@ func (s groups) PathCategories() selectorPathCategories {
 	}
 }
 
+// Reasons returns a deduplicated set of the backup reasons produced
+// using the selector's discrete owner and each scopes' service and
+// category types.
+func (s groups) Reasons(tenantID string, useOwnerNameForID bool) []identity.Reasoner {
+	return reasonsFor(s, tenantID, useOwnerNameForID)
+}
+
 // ---------------------------------------------------------------------------
 // Stringers and Concealers
 // ---------------------------------------------------------------------------

src/pkg/selectors/helpers_test.go

@@ -167,6 +167,8 @@ func (s mockScope) PlainString() string         { return plainString(s) }
 // selectors
 // ---------------------------------------------------------------------------
 
+var _ servicerCategorizerProvider = &mockSel{}
+
 type mockSel struct {
 	Selector
 }
@@ -183,6 +185,10 @@ func stubSelector(resourceOwners []string) mockSel {
 	}
 }
 
+func (m mockSel) PathCategories() selectorPathCategories {
+	return m.PathCategories()
+}
+
 // ---------------------------------------------------------------------------
 // helper funcs
 // ---------------------------------------------------------------------------

src/pkg/selectors/onedrive.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/alcionai/corso/src/internal/common/dttm"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/filters"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -42,6 +43,7 @@ type (
 var (
 	_ Reducer        = &OneDriveRestore{}
 	_ pathCategorier = &OneDriveRestore{}
+	_ reasoner       = &OneDriveRestore{}
 )
 
 // NewOneDriveBackup produces a new Selector with the service set to ServiceOneDrive.
@@ -68,7 +70,7 @@ func (s Selector) ToOneDriveBackup() (*OneDriveBackup, error) {
 }
 
 func (s OneDriveBackup) SplitByResourceOwner(users []string) []OneDriveBackup {
-	sels := splitByResourceOwner[OneDriveScope](s.Selector, users, OneDriveUser)
+	sels := splitByProtectedResource[OneDriveScope](s.Selector, users, OneDriveUser)
 
 	ss := make([]OneDriveBackup, 0, len(sels))
 	for _, sel := range sels {
@@ -102,7 +104,7 @@ func (s Selector) ToOneDriveRestore() (*OneDriveRestore, error) {
 }
 
 func (s OneDriveRestore) SplitByResourceOwner(users []string) []OneDriveRestore {
-	sels := splitByResourceOwner[OneDriveScope](s.Selector, users, OneDriveUser)
+	sels := splitByProtectedResource[OneDriveScope](s.Selector, users, OneDriveUser)
 
 	ss := make([]OneDriveRestore, 0, len(sels))
 	for _, sel := range sels {
@@ -121,6 +123,13 @@ func (s oneDrive) PathCategories() selectorPathCategories {
 	}
 }
 
+// Reasons returns a deduplicated set of the backup reasons produced
+// using the selector's discrete owner and each scopes' service and
+// category types.
+func (s oneDrive) Reasons(tenantID string, useOwnerNameForID bool) []identity.Reasoner {
+	return reasonsFor(s, tenantID, useOwnerNameForID)
+}
+
 // ---------------------------------------------------------------------------
 // Stringers and Concealers
 // ---------------------------------------------------------------------------

src/pkg/selectors/onedrive_test.go

@@ -43,16 +43,12 @@ func (suite *OneDriveSelectorSuite) TestToOneDriveBackup() {
 }
 
 func (suite *OneDriveSelectorSuite) TestOneDriveSelector_AllData() {
-	t := suite.T()
-
 	var (
 		users     = []string{"u1", "u2"}
 		sel       = NewOneDriveBackup(users)
 		allScopes = sel.AllData()
 	)
 
-	assert.ElementsMatch(t, users, sel.DiscreteResourceOwners())
-
 	// Initialize the selector Include, Exclude, Filter
 	sel.Exclude(allScopes)
 	sel.Include(allScopes)

src/pkg/selectors/reasons.go

@@ -0,0 +1,91 @@
+package selectors
+
+import (
+	"golang.org/x/exp/maps"
+
+	"github.com/alcionai/corso/src/internal/common/idname"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
+	"github.com/alcionai/corso/src/pkg/path"
+)
+
+// ---------------------------------------------------------------------------
+// reasoner interface compliance
+// ---------------------------------------------------------------------------
+
+var _ identity.Reasoner = &backupReason{}
+
+type backupReason struct {
+	category path.CategoryType
+	resource string
+	service  path.ServiceType
+	tenant   string
+}
+
+func (br backupReason) Tenant() string {
+	return br.tenant
+}
+
+func (br backupReason) ProtectedResource() string {
+	return br.resource
+}
+
+func (br backupReason) Service() path.ServiceType {
+	return br.service
+}
+
+func (br backupReason) Category() path.CategoryType {
+	return br.category
+}
+
+func (br backupReason) SubtreePath() (path.Path, error) {
+	return path.BuildPrefix(
+		br.tenant,
+		br.resource,
+		br.service,
+		br.category)
+}
+
+func (br backupReason) key() string {
+	return br.category.String() + br.resource + br.service.String() + br.tenant
+}
+
+// ---------------------------------------------------------------------------
+// common transformer
+// ---------------------------------------------------------------------------
+
+type servicerCategorizerProvider interface {
+	pathServicer
+	pathCategorier
+	idname.Provider
+}
+
+func reasonsFor(
+	sel servicerCategorizerProvider,
+	tenantID string,
+	useOwnerNameForID bool,
+) []identity.Reasoner {
+	service := sel.PathService()
+	reasons := map[string]identity.Reasoner{}
+
+	resource := sel.ID()
+	if useOwnerNameForID {
+		resource = sel.Name()
+	}
+
+	pc := sel.PathCategories()
+
+	for _, sl := range [][]path.CategoryType{pc.Includes, pc.Filters} {
+		for _, cat := range sl {
+			br := backupReason{
+				category: cat,
+				resource: resource,
+				service:  service,
+				tenant:   tenantID,
+			}
+
+			reasons[br.key()] = br
+		}
+	}
+
+	return maps.Values(reasons)
+}

src/pkg/selectors/reasons_test.go

@@ -0,0 +1,406 @@
+package selectors
+
+import (
+	"testing"
+
+	"github.com/alcionai/clues"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/stretchr/testify/suite"
+
+	"github.com/alcionai/corso/src/internal/tester"
+	"github.com/alcionai/corso/src/pkg/path"
+)
+
+type ReasonsUnitSuite struct {
+	tester.Suite
+}
+
+func TestReasonsUnitSuite(t *testing.T) {
+	suite.Run(t, &ReasonsUnitSuite{Suite: tester.NewUnitSuite(t)})
+}
+
+func (suite *ReasonsUnitSuite) TestReasonsFor_thorough() {
+	var (
+		tenantID = "tid"
+		exchange = path.ExchangeService.String()
+		email    = path.EmailCategory.String()
+		contacts = path.ContactsCategory.String()
+	)
+
+	type expect struct {
+		tenant            string
+		resource          string
+		category          string
+		service           string
+		subtreePath       string
+		subtreePathHadErr bool
+	}
+
+	stpFor := func(resource, category, service string) string {
+		return path.Builder{}.Append(tenantID, service, resource, category).String()
+	}
+
+	table := []struct {
+		name    string
+		sel     func() ExchangeRestore
+		useName bool
+		expect  []expect
+	}{
+		{
+			name: "no scopes",
+			sel: func() ExchangeRestore {
+				return *NewExchangeRestore([]string{"timbo"})
+			},
+			expect: []expect{},
+		},
+		{
+			name: "use name",
+			sel: func() ExchangeRestore {
+				sel := NewExchangeRestore([]string{"timbo"})
+				sel.Include(sel.MailFolders(Any()))
+				plainSel := sel.SetDiscreteOwnerIDName("timbo", "timbubba")
+
+				sel, err := plainSel.ToExchangeRestore()
+				require.NoError(suite.T(), err, clues.ToCore(err))
+
+				return *sel
+			},
+			useName: true,
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "timbubba",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("timbubba", email, exchange),
+				},
+			},
+		},
+		{
+			name: "only includes",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"bubba"})
+				sel.Include(sel.MailFolders(Any()))
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "bubba",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("bubba", email, exchange),
+				},
+			},
+		},
+		{
+			name: "only filters",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"tachoma dhaume"})
+				sel.Filter(sel.MailFolders(Any()))
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "tachoma dhaume",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("tachoma dhaume", email, exchange),
+				},
+			},
+		},
+		{
+			name: "duplicate includes and filters",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"vyng vang zoombah"})
+				sel.Include(sel.MailFolders(Any()))
+				sel.Filter(sel.MailFolders(Any()))
+
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "vyng vang zoombah",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("vyng vang zoombah", email, exchange),
+				},
+			},
+		},
+		{
+			name: "duplicate includes",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"fat billie"})
+				sel.Include(sel.MailFolders(Any()), sel.MailFolders(Any()))
+
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "fat billie",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("fat billie", email, exchange),
+				},
+			},
+		},
+		{
+			name: "duplicate filters",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"seathane"})
+				sel.Filter(sel.MailFolders(Any()), sel.MailFolders(Any()))
+
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "seathane",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("seathane", email, exchange),
+				},
+			},
+		},
+		{
+			name: "no duplicates",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"perell"})
+				sel.Include(sel.MailFolders(Any()), sel.ContactFolders(Any()))
+
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "perell",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("perell", email, exchange),
+				},
+				{
+					tenant:      tenantID,
+					resource:    "perell",
+					category:    contacts,
+					service:     exchange,
+					subtreePath: stpFor("perell", contacts, exchange),
+				},
+			},
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			results := []expect{}
+			rs := reasonsFor(test.sel(), tenantID, test.useName)
+
+			for _, r := range rs {
+				stp, err := r.SubtreePath()
+
+				t.Log("stp err", err)
+
+				stpStr := ""
+				if stp != nil {
+					stpStr = stp.String()
+				}
+
+				results = append(results, expect{
+					tenant:            r.Tenant(),
+					resource:          r.ProtectedResource(),
+					service:           r.Service().String(),
+					category:          r.Category().String(),
+					subtreePath:       stpStr,
+					subtreePathHadErr: err != nil,
+				})
+			}
+
+			assert.ElementsMatch(t, test.expect, results)
+		})
+	}
+}
+
+func (suite *ReasonsUnitSuite) TestReasonsFor_serviceChecks() {
+	var (
+		tenantID = "tid"
+		exchange = path.ExchangeService.String()
+		email    = path.EmailCategory.String()
+		contacts = path.ContactsCategory.String()
+	)
+
+	type expect struct {
+		tenant            string
+		resource          string
+		category          string
+		service           string
+		subtreePath       string
+		subtreePathHadErr bool
+	}
+
+	stpFor := func(resource, category, service string) string {
+		return path.Builder{}.Append(tenantID, service, resource, category).String()
+	}
+
+	table := []struct {
+		name    string
+		sel     func() ExchangeRestore
+		useName bool
+		expect  []expect
+	}{
+		{
+			name: "no scopes",
+			sel: func() ExchangeRestore {
+				return *NewExchangeRestore([]string{"timbo"})
+			},
+			expect: []expect{},
+		},
+		{
+			name: "only includes",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"bubba"})
+				sel.Include(sel.MailFolders(Any()))
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "bubba",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("bubba", email, exchange),
+				},
+			},
+		},
+		{
+			name: "only filters",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"tachoma dhaume"})
+				sel.Filter(sel.MailFolders(Any()))
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "tachoma dhaume",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("tachoma dhaume", email, exchange),
+				},
+			},
+		},
+		{
+			name: "duplicate includes and filters",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"vyng vang zoombah"})
+				sel.Include(sel.MailFolders(Any()))
+				sel.Filter(sel.MailFolders(Any()))
+
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "vyng vang zoombah",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("vyng vang zoombah", email, exchange),
+				},
+			},
+		},
+		{
+			name: "duplicate includes",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"fat billie"})
+				sel.Include(sel.MailFolders(Any()), sel.MailFolders(Any()))
+
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "fat billie",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("fat billie", email, exchange),
+				},
+			},
+		},
+		{
+			name: "duplicate filters",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"seathane"})
+				sel.Filter(sel.MailFolders(Any()), sel.MailFolders(Any()))
+
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "seathane",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("seathane", email, exchange),
+				},
+			},
+		},
+		{
+			name: "no duplicates",
+			sel: func() ExchangeRestore {
+				sel := *NewExchangeRestore([]string{"perell"})
+				sel.Include(sel.MailFolders(Any()), sel.ContactFolders(Any()))
+
+				return sel
+			},
+			expect: []expect{
+				{
+					tenant:      tenantID,
+					resource:    "perell",
+					category:    email,
+					service:     exchange,
+					subtreePath: stpFor("perell", email, exchange),
+				},
+				{
+					tenant:      tenantID,
+					resource:    "perell",
+					category:    contacts,
+					service:     exchange,
+					subtreePath: stpFor("perell", contacts, exchange),
+				},
+			},
+		},
+	}
+	for _, test := range table {
+		suite.Run(test.name, func() {
+			t := suite.T()
+
+			results := []expect{}
+			rs := reasonsFor(test.sel(), tenantID, test.useName)
+
+			for _, r := range rs {
+				stp, err := r.SubtreePath()
+
+				t.Log("stp err", err)
+
+				stpStr := ""
+				if stp != nil {
+					stpStr = stp.String()
+				}
+
+				results = append(results, expect{
+					tenant:            r.Tenant(),
+					resource:          r.ProtectedResource(),
+					service:           r.Service().String(),
+					category:          r.Category().String(),
+					subtreePath:       stpStr,
+					subtreePathHadErr: err != nil,
+				})
+			}
+
+			assert.ElementsMatch(t, test.expect, results)
+		})
+	}
+}

src/pkg/selectors/scopes.go

@@ -161,6 +161,267 @@ type (
 	}
 )
 
+// appendScopes iterates through each scope in the list of scope slices,
+// calling setDefaults() to ensure it is completely populated, and appends
+// those scopes to the `to` slice.
+func appendScopes[T scopeT](to []scope, scopes ...[]T) []scope {
+	if len(to) == 0 {
+		to = []scope{}
+	}
+
+	for _, scopeSl := range scopes {
+		for _, s := range scopeSl {
+			s.setDefaults()
+			to = append(to, scope(s))
+		}
+	}
+
+	return to
+}
+
+// scopes retrieves the list of scopes in the selector.
+func scopes[T scopeT](s Selector) []T {
+	scopes := []T{}
+
+	for _, v := range s.Includes {
+		scopes = append(scopes, T(v))
+	}
+
+	return scopes
+}
+
+// ---------------------------------------------------------------------------
+// scope config & constructors
+// ---------------------------------------------------------------------------
+
+// constructs the default item-scope comparator options according
+// to the selector configuration.
+//   - if cfg.OnlyMatchItemNames == false, then comparison assumes item IDs,
+//     which are case sensitive, resulting in StrictEqualsMatch
+func defaultItemOptions(cfg Config) []option {
+	opts := []option{}
+
+	if !cfg.OnlyMatchItemNames {
+		opts = append(opts, StrictEqualMatch())
+	}
+
+	return opts
+}
+
+type scopeConfig struct {
+	usePathFilter         bool
+	usePrefixFilter       bool
+	useSuffixFilter       bool
+	useEqualsFilter       bool
+	useStrictEqualsFilter bool
+}
+
+type option func(*scopeConfig)
+
+func (sc *scopeConfig) populate(opts ...option) {
+	for _, opt := range opts {
+		opt(sc)
+	}
+}
+
+// PrefixMatch ensures the selector uses a Prefix comparator, instead
+// of contains or equals.  Will not override a default Any() or None()
+// comparator.
+func PrefixMatch() option {
+	return func(sc *scopeConfig) {
+		sc.usePrefixFilter = true
+	}
+}
+
+// SuffixMatch ensures the selector uses a Suffix comparator, instead
+// of contains or equals.  Will not override a default Any() or None()
+// comparator.
+func SuffixMatch() option {
+	return func(sc *scopeConfig) {
+		sc.useSuffixFilter = true
+	}
+}
+
+// StrictEqualsMatch ensures the selector uses a StrictEquals comparator, instead
+// of contains.  Will not override a default Any() or None() comparator.
+func StrictEqualMatch() option {
+	return func(sc *scopeConfig) {
+		sc.useStrictEqualsFilter = true
+	}
+}
+
+// ExactMatch ensures the selector uses an Equals comparator, instead
+// of contains.  Will not override a default Any() or None() comparator.
+func ExactMatch() option {
+	return func(sc *scopeConfig) {
+		sc.useEqualsFilter = true
+	}
+}
+
+// pathComparator is an internal-facing option.  It is assumed that scope
+// constructors will provide the pathComparator option whenever a folder-
+// level scope (ie, a scope that compares path hierarchies) is created.
+func pathComparator() option {
+	return func(sc *scopeConfig) {
+		sc.usePathFilter = true
+	}
+}
+
+func badCastErr(cast, is service) error {
+	return clues.Stack(ErrorBadSelectorCast, clues.New(fmt.Sprintf("%s is not %s", cast, is)))
+}
+
+// if the provided slice contains Any, returns [Any]
+// if the slice contains None, returns [None]
+// if the slice contains Any and None, returns the first
+// if the slice is empty, returns [None]
+// otherwise returns the input
+func clean(s []string) []string {
+	if len(s) == 0 {
+		return None()
+	}
+
+	for _, e := range s {
+		if e == AnyTgt {
+			return Any()
+		}
+
+		if e == NoneTgt {
+			return None()
+		}
+	}
+
+	return s
+}
+
+type filterFunc func([]string) filters.Filter
+
+// filterize turns the slice into a filter.
+// if the input is Any(), returns a passAny filter.
+// if the input is None(), returns a failAny filter.
+// if the scopeConfig specifies a filter, use that filter.
+// if the input is len(1), returns an Equals filter.
+// otherwise returns a Contains filter.
+func filterFor(sc scopeConfig, targets ...string) filters.Filter {
+	return filterize(sc, nil, targets...)
+}
+
+// filterize turns the slice into a filter.
+// if the input is Any(), returns a passAny filter.
+// if the input is None(), returns a failAny filter.
+// if the scopeConfig specifies a filter, use that filter.
+// if defaultFilter is non-nil, returns that filter.
+// if the input is len(1), returns an Equals filter.
+// otherwise returns a Contains filter.
+func filterize(
+	sc scopeConfig,
+	defaultFilter filterFunc,
+	targets ...string,
+) filters.Filter {
+	targets = clean(targets)
+
+	if len(targets) == 0 || targets[0] == NoneTgt {
+		return failAny
+	}
+
+	if targets[0] == AnyTgt {
+		return passAny
+	}
+
+	if sc.usePathFilter {
+		if sc.useEqualsFilter {
+			return filters.PathEquals(targets)
+		}
+
+		if sc.usePrefixFilter {
+			return filters.PathPrefix(targets)
+		}
+
+		if sc.useSuffixFilter {
+			return filters.PathSuffix(targets)
+		}
+
+		return filters.PathContains(targets)
+	}
+
+	if sc.usePrefixFilter {
+		return filters.Prefix(targets)
+	}
+
+	if sc.useSuffixFilter {
+		return filters.Suffix(targets)
+	}
+
+	if sc.useStrictEqualsFilter {
+		return filters.StrictEqual(targets)
+	}
+
+	if defaultFilter != nil {
+		return defaultFilter(targets)
+	}
+
+	return filters.Equal(targets)
+}
+
+// pathFilterFactory returns the appropriate path filter
+// (contains, prefix, or suffix) for the provided options.
+// If multiple options are flagged, Prefix takes priority.
+// If no options are provided, returns PathContains.
+func pathFilterFactory(opts ...option) filterFunc {
+	sc := &scopeConfig{}
+	sc.populate(opts...)
+
+	var ff filterFunc
+
+	switch true {
+	case sc.usePrefixFilter:
+		ff = filters.PathPrefix
+	case sc.useSuffixFilter:
+		ff = filters.PathSuffix
+	case sc.useEqualsFilter:
+		ff = filters.PathEquals
+	default:
+		ff = filters.PathContains
+	}
+
+	return wrapSliceFilter(ff)
+}
+
+func wrapSliceFilter(ff filterFunc) filterFunc {
+	return func(s []string) filters.Filter {
+		s = clean(s)
+
+		if f, ok := isAnyOrNone(s); ok {
+			return f
+		}
+
+		return ff(s)
+	}
+}
+
+// returns (<filter>, true) if s is len==1 and s[0] is
+// anyTgt or noneTgt, implying that the caller should use
+// the returned filter.  On (<filter>, false), the caller
+// can ignore the returned filter.
+// a special case exists for len(s)==0, interpreted as
+// "noneTgt"
+func isAnyOrNone(s []string) (filters.Filter, bool) {
+	switch len(s) {
+	case 0:
+		return failAny, true
+
+	case 1:
+		switch s[0] {
+		case AnyTgt:
+			return passAny, true
+		case NoneTgt:
+			return failAny, true
+		}
+	}
+
+	return failAny, false
+}
+
 // makeScope produces a well formatted, typed scope that ensures all base values are populated.
 func makeScope[T scopeT](
 	cat categorizer,
@@ -239,95 +500,9 @@ func marshalScope(mss map[string]string) string {
 }
 
 // ---------------------------------------------------------------------------
-// scope funcs
+// reducer & filtering
 // ---------------------------------------------------------------------------
 
-// matches returns true if the category is included in the scope's
-// data type, and the input string passes the scope's filter for
-// that category.
-func matches[T scopeT, C categoryT](s T, cat C, inpt string) bool {
-	if !typeAndCategoryMatches(cat, s.categorizer()) {
-		return false
-	}
-
-	if len(inpt) == 0 {
-		return false
-	}
-
-	return s[cat.String()].Compare(inpt)
-}
-
-// matchesAny returns true if the category is included in the scope's
-// data type, and any one of the input strings passes the scope's filter.
-func matchesAny[T scopeT, C categoryT](s T, cat C, inpts []string) bool {
-	if !typeAndCategoryMatches(cat, s.categorizer()) {
-		return false
-	}
-
-	if len(inpts) == 0 {
-		return false
-	}
-
-	return s[cat.String()].CompareAny(inpts...)
-}
-
-// getCategory returns the scope's category value.
-// if s is an info-type scope, returns the info category.
-func getCategory[T scopeT](s T) string {
-	return s[scopeKeyCategory].Identity
-}
-
-// getInfoCategory returns the scope's infoFilter category value.
-func getInfoCategory[T scopeT](s T) string {
-	return s[scopeKeyInfoCategory].Identity
-}
-
-// getCatValue takes the value of s[cat] and returns the slice.
-// If s[cat] is nil, returns None().
-func getCatValue[T scopeT](s T, cat categorizer) []string {
-	filt, ok := s[cat.String()]
-	if !ok {
-		return None()
-	}
-
-	if len(filt.Targets) > 0 {
-		return filt.Targets
-	}
-
-	return filt.Targets
-}
-
-// set sets a value by category to the scope.  Only intended for internal
-// use, not for exporting to callers.
-func set[T scopeT](s T, cat categorizer, v []string, opts ...option) T {
-	sc := &scopeConfig{}
-	sc.populate(opts...)
-
-	s[cat.String()] = filterFor(*sc, v...)
-
-	return s
-}
-
-// returns true if the category is included in the scope's category type,
-// and the value is set to None().
-func isNoneTarget[T scopeT, C categoryT](s T, cat C) bool {
-	if !typeAndCategoryMatches(cat, s.categorizer()) {
-		return false
-	}
-
-	return s[cat.String()].Comparator == filters.Fails
-}
-
-// returns true if the category is included in the scope's category type,
-// and the value is set to Any().
-func isAnyTarget[T scopeT, C categoryT](s T, cat C) bool {
-	if !typeAndCategoryMatches(cat, s.categorizer()) {
-		return false
-	}
-
-	return s[cat.String()].Comparator == filters.Passes
-}
-
 // reduce filters the entries in the details to only those that match the
 // inclusions, filters, and exclusions in the selector.
 func reduce[T scopeT, C categoryT](
@@ -370,7 +545,7 @@ func reduce[T scopeT, C categoryT](
 		}
 
 		// first check, every entry needs to match the selector's resource owners.
-		if !matchesResourceOwner.Compare(repoPath.ResourceOwner()) {
+		if !matchesResourceOwner.Compare(repoPath.ProtectedResource()) {
 			continue
 		}
 
@@ -542,6 +717,92 @@ func matchesPathValues[T scopeT, C categoryT](
 // helper funcs
 // ---------------------------------------------------------------------------
 
+// matches returns true if the category is included in the scope's
+// data type, and the input string passes the scope's filter for
+// that category.
+func matches[T scopeT, C categoryT](s T, cat C, inpt string) bool {
+	if !typeAndCategoryMatches(cat, s.categorizer()) {
+		return false
+	}
+
+	if len(inpt) == 0 {
+		return false
+	}
+
+	return s[cat.String()].Compare(inpt)
+}
+
+// matchesAny returns true if the category is included in the scope's
+// data type, and any one of the input strings passes the scope's filter.
+func matchesAny[T scopeT, C categoryT](s T, cat C, inpts []string) bool {
+	if !typeAndCategoryMatches(cat, s.categorizer()) {
+		return false
+	}
+
+	if len(inpts) == 0 {
+		return false
+	}
+
+	return s[cat.String()].CompareAny(inpts...)
+}
+
+// getCategory returns the scope's category value.
+// if s is an info-type scope, returns the info category.
+func getCategory[T scopeT](s T) string {
+	return s[scopeKeyCategory].Identity
+}
+
+// getInfoCategory returns the scope's infoFilter category value.
+func getInfoCategory[T scopeT](s T) string {
+	return s[scopeKeyInfoCategory].Identity
+}
+
+// getCatValue takes the value of s[cat] and returns the slice.
+// If s[cat] is nil, returns None().
+func getCatValue[T scopeT](s T, cat categorizer) []string {
+	filt, ok := s[cat.String()]
+	if !ok {
+		return None()
+	}
+
+	if len(filt.Targets) > 0 {
+		return filt.Targets
+	}
+
+	return filt.Targets
+}
+
+// set sets a value by category to the scope.  Only intended for internal
+// use, not for exporting to callers.
+func set[T scopeT](s T, cat categorizer, v []string, opts ...option) T {
+	sc := &scopeConfig{}
+	sc.populate(opts...)
+
+	s[cat.String()] = filterFor(*sc, v...)
+
+	return s
+}
+
+// returns true if the category is included in the scope's category type,
+// and the value is set to None().
+func isNoneTarget[T scopeT, C categoryT](s T, cat C) bool {
+	if !typeAndCategoryMatches(cat, s.categorizer()) {
+		return false
+	}
+
+	return s[cat.String()].Comparator == filters.Fails
+}
+
+// returns true if the category is included in the scope's category type,
+// and the value is set to Any().
+func isAnyTarget[T scopeT, C categoryT](s T, cat C) bool {
+	if !typeAndCategoryMatches(cat, s.categorizer()) {
+		return false
+	}
+
+	return s[cat.String()].Comparator == filters.Passes
+}
+
 // categoryMatches returns true if:
 // - neither type is 'unknown'
 // - either type is the root type

src/pkg/selectors/selectors.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/alcionai/corso/src/internal/common/idname"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/filters"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -87,6 +88,14 @@ type pathCategorier interface {
 	PathCategories() selectorPathCategories
 }
 
+type pathServicer interface {
+	PathService() path.ServiceType
+}
+
+type reasoner interface {
+	Reasons(tenantID string, useOwnerNameForID bool) []identity.Reasoner
+}
+
 // ---------------------------------------------------------------------------
 // Selector
 // ---------------------------------------------------------------------------
@@ -159,11 +168,25 @@ func (s *Selector) Configure(cfg Config) {
 	s.Cfg = cfg
 }
 
-// DiscreteResourceOwners returns the list of individual resourceOwners used
-// in the selector.
-// TODO(rkeepers): remove in favor of split and s.DiscreteOwner
-func (s Selector) DiscreteResourceOwners() []string {
-	return s.ResourceOwners.Targets
+// ---------------------------------------------------------------------------
+// protected resources & idname provider compliance
+// ---------------------------------------------------------------------------
+
+var _ idname.Provider = &Selector{}
+
+// ID returns s.discreteOwner, which is assumed to be a stable ID.
+func (s Selector) ID() string {
+	return s.DiscreteOwner
+}
+
+// Name returns s.discreteOwnerName.  If that value is empty, it returns
+// s.DiscreteOwner instead.
+func (s Selector) Name() string {
+	if len(s.DiscreteOwnerName) == 0 {
+		return s.DiscreteOwner
+	}
+
+	return s.DiscreteOwnerName
 }
 
 // SetDiscreteOwnerIDName ensures the selector has the correct discrete owner
@@ -193,32 +216,17 @@ func (s Selector) SetDiscreteOwnerIDName(id, name string) Selector {
 	return r
 }
 
-// ID returns s.discreteOwner, which is assumed to be a stable ID.
-func (s Selector) ID() string {
-	return s.DiscreteOwner
-}
-
-// Name returns s.discreteOwnerName.  If that value is empty, it returns
-// s.DiscreteOwner instead.
-func (s Selector) Name() string {
-	if len(s.DiscreteOwnerName) == 0 {
-		return s.DiscreteOwner
-	}
-
-	return s.DiscreteOwnerName
-}
-
-// isAnyResourceOwner returns true if the selector includes all resource owners.
-func isAnyResourceOwner(s Selector) bool {
+// isAnyProtectedResource returns true if the selector includes all resource owners.
+func isAnyProtectedResource(s Selector) bool {
 	return s.ResourceOwners.Comparator == filters.Passes
 }
 
-// isNoneResourceOwner returns true if the selector includes no resource owners.
-func isNoneResourceOwner(s Selector) bool {
+// isNoneProtectedResource returns true if the selector includes no resource owners.
+func isNoneProtectedResource(s Selector) bool {
 	return s.ResourceOwners.Comparator == filters.Fails
 }
 
-// SplitByResourceOwner makes one shallow clone for each resourceOwner in the
+// splitByProtectedResource makes one shallow clone for each resourceOwner in the
 // selector, specifying a new DiscreteOwner for each one.
 // If the original selector already specified a discrete slice of resource owners,
 // only those owners are used in the result.
@@ -230,14 +238,14 @@ func isNoneResourceOwner(s Selector) bool {
 //
 // temporarily, clones all scopes in each selector and replaces the owners with
 // the discrete owner.
-func splitByResourceOwner[T scopeT, C categoryT](s Selector, allOwners []string, rootCat C) []Selector {
-	if isNoneResourceOwner(s) {
+func splitByProtectedResource[T scopeT, C categoryT](s Selector, allOwners []string, rootCat C) []Selector {
+	if isNoneProtectedResource(s) {
 		return []Selector{}
 	}
 
 	targets := allOwners
 
-	if !isAnyResourceOwner(s) {
+	if !isAnyProtectedResource(s) {
 		targets = s.ResourceOwners.Targets
 	}
 
@@ -252,35 +260,6 @@ func splitByResourceOwner[T scopeT, C categoryT](s Selector, allOwners []string,
 	return ss
 }
 
-// appendScopes iterates through each scope in the list of scope slices,
-// calling setDefaults() to ensure it is completely populated, and appends
-// those scopes to the `to` slice.
-func appendScopes[T scopeT](to []scope, scopes ...[]T) []scope {
-	if len(to) == 0 {
-		to = []scope{}
-	}
-
-	for _, scopeSl := range scopes {
-		for _, s := range scopeSl {
-			s.setDefaults()
-			to = append(to, scope(s))
-		}
-	}
-
-	return to
-}
-
-// scopes retrieves the list of scopes in the selector.
-func scopes[T scopeT](s Selector) []T {
-	scopes := []T{}
-
-	for _, v := range s.Includes {
-		scopes = append(scopes, T(v))
-	}
-
-	return scopes
-}
-
 // Returns the path.ServiceType matching the selector service.
 func (s Selector) PathService() path.ServiceType {
 	return serviceToPathType[s.Service]
@@ -303,7 +282,7 @@ func (s Selector) Reduce(
 	return r.Reduce(ctx, deets, errs), nil
 }
 
-// returns the sets of path categories identified in each scope set.
+// PathCategories returns the sets of path categories identified in each scope set.
 func (s Selector) PathCategories() (selectorPathCategories, error) {
 	ro, err := selectorAsIface[pathCategorier](s)
 	if err != nil {
@@ -313,6 +292,18 @@ func (s Selector) PathCategories() (selectorPathCategories, error) {
 	return ro.PathCategories(), nil
 }
 
+// Reasons returns a deduplicated set of the backup reasons produced
+// using the selector's discrete owner and each scopes' service and
+// category types.
+func (s Selector) Reasons(tenantID string, useOwnerNameForID bool) ([]identity.Reasoner, error) {
+	ro, err := selectorAsIface[reasoner](s)
+	if err != nil {
+		return nil, err
+	}
+
+	return ro.Reasons(tenantID, useOwnerNameForID), nil
+}
+
 // transformer for arbitrary selector interfaces
 func selectorAsIface[T any](s Selector) (T, error) {
 	var (
@@ -331,6 +322,9 @@ func selectorAsIface[T any](s Selector) (T, error) {
 	case ServiceSharePoint:
 		a, err = func() (any, error) { return s.ToSharePointRestore() }()
 		t = a.(T)
+	case ServiceGroups:
+		a, err = func() (any, error) { return s.ToGroupsRestore() }()
+		t = a.(T)
 	default:
 		err = clues.Stack(ErrorUnrecognizedService, clues.New(s.Service.String()))
 	}
@@ -420,28 +414,6 @@ func (ls loggableSelector) marshal() string {
 // helpers
 // ---------------------------------------------------------------------------
 
-// produces the discrete set of resource owners in the slice of scopes.
-// Any and None values are discarded.
-func resourceOwnersIn(s []scope, rootCat string) []string {
-	rm := map[string]struct{}{}
-
-	for _, sc := range s {
-		for _, v := range sc[rootCat].Targets {
-			rm[v] = struct{}{}
-		}
-	}
-
-	rs := []string{}
-
-	for k := range rm {
-		if k != AnyTgt && k != NoneTgt {
-			rs = append(rs, k)
-		}
-	}
-
-	return rs
-}
-
 // produces the discrete set of path categories in the slice of scopes.
 func pathCategoriesIn[T scopeT, C categoryT](ss []scope) []path.CategoryType {
 	m := map[path.CategoryType]struct{}{}
@@ -459,235 +431,3 @@ func pathCategoriesIn[T scopeT, C categoryT](ss []scope) []path.CategoryType {
 
 	return maps.Keys(m)
 }
-
-// ---------------------------------------------------------------------------
-// scope constructors
-// ---------------------------------------------------------------------------
-
-// constructs the default item-scope comparator options according
-// to the selector configuration.
-//   - if cfg.OnlyMatchItemNames == false, then comparison assumes item IDs,
-//     which are case sensitive, resulting in StrictEqualsMatch
-func defaultItemOptions(cfg Config) []option {
-	opts := []option{}
-
-	if !cfg.OnlyMatchItemNames {
-		opts = append(opts, StrictEqualMatch())
-	}
-
-	return opts
-}
-
-type scopeConfig struct {
-	usePathFilter         bool
-	usePrefixFilter       bool
-	useSuffixFilter       bool
-	useEqualsFilter       bool
-	useStrictEqualsFilter bool
-}
-
-type option func(*scopeConfig)
-
-func (sc *scopeConfig) populate(opts ...option) {
-	for _, opt := range opts {
-		opt(sc)
-	}
-}
-
-// PrefixMatch ensures the selector uses a Prefix comparator, instead
-// of contains or equals.  Will not override a default Any() or None()
-// comparator.
-func PrefixMatch() option {
-	return func(sc *scopeConfig) {
-		sc.usePrefixFilter = true
-	}
-}
-
-// SuffixMatch ensures the selector uses a Suffix comparator, instead
-// of contains or equals.  Will not override a default Any() or None()
-// comparator.
-func SuffixMatch() option {
-	return func(sc *scopeConfig) {
-		sc.useSuffixFilter = true
-	}
-}
-
-// StrictEqualsMatch ensures the selector uses a StrictEquals comparator, instead
-// of contains.  Will not override a default Any() or None() comparator.
-func StrictEqualMatch() option {
-	return func(sc *scopeConfig) {
-		sc.useStrictEqualsFilter = true
-	}
-}
-
-// ExactMatch ensures the selector uses an Equals comparator, instead
-// of contains.  Will not override a default Any() or None() comparator.
-func ExactMatch() option {
-	return func(sc *scopeConfig) {
-		sc.useEqualsFilter = true
-	}
-}
-
-// pathComparator is an internal-facing option.  It is assumed that scope
-// constructors will provide the pathComparator option whenever a folder-
-// level scope (ie, a scope that compares path hierarchies) is created.
-func pathComparator() option {
-	return func(sc *scopeConfig) {
-		sc.usePathFilter = true
-	}
-}
-
-func badCastErr(cast, is service) error {
-	return clues.Stack(ErrorBadSelectorCast, clues.New(fmt.Sprintf("%s is not %s", cast, is)))
-}
-
-// if the provided slice contains Any, returns [Any]
-// if the slice contains None, returns [None]
-// if the slice contains Any and None, returns the first
-// if the slice is empty, returns [None]
-// otherwise returns the input
-func clean(s []string) []string {
-	if len(s) == 0 {
-		return None()
-	}
-
-	for _, e := range s {
-		if e == AnyTgt {
-			return Any()
-		}
-
-		if e == NoneTgt {
-			return None()
-		}
-	}
-
-	return s
-}
-
-type filterFunc func([]string) filters.Filter
-
-// filterize turns the slice into a filter.
-// if the input is Any(), returns a passAny filter.
-// if the input is None(), returns a failAny filter.
-// if the scopeConfig specifies a filter, use that filter.
-// if the input is len(1), returns an Equals filter.
-// otherwise returns a Contains filter.
-func filterFor(sc scopeConfig, targets ...string) filters.Filter {
-	return filterize(sc, nil, targets...)
-}
-
-// filterize turns the slice into a filter.
-// if the input is Any(), returns a passAny filter.
-// if the input is None(), returns a failAny filter.
-// if the scopeConfig specifies a filter, use that filter.
-// if defaultFilter is non-nil, returns that filter.
-// if the input is len(1), returns an Equals filter.
-// otherwise returns a Contains filter.
-func filterize(
-	sc scopeConfig,
-	defaultFilter filterFunc,
-	targets ...string,
-) filters.Filter {
-	targets = clean(targets)
-
-	if len(targets) == 0 || targets[0] == NoneTgt {
-		return failAny
-	}
-
-	if targets[0] == AnyTgt {
-		return passAny
-	}
-
-	if sc.usePathFilter {
-		if sc.useEqualsFilter {
-			return filters.PathEquals(targets)
-		}
-
-		if sc.usePrefixFilter {
-			return filters.PathPrefix(targets)
-		}
-
-		if sc.useSuffixFilter {
-			return filters.PathSuffix(targets)
-		}
-
-		return filters.PathContains(targets)
-	}
-
-	if sc.usePrefixFilter {
-		return filters.Prefix(targets)
-	}
-
-	if sc.useSuffixFilter {
-		return filters.Suffix(targets)
-	}
-
-	if sc.useStrictEqualsFilter {
-		return filters.StrictEqual(targets)
-	}
-
-	if defaultFilter != nil {
-		return defaultFilter(targets)
-	}
-
-	return filters.Equal(targets)
-}
-
-// pathFilterFactory returns the appropriate path filter
-// (contains, prefix, or suffix) for the provided options.
-// If multiple options are flagged, Prefix takes priority.
-// If no options are provided, returns PathContains.
-func pathFilterFactory(opts ...option) filterFunc {
-	sc := &scopeConfig{}
-	sc.populate(opts...)
-
-	var ff filterFunc
-
-	switch true {
-	case sc.usePrefixFilter:
-		ff = filters.PathPrefix
-	case sc.useSuffixFilter:
-		ff = filters.PathSuffix
-	case sc.useEqualsFilter:
-		ff = filters.PathEquals
-	default:
-		ff = filters.PathContains
-	}
-
-	return wrapSliceFilter(ff)
-}
-
-func wrapSliceFilter(ff filterFunc) filterFunc {
-	return func(s []string) filters.Filter {
-		s = clean(s)
-
-		if f, ok := isAnyOrNone(s); ok {
-			return f
-		}
-
-		return ff(s)
-	}
-}
-
-// returns (<filter>, true) if s is len==1 and s[0] is
-// anyTgt or noneTgt, implying that the caller should use
-// the returned filter.  On (<filter>, false), the caller
-// can ignore the returned filter.
-// a special case exists for len(s)==0, interpreted as
-// "noneTgt"
-func isAnyOrNone(s []string) (filters.Filter, bool) {
-	switch len(s) {
-	case 0:
-		return failAny, true
-
-	case 1:
-		switch s[0] {
-		case AnyTgt:
-			return passAny, true
-		case NoneTgt:
-			return failAny, true
-		}
-	}
-
-	return failAny, false
-}

src/pkg/selectors/selectors_test.go

@@ -44,56 +44,6 @@ func (suite *SelectorSuite) TestBadCastErr() {
 	assert.Error(suite.T(), err, clues.ToCore(err))
 }
 
-func (suite *SelectorSuite) TestResourceOwnersIn() {
-	rootCat := rootCatStub.String()
-
-	table := []struct {
-		name   string
-		input  []scope
-		expect []string
-	}{
-		{
-			name:   "nil",
-			input:  nil,
-			expect: []string{},
-		},
-		{
-			name:   "empty",
-			input:  []scope{},
-			expect: []string{},
-		},
-		{
-			name:   "single",
-			input:  []scope{{rootCat: filters.Identity("foo")}},
-			expect: []string{"foo"},
-		},
-		{
-			name: "multiple scopes",
-			input: []scope{
-				{rootCat: filters.Identity("foo,bar")},
-				{rootCat: filters.Identity("baz")},
-			},
-			expect: []string{"foo,bar", "baz"},
-		},
-		{
-			name: "multiple scopes with duplicates",
-			input: []scope{
-				{rootCat: filters.Identity("foo")},
-				{rootCat: filters.Identity("foo")},
-			},
-			expect: []string{"foo"},
-		},
-	}
-	for _, test := range table {
-		suite.Run(test.name, func() {
-			t := suite.T()
-
-			result := resourceOwnersIn(test.input, rootCat)
-			assert.ElementsMatch(t, test.expect, result)
-		})
-	}
-}
-
 func (suite *SelectorSuite) TestPathCategoriesIn() {
 	leafCat := leafCatStub.String()
 	f := filters.Identity(leafCat)
@@ -144,20 +94,20 @@ func (suite *SelectorSuite) TestContains() {
 
 func (suite *SelectorSuite) TestIsAnyResourceOwner() {
 	t := suite.T()
-	assert.False(t, isAnyResourceOwner(newSelector(ServiceUnknown, []string{"foo"})))
-	assert.False(t, isAnyResourceOwner(newSelector(ServiceUnknown, []string{})))
-	assert.False(t, isAnyResourceOwner(newSelector(ServiceUnknown, nil)))
-	assert.True(t, isAnyResourceOwner(newSelector(ServiceUnknown, []string{AnyTgt})))
-	assert.True(t, isAnyResourceOwner(newSelector(ServiceUnknown, Any())))
+	assert.False(t, isAnyProtectedResource(newSelector(ServiceUnknown, []string{"foo"})))
+	assert.False(t, isAnyProtectedResource(newSelector(ServiceUnknown, []string{})))
+	assert.False(t, isAnyProtectedResource(newSelector(ServiceUnknown, nil)))
+	assert.True(t, isAnyProtectedResource(newSelector(ServiceUnknown, []string{AnyTgt})))
+	assert.True(t, isAnyProtectedResource(newSelector(ServiceUnknown, Any())))
 }
 
 func (suite *SelectorSuite) TestIsNoneResourceOwner() {
 	t := suite.T()
-	assert.False(t, isNoneResourceOwner(newSelector(ServiceUnknown, []string{"foo"})))
-	assert.True(t, isNoneResourceOwner(newSelector(ServiceUnknown, []string{})))
-	assert.True(t, isNoneResourceOwner(newSelector(ServiceUnknown, nil)))
-	assert.True(t, isNoneResourceOwner(newSelector(ServiceUnknown, []string{NoneTgt})))
-	assert.True(t, isNoneResourceOwner(newSelector(ServiceUnknown, None())))
+	assert.False(t, isNoneProtectedResource(newSelector(ServiceUnknown, []string{"foo"})))
+	assert.True(t, isNoneProtectedResource(newSelector(ServiceUnknown, []string{})))
+	assert.True(t, isNoneProtectedResource(newSelector(ServiceUnknown, nil)))
+	assert.True(t, isNoneProtectedResource(newSelector(ServiceUnknown, []string{NoneTgt})))
+	assert.True(t, isNoneProtectedResource(newSelector(ServiceUnknown, None())))
 }
 
 func (suite *SelectorSuite) TestSplitByResourceOnwer() {
@@ -224,7 +174,7 @@ func (suite *SelectorSuite) TestSplitByResourceOnwer() {
 			t := suite.T()
 
 			s := newSelector(ServiceUnknown, test.input)
-			result := splitByResourceOwner[mockScope](s, allOwners, rootCatStub)
+			result := splitByProtectedResource[mockScope](s, allOwners, rootCatStub)
 
 			assert.Len(t, result, test.expectLen)
 

src/pkg/selectors/sharepoint.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/alcionai/corso/src/internal/common/dttm"
 	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/backup/identity"
 	"github.com/alcionai/corso/src/pkg/fault"
 	"github.com/alcionai/corso/src/pkg/filters"
 	"github.com/alcionai/corso/src/pkg/path"
@@ -42,6 +43,7 @@ type (
 var (
 	_ Reducer        = &SharePointRestore{}
 	_ pathCategorier = &SharePointRestore{}
+	_ reasoner       = &SharePointRestore{}
 )
 
 // NewSharePointBackup produces a new Selector with the service set to ServiceSharePoint.
@@ -68,7 +70,7 @@ func (s Selector) ToSharePointBackup() (*SharePointBackup, error) {
 }
 
 func (s SharePointBackup) SplitByResourceOwner(sites []string) []SharePointBackup {
-	sels := splitByResourceOwner[SharePointScope](s.Selector, sites, SharePointSite)
+	sels := splitByProtectedResource[SharePointScope](s.Selector, sites, SharePointSite)
 
 	ss := make([]SharePointBackup, 0, len(sels))
 	for _, sel := range sels {
@@ -102,7 +104,7 @@ func (s Selector) ToSharePointRestore() (*SharePointRestore, error) {
 }
 
 func (s SharePointRestore) SplitByResourceOwner(sites []string) []SharePointRestore {
-	sels := splitByResourceOwner[SharePointScope](s.Selector, sites, SharePointSite)
+	sels := splitByProtectedResource[SharePointScope](s.Selector, sites, SharePointSite)
 
 	ss := make([]SharePointRestore, 0, len(sels))
 	for _, sel := range sels {
@@ -121,6 +123,13 @@ func (s sharePoint) PathCategories() selectorPathCategories {
 	}
 }
 
+// Reasons returns a deduplicated set of the backup reasons produced
+// using the selector's discrete owner and each scopes' service and
+// category types.
+func (s sharePoint) Reasons(tenantID string, useOwnerNameForID bool) []identity.Reasoner {
+	return reasonsFor(s, tenantID, useOwnerNameForID)
+}
+
 // ---------------------------------------------------------------------------
 // Stringers and Concealers
 // ---------------------------------------------------------------------------

src/pkg/selectors/sharepoint_test.go

@@ -44,66 +44,6 @@ func (suite *SharePointSelectorSuite) TestToSharePointBackup() {
 	assert.NotZero(t, ob.Scopes())
 }
 
-func (suite *SharePointSelectorSuite) TestSharePointSelector_AllData() {
-	t := suite.T()
-
-	sites := []string{"s1", "s2"}
-
-	sel := NewSharePointBackup(sites)
-	siteScopes := sel.AllData()
-
-	assert.ElementsMatch(t, sites, sel.DiscreteResourceOwners())
-
-	// Initialize the selector Include, Exclude, Filter
-	sel.Exclude(siteScopes)
-	sel.Include(siteScopes)
-	sel.Filter(siteScopes)
-
-	table := []struct {
-		name          string
-		scopesToCheck []scope
-	}{
-		{"Include Scopes", sel.Includes},
-		{"Exclude Scopes", sel.Excludes},
-		{"info scopes", sel.Filters},
-	}
-	for _, test := range table {
-		require.Len(t, test.scopesToCheck, 3)
-
-		for _, scope := range test.scopesToCheck {
-			var (
-				spsc = SharePointScope(scope)
-				cat  = spsc.Category()
-			)
-
-			suite.Run(test.name+"-"+cat.String(), func() {
-				t := suite.T()
-
-				switch cat {
-				case SharePointLibraryItem:
-					scopeMustHave(
-						t,
-						spsc,
-						map[categorizer][]string{
-							SharePointLibraryItem:   Any(),
-							SharePointLibraryFolder: Any(),
-						},
-					)
-				case SharePointListItem:
-					scopeMustHave(
-						t,
-						spsc,
-						map[categorizer][]string{
-							SharePointListItem: Any(),
-							SharePointList:     Any(),
-						},
-					)
-				}
-			})
-		}
-	}
-}
-
 func (suite *SharePointSelectorSuite) TestSharePointSelector_Include_WebURLs() {
 	t := suite.T()