channels and messages API (#4068)

<!-- PR description-->

Message handler implementation and other APIs to fetch channels and messages data

#### Does this PR need a docs update or release note?
- [ ] ⛔ No

#### Type of change

<!--- Please check the type of change your PR introduces: --->
- [ ] 🌻 Feature

#### Issue(s)

<!-- Can reference multiple issues. Use one of the following "magic words" - "closes, fixes" to auto-close the Github issue. -->
* #<issue>

#### Test Plan

<!-- How will this be tested prior to merging.-->
- [ ] 💪 Manual
- [ ] ⚡ Unit test
- [ ] 💚 E2E

src/internal/m365/collection/groups/handlers.go

@@ -31,3 +31,10 @@ type BackupHandler interface {
 		teamID, channelID, messageID string,
 	) (serialization.Parsable, error)
 }
+
+type BackupMessagesHandler interface {
+	GetMessage(ctx context.Context, teamID, channelID, itemID string) (models.ChatMessageable, error)
+	NewMessagePager(teamID, channelID string) api.ChannelMessageDeltaEnumerator
+	GetChannel(ctx context.Context, teamID, channelID string) (models.Channelable, error)
+	GetReply(ctx context.Context, teamID, channelID, messageID string) (serialization.Parsable, error)
+}

src/pkg/services/m365/api/channels.go

@@ -1 +1,194 @@
 package api
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/alcionai/clues"
+	"github.com/microsoft/kiota-abstractions-go/serialization"
+	"github.com/microsoftgraph/msgraph-sdk-go/models"
+	"github.com/microsoftgraph/msgraph-sdk-go/teams"
+
+	"github.com/alcionai/corso/src/internal/common/ptr"
+	"github.com/alcionai/corso/src/internal/m365/graph"
+	"github.com/alcionai/corso/src/pkg/backup/details"
+	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/logger"
+)
+
+// ---------------------------------------------------------------------------
+// controller
+// ---------------------------------------------------------------------------
+
+func (c Client) Channels() Channels {
+	return Channels{c}
+}
+
+// Channels is an interface-compliant provider of the client.
+type Channels struct {
+	Client
+}
+
+// ---------------------------------------------------------------------------
+// containers
+// ---------------------------------------------------------------------------
+
+func (c Channels) GetChannel(
+	ctx context.Context,
+	teamID, containerID string,
+) (models.Channelable, error) {
+	config := &teams.ItemChannelsChannelItemRequestBuilderGetRequestConfiguration{
+		QueryParameters: &teams.ItemChannelsChannelItemRequestBuilderGetQueryParameters{
+			Select: idAnd("displayName"),
+		},
+	}
+
+	resp, err := c.Stable.
+		Client().
+		Teams().
+		ByTeamId(teamID).
+		Channels().
+		ByChannelId(containerID).
+		Get(ctx, config)
+	if err != nil {
+		return nil, graph.Stack(ctx, err)
+	}
+
+	return resp, nil
+}
+
+// GetChannelByName fetches a channel by name
+func (c Channels) GetChannelByName(
+	ctx context.Context,
+	teamID, containerName string,
+) (models.Channelable, error) {
+	ctx = clues.Add(ctx, "channel_name", containerName)
+
+	filter := fmt.Sprintf("displayName eq '%s'", containerName)
+	options := &teams.ItemChannelsRequestBuilderGetRequestConfiguration{
+		QueryParameters: &teams.ItemChannelsRequestBuilderGetQueryParameters{
+			Filter: &filter,
+		},
+	}
+
+	resp, err := c.Stable.
+		Client().
+		Teams().
+		ByTeamId(teamID).
+		Channels().
+		Get(ctx, options)
+	if err != nil {
+		return nil, graph.Stack(ctx, err).WithClues(ctx)
+	}
+
+	gv := resp.GetValue()
+	if len(gv) == 0 {
+		return nil, clues.New("channel not found").WithClues(ctx)
+	}
+
+	// We only allow the api to match one channel with the provided name.
+	// If we match multiples, we'll eagerly return the first one.
+	logger.Ctx(ctx).Debugw("channels matched the name search")
+
+	// Sanity check ID and name
+	cal := gv[0]
+
+	if err := CheckIDAndName(cal); err != nil {
+		return nil, clues.Stack(err).WithClues(ctx)
+	}
+
+	return cal, nil
+}
+
+// ---------------------------------------------------------------------------
+// message
+// ---------------------------------------------------------------------------
+
+// GetMessage retrieves a ChannelMessage item.
+func (c Channels) GetMessage(
+	ctx context.Context,
+	teamID, channelID, itemID string,
+	errs *fault.Bus,
+) (serialization.Parsable, *details.GroupsInfo, error) {
+	var size int64
+
+	message, err := c.Stable.
+		Client().
+		Teams().
+		ByTeamId(teamID).
+		Channels().
+		ByChannelId(channelID).
+		Messages().
+		ByChatMessageId(itemID).
+		Get(ctx, nil)
+	if err != nil {
+		return nil, nil, graph.Stack(ctx, err)
+	}
+
+	return message, ChannelMessageInfo(message, size), nil
+}
+
+// ---------------------------------------------------------------------------
+// replies
+// ---------------------------------------------------------------------------
+
+// GetReplies retrieves all replies to a Channel Message.
+func (c Channels) GetReplies(
+	ctx context.Context,
+	teamID, channelID, messageID string,
+) (serialization.Parsable, error) {
+	replies, err := c.Stable.
+		Client().
+		Teams().
+		ByTeamId(teamID).
+		Channels().
+		ByChannelId(channelID).
+		Messages().
+		ByChatMessageId(messageID).
+		Replies().
+		Get(ctx, nil)
+	if err != nil {
+		return nil, graph.Stack(ctx, err)
+	}
+
+	return replies, nil
+}
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+func ChannelMessageInfo(msg models.ChatMessageable, size int64) *details.GroupsInfo {
+	created := ptr.Val(msg.GetCreatedDateTime())
+
+	return &details.GroupsInfo{
+		ItemType: details.TeamsChannelMessage,
+		Size:     size,
+		Created:  created,
+		Modified: ptr.OrNow(msg.GetLastModifiedDateTime()),
+	}
+}
+
+// ---------------------------------------------------------------------------
+// helper funcs
+// ---------------------------------------------------------------------------
+
+// CheckIDAndName is a validator that ensures the ID
+// and name are populated and not zero valued.
+func CheckIDAndName(c models.Channelable) error {
+	if c == nil {
+		return clues.New("nil container")
+	}
+
+	id := ptr.Val(c.GetId())
+	if len(id) == 0 {
+		return clues.New("container missing ID")
+	}
+
+	dn := ptr.Val(c.GetDisplayName())
+	if len(dn) == 0 {
+		return clues.New("container missing display name").With("container_id", id)
+	}
+
+	return nil
+}

src/pkg/services/m365/api/channels_pager_test.go

@@ -0,0 +1,67 @@
+package api_test
+
+import (
+	"testing"
+
+	"github.com/alcionai/clues"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
+
+	"github.com/alcionai/corso/src/internal/common/ptr"
+	"github.com/alcionai/corso/src/internal/tester"
+	"github.com/alcionai/corso/src/internal/tester/tconfig"
+)
+
+type ChannelPagerIntgSuite struct {
+	tester.Suite
+	its intgTesterSetup
+}
+
+func TestChannelPagerIntgSuite(t *testing.T) {
+	suite.Run(t, &ChannelPagerIntgSuite{
+		Suite: tester.NewIntegrationSuite(
+			t,
+			[][]string{tconfig.M365AcctCredEnvs}),
+	})
+}
+
+func (suite *ChannelPagerIntgSuite) SetupSuite() {
+	suite.its = newIntegrationTesterSetup(suite.T())
+}
+
+// This will be added once 'pager' is implemented
+// func (suite *ChannelPagerIntgSuite) TestChannels_GetPage() {
+// 	t := suite.T()
+
+// 	ctx, flush := tester.NewContext(t)
+// 	defer flush()
+
+// 	teamID := tconfig.M365TeamID(t)
+// 	channelID := tconfig.M365ChannelID(t)
+// 	pager := suite.its.ac.Channels().NewMessagePager(teamID, channelID, []string{})
+// 	a, err := pager.GetPage(ctx)
+// 	assert.NoError(t, err, clues.ToCore(err))
+// 	assert.NotNil(t, a)
+// }
+
+func (suite *ChannelPagerIntgSuite) TestChannels_Get() {
+	t := suite.T()
+	ctx, flush := tester.NewContext(t)
+
+	defer flush()
+
+	var (
+		containerName = "General"
+		teamID        = tconfig.M365TeamID(t)
+		chanClient    = suite.its.ac.Channels()
+	)
+
+	// GET channel -should be found
+	channel, err := chanClient.GetChannelByName(ctx, teamID, containerName)
+	assert.NoError(t, err, clues.ToCore(err))
+	assert.Equal(t, ptr.Val(channel.GetDisplayName()), containerName)
+
+	// GET channel -should be found
+	_, err = chanClient.GetChannel(ctx, teamID, ptr.Val(channel.GetId()))
+	assert.NoError(t, err, clues.ToCore(err))
+}