Use delta endpoint to fetch exchange mail items (#1620)

## Description

Use delta endpoint to fetch exchange mail items. Disables picking only some item attributes as query parameters are not implemented in this version of Graph SDK.

Switches to custom pagination iteration method so that next links and delta tokens can be extracted later on.

## Type of change

<!--- Please check the type of change your PR introduces: --->
- [x] 🌻 Feature
- [ ] 🐛 Bugfix
- [ ] 🗺️ Documentation
- [ ] 🤖 Test
- [ ] 💻 CI/Deployment
- [ ] 🐹 Trivial/Minor

## Issue(s)

* #1612 

## Test Plan

- [ ] 💪 Manual
- [x] ⚡ Unit test
- [x] 💚 E2E

src/internal/connector/exchange/delta_get.go

@@ -18,7 +18,6 @@ const (
 // The following functions are based off the code in v0.41.0 of msgraph-sdk-go
 // for sending delta requests with query parameters.
 
-//nolint:unused
 func createGetRequestInformationWithRequestConfiguration(
 	baseRequestInfoFunc func() (*abs.RequestInformation, error),
 	requestConfig *DeltaRequestBuilderGetRequestConfiguration,
@@ -43,7 +42,6 @@ func createGetRequestInformationWithRequestConfiguration(
 	return requestInfo, nil
 }
 
-//nolint:unused
 func sendMessagesDeltaGet(
 	ctx context.Context,
 	m *msmaildelta.DeltaRequestBuilder,

src/internal/connector/exchange/query_options.go

@@ -14,7 +14,6 @@ import (
 	msevents "github.com/microsoftgraph/msgraph-sdk-go/users/item/events"
 	msfolder "github.com/microsoftgraph/msgraph-sdk-go/users/item/mailfolders"
 	msfolderitem "github.com/microsoftgraph/msgraph-sdk-go/users/item/mailfolders/item"
-	msmfmessage "github.com/microsoftgraph/msgraph-sdk-go/users/item/mailfolders/item/messages"
 	msmessage "github.com/microsoftgraph/msgraph-sdk-go/users/item/messages"
 	msitem "github.com/microsoftgraph/msgraph-sdk-go/users/item/messages/item"
 	"github.com/pkg/errors"
@@ -144,16 +143,16 @@ type DeltaRequestBuilderGetRequestConfiguration struct {
 	QueryParameters *DeltaRequestBuilderGetQueryParameters
 }
 
-func optionsForFolderMessages(moreOps []string) (*msmfmessage.MessagesRequestBuilderGetRequestConfiguration, error) {
+func optionsForFolderMessages(moreOps []string) (*DeltaRequestBuilderGetRequestConfiguration, error) {
 	selecting, err := buildOptions(moreOps, messages)
 	if err != nil {
 		return nil, err
 	}
 
-	requestParameters := &msmfmessage.MessagesRequestBuilderGetQueryParameters{
+	requestParameters := &DeltaRequestBuilderGetQueryParameters{
 		Select: selecting,
 	}
-	options := &msmfmessage.MessagesRequestBuilderGetRequestConfiguration{
+	options := &DeltaRequestBuilderGetRequestConfiguration{
 		QueryParameters: requestParameters,
 	}
 

src/internal/connector/exchange/service_iterators.go

@@ -8,6 +8,7 @@ import (
 	multierror "github.com/hashicorp/go-multierror"
 	msgraphgocore "github.com/microsoftgraph/msgraph-sdk-go-core"
 	"github.com/microsoftgraph/msgraph-sdk-go/models"
+	mdelta "github.com/microsoftgraph/msgraph-sdk-go/users/item/mailfolders/item/messages/delta"
 	"github.com/pkg/errors"
 
 	"github.com/alcionai/corso/src/internal/connector/graph"
@@ -16,6 +17,8 @@ import (
 	"github.com/alcionai/corso/src/pkg/selectors"
 )
 
+const nextLinkKey = "@odata.nextLink"
+
 // FilterContainersAndFillCollections is a utility function
 // that places the M365 object ids belonging to specific directories
 // into a Collection. Messages outside of those directories are omitted.
@@ -281,57 +284,54 @@ func FetchMessageIDsFromDirectory(
 	gs graph.Service,
 	user, directoryID string,
 ) ([]string, error) {
-	ids := []string{}
+	var (
+		errs *multierror.Error
+		ids  []string
+	)
 
 	options, err := optionsForFolderMessages([]string{"id"})
 	if err != nil {
 		return nil, errors.Wrap(err, "getting query options")
 	}
 
-	response, err := gs.Client().
+	builder := gs.Client().
 		UsersById(user).
 		MailFoldersById(directoryID).
 		Messages().
-		Get(ctx, options)
-	if err != nil {
-		return nil,
-			errors.Wrap(err, support.ConnectorStackErrorTrace(err))
-	}
+		Delta()
 
-	pageIter, err := msgraphgocore.NewPageIterator(
-		response,
-		gs.Adapter(),
-		models.CreateMessageCollectionResponseFromDiscriminatorValue,
-	)
-	if err != nil {
-		return nil, errors.Wrap(err, "creating graph iterator")
-	}
-
-	var errs *multierror.Error
-
-	err = pageIter.Iterate(ctx, func(pageItem any) bool {
-		item, ok := pageItem.(graph.Idable)
-		if !ok {
-			errs = multierror.Append(errs, errors.New("item without ID function"))
-			return true
+	for {
+		// TODO(ashmrtn): Update to pass options once graph SDK dependency is updated.
+		resp, err := sendMessagesDeltaGet(ctx, builder, options, gs.Adapter())
+		if err != nil {
+			return nil, errors.Wrap(err, support.ConnectorStackErrorTrace(err))
 		}
 
-		if item.GetId() == nil {
-			errs = multierror.Append(errs, errors.New("item with nil ID"))
-			return true
+		for _, item := range resp.GetValue() {
+			if item.GetId() == nil {
+				errs = multierror.Append(
+					errs,
+					errors.Errorf("item with nil ID in folder %s", directoryID),
+				)
+
+				// TODO(ashmrtn): Handle fail-fast.
+				continue
+			}
+
+			ids = append(ids, *item.GetId())
 		}
 
-		ids = append(ids, *item.GetId())
+		nextLinkIface := resp.GetAdditionalData()[nextLinkKey]
+		if nextLinkIface == nil {
+			break
+		}
 
-		return true
-	})
+		nextLink := nextLinkIface.(*string)
+		if len(*nextLink) == 0 {
+			break
+		}
 
-	if err != nil {
-		return nil, errors.Wrap(
-			err,
-			support.ConnectorStackErrorTrace(err)+
-				" :fetching messages from directory "+directoryID,
-		)
+		builder = mdelta.NewDeltaRequestBuilder(*nextLink, gs.Adapter())
 	}
 
 	return ids, errs.ErrorOrNil()