move event instance funcs to new file (#3659)

No logic changes, just code movement.

---

#### Does this PR need a docs update or release note?

- [x] ⛔ No

#### Type of change

- [x] 🧹 Tech Debt/Cleanup

#### Test Plan

- [x] ⚡ Unit test
- [x] 💚 E2E

src/internal/m365/exchange/events_instance_restore.go

@@ -0,0 +1,215 @@
+package exchange
+
+import (
+	"context"
+	"fmt"
+	"strings"
+	"time"
+
+	"github.com/alcionai/clues"
+	"github.com/microsoftgraph/msgraph-sdk-go/models"
+
+	"github.com/alcionai/corso/src/internal/common/dttm"
+	"github.com/alcionai/corso/src/internal/common/ptr"
+	"github.com/alcionai/corso/src/internal/common/str"
+	"github.com/alcionai/corso/src/pkg/fault"
+	"github.com/alcionai/corso/src/pkg/services/m365/api"
+)
+
+type eventInstanceAndAttachmenter interface {
+	attachmentGetDeletePoster
+	DeleteItem(
+		ctx context.Context,
+		userID, itemID string,
+	) error
+	GetItemInstances(
+		ctx context.Context,
+		userID, itemID string,
+		startDate, endDate string,
+	) ([]models.Eventable, error)
+	PatchItem(
+		ctx context.Context,
+		userID, eventID string,
+		body models.Eventable,
+	) (models.Eventable, error)
+}
+
+func updateRecurringEvents(
+	ctx context.Context,
+	eiaa eventInstanceAndAttachmenter,
+	userID, containerID, itemID string,
+	event models.Eventable,
+	errs *fault.Bus,
+) error {
+	if event.GetRecurrence() == nil {
+		return nil
+	}
+
+	// Cancellations and exceptions are currently in additional data
+	// but will get their own fields once the beta API lands and
+	// should be moved then
+	cancelledOccurrences := event.GetAdditionalData()["cancelledOccurrences"]
+	exceptionOccurrences := event.GetAdditionalData()["exceptionOccurrences"]
+
+	err := updateCancelledOccurrences(ctx, eiaa, userID, itemID, cancelledOccurrences)
+	if err != nil {
+		return clues.Wrap(err, "update cancelled occurrences")
+	}
+
+	err = updateExceptionOccurrences(ctx, eiaa, userID, containerID, itemID, exceptionOccurrences, errs)
+	if err != nil {
+		return clues.Wrap(err, "update exception occurrences")
+	}
+
+	return nil
+}
+
+// updateExceptionOccurrences take events that have exceptions, uses
+// the originalStart date to find the instance and modify it to match
+// the backup by updating the instance to match the backed up one
+func updateExceptionOccurrences(
+	ctx context.Context,
+	eiaa eventInstanceAndAttachmenter,
+	userID string,
+	containerID string,
+	itemID string,
+	exceptionOccurrences any,
+	errs *fault.Bus,
+) error {
+	if exceptionOccurrences == nil {
+		return nil
+	}
+
+	eo, ok := exceptionOccurrences.([]any)
+	if !ok {
+		return clues.New("converting exceptionOccurrences to []any").
+			With("type", fmt.Sprintf("%T", exceptionOccurrences))
+	}
+
+	for _, instance := range eo {
+		instance, ok := instance.(map[string]any)
+		if !ok {
+			return clues.New("converting instance to map[string]any").
+				With("type", fmt.Sprintf("%T", instance))
+		}
+
+		evt, err := api.EventFromMap(instance)
+		if err != nil {
+			return clues.Wrap(err, "parsing exception event")
+		}
+
+		start := ptr.Val(evt.GetOriginalStart())
+		startStr := dttm.FormatTo(start, dttm.DateOnly)
+		endStr := dttm.FormatTo(start.Add(24*time.Hour), dttm.DateOnly)
+
+		ictx := clues.Add(ctx, "event_instance_id", ptr.Val(evt.GetId()), "event_instance_date", start)
+
+		// Get all instances on the day of the instance which should
+		// just the one we need to modify
+		instances, err := eiaa.GetItemInstances(ictx, userID, itemID, startStr, endStr)
+		if err != nil {
+			return clues.Wrap(err, "getting instances")
+		}
+
+		// Since the min recurrence interval is 1 day and we are
+		// querying for only a single day worth of instances, we
+		// should not have more than one instance here.
+		if len(instances) != 1 {
+			return clues.New("invalid number of instances for modified").
+				With("instances_count", len(instances), "search_start", startStr, "search_end", endStr)
+		}
+
+		evt = toEventSimplified(evt)
+
+		_, err = eiaa.PatchItem(ictx, userID, ptr.Val(instances[0].GetId()), evt)
+		if err != nil {
+			return clues.Wrap(err, "updating event instance")
+		}
+
+		// We are creating event again from map as `toEventSimplified`
+		// removed the attachments and creating a clone from start of
+		// the event is non-trivial
+		evt, err = api.EventFromMap(instance)
+		if err != nil {
+			return clues.Wrap(err, "parsing event instance")
+		}
+
+		err = updateAttachments(
+			ictx,
+			eiaa,
+			userID,
+			containerID,
+			ptr.Val(instances[0].GetId()),
+			evt,
+			errs)
+		if err != nil {
+			return clues.Wrap(err, "updating event instance attachments")
+		}
+	}
+
+	return nil
+}
+
+// updateCancelledOccurrences get the cancelled occurrences which is a
+// list of strings of the format "<id>.<date>", parses the date out of
+// that and uses the to get the event instance at that date to delete.
+func updateCancelledOccurrences(
+	ctx context.Context,
+	eiaa eventInstanceAndAttachmenter,
+	userID string,
+	itemID string,
+	cancelledOccurrences any,
+) error {
+	if cancelledOccurrences == nil {
+		return nil
+	}
+
+	co, ok := cancelledOccurrences.([]any)
+	if !ok {
+		return clues.New("converting cancelledOccurrences to []any").
+			With("type", fmt.Sprintf("%T", cancelledOccurrences))
+	}
+
+	// OPTIMIZATION: We can fetch a date range instead of fetching
+	// instances if we have multiple cancelled events which are nearby
+	// and reduce the number of API calls that we have to make
+	for _, instance := range co {
+		instance, err := str.AnyToString(instance)
+		if err != nil {
+			return err
+		}
+
+		splits := strings.Split(instance, ".")
+
+		startStr := splits[len(splits)-1]
+
+		start, err := dttm.ParseTime(startStr)
+		if err != nil {
+			return clues.Wrap(err, "parsing cancelled event date")
+		}
+
+		endStr := dttm.FormatTo(start.Add(24*time.Hour), dttm.DateOnly)
+
+		// Get all instances on the day of the instance which should
+		// just the one we need to modify
+		instances, err := eiaa.GetItemInstances(ctx, userID, itemID, startStr, endStr)
+		if err != nil {
+			return clues.Wrap(err, "getting instances")
+		}
+
+		// Since the min recurrence interval is 1 day and we are
+		// querying for only a single day worth of instances, we
+		// should not have more than one instance here.
+		if len(instances) != 1 {
+			return clues.New("invalid number of instances for cancelled").
+				With("instances_count", len(instances), "search_start", startStr, "search_end", endStr)
+		}
+
+		err = eiaa.DeleteItem(ctx, userID, ptr.Val(instances[0].GetId()))
+		if err != nil {
+			return clues.Wrap(err, "deleting event instance")
+		}
+	}
+
+	return nil
+}

src/internal/m365/exchange/events_restore.go

@@ -3,16 +3,11 @@ package exchange
 import (
 	"bytes"
 	"context"
-	"fmt"
-	"strings"
-	"time"
 
 	"github.com/alcionai/clues"
 	"github.com/microsoftgraph/msgraph-sdk-go/models"
 
-	"github.com/alcionai/corso/src/internal/common/dttm"
 	"github.com/alcionai/corso/src/internal/common/ptr"
-	"github.com/alcionai/corso/src/internal/common/str"
 	"github.com/alcionai/corso/src/internal/m365/graph"
 	"github.com/alcionai/corso/src/pkg/backup/details"
 	"github.com/alcionai/corso/src/pkg/control"
@@ -191,140 +186,6 @@ func restoreEvent(
 	return info, nil
 }
 
-func updateRecurringEvents(
-	ctx context.Context,
-	eiaa eventInstanceAndAttachmenter,
-	userID, containerID, itemID string,
-	event models.Eventable,
-	errs *fault.Bus,
-) error {
-	if event.GetRecurrence() == nil {
-		return nil
-	}
-
-	// Cancellations and exceptions are currently in additional data
-	// but will get their own fields once the beta API lands and
-	// should be moved then
-	cancelledOccurrences := event.GetAdditionalData()["cancelledOccurrences"]
-	exceptionOccurrences := event.GetAdditionalData()["exceptionOccurrences"]
-
-	err := updateCancelledOccurrences(ctx, eiaa, userID, itemID, cancelledOccurrences)
-	if err != nil {
-		return clues.Wrap(err, "update cancelled occurrences")
-	}
-
-	err = updateExceptionOccurrences(ctx, eiaa, userID, containerID, itemID, exceptionOccurrences, errs)
-	if err != nil {
-		return clues.Wrap(err, "update exception occurrences")
-	}
-
-	return nil
-}
-
-type eventInstanceAndAttachmenter interface {
-	attachmentGetDeletePoster
-	DeleteItem(
-		ctx context.Context,
-		userID, itemID string,
-	) error
-	GetItemInstances(
-		ctx context.Context,
-		userID, itemID string,
-		startDate, endDate string,
-	) ([]models.Eventable, error)
-	PatchItem(
-		ctx context.Context,
-		userID, eventID string,
-		body models.Eventable,
-	) (models.Eventable, error)
-}
-
-// updateExceptionOccurrences take events that have exceptions, uses
-// the originalStart date to find the instance and modify it to match
-// the backup by updating the instance to match the backed up one
-func updateExceptionOccurrences(
-	ctx context.Context,
-	eiaa eventInstanceAndAttachmenter,
-	userID string,
-	containerID string,
-	itemID string,
-	exceptionOccurrences any,
-	errs *fault.Bus,
-) error {
-	if exceptionOccurrences == nil {
-		return nil
-	}
-
-	eo, ok := exceptionOccurrences.([]any)
-	if !ok {
-		return clues.New("converting exceptionOccurrences to []any").
-			With("type", fmt.Sprintf("%T", exceptionOccurrences))
-	}
-
-	for _, instance := range eo {
-		instance, ok := instance.(map[string]any)
-		if !ok {
-			return clues.New("converting instance to map[string]any").
-				With("type", fmt.Sprintf("%T", instance))
-		}
-
-		evt, err := api.EventFromMap(instance)
-		if err != nil {
-			return clues.Wrap(err, "parsing exception event")
-		}
-
-		start := ptr.Val(evt.GetOriginalStart())
-		startStr := dttm.FormatTo(start, dttm.DateOnly)
-		endStr := dttm.FormatTo(start.Add(24*time.Hour), dttm.DateOnly)
-
-		ictx := clues.Add(ctx, "event_instance_id", ptr.Val(evt.GetId()), "event_instance_date", start)
-
-		// Get all instances on the day of the instance which should
-		// just the one we need to modify
-		instances, err := eiaa.GetItemInstances(ictx, userID, itemID, startStr, endStr)
-		if err != nil {
-			return clues.Wrap(err, "getting instances")
-		}
-
-		// Since the min recurrence interval is 1 day and we are
-		// querying for only a single day worth of instances, we
-		// should not have more than one instance here.
-		if len(instances) != 1 {
-			return clues.New("invalid number of instances for modified").
-				With("instances_count", len(instances), "search_start", startStr, "search_end", endStr)
-		}
-
-		evt = toEventSimplified(evt)
-
-		_, err = eiaa.PatchItem(ictx, userID, ptr.Val(instances[0].GetId()), evt)
-		if err != nil {
-			return clues.Wrap(err, "updating event instance")
-		}
-
-		// We are creating event again from map as `toEventSimplified`
-		// removed the attachments and creating a clone from start of
-		// the event is non-trivial
-		evt, err = api.EventFromMap(instance)
-		if err != nil {
-			return clues.Wrap(err, "parsing event instance")
-		}
-
-		err = updateAttachments(
-			ictx,
-			eiaa,
-			userID,
-			containerID,
-			ptr.Val(instances[0].GetId()),
-			evt,
-			errs)
-		if err != nil {
-			return clues.Wrap(err, "updating event instance attachments")
-		}
-	}
-
-	return nil
-}
-
 type attachmentGetDeletePoster interface {
 	attachmentPoster
 	GetAttachments(
@@ -346,9 +207,7 @@ type attachmentGetDeletePoster interface {
 // the id changes which makes the ids unusable. In this function, we
 // use the name and content bytes to detect the changes. This function
 // can be used to update the attachments of any event irrespective of
-// whether they are event instances of a series master although for
+// whether they are event instances of a series master.
-// newer event, since we probably won't already have any events it
-// would be better use Post[Small|Large]Attachment.
 func updateAttachments(
 	ctx context.Context,
 	agdp attachmentGetDeletePoster,
@@ -445,70 +304,6 @@ func updateAttachments(
 	return el.Failure()
 }
 
-// updateCancelledOccurrences get the cancelled occurrences which is a
-// list of strings of the format "<id>.<date>", parses the date out of
-// that and uses the to get the event instance at that date to delete.
-func updateCancelledOccurrences(
-	ctx context.Context,
-	eiaa eventInstanceAndAttachmenter,
-	userID string,
-	itemID string,
-	cancelledOccurrences any,
-) error {
-	if cancelledOccurrences == nil {
-		return nil
-	}
-
-	co, ok := cancelledOccurrences.([]any)
-	if !ok {
-		return clues.New("converting cancelledOccurrences to []any").
-			With("type", fmt.Sprintf("%T", cancelledOccurrences))
-	}
-
-	// OPTIMIZATION: We can fetch a date range instead of fetching
-	// instances if we have multiple cancelled events which are nearby
-	// and reduce the number of API calls that we have to make
-	for _, instance := range co {
-		instance, err := str.AnyToString(instance)
-		if err != nil {
-			return err
-		}
-
-		splits := strings.Split(instance, ".")
-
-		startStr := splits[len(splits)-1]
-
-		start, err := dttm.ParseTime(startStr)
-		if err != nil {
-			return clues.Wrap(err, "parsing cancelled event date")
-		}
-
-		endStr := dttm.FormatTo(start.Add(24*time.Hour), dttm.DateOnly)
-
-		// Get all instances on the day of the instance which should
-		// just the one we need to modify
-		instances, err := eiaa.GetItemInstances(ctx, userID, itemID, startStr, endStr)
-		if err != nil {
-			return clues.Wrap(err, "getting instances")
-		}
-
-		// Since the min recurrence interval is 1 day and we are
-		// querying for only a single day worth of instances, we
-		// should not have more than one instance here.
-		if len(instances) != 1 {
-			return clues.New("invalid number of instances for cancelled").
-				With("instances_count", len(instances), "search_start", startStr, "search_end", endStr)
-		}
-
-		err = eiaa.DeleteItem(ctx, userID, ptr.Val(instances[0].GetId()))
-		if err != nil {
-			return clues.Wrap(err, "deleting event instance")
-		}
-	}
-
-	return nil
-}
-
 func (h eventRestoreHandler) getItemsInContainerByCollisionKey(
 	ctx context.Context,
 	userID, containerID string,