Support file-less scenes. Add scene split, merge and reassign file (#3006)

* Reassign scene file functionality
* Implement scene create
* Add scene create UI
* Add sceneMerge backend support
* Add merge scene to UI
* Populate split create with scene details
* Add merge button to duplicate checker
* Handle file-less scenes in marker preview generate
* Make unique file name for file-less scene exports
* Add o-counter to scene update input
* Hide rescan for file-less scenes
* Generate heatmap if no speed set on file
* Fix count in scene/image queries

pkg/scene/merge.go

@@ -0,0 +1,144 @@
+package scene
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/stashapp/stash/pkg/file"
+	"github.com/stashapp/stash/pkg/fsutil"
+	"github.com/stashapp/stash/pkg/logger"
+	"github.com/stashapp/stash/pkg/models"
+	"github.com/stashapp/stash/pkg/sliceutil/intslice"
+	"github.com/stashapp/stash/pkg/txn"
+)
+
+func (s *Service) Merge(ctx context.Context, sourceIDs []int, destinationID int, scenePartial models.ScenePartial) error {
+	// ensure source ids are unique
+	sourceIDs = intslice.IntAppendUniques(nil, sourceIDs)
+
+	// ensure destination is not in source list
+	if intslice.IntInclude(sourceIDs, destinationID) {
+		return errors.New("destination scene cannot be in source list")
+	}
+
+	dest, err := s.Repository.Find(ctx, destinationID)
+	if err != nil {
+		return fmt.Errorf("finding destination scene ID %d: %w", destinationID, err)
+	}
+
+	sources, err := s.Repository.FindMany(ctx, sourceIDs)
+	if err != nil {
+		return fmt.Errorf("finding source scenes: %w", err)
+	}
+
+	var fileIDs []file.ID
+
+	for _, src := range sources {
+		// TODO - delete generated files as needed
+
+		if err := src.LoadRelationships(ctx, s.Repository); err != nil {
+			return fmt.Errorf("loading scene relationships from %d: %w", src.ID, err)
+		}
+
+		for _, f := range src.Files.List() {
+			fileIDs = append(fileIDs, f.Base().ID)
+		}
+
+		if err := s.mergeSceneMarkers(ctx, dest, src); err != nil {
+			return err
+		}
+	}
+
+	// move files to destination scene
+	if len(fileIDs) > 0 {
+		if err := s.Repository.AssignFiles(ctx, destinationID, fileIDs); err != nil {
+			return fmt.Errorf("moving files to destination scene: %w", err)
+		}
+
+		// if scene didn't already have a primary file, then set it now
+		if dest.PrimaryFileID == nil {
+			scenePartial.PrimaryFileID = &fileIDs[0]
+		} else {
+			// don't allow changing primary file ID from the input values
+			scenePartial.PrimaryFileID = nil
+		}
+	}
+
+	if _, err := s.Repository.UpdatePartial(ctx, destinationID, scenePartial); err != nil {
+		return fmt.Errorf("updating scene: %w", err)
+	}
+
+	// delete old scenes
+	for _, srcID := range sourceIDs {
+		if err := s.Repository.Destroy(ctx, srcID); err != nil {
+			return fmt.Errorf("deleting scene %d: %w", srcID, err)
+		}
+	}
+
+	return nil
+}
+
+func (s *Service) mergeSceneMarkers(ctx context.Context, dest *models.Scene, src *models.Scene) error {
+	markers, err := s.MarkerRepository.FindBySceneID(ctx, src.ID)
+	if err != nil {
+		return fmt.Errorf("finding scene markers: %w", err)
+	}
+
+	type rename struct {
+		src  string
+		dest string
+	}
+
+	var toRename []rename
+
+	destHash := dest.GetHash(s.Config.GetVideoFileNamingAlgorithm())
+
+	for _, m := range markers {
+		srcHash := src.GetHash(s.Config.GetVideoFileNamingAlgorithm())
+
+		// updated the scene id
+		m.SceneID.Int64 = int64(dest.ID)
+
+		if _, err := s.MarkerRepository.Update(ctx, *m); err != nil {
+			return fmt.Errorf("updating scene marker %d: %w", m.ID, err)
+		}
+
+		// move generated files to new location
+		toRename = append(toRename, []rename{
+			{
+				src:  s.Paths.SceneMarkers.GetScreenshotPath(srcHash, int(m.Seconds)),
+				dest: s.Paths.SceneMarkers.GetScreenshotPath(destHash, int(m.Seconds)),
+			},
+			{
+				src:  s.Paths.SceneMarkers.GetThumbnailPath(srcHash, int(m.Seconds)),
+				dest: s.Paths.SceneMarkers.GetThumbnailPath(destHash, int(m.Seconds)),
+			},
+			{
+				src:  s.Paths.SceneMarkers.GetWebpPreviewPath(srcHash, int(m.Seconds)),
+				dest: s.Paths.SceneMarkers.GetWebpPreviewPath(destHash, int(m.Seconds)),
+			},
+		}...)
+	}
+
+	if len(toRename) > 0 {
+		txn.AddPostCommitHook(ctx, func(ctx context.Context) error {
+			// rename the files if they exist
+			for _, e := range toRename {
+				srcExists, _ := fsutil.FileExists(e.src)
+				destExists, _ := fsutil.FileExists(e.dest)
+
+				if srcExists && !destExists {
+					if err := os.Rename(e.src, e.dest); err != nil {
+						logger.Errorf("Error renaming generated marker file from %s to %s: %v", e.src, e.dest, err)
+					}
+				}
+			}
+
+			return nil
+		})
+	}
+
+	return nil
+}