From f8597727234bee53de31a5fe404046f7a2c6fea8 Mon Sep 17 00:00:00 2001
From: Deluan <deluan@navidrome.org>
Date: Fri, 2 Oct 2020 16:18:45 -0400
Subject: [PATCH] Remove dangling tracks after changing MusicFolder. Fix #445

---
 model/datastore.go                  |  2 +-
 persistence/mediafile_repository.go | 13 ++++++++++++-
 persistence/mock_persistence.go     |  2 +-
 persistence/persistence.go          |  9 +++++++--
 scanner/tag_scanner.go              | 14 ++++++--------
 5 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/model/datastore.go b/model/datastore.go
index 819323ec6..136083b53 100644
--- a/model/datastore.go
+++ b/model/datastore.go
@@ -35,5 +35,5 @@ type DataStore interface {
 	Resource(ctx context.Context, model interface{}) ResourceRepository
 
 	WithTx(func(tx DataStore) error) error
-	GC(ctx context.Context) error
+	GC(ctx context.Context, rootFolder string) error
 }
diff --git a/persistence/mediafile_repository.go b/persistence/mediafile_repository.go
index 8abf30e53..ffda9c17b 100644
--- a/persistence/mediafile_repository.go
+++ b/persistence/mediafile_repository.go
@@ -108,7 +108,7 @@ func (r mediaFileRepository) FindAllByPath(path string) (model.MediaFiles, error
 	return res, err
 }
 
-func pathStartsWith(path string) Sqlizer {
+func pathStartsWith(path string) Eq {
 	cleanPath := filepath.Clean(path)
 	substr := fmt.Sprintf("substr(path, 1, %d)", utf8.RuneCountInString(cleanPath))
 	return Eq{substr: cleanPath}
@@ -124,6 +124,17 @@ func (r mediaFileRepository) FindPathsRecursively(basePath string) ([]string, er
 	return res, err
 }
 
+func (r mediaFileRepository) deleteNotInPath(basePath string) error {
+	sel := Delete(r.tableName).Where(NotEq(pathStartsWith(basePath)))
+	c, err := r.executeSQL(sel)
+	if err == nil {
+		if c > 0 {
+			log.Debug(r.ctx, "Deleted dangling tracks", "totalDeleted", c)
+		}
+	}
+	return err
+}
+
 func (r mediaFileRepository) GetStarred(options ...model.QueryOptions) (model.MediaFiles, error) {
 	sq := r.selectMediaFile(options...).Where("starred = true")
 	starred := model.MediaFiles{}
diff --git a/persistence/mock_persistence.go b/persistence/mock_persistence.go
index e956831b5..3f88e8600 100644
--- a/persistence/mock_persistence.go
+++ b/persistence/mock_persistence.go
@@ -89,7 +89,7 @@ func (db *MockDataStore) Resource(ctx context.Context, m interface{}) model.Reso
 	return struct{ model.ResourceRepository }{}
 }
 
-func (db *MockDataStore) GC(ctx context.Context) error {
+func (db *MockDataStore) GC(ctx context.Context, rootFolder string) error {
 	return nil
 }
 
diff --git a/persistence/persistence.go b/persistence/persistence.go
index fac59e71f..eabe52d9f 100644
--- a/persistence/persistence.go
+++ b/persistence/persistence.go
@@ -111,8 +111,13 @@ func (s *SQLStore) WithTx(block func(tx model.DataStore) error) error {
 	return nil
 }
 
-func (s *SQLStore) GC(ctx context.Context) error {
-	err := s.Album(ctx).(*albumRepository).purgeEmpty()
+func (s *SQLStore) GC(ctx context.Context, rootFolder string) error {
+	err := s.MediaFile(ctx).(*mediaFileRepository).deleteNotInPath(rootFolder)
+	if err != nil {
+		log.Error(ctx, "Error removing dangling tracks", err)
+		return err
+	}
+	err = s.Album(ctx).(*albumRepository).purgeEmpty()
 	if err != nil {
 		log.Error(ctx, "Error removing empty albums", err)
 		return err
diff --git a/scanner/tag_scanner.go b/scanner/tag_scanner.go
index 13b95ae54..b9369f9f9 100644
--- a/scanner/tag_scanner.go
+++ b/scanner/tag_scanner.go
@@ -33,13 +33,11 @@ func NewTagScanner(rootFolder string, ds model.DataStore) *TagScanner {
 	}
 }
 
-type (
-	counters struct {
-		added   int64
-		updated int64
-		deleted int64
-	}
-)
+type counters struct {
+	added   int64
+	updated int64
+	deleted int64
+}
 
 const (
 	// filesBatchSize used for batching file metadata extraction
@@ -125,7 +123,7 @@ func (s *TagScanner) Scan(ctx context.Context, lastModifiedSince time.Time) erro
 		log.Debug("Playlist auto-import is disabled")
 	}
 
-	err = s.ds.GC(log.NewContext(ctx))
+	err = s.ds.GC(log.NewContext(ctx), s.rootFolder)
 	log.Info("Finished processing Music Folder", "folder", s.rootFolder, "elapsed", time.Since(start),
 		"added", s.cnt.added, "updated", s.cnt.updated, "deleted", s.cnt.deleted, "playlistsImported", plsCount)