fix(artwork): simplify lastUpdate logic using TimeNewest utility

Signed-off-by: Deluan <deluan@navidrome.org>

core/artwork/e2e/album_test.go

@@ -37,15 +37,15 @@ var _ = Describe("Album artwork resolution", func() {
 		})
 	})
 
-	// Bug 2 variant: cover.* basenames tie across album-root and per-disc folders;
-	// compareImageFiles' lexicographic full-path tiebreaker ranks disc-subfolder
-	// files first.
+	// https://github.com/navidrome/navidrome/issues/5376
+	// cover.* basenames tie across album-root and per-disc folders;
+	// compareImageFiles must prefer shallower paths.
 	When("a multi-disc album has a cover.jpg at the album root and per-disc covers", func() {
 		// Artist/
 		// └── Album/
 		//     ├── CD1/
 		//     │   ├── 01 - Track.mp3
-		//     │   └── cover.jpg        ← currently wins (bug)
+		//     │   └── cover.jpg        ← should not win
 		//     ├── CD2/
 		//     │   ├── 01 - Track.mp3
 		//     │   └── cover.jpg
@@ -68,15 +68,15 @@ var _ = Describe("Album artwork resolution", func() {
 		})
 	})
 
-	// Bug 2: folder.jpg basenames tie across album-root and per-disc folders;
-	// the lexicographic full-path tiebreaker in compareImageFiles ranks
-	// "Artist/Album/CD1/folder.jpg" ahead of "Artist/Album/folder.jpg".
+	// https://github.com/navidrome/navidrome/issues/5376
+	// folder.jpg basenames tie across album-root and per-disc folders;
+	// compareImageFiles must prefer shallower paths.
 	When("a multi-disc album has folder.jpg at the album root AND in each disc subfolder", func() {
 		// Artist/
 		// └── Album/
 		//     ├── CD1/
 		//     │   ├── 01 - Track.mp3
-		//     │   └── folder.jpg       ← currently wins (bug)
+		//     │   └── folder.jpg       ← should not win
 		//     ├── CD2/
 		//     │   ├── 01 - Track.mp3
 		//     │   └── folder.jpg
@@ -97,15 +97,14 @@ var _ = Describe("Album artwork resolution", func() {
 		})
 	})
 
-	// Bug 1: commonParentFolder's `len(folders) < 2` guard skips the parent-folder
-	// lookup whenever an album lives entirely under a single subfolder, so an
-	// album-root cover is never considered.
+	// https://github.com/navidrome/navidrome/issues/5376
+	// Single-subfolder albums must still consider the parent folder's images.
 	When("an album lives entirely under a single disc subfolder with cover.jpg at the parent", func() {
 		// Artist/
 		// └── Album/
 		//     ├── disc1/
 		//     │   └── 01 - Track.mp3
-		//     └── cover.jpg            ← should win (parent-folder fallback, currently ignored — bug)
+		//     └── cover.jpg            ← should win (parent-folder fallback)
 		It("uses the parent-folder cover for single-disc-subfolder albums", func() {
 			conf.Server.CoverArtPriority = defaultCoverPriority
 			setLayout(fstest.MapFS{
@@ -119,6 +118,32 @@ var _ = Describe("Album artwork resolution", func() {
 		})
 	})
 
+	// https://github.com/navidrome/navidrome/issues/5456
+	When("a top-level multi-disc album has cover.jpg at the album root and per-disc folder.jpg", func() {
+		// Album/                        (top-level folder, Path=".")
+		// ├── CD1/
+		// │   ├── 01 - Track.mp3
+		// │   └── folder.jpg
+		// ├── CD2/
+		// │   ├── 01 - Track.mp3
+		// │   └── folder.jpg
+		// └── cover.jpg                ← should win (album-root)
+		It("prefers the album-root cover.jpg", func() {
+			conf.Server.CoverArtPriority = defaultCoverPriority
+			setLayout(fstest.MapFS{
+				"Album/CD1/01 - Track.mp3": trackFile(1, "Track CD1"),
+				"Album/CD2/01 - Track.mp3": trackFile(1, "Track CD2"),
+				"Album/cover.jpg":          imageFile("album-root"),
+				"Album/CD1/folder.jpg":     imageFile("disc1"),
+				"Album/CD2/folder.jpg":     imageFile("disc2"),
+			})
+			scan()
+
+			al := firstAlbum()
+			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root")))
+		})
+	})
+
 	When("CoverArtPriority puts embedded first and the album has both embedded and external art", func() {
 		// Artist/
 		// └── Album/

core/artwork/e2e/disc_test.go

@@ -1,6 +1,7 @@
 package artworke2e_test
 
 import (
+	"fmt"
 	"testing/fstest"
 
 	"github.com/navidrome/navidrome/conf"
@@ -255,6 +256,100 @@ var _ = Describe("Disc artwork resolution", func() {
 		})
 	})
 
+	// Reproduces https://github.com/navidrome/navidrome/issues/5456
+	// Deeply nested layout matching the reporter's actual structure.
+	When("a deeply nested multi-disc album has cover.jpg and per-disc folder.jpg", func() {
+		// Genre/Artist/Album/                 ← album root with cover.jpg
+		// ├── cover.jpg                       ← album-level cover
+		// ├── Disc 01 (Subtitle)/
+		// │   ├── 01 - Track.mp3
+		// │   └── folder.jpg                  ← disc 1 art
+		// ├── Disc 02 (Subtitle)/
+		// │   ├── 01 - Track.mp3
+		// │   └── folder.jpg
+		// └── ... (12 discs)
+		It("uses album-root cover.jpg for album art and per-disc folder.jpg for each disc", func() {
+			conf.Server.DiscArtPriority = defaultDiscPriority
+			conf.Server.CoverArtPriority = defaultCoverPriority
+			discNames := []string{
+				"Disc 01 (Birth of the Dead - The Studio Sides)",
+				"Disc 02 (Birth of the Dead - The Live Sides)",
+				"Disc 03 (The Grateful Dead)",
+				"Disc 04 (Anthem of the Sun)",
+				"Disc 05 (Aoxomoxoa)",
+				"Disc 06 (Live; Dead)",
+				"Disc 07 (Workingman's Dead)",
+				"Disc 08 (American Beauty)",
+				"Disc 09 (Grateful Dead)",
+				"Disc 10 (Europe '72)",
+				"Disc 11 (Europe '72)",
+				"Disc 12 (History of the Grateful Dead, Volume One (Bear's Choice))",
+			}
+			layout := fstest.MapFS{
+				"Pop; Rock/Grateful Dead/(2001) The Golden Road/cover.jpg": imageFile("album-root-cover"),
+			}
+			for i, name := range discNames {
+				discNum := i + 1
+				prefix := fmt.Sprintf("Pop; Rock/Grateful Dead/(2001) The Golden Road/%s/", name)
+				layout[prefix+"01 - Track.mp3"] = trackFile(1, fmt.Sprintf("T%d", discNum), map[string]any{"disc": fmt.Sprintf("%d", discNum)})
+				layout[prefix+"folder.jpg"] = imageFile(fmt.Sprintf("disc-%02d-folder", discNum))
+			}
+			setLayout(layout)
+			scan()
+
+			al := firstAlbum()
+
+			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root-cover")))
+
+			for i := range discNames {
+				discNum := i + 1
+				discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, discNum), &al.UpdatedAt)
+				Expect(readArtwork(discID)).To(Equal(imageBytes(fmt.Sprintf("disc-%02d-folder", discNum))),
+					"disc %d should use its own folder.jpg", discNum)
+			}
+		})
+	})
+
+	// https://github.com/navidrome/navidrome/issues/5456
+	// Top-level album variant — album folder at library root (Path=".").
+	When("a top-level multi-disc album has cover.jpg and per-disc folder.jpg", func() {
+		// Album/                       (top-level, Path=".")
+		// ├── cover.jpg                ← album-level cover
+		// ├── Disc 01/
+		// │   ├── 01 - Track.mp3
+		// │   └── folder.jpg           ← disc 1 art
+		// ├── Disc 02/
+		// │   ├── 01 - Track.mp3
+		// │   └── folder.jpg
+		// └── Disc 03/
+		//     ├── 01 - Track.mp3
+		//     └── folder.jpg
+		It("uses album-root cover.jpg for album art and per-disc folder.jpg for each disc", func() {
+			conf.Server.DiscArtPriority = defaultDiscPriority
+			conf.Server.CoverArtPriority = defaultCoverPriority
+			layout := fstest.MapFS{
+				"Album/cover.jpg": imageFile("album-root-cover"),
+			}
+			for i := 1; i <= 3; i++ {
+				prefix := fmt.Sprintf("Album/Disc %02d/", i)
+				layout[prefix+"01 - Track.mp3"] = trackFile(1, fmt.Sprintf("T%d", i), map[string]any{"disc": fmt.Sprintf("%d", i)})
+				layout[prefix+"folder.jpg"] = imageFile(fmt.Sprintf("disc-%02d-folder", i))
+			}
+			setLayout(layout)
+			scan()
+
+			al := firstAlbum()
+
+			Expect(readArtwork(al.CoverArtID())).To(Equal(imageBytes("album-root-cover")))
+
+			for i := 1; i <= 3; i++ {
+				discID := model.NewArtworkID(model.KindDiscArtwork, model.DiscArtworkID(al.ID, i), &al.UpdatedAt)
+				Expect(readArtwork(discID)).To(Equal(imageBytes(fmt.Sprintf("disc-%02d-folder", i))),
+					"disc %d should use its own folder.jpg", i)
+			}
+		})
+	})
+
 	When("discsubtitle is set but no image filename matches the subtitle", func() {
 		// Artist/
 		// └── Album/

core/artwork/reader_album.go

@@ -18,6 +18,7 @@ import (
 	"github.com/navidrome/navidrome/core/ffmpeg"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils"
 	"github.com/navidrome/navidrome/utils/natural"
 )
 
@@ -53,10 +54,9 @@ func newAlbumArtworkReader(ctx context.Context, artwork *artwork, artID model.Ar
 		lib:       lib,
 	}
 	a.cacheKey.artID = artID
-	if a.updatedAt != nil && a.updatedAt.After(al.UpdatedAt) {
-		a.cacheKey.lastUpdate = *a.updatedAt
-	} else {
-		a.cacheKey.lastUpdate = al.UpdatedAt
+	a.cacheKey.lastUpdate = utils.TimeNewest(al.UpdatedAt, al.ImportedAt)
+	if imagesUpdateAt != nil {
+		a.cacheKey.lastUpdate = utils.TimeNewest(a.cacheKey.lastUpdate, *imagesUpdateAt)
 	}
 	return a, nil
 }
@@ -131,7 +131,7 @@ func loadAlbumFoldersPaths(ctx context.Context, ds model.DataStore, albums ...mo
 			} else if err != nil {
 				return nil, nil, nil, err
 			}
-			if parentFolder != nil && parentFolder.Path != "." {
+			if parentFolder != nil && parentFolder.ParentID != "" {
 				folders = append(folders, *parentFolder)
 			}
 		}

core/artwork/reader_album_test.go

@@ -141,6 +141,7 @@ var _ = Describe("Album Artwork Reader", func() {
 				ID:              "parentFolder",
 				Path:            "Artist",
 				Name:            "Album",
+				ParentID:        "artistFolder",
 				ImagesUpdatedAt: expectedAt,
 				ImageFiles:      []string{"cover.jpg", "back.jpg"},
 			}
@@ -213,14 +214,14 @@ var _ = Describe("Album Artwork Reader", func() {
 			Expect(repo.getCallCount).To(Equal(0))
 		})
 
-		It("does not include top-level parent for multi-folder albums", func() {
-			// Two album parts under the same artist folder — parent is artist-level
+		It("does not include library root parent for multi-folder albums", func() {
+			// Two album parts directly under the library root — parent is the root itself
 			repo.result = []model.Folder{
 				{
 					ID:              "folder1",
 					Path:            ".",
 					Name:            "AlbumPart1",
-					ParentID:        "artistFolder",
+					ParentID:        "rootFolder",
 					ImagesUpdatedAt: now,
 					ImageFiles:      []string{"cover.jpg"},
 				},
@@ -228,16 +229,17 @@ var _ = Describe("Album Artwork Reader", func() {
 					ID:              "folder2",
 					Path:            ".",
 					Name:            "AlbumPart2",
-					ParentID:        "artistFolder",
+					ParentID:        "rootFolder",
 					ImagesUpdatedAt: now,
 					ImageFiles:      []string{},
 				},
 			}
 			repo.parentResult = &model.Folder{
-				ID:         "artistFolder",
-				Path:       ".",
-				Name:       "Artist",
-				ImageFiles: []string{"artist.jpg"},
+				ID:         "rootFolder",
+				Path:       "",
+				Name:       ".",
+				ParentID:   "",
+				ImageFiles: []string{"unrelated.jpg"},
 			}
 
 			_, imgFiles, _, err := loadAlbumFoldersPaths(ctx, ds, album)
@@ -248,6 +250,46 @@ var _ = Describe("Album Artwork Reader", func() {
 			Expect(repo.getCallCount).To(Equal(1))
 		})
 
+		It("includes top-level album folder for multi-disc albums", func() {
+			// Album folder directly under library root, with disc subfolders
+			repo.result = []model.Folder{
+				{
+					ID:              "folder1",
+					Path:            "Album",
+					Name:            "Disc1",
+					ParentID:        "albumFolder",
+					ImagesUpdatedAt: now,
+					ImageFiles:      []string{"folder.jpg"},
+				},
+				{
+					ID:              "folder2",
+					Path:            "Album",
+					Name:            "Disc2",
+					ParentID:        "albumFolder",
+					ImagesUpdatedAt: now,
+					ImageFiles:      []string{"folder.jpg"},
+				},
+			}
+			repo.parentResult = &model.Folder{
+				ID:              "albumFolder",
+				Path:            ".",
+				Name:            "Album",
+				ParentID:        "rootFolder",
+				ImagesUpdatedAt: expectedAt,
+				ImageFiles:      []string{"cover.jpg"},
+			}
+
+			_, imgFiles, imagesUpdatedAt, err := loadAlbumFoldersPaths(ctx, ds, album)
+
+			Expect(err).ToNot(HaveOccurred())
+			Expect(*imagesUpdatedAt).To(Equal(expectedAt))
+			Expect(imgFiles).To(HaveLen(3))
+			Expect(imgFiles[0]).To(Equal("Album/cover.jpg"))
+			Expect(imgFiles[1]).To(Equal("Album/Disc1/folder.jpg"))
+			Expect(imgFiles[2]).To(Equal("Album/Disc2/folder.jpg"))
+			Expect(repo.getCallCount).To(Equal(1))
+		})
+
 		It("does not query parent for single-folder albums that already have images", func() {
 			repo.result = []model.Folder{
 				{
@@ -283,6 +325,7 @@ var _ = Describe("Album Artwork Reader", func() {
 				ID:              "albumFolder",
 				Path:            "Artist",
 				Name:            "Album",
+				ParentID:        "artistFolder",
 				ImagesUpdatedAt: expectedAt,
 				ImageFiles:      []string{"cover.jpg"},
 			}

core/artwork/reader_disc.go

@@ -16,6 +16,7 @@ import (
 	"github.com/navidrome/navidrome/core/ffmpeg"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils"
 )
 
 type discArtworkReader struct {
@@ -105,10 +106,9 @@ func newDiscArtworkReader(ctx context.Context, a *artwork, artID model.ArtworkID
 		updatedAt:      imagesUpdatedAt,
 	}
 	r.cacheKey.artID = artID
-	if r.updatedAt != nil && r.updatedAt.After(al.UpdatedAt) {
-		r.cacheKey.lastUpdate = *r.updatedAt
-	} else {
-		r.cacheKey.lastUpdate = al.UpdatedAt
+	r.cacheKey.lastUpdate = utils.TimeNewest(al.UpdatedAt, al.ImportedAt)
+	if imagesUpdatedAt != nil {
+		r.cacheKey.lastUpdate = utils.TimeNewest(r.cacheKey.lastUpdate, *imagesUpdatedAt)
 	}
 	return r, nil
 }