feat(subsonic): make it easier to add more tag reading backends

related #379
related #324
related #244

Dockerfile

@@ -21,7 +21,8 @@ RUN apk add -U --no-cache \
     mpv \
     ca-certificates \
     tzdata \
-    tini
+    tini \
+    shared-mime-info
 
 COPY --from=builder \
     /usr/lib/libgcc_s.so.1 \

Dockerfile.debug

@@ -5,5 +5,6 @@ RUN apk add -U --no-cache \
     git \
     sqlite \
     taglib-dev \
-    zlib-dev
+    zlib-dev \
+    shared-mime-info
 WORKDIR /src

Dockerfile.dev

@@ -18,7 +18,8 @@ FROM alpine:3.18
 RUN apk add -U --no-cache \
     ffmpeg \
     mpv \
-    ca-certificates
+    ca-certificates \
+    shared-mime-info
 COPY --from=builder \
     /usr/lib/libgcc_s.so.1 \
     /usr/lib/libstdc++.so.6 \

cmd/gonic/gonic.go

@@ -35,7 +35,8 @@ import (
 	"go.senan.xyz/gonic/playlist"
 	"go.senan.xyz/gonic/podcasts"
 	"go.senan.xyz/gonic/scanner"
-	"go.senan.xyz/gonic/scanner/tags"
+	"go.senan.xyz/gonic/scanner/tags/tagcommon"
+	"go.senan.xyz/gonic/scanner/tags/taglib"
 	"go.senan.xyz/gonic/scrobble"
 	"go.senan.xyz/gonic/server/ctrladmin"
 	"go.senan.xyz/gonic/server/ctrlsubsonic"
@@ -167,18 +168,23 @@ func main() {
 		log.Printf("    %-25s %s\n", f.Name, value)
 	})
 
-	tagger := &tags.TagReader{}
+	tagReader := tagcommon.ChainReader{
+		taglib.TagLib{},
+		// ffprobe reader?
+		// nfo reader?
+	}
+
 	scannr := scanner.New(
 		ctrlsubsonic.MusicPaths(musicPaths),
 		dbc,
 		map[scanner.Tag]scanner.MultiValueSetting{
 			scanner.Genre:       scanner.MultiValueSetting(confMultiValueGenre),
 			scanner.AlbumArtist: scanner.MultiValueSetting(confMultiValueAlbumArtist),
 		},
-		tagger,
+		tagReader,
 		*confExcludePatterns,
 	)
-	podcast := podcasts.New(dbc, *confPodcastPath, tagger)
+	podcast := podcasts.New(dbc, *confPodcastPath, tagReader)
 	transcoder := transcode.NewCachingTranscoder(
 		transcode.NewFFmpegTranscoder(),
 		cacheDirAudio,

db/model.go

@@ -3,13 +3,12 @@ package db
 
 import (
 	"fmt"
+	"mime"
 	"path/filepath"
 	"sort"
 	"strings"
 	"time"
 
-	"go.senan.xyz/gonic/mime"
-
 	// TODO: remove this dep
 	"go.senan.xyz/gonic/server/ctrlsubsonic/specid"
 )

mockfs/mockfs.go

@@ -15,7 +15,7 @@ import (
 	"github.com/mattn/go-sqlite3"
 	"go.senan.xyz/gonic/db"
 	"go.senan.xyz/gonic/scanner"
-	"go.senan.xyz/gonic/scanner/tags"
+	"go.senan.xyz/gonic/scanner/tags/tagcommon"
 )
 
 var ErrPathNotFound = errors.New("path not found")
@@ -69,7 +69,7 @@ func newMockFS(tb testing.TB, dirs []string, excludePattern string) *MockFS {
 		scanner.AlbumArtist: {Mode: scanner.Multi},
 	}
 
-	tagReader := &tagReader{paths: map[string]*tagReaderResult{}}
+	tagReader := &tagReader{paths: map[string]*TagInfo{}}
 	scanner := scanner.New(absDirs, dbc, multiValueSettings, tagReader, excludePattern)
 
 	return &MockFS{
@@ -81,11 +81,13 @@ func newMockFS(tb testing.TB, dirs []string, excludePattern string) *MockFS {
 	}
 }
 
-func (m *MockFS) DB() *db.DB             { return m.db }
-func (m *MockFS) TmpDir() string         { return m.dir }
-func (m *MockFS) TagReader() tags.Reader { return m.tagReader }
+func (m *MockFS) DB() *db.DB                  { return m.db }
+func (m *MockFS) TmpDir() string              { return m.dir }
+func (m *MockFS) TagReader() tagcommon.Reader { return m.tagReader }
 
 func (m *MockFS) ScanAndClean() *scanner.Context {
+	m.t.Helper()
+
 	ctx, err := m.scanner.ScanAndClean(scanner.ScanOptions{})
 	if err != nil {
 		m.t.Fatalf("error scan and cleaning: %v", err)
@@ -94,6 +96,8 @@ func (m *MockFS) ScanAndClean() *scanner.Context {
 }
 
 func (m *MockFS) ScanAndCleanErr() (*scanner.Context, error) {
+	m.t.Helper()
+
 	return m.scanner.ScanAndClean(scanner.ScanOptions{})
 }
 
@@ -126,12 +130,11 @@ func (m *MockFS) addItems(prefix string, onlyGlob string, covers bool) {
 				}
 
 				m.AddTrack(path)
-				m.SetTags(path, func(tags *Tags) error {
+				m.SetTags(path, func(tags *TagInfo) {
 					tags.RawArtist = fmt.Sprintf("artist-%d", ar)
 					tags.RawAlbumArtist = fmt.Sprintf("artist-%d", ar)
 					tags.RawAlbum = fmt.Sprintf("album-%d", al)
 					tags.RawTitle = fmt.Sprintf("title-%d", tr)
-					return nil
 				})
 			}
 			if covers {
@@ -180,10 +183,9 @@ func (m *MockFS) SetRealAudio(path string, length int, audioPath string) {
 	if err := os.Symlink(filepath.Join(wd, audioPath), abspath); err != nil {
 		m.t.Fatalf("symlink: %v", err)
 	}
-	m.SetTags(path, func(tags *Tags) error {
+	m.SetTags(path, func(tags *TagInfo) {
 		tags.RawLength = length
 		tags.RawBitrate = 0
-		return nil
 	})
 }
 
@@ -288,18 +290,15 @@ func (m *MockFS) AddCover(path string) {
 	defer f.Close()
 }
 
-func (m *MockFS) SetTags(path string, cb func(*Tags) error) {
-	abspath := filepath.Join(m.dir, path)
-	if err := os.Chtimes(abspath, time.Time{}, time.Now()); err != nil {
+func (m *MockFS) SetTags(path string, cb func(*TagInfo)) {
+	absPath := filepath.Join(m.dir, path)
+	if err := os.Chtimes(absPath, time.Time{}, time.Now()); err != nil {
 		m.t.Fatalf("touch track: %v", err)
 	}
-	r := m.tagReader
-	if _, ok := r.paths[abspath]; !ok {
-		r.paths[abspath] = &tagReaderResult{tags: &Tags{}}
-	}
-	if err := cb(r.paths[abspath].tags); err != nil {
-		r.paths[abspath].err = err
+	if _, ok := m.tagReader.paths[absPath]; !ok {
+		m.tagReader.paths[absPath] = &TagInfo{}
 	}
+	cb(m.tagReader.paths[absPath])
 }
 
 func (m *MockFS) DumpDB(suffix ...string) {
@@ -353,54 +352,54 @@ func (m *MockFS) DumpDB(suffix ...string) {
 	m.t.Error(destPath)
 }
 
-type tagReaderResult struct {
-	tags *Tags
-	err  error
+type tagReader struct {
+	paths map[string]*TagInfo
 }
 
-type tagReader struct {
-	paths map[string]*tagReaderResult
+func (m *tagReader) CanRead(absPath string) bool {
+	stat, _ := os.Stat(absPath)
+	return stat.Mode().IsRegular()
 }
 
-func (m *tagReader) Read(abspath string) (tags.Parser, error) {
-	p, ok := m.paths[abspath]
+func (m *tagReader) Read(absPath string) (tagcommon.Info, error) {
+	p, ok := m.paths[absPath]
 	if !ok {
 		return nil, ErrPathNotFound
 	}
-	return p.tags, p.err
+	if p.Error != nil {
+		return nil, p.Error
+	}
+	return p, nil
 }
 
-var _ tags.Reader = (*tagReader)(nil)
-
-type Tags struct {
+type TagInfo struct {
 	RawTitle        string
 	RawArtist       string
 	RawAlbum        string
 	RawAlbumArtist  string
 	RawAlbumArtists []string
 	RawGenre        string
-
-	RawBitrate int
-	RawLength  int
+	RawBitrate      int
+	RawLength       int
+	Error           error
 }
 
-func (m *Tags) Title() string          { return m.RawTitle }
-func (m *Tags) BrainzID() string       { return "" }
-func (m *Tags) Artist() string         { return m.RawArtist }
-func (m *Tags) Album() string          { return m.RawAlbum }
-func (m *Tags) AlbumArtist() string    { return m.RawAlbumArtist }
-func (m *Tags) AlbumArtists() []string { return m.RawAlbumArtists }
-func (m *Tags) AlbumBrainzID() string  { return "" }
-func (m *Tags) Genre() string          { return m.RawGenre }
-func (m *Tags) Genres() []string       { return []string{m.RawGenre} }
-func (m *Tags) TrackNumber() int       { return 1 }
-func (m *Tags) DiscNumber() int        { return 1 }
-func (m *Tags) Year() int              { return 2021 }
-
-func (m *Tags) Length() int  { return firstInt(100, m.RawLength) }
-func (m *Tags) Bitrate() int { return firstInt(100, m.RawBitrate) }
-
-var _ tags.Parser = (*Tags)(nil)
+func (i *TagInfo) Title() string          { return i.RawTitle }
+func (i *TagInfo) BrainzID() string       { return "" }
+func (i *TagInfo) Artist() string         { return i.RawArtist }
+func (i *TagInfo) Album() string          { return i.RawAlbum }
+func (i *TagInfo) AlbumArtist() string    { return i.RawAlbumArtist }
+func (i *TagInfo) AlbumArtists() []string { return i.RawAlbumArtists }
+func (i *TagInfo) AlbumBrainzID() string  { return "" }
+func (i *TagInfo) Genre() string          { return i.RawGenre }
+func (i *TagInfo) Genres() []string       { return []string{i.RawGenre} }
+func (i *TagInfo) TrackNumber() int       { return 1 }
+func (i *TagInfo) DiscNumber() int        { return 1 }
+func (i *TagInfo) Year() int              { return 2021 }
+func (i *TagInfo) Length() int            { return firstInt(100, i.RawLength) }
+func (i *TagInfo) Bitrate() int           { return firstInt(100, i.RawBitrate) }
+
+var _ tagcommon.Reader = (*tagReader)(nil)
 
 func firstInt(or int, ints ...int) int {
 	for _, int := range ints {