Use github.com/dhowden/tag as backup tag parser

Taglib appears to be unable to parse Vorbis tags in OGG files. And there
are places where it will be useful, even in my own collection.
Unfortunately github.com/dhowden/tag does not support getting media
duration and bitrate.

go.mod

@@ -3,6 +3,7 @@ module github.com/ironsmile/euterpe
 go 1.21
 
 require (
+	github.com/dhowden/tag v0.0.0-20240417053706-3d75831295e8
 	github.com/gbrlsnchs/jwt/v3 v3.0.1
 	github.com/gorilla/mux v1.6.2
 	github.com/howeyc/fsnotify v0.9.0

go.sum

@@ -7,6 +7,8 @@ github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwc
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/dhowden/tag v0.0.0-20240417053706-3d75831295e8 h1:OtSeLS5y0Uy01jaKK4mA/WVIYtpzVm63vLVAPzJXigg=
+github.com/dhowden/tag v0.0.0-20240417053706-3d75831295e8/go.mod h1:apkPC/CR3s48O2D7Y++n1XWEpgPNNCjXYga3PPbJe2E=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/gbrlsnchs/jwt/v3 v3.0.1 h1:lbUmgAKpxnClrKloyIwpxm4OuWeDl5wLk52G91ODPw4=
 github.com/gbrlsnchs/jwt/v3 v3.0.1/go.mod h1:AncDcjXz18xetI3A6STfXq2w+LuTx8pQ8bGEwRN8zVM=

src/library/local_library.go

@@ -16,7 +16,6 @@ import (
 	"time"
 
 	"github.com/howeyc/fsnotify"
-	taglib "github.com/wtolson/go-taglib"
 
 	// Blind import is the way a SQL driver is imported. This is the proposed way
 	// from the golang documentation.
@@ -867,11 +866,10 @@ func (lib *LocalLibrary) AddMedia(filename string) error {
 		return err
 	}
 
-	file, err := taglib.Read(filename)
+	file, err := parseFileTags(filename)
 	if err != nil {
-		return fmt.Errorf("Taglib error for %s: %s", filename, err.Error())
+		return fmt.Errorf("parsing tags error for %s: %s", filename, err.Error())
 	}
-	defer file.Close()
 
 	fi := fileInfo{
 		FilePath: filename,
@@ -1348,13 +1346,18 @@ func (lib *LocalLibrary) setTrackID(
 			yearArg = sql.Named("year", nil)
 		}
 
+		durationArg := sql.Named("duration", duration)
+		if duration == 0 {
+			durationArg = sql.Named("duration", nil)
+		}
+
 		res, err := stmt.Exec(
 			sql.Named("title", title),
 			sql.Named("albumID", albumID),
 			sql.Named("artistID", artistID),
 			sql.Named("fsPath", fsPath),
 			sql.Named("trackNumber", trackNumber),
-			sql.Named("duration", duration),
+			durationArg,
 			yearArg,
 			sql.Named("size", size),
 			bitrateArg,

src/library/local_library_scan.go

@@ -8,8 +8,6 @@ import (
 	"os"
 	"path/filepath"
 	"time"
-
-	taglib "github.com/wtolson/go-taglib"
 )
 
 // Scan scans all of the folders in paths for media files. New files will be added to the
@@ -135,9 +133,9 @@ func (lib *LocalLibrary) Rescan(ctx context.Context) error {
 				continue
 			}
 
-			file, err := taglib.Read(fileName)
+			file, err := parseFileTags(fileName)
 			if err != nil {
-				log.Printf("Taglib error for %s: %s\n", fileName, err)
+				log.Printf("Parsing tags error for %s: %s\n", fileName, err)
 				continue
 			}
 
@@ -149,7 +147,6 @@ func (lib *LocalLibrary) Rescan(ctx context.Context) error {
 			if err := lib.insertMediaIntoDatabase(file, fi); err != nil {
 				log.Printf("failed updating file %s: %s\n", fileName, err)
 			}
-			file.Close()
 		}
 	}
 

src/library/media_file.go

@@ -1,6 +1,13 @@
 package library
 
-import "time"
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/dhowden/tag"
+	taglib "github.com/wtolson/go-taglib"
+)
 
 // MediaFile is an interface which a media object should satisfy in order to be inserted
 // in the library database.
@@ -27,3 +34,77 @@ type MediaFile interface {
 	// Returns the bitrate of the file in kb/s.
 	Bitrate() int
 }
+
+// parseFileTags reads a file and returns its metadata tags as a MediaFile object.
+func parseFileTags(fileName string) (MediaFile, error) {
+	file, tglErr := taglib.Read(fileName)
+	if tglErr == nil {
+		defer file.Close()
+		return medaFileFromTaglib(file), nil
+	}
+
+	mf, tagErr := mediaFileFromTag(fileName)
+	if tagErr != nil {
+		return nil, fmt.Errorf(
+			"failed to parse file with both tagging libs: (tag: %s, taglib: %w)",
+			tagErr, tglErr,
+		)
+	}
+
+	return mf, nil
+}
+
+type mediaFile struct {
+	artist  string
+	album   string
+	title   string
+	track   int
+	length  time.Duration
+	year    int
+	bitrate int
+}
+
+func (f *mediaFile) Artist() string        { return f.artist }
+func (f *mediaFile) Album() string         { return f.album }
+func (f *mediaFile) Title() string         { return f.title }
+func (f *mediaFile) Track() int            { return f.track }
+func (f *mediaFile) Length() time.Duration { return f.length }
+func (f *mediaFile) Year() int             { return f.year }
+func (f *mediaFile) Bitrate() int          { return f.bitrate }
+
+// medaFileFromTaglib returns a MediaFile from a taglib parsed file.
+func medaFileFromTaglib(file *taglib.File) MediaFile {
+	return &mediaFile{
+		artist:  file.Artist(),
+		album:   file.Album(),
+		title:   file.Title(),
+		track:   file.Track(),
+		length:  file.Length(),
+		year:    file.Year(),
+		bitrate: file.Bitrate(),
+	}
+}
+
+func mediaFileFromTag(fileName string) (MediaFile, error) {
+	fh, err := os.Open(fileName)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open file: %w", err)
+	}
+	defer fh.Close()
+
+	md, err := tag.ReadFrom(fh)
+	if err != nil {
+		return nil, fmt.Errorf("parsing tags: %w", err)
+	}
+
+	track, _ := md.Track()
+	file := &mediaFile{
+		artist: md.Artist(),
+		album:  md.Album(),
+		title:  md.Title(),
+		track:  track,
+		year:   md.Year(),
+	}
+
+	return file, nil
+}