Move alternative tag names mapping to metadata

scanner/metadata/metadata.go

@@ -16,10 +16,9 @@ import (
 	"github.com/navidrome/navidrome/log"
 )
 
-type ParsedTags = map[string][]string
-
 type Extractor interface {
 	Parse(files ...string) (map[string]ParsedTags, error)
+	CustomMappings() ParsedTags
 }
 
 var extractors = map[string]Extractor{}
@@ -49,6 +48,7 @@ func Extract(files ...string) (map[string]Tags, error) {
 			continue
 		}
 
+		tags = tags.Map(p.CustomMappings())
 		result[filePath] = Tags{
 			filePath: filePath,
 			fileInfo: fileInfo,
@@ -59,10 +59,27 @@ func Extract(files ...string) (map[string]Tags, error) {
 	return result, nil
 }
 
+type ParsedTags map[string][]string
+
+func (p ParsedTags) Map(customMappings ParsedTags) ParsedTags {
+	if customMappings == nil {
+		return p
+	}
+	for tagName, alternatives := range customMappings {
+		for _, altName := range alternatives {
+			if altValue, ok := p[altName]; ok {
+				p[tagName] = append(p[tagName], altValue...)
+				delete(p, altName)
+			}
+		}
+	}
+	return p
+}
+
 type Tags struct {
 	filePath string
 	fileInfo os.FileInfo
-	tags     map[string][]string
+	tags     ParsedTags
 }
 
 // Common tags
@@ -92,6 +109,7 @@ func (t Tags) Bpm() int           { return (int)(math.Round(t.getFloat("tbpm", "
 func (t Tags) HasPicture() bool   { return t.getFirstTagValue("has_picture") != "" }
 
 // MusicBrainz Identifiers
+
 func (t Tags) MbzReleaseTrackID() string {
 	return t.getMbzID("musicbrainz_releasetrackid", "musicbrainz release track id")
 }
@@ -148,10 +166,10 @@ func (t Tags) getAllTagValues(tagNames ...string) []string {
 	return values
 }
 
-func (t Tags) getSortTag(originalTag string, tagNamess ...string) string {
+func (t Tags) getSortTag(originalTag string, tagNames ...string) string {
 	formats := []string{"sort%s", "sort_%s", "sort-%s", "%ssort", "%s_sort", "%s-sort"}
 	all := []string{originalTag}
-	for _, tag := range tagNamess {
+	for _, tag := range tagNames {
 		for _, format := range formats {
 			name := fmt.Sprintf(format, tag)
 			all = append(all, name)