JSPF: Implemented export as loves and listens

CHANGES.md

@@ -1,5 +1,9 @@
 # Scotty Changelog
 
+## 0.6.0 - WIP
+- JSPF: Implemented export as loves and listens
+
+
 ## 0.5.2 - 2025-05-01
 - ListenBrainz: fixed loves export not considering latest timestamp
 

README.md

@@ -121,7 +121,7 @@ Backend         | Listens Export | Listens Import | Loves Export | Loves Import
 ----------------|----------------|----------------|--------------|-------------
 deezer          | ✓              | ⨯              | ✓            | -
 funkwhale       | ✓              | ⨯              | ✓            | -
-jspf            | -              | ✓              | -            | ✓
+jspf            | ✓              | ✓              | ✓            | ✓
 lastfm          | ✓              | ✓              | ✓            | ✓
 listenbrainz    | ✓              | ✓              | ✓            | ✓
 maloja          | ✓              | ✓              | ⨯            | ⨯

internal/backends/jspf/jspf.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2023-2024 Philipp Wolfer <phw@uploadedlobster.com>
+Copyright © 2023-2025 Philipp Wolfer <phw@uploadedlobster.com>
 
 This file is part of Scotty.
 
@@ -18,15 +18,25 @@ Scotty. If not, see <https://www.gnu.org/licenses/>.
 package jspf
 
 import (
+	"errors"
 	"os"
+	"sort"
+	"strings"
 	"time"
 
+	"go.uploadedlobster.com/mbtypes"
 	"go.uploadedlobster.com/scotty/internal/config"
 	"go.uploadedlobster.com/scotty/internal/i18n"
 	"go.uploadedlobster.com/scotty/internal/models"
 	"go.uploadedlobster.com/scotty/pkg/jspf"
 )
 
+const (
+	artistMBIDPrefix    = "https://musicbrainz.org/artist/"
+	recordingMBIDPrefix = "https://musicbrainz.org/recording/"
+	releaseMBIDPrefix   = "https://musicbrainz.org/release/"
+)
+
 type JSPFBackend struct {
 	filePath string
 	playlist jspf.Playlist
@@ -68,7 +78,7 @@ func (b *JSPFBackend) InitConfig(config *config.ServiceConfig) error {
 		Creator:    config.GetString("username"),
 		Identifier: config.GetString("identifier"),
 		Tracks:     make([]jspf.Track, 0),
-		Extension: map[string]any{
+		Extension: jspf.ExtensionMap{
 			jspf.MusicBrainzPlaylistExtensionID: jspf.MusicBrainzPlaylistExtension{
 				LastModifiedAt: time.Now(),
 				Public:         true,
@@ -86,6 +96,28 @@ func (b *JSPFBackend) FinishImport() error {
 	return b.writeJSPF()
 }
 
+func (b *JSPFBackend) ExportListens(oldestTimestamp time.Time, results chan models.ListensResult, progress chan models.Progress) {
+	defer close(results)
+
+	err := b.readJSPF()
+	if err != nil {
+		progress <- models.Progress{}.Complete()
+		results <- models.ListensResult{Error: err}
+		return
+	}
+
+	listens := make(models.ListensList, 0, len(b.playlist.Tracks))
+	for _, track := range b.playlist.Tracks {
+		listen, err := trackAsListen(track)
+		if err == nil && listen != nil && listen.ListenedAt.After(oldestTimestamp) {
+			listens = append(listens, *listen)
+		}
+	}
+	sort.Sort(listens)
+	progress <- models.Progress{Total: int64(len(listens))}.Complete()
+	results <- models.ListensResult{Items: listens}
+}
+
 func (b *JSPFBackend) ImportListens(export models.ListensResult, importResult models.ImportResult, progress chan models.Progress) (models.ImportResult, error) {
 	for _, listen := range export.Items {
 		track := listenAsTrack(listen)
@@ -98,6 +130,28 @@ func (b *JSPFBackend) ImportListens(export models.ListensResult, importResult mo
 	return importResult, nil
 }
 
+func (b *JSPFBackend) ExportLoves(oldestTimestamp time.Time, results chan models.LovesResult, progress chan models.Progress) {
+	defer close(results)
+
+	err := b.readJSPF()
+	if err != nil {
+		progress <- models.Progress{}.Complete()
+		results <- models.LovesResult{Error: err}
+		return
+	}
+
+	loves := make(models.LovesList, 0, len(b.playlist.Tracks))
+	for _, track := range b.playlist.Tracks {
+		love, err := trackAsLove(track)
+		if err == nil && love != nil && love.Created.After(oldestTimestamp) {
+			loves = append(loves, *love)
+		}
+	}
+	sort.Sort(loves)
+	progress <- models.Progress{Total: int64(len(loves))}.Complete()
+	results <- models.LovesResult{Items: loves}
+}
+
 func (b *JSPFBackend) ImportLoves(export models.LovesResult, importResult models.ImportResult, progress chan models.Progress) (models.ImportResult, error) {
 	for _, love := range export.Items {
 		track := loveAsTrack(love)
@@ -112,22 +166,35 @@ func (b *JSPFBackend) ImportLoves(export models.LovesResult, importResult models
 
 func listenAsTrack(l models.Listen) jspf.Track {
 	l.FillAdditionalInfo()
-	track := trackAsTrack(l.Track)
+	track := trackAsJSPFTrack(l.Track)
 	extension := makeMusicBrainzExtension(l.Track)
 	extension.AddedAt = l.ListenedAt
 	extension.AddedBy = l.UserName
 	track.Extension[jspf.MusicBrainzTrackExtensionID] = extension
 
 	if l.RecordingMBID != "" {
-		track.Identifier = append(track.Identifier, "https://musicbrainz.org/recording/"+string(l.RecordingMBID))
+		track.Identifier = append(track.Identifier, recordingMBIDPrefix+string(l.RecordingMBID))
 	}
 
 	return track
 }
 
+func trackAsListen(t jspf.Track) (*models.Listen, error) {
+	track, addedAt, err := jspfTrackAsTrack(t)
+	if err != nil {
+		return nil, err
+	}
+
+	listen := models.Listen{
+		ListenedAt: *addedAt,
+		Track:      *track,
+	}
+	return &listen, err
+}
+
 func loveAsTrack(l models.Love) jspf.Track {
 	l.FillAdditionalInfo()
-	track := trackAsTrack(l.Track)
+	track := trackAsJSPFTrack(l.Track)
 	extension := makeMusicBrainzExtension(l.Track)
 	extension.AddedAt = l.Created
 	extension.AddedBy = l.UserName
@@ -138,25 +205,62 @@ func loveAsTrack(l models.Love) jspf.Track {
 		recordingMBID = l.RecordingMBID
 	}
 	if recordingMBID != "" {
-		track.Identifier = append(track.Identifier, "https://musicbrainz.org/recording/"+string(recordingMBID))
+		track.Identifier = append(track.Identifier, recordingMBIDPrefix+string(recordingMBID))
 	}
 
 	return track
 }
 
-func trackAsTrack(t models.Track) jspf.Track {
+func trackAsLove(t jspf.Track) (*models.Love, error) {
+	track, addedAt, err := jspfTrackAsTrack(t)
+	if err != nil {
+		return nil, err
+	}
+
+	love := models.Love{
+		Created:       *addedAt,
+		RecordingMBID: track.RecordingMBID,
+		Track:         *track,
+	}
+	return &love, err
+}
+
+func trackAsJSPFTrack(t models.Track) jspf.Track {
 	track := jspf.Track{
 		Title:     t.TrackName,
 		Album:     t.ReleaseName,
 		Creator:   t.ArtistName(),
 		TrackNum:  t.TrackNumber,
 		Duration:  t.Duration.Milliseconds(),
-		Extension: map[string]any{},
+		Extension: jspf.ExtensionMap{},
 	}
 
 	return track
 }
 
+func jspfTrackAsTrack(t jspf.Track) (*models.Track, *time.Time, error) {
+	track := models.Track{
+		ArtistNames: []string{t.Creator},
+		ReleaseName: t.Album,
+		TrackName:   t.Title,
+		TrackNumber: t.TrackNum,
+		Duration:    time.Duration(t.Duration) * time.Millisecond,
+	}
+
+	for _, id := range t.Identifier {
+		if strings.HasPrefix(id, recordingMBIDPrefix) {
+			track.RecordingMBID = mbtypes.MBID(id[len(recordingMBIDPrefix):])
+		}
+	}
+
+	addedAt, err := readMusicBrainzExtension(t, &track)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return &track, addedAt, nil
+}
+
 func makeMusicBrainzExtension(t models.Track) jspf.MusicBrainzTrackExtension {
 	extension := jspf.MusicBrainzTrackExtension{
 		AdditionalMetadata: t.AdditionalInfo,
@@ -164,11 +268,11 @@ func makeMusicBrainzExtension(t models.Track) jspf.MusicBrainzTrackExtension {
 	}
 
 	for i, mbid := range t.ArtistMBIDs {
-		extension.ArtistIdentifiers[i] = "https://musicbrainz.org/artist/" + string(mbid)
+		extension.ArtistIdentifiers[i] = artistMBIDPrefix + string(mbid)
 	}
 
 	if t.ReleaseMBID != "" {
-		extension.ReleaseIdentifier = "https://musicbrainz.org/release/" + string(t.ReleaseMBID)
+		extension.ReleaseIdentifier = releaseMBIDPrefix + string(t.ReleaseMBID)
 	}
 
 	// The tracknumber tag would be redundant
@@ -177,6 +281,25 @@ func makeMusicBrainzExtension(t models.Track) jspf.MusicBrainzTrackExtension {
 	return extension
 }
 
+func readMusicBrainzExtension(jspfTrack jspf.Track, outputTrack *models.Track) (*time.Time, error) {
+	ext := jspf.MusicBrainzTrackExtension{}
+	err := jspfTrack.Extension.Get(jspf.MusicBrainzTrackExtensionID, &ext)
+	if err != nil {
+		return nil, errors.New("missing MusicBrainz track extension")
+	}
+
+	outputTrack.AdditionalInfo = ext.AdditionalMetadata
+	outputTrack.ReleaseMBID = mbtypes.MBID(ext.ReleaseIdentifier)
+	outputTrack.ArtistMBIDs = make([]mbtypes.MBID, len(ext.ArtistIdentifiers))
+	for i, mbid := range ext.ArtistIdentifiers {
+		if strings.HasPrefix(mbid, artistMBIDPrefix) {
+			outputTrack.ArtistMBIDs[i] = mbtypes.MBID(mbid[len(artistMBIDPrefix):])
+		}
+	}
+
+	return &ext.AddedAt, nil
+}
+
 func (b *JSPFBackend) readJSPF() error {
 	if b.append {
 		file, err := os.Open(b.filePath)

pkg/jspf/extensions.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2023 Philipp Wolfer <phw@uploadedlobster.com>
+Copyright © 2023-2025 Philipp Wolfer <phw@uploadedlobster.com>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -22,7 +22,28 @@ THE SOFTWARE.
 
 package jspf
 
-import "time"
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+)
+
+// Represents a JSPF extension
+type Extension any
+
+// A map of JSPF extensions
+type ExtensionMap map[string]Extension
+
+// Parses the extension with the given ID and unmarshals it into "v".
+// If the extensions is not found or the data cannot be unmarshalled,
+// an error is returned.
+func (e ExtensionMap) Get(id string, v any) error {
+	ext, ok := e[id]
+	if !ok {
+		return fmt.Errorf("extension %q not found", id)
+	}
+	return unmarshalExtension(ext, v)
+}
 
 const (
 	// The identifier for the MusicBrainz / ListenBrainz JSPF playlist extension
@@ -83,3 +104,11 @@ type MusicBrainzTrackExtension struct {
 	// this document.
 	AdditionalMetadata map[string]any `json:"additional_metadata,omitempty"`
 }
+
+func unmarshalExtension(ext Extension, v any) error {
+	asJson, err := json.Marshal(ext)
+	if err != nil {
+		return err
+	}
+	return json.Unmarshal(asJson, v)
+}

pkg/jspf/extensions_test.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2023 Philipp Wolfer <phw@uploadedlobster.com>
+Copyright © 2023-2025 Philipp Wolfer <phw@uploadedlobster.com>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -26,6 +26,7 @@ import (
 	"bytes"
 	"fmt"
 	"log"
+	"testing"
 	"time"
 
 	"go.uploadedlobster.com/scotty/pkg/jspf"
@@ -38,7 +39,7 @@ func ExampleMusicBrainzTrackExtension() {
 			Tracks: []jspf.Track{
 				{
 					Title: "Oweynagat",
-					Extension: map[string]any{
+					Extension: jspf.ExtensionMap{
 						jspf.MusicBrainzTrackExtensionID: jspf.MusicBrainzTrackExtension{
 							AddedAt: time.Date(2023, 11, 24, 07, 47, 50, 0, time.UTC),
 							AddedBy: "scotty",
@@ -72,3 +73,29 @@ func ExampleMusicBrainzTrackExtension() {
 	// 	}
 	// }
 }
+
+func TestExtensionMapGet(t *testing.T) {
+	ext := jspf.ExtensionMap{
+		jspf.MusicBrainzTrackExtensionID: jspf.MusicBrainzTrackExtension{
+			AddedAt: time.Date(2023, 11, 24, 07, 47, 50, 0, time.UTC),
+			AddedBy: "scotty",
+		},
+	}
+	var trackExt jspf.MusicBrainzTrackExtension
+	err := ext.Get(jspf.MusicBrainzTrackExtensionID, &trackExt)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if trackExt.AddedBy != "scotty" {
+		t.Fatalf("expected 'scotty', got '%s'", trackExt.AddedBy)
+	}
+}
+
+func TestExtensionMapGetNotFound(t *testing.T) {
+	ext := jspf.ExtensionMap{}
+	var trackExt jspf.MusicBrainzTrackExtension
+	err := ext.Get(jspf.MusicBrainzTrackExtensionID, &trackExt)
+	if err == nil {
+		t.Fatal("expected ExtensionMap.Get to return an error")
+	}
+}

pkg/jspf/models.go

@@ -1,5 +1,5 @@
 /*
-Copyright © 2023 Philipp Wolfer <phw@uploadedlobster.com>
+Copyright © 2023-2025 Philipp Wolfer <phw@uploadedlobster.com>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -32,35 +32,35 @@ type JSPF struct {
 }
 
 type Playlist struct {
-	Title       string         `json:"title,omitempty"`
-	Creator     string         `json:"creator,omitempty"`
-	Annotation  string         `json:"annotation,omitempty"`
-	Info        string         `json:"info,omitempty"`
-	Location    string         `json:"location,omitempty"`
-	Identifier  string         `json:"identifier,omitempty"`
-	Image       string         `json:"image,omitempty"`
-	Date        time.Time      `json:"date,omitempty"`
-	License     string         `json:"license,omitempty"`
-	Attribution []Attribution  `json:"attribution,omitempty"`
-	Links       []Link         `json:"link,omitempty"`
-	Meta        []Meta         `json:"meta,omitempty"`
-	Extension   map[string]any `json:"extension,omitempty"`
-	Tracks      []Track        `json:"track"`
+	Title       string        `json:"title,omitempty"`
+	Creator     string        `json:"creator,omitempty"`
+	Annotation  string        `json:"annotation,omitempty"`
+	Info        string        `json:"info,omitempty"`
+	Location    string        `json:"location,omitempty"`
+	Identifier  string        `json:"identifier,omitempty"`
+	Image       string        `json:"image,omitempty"`
+	Date        time.Time     `json:"date,omitempty"`
+	License     string        `json:"license,omitempty"`
+	Attribution []Attribution `json:"attribution,omitempty"`
+	Links       []Link        `json:"link,omitempty"`
+	Meta        []Meta        `json:"meta,omitempty"`
+	Extension   ExtensionMap  `json:"extension,omitempty"`
+	Tracks      []Track       `json:"track"`
 }
 
 type Track struct {
-	Location   []string       `json:"location,omitempty"`
-	Identifier []string       `json:"identifier,omitempty"`
-	Title      string         `json:"title,omitempty"`
-	Creator    string         `json:"creator,omitempty"`
-	Annotation string         `json:"annotation,omitempty"`
-	Info       string         `json:"info,omitempty"`
-	Album      string         `json:"album,omitempty"`
-	TrackNum   int            `json:"trackNum,omitempty"`
-	Duration   int64          `json:"duration,omitempty"`
-	Links      []Link         `json:"link,omitempty"`
-	Meta       []Meta         `json:"meta,omitempty"`
-	Extension  map[string]any `json:"extension,omitempty"`
+	Location   []string     `json:"location,omitempty"`
+	Identifier []string     `json:"identifier,omitempty"`
+	Title      string       `json:"title,omitempty"`
+	Creator    string       `json:"creator,omitempty"`
+	Annotation string       `json:"annotation,omitempty"`
+	Info       string       `json:"info,omitempty"`
+	Album      string       `json:"album,omitempty"`
+	TrackNum   int          `json:"trackNum,omitempty"`
+	Duration   int64        `json:"duration,omitempty"`
+	Links      []Link       `json:"link,omitempty"`
+	Meta       []Meta       `json:"meta,omitempty"`
+	Extension  ExtensionMap `json:"extension,omitempty"`
 }
 
 type Attribution map[string]string