update

core/agents/lastfm/agent.go

@@ -0,0 +1,383 @@
+package lastfm
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+	"regexp"
+	"strconv"
+	"strings"
+	"sync"
+
+	"github.com/andybalholm/cascadia"
+	"github.com/navidrome/navidrome/conf"
+	"github.com/navidrome/navidrome/consts"
+	"github.com/navidrome/navidrome/core/agents"
+	"github.com/navidrome/navidrome/core/scrobbler"
+	"github.com/navidrome/navidrome/log"
+	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/utils/cache"
+	"golang.org/x/net/html"
+)
+
+const (
+	lastFMAgentName    = "lastfm"
+	sessionKeyProperty = "LastFMSessionKey"
+)
+
+var ignoredBiographies = []string{
+	// Unknown Artist
+	`<a href="https://www.last.fm/music/`,
+}
+
+type lastfmAgent struct {
+	ds           model.DataStore
+	sessionKeys  *agents.SessionKeys
+	apiKey       string
+	secret       string
+	lang         string
+	client       *client
+	httpClient   httpDoer
+	getInfoMutex sync.Mutex
+}
+
+func lastFMConstructor(ds model.DataStore) *lastfmAgent {
+	if !conf.Server.LastFM.Enabled || conf.Server.LastFM.ApiKey == "" || conf.Server.LastFM.Secret == "" {
+		return nil
+	}
+	l := &lastfmAgent{
+		ds:          ds,
+		lang:        conf.Server.LastFM.Language,
+		apiKey:      conf.Server.LastFM.ApiKey,
+		secret:      conf.Server.LastFM.Secret,
+		sessionKeys: &agents.SessionKeys{DataStore: ds, KeyName: sessionKeyProperty},
+	}
+	hc := &http.Client{
+		Timeout: consts.DefaultHttpClientTimeOut,
+	}
+	chc := cache.NewHTTPClient(hc, consts.DefaultHttpClientTimeOut)
+	l.httpClient = chc
+	l.client = newClient(l.apiKey, l.secret, l.lang, chc)
+	return l
+}
+
+func (l *lastfmAgent) AgentName() string {
+	return lastFMAgentName
+}
+
+var imageRegex = regexp.MustCompile(`u\/(\d+)`)
+
+func (l *lastfmAgent) GetAlbumInfo(ctx context.Context, name, artist, mbid string) (*agents.AlbumInfo, error) {
+	a, err := l.callAlbumGetInfo(ctx, name, artist, mbid)
+	if err != nil {
+		return nil, err
+	}
+
+	return &agents.AlbumInfo{
+		Name:        a.Name,
+		MBID:        a.MBID,
+		Description: a.Description.Summary,
+		URL:         a.URL,
+	}, nil
+}
+
+func (l *lastfmAgent) GetAlbumImages(ctx context.Context, name, artist, mbid string) ([]agents.ExternalImage, error) {
+	a, err := l.callAlbumGetInfo(ctx, name, artist, mbid)
+	if err != nil {
+		return nil, err
+	}
+
+	// Last.fm can return duplicate sizes.
+	seenSizes := map[int]bool{}
+	images := make([]agents.ExternalImage, 0)
+
+	// This assumes that Last.fm returns images with size small, medium, and large.
+	// This is true as of December 29, 2022
+	for _, img := range a.Image {
+		size := imageRegex.FindStringSubmatch(img.URL)
+		// Last.fm can return images without URL
+		if len(size) == 0 || len(size[0]) < 4 {
+			log.Trace(ctx, "LastFM/albuminfo image URL does not match expected regex or is empty", "url", img.URL, "size", img.Size)
+			continue
+		}
+		numericSize, err := strconv.Atoi(size[0][2:])
+		if err != nil {
+			log.Error(ctx, "LastFM/albuminfo image URL does not match expected regex", "url", img.URL, "size", img.Size, err)
+			return nil, err
+		}
+		if _, exists := seenSizes[numericSize]; !exists {
+			images = append(images, agents.ExternalImage{
+				Size: numericSize,
+				URL:  img.URL,
+			})
+			seenSizes[numericSize] = true
+		}
+	}
+	return images, nil
+}
+
+func (l *lastfmAgent) GetArtistMBID(ctx context.Context, id string, name string) (string, error) {
+	a, err := l.callArtistGetInfo(ctx, name)
+	if err != nil {
+		return "", err
+	}
+	if a.MBID == "" {
+		return "", agents.ErrNotFound
+	}
+	return a.MBID, nil
+}
+
+func (l *lastfmAgent) GetArtistURL(ctx context.Context, id, name, mbid string) (string, error) {
+	a, err := l.callArtistGetInfo(ctx, name)
+	if err != nil {
+		return "", err
+	}
+	if a.URL == "" {
+		return "", agents.ErrNotFound
+	}
+	return a.URL, nil
+}
+
+func (l *lastfmAgent) GetArtistBiography(ctx context.Context, id, name, mbid string) (string, error) {
+	a, err := l.callArtistGetInfo(ctx, name)
+	if err != nil {
+		return "", err
+	}
+	a.Bio.Summary = strings.TrimSpace(a.Bio.Summary)
+	if a.Bio.Summary == "" {
+		return "", agents.ErrNotFound
+	}
+	for _, ign := range ignoredBiographies {
+		if strings.HasPrefix(a.Bio.Summary, ign) {
+			return "", nil
+		}
+	}
+	return a.Bio.Summary, nil
+}
+
+func (l *lastfmAgent) GetSimilarArtists(ctx context.Context, id, name, mbid string, limit int) ([]agents.Artist, error) {
+	resp, err := l.callArtistGetSimilar(ctx, name, limit)
+	if err != nil {
+		return nil, err
+	}
+	if len(resp) == 0 {
+		return nil, agents.ErrNotFound
+	}
+	var res []agents.Artist
+	for _, a := range resp {
+		res = append(res, agents.Artist{
+			Name: a.Name,
+			MBID: a.MBID,
+		})
+	}
+	return res, nil
+}
+
+func (l *lastfmAgent) GetArtistTopSongs(ctx context.Context, id, artistName, mbid string, count int) ([]agents.Song, error) {
+	resp, err := l.callArtistGetTopTracks(ctx, artistName, count)
+	if err != nil {
+		return nil, err
+	}
+	if len(resp) == 0 {
+		return nil, agents.ErrNotFound
+	}
+	var res []agents.Song
+	for _, t := range resp {
+		res = append(res, agents.Song{
+			Name: t.Name,
+			MBID: t.MBID,
+		})
+	}
+	return res, nil
+}
+
+var (
+	artistOpenGraphQuery = cascadia.MustCompile(`html > head > meta[property="og:image"]`)
+	artistIgnoredImage   = "2a96cbd8b46e442fc41c2b86b821562f" // Last.fm artist placeholder image name
+)
+
+func (l *lastfmAgent) GetArtistImages(ctx context.Context, _, name, mbid string) ([]agents.ExternalImage, error) {
+	log.Debug(ctx, "Getting artist images from Last.fm", "name", name)
+	a, err := l.callArtistGetInfo(ctx, name)
+	if err != nil {
+		return nil, fmt.Errorf("get artist info: %w", err)
+	}
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, a.URL, nil)
+	if err != nil {
+		return nil, fmt.Errorf("create artist image request: %w", err)
+	}
+	resp, err := l.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("get artist url: %w", err)
+	}
+	defer resp.Body.Close()
+
+	node, err := html.Parse(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("parse html: %w", err)
+	}
+
+	var res []agents.ExternalImage
+	n := cascadia.Query(node, artistOpenGraphQuery)
+	if n == nil {
+		return res, nil
+	}
+	for _, attr := range n.Attr {
+		if attr.Key != "content" {
+			continue
+		}
+		if strings.Contains(attr.Val, artistIgnoredImage) {
+			log.Debug(ctx, "Artist image is ignored default image", "name", name, "url", attr.Val)
+			return res, nil
+		}
+
+		res = []agents.ExternalImage{
+			{URL: attr.Val},
+		}
+	}
+	return res, nil
+}
+
+func (l *lastfmAgent) callAlbumGetInfo(ctx context.Context, name, artist, mbid string) (*Album, error) {
+	a, err := l.client.albumGetInfo(ctx, name, artist, mbid)
+	var lfErr *lastFMError
+	isLastFMError := errors.As(err, &lfErr)
+
+	if mbid != "" && (isLastFMError && lfErr.Code == 6) {
+		log.Debug(ctx, "LastFM/album.getInfo could not find album by mbid, trying again", "album", name, "mbid", mbid)
+		return l.callAlbumGetInfo(ctx, name, artist, "")
+	}
+
+	if err != nil {
+		if isLastFMError && lfErr.Code == 6 {
+			log.Debug(ctx, "Album not found", "album", name, "mbid", mbid, err)
+		} else {
+			log.Error(ctx, "Error calling LastFM/album.getInfo", "album", name, "mbid", mbid, err)
+		}
+		return nil, err
+	}
+	return a, nil
+}
+
+func (l *lastfmAgent) callArtistGetInfo(ctx context.Context, name string) (*Artist, error) {
+	l.getInfoMutex.Lock()
+	defer l.getInfoMutex.Unlock()
+
+	a, err := l.client.artistGetInfo(ctx, name)
+	if err != nil {
+		log.Error(ctx, "Error calling LastFM/artist.getInfo", "artist", name, err)
+		return nil, err
+	}
+	return a, nil
+}
+
+func (l *lastfmAgent) callArtistGetSimilar(ctx context.Context, name string, limit int) ([]Artist, error) {
+	s, err := l.client.artistGetSimilar(ctx, name, limit)
+	if err != nil {
+		log.Error(ctx, "Error calling LastFM/artist.getSimilar", "artist", name, err)
+		return nil, err
+	}
+	return s.Artists, nil
+}
+
+func (l *lastfmAgent) callArtistGetTopTracks(ctx context.Context, artistName string, count int) ([]Track, error) {
+	t, err := l.client.artistGetTopTracks(ctx, artistName, count)
+	if err != nil {
+		log.Error(ctx, "Error calling LastFM/artist.getTopTracks", "artist", artistName, err)
+		return nil, err
+	}
+	return t.Track, nil
+}
+
+func (l *lastfmAgent) getArtistForScrobble(track *model.MediaFile, role model.Role, displayName string) string {
+	if conf.Server.LastFM.ScrobbleFirstArtistOnly && len(track.Participants[role]) > 0 {
+		return track.Participants[role][0].Name
+	}
+	return displayName
+}
+
+func (l *lastfmAgent) NowPlaying(ctx context.Context, userId string, track *model.MediaFile, position int) error {
+	sk, err := l.sessionKeys.Get(ctx, userId)
+	if err != nil || sk == "" {
+		return scrobbler.ErrNotAuthorized
+	}
+
+	err = l.client.updateNowPlaying(ctx, sk, ScrobbleInfo{
+		artist:      l.getArtistForScrobble(track, model.RoleArtist, track.Artist),
+		track:       track.Title,
+		album:       track.Album,
+		trackNumber: track.TrackNumber,
+		mbid:        track.MbzRecordingID,
+		duration:    int(track.Duration),
+		albumArtist: l.getArtistForScrobble(track, model.RoleAlbumArtist, track.AlbumArtist),
+	})
+	if err != nil {
+		log.Warn(ctx, "Last.fm client.updateNowPlaying returned error", "track", track.Title, err)
+		return errors.Join(err, scrobbler.ErrUnrecoverable)
+	}
+	return nil
+}
+
+func (l *lastfmAgent) Scrobble(ctx context.Context, userId string, s scrobbler.Scrobble) error {
+	sk, err := l.sessionKeys.Get(ctx, userId)
+	if err != nil || sk == "" {
+		return errors.Join(err, scrobbler.ErrNotAuthorized)
+	}
+
+	if s.Duration <= 30 {
+		log.Debug(ctx, "Skipping Last.fm scrobble for short song", "track", s.Title, "duration", s.Duration)
+		return nil
+	}
+	err = l.client.scrobble(ctx, sk, ScrobbleInfo{
+		artist:      l.getArtistForScrobble(&s.MediaFile, model.RoleArtist, s.Artist),
+		track:       s.Title,
+		album:       s.Album,
+		trackNumber: s.TrackNumber,
+		mbid:        s.MbzRecordingID,
+		duration:    int(s.Duration),
+		albumArtist: l.getArtistForScrobble(&s.MediaFile, model.RoleAlbumArtist, s.AlbumArtist),
+		timestamp:   s.TimeStamp,
+	})
+	if err == nil {
+		return nil
+	}
+	var lfErr *lastFMError
+	isLastFMError := errors.As(err, &lfErr)
+	if !isLastFMError {
+		log.Warn(ctx, "Last.fm client.scrobble returned error", "track", s.Title, err)
+		return errors.Join(err, scrobbler.ErrRetryLater)
+	}
+	if lfErr.Code == 11 || lfErr.Code == 16 {
+		return errors.Join(err, scrobbler.ErrRetryLater)
+	}
+	return errors.Join(err, scrobbler.ErrUnrecoverable)
+}
+
+func (l *lastfmAgent) IsAuthorized(ctx context.Context, userId string) bool {
+	sk, err := l.sessionKeys.Get(ctx, userId)
+	return err == nil && sk != ""
+}
+
+func init() {
+	conf.AddHook(func() {
+		agents.Register(lastFMAgentName, func(ds model.DataStore) agents.Interface {
+			// This is a workaround for the fact that a (Interface)(nil) is not the same as a (*lastfmAgent)(nil)
+			// See https://go.dev/doc/faq#nil_error
+			a := lastFMConstructor(ds)
+			if a != nil {
+				return a
+			}
+			return nil
+		})
+		scrobbler.Register(lastFMAgentName, func(ds model.DataStore) scrobbler.Scrobbler {
+			// Same as above - this is a workaround for the fact that a (Scrobbler)(nil) is not the same as a (*lastfmAgent)(nil)
+			// See https://go.dev/doc/faq#nil_error
+			a := lastFMConstructor(ds)
+			if a != nil {
+				return a
+			}
+			return nil
+		})
+	})
+}