first commit

apps/backend/internal/provider/mapper.go

@@ -0,0 +1,105 @@
+package provider
+
+import (
+	"strings"
+
+	"github.com/tdvorak/spotifyrecalg/apps/backend/internal/provider/musicbrainz"
+	"github.com/tdvorak/spotifyrecalg/apps/backend/internal/provider/spotify"
+	"github.com/tdvorak/spotifyrecalg/apps/backend/internal/recommendation"
+)
+
+func mapSpotifyTrack(track spotify.Track, features spotify.AudioFeatures, mb musicbrainz.Recording, missingFeatures bool) recommendation.Track {
+	artist := ""
+	if len(track.Artists) > 0 {
+		artist = track.Artists[0].Name
+	}
+
+	spotifyURL := "https://open.spotify.com/track/" + track.ID
+	external := map[string]string{
+		"source":      ProviderSpotify,
+		"spotify_id":  track.ID,
+		"spotify":     spotifyURL,
+		"spotify_url": spotifyURL,
+	}
+	if value := strings.TrimSpace(track.ExternalURLs["spotify"]); value != "" {
+		external["spotify"] = value
+		external["spotify_url"] = value
+	}
+	if isrc := strings.ToUpper(strings.TrimSpace(track.ExternalIDs["isrc"])); isrc != "" {
+		external["isrc"] = isrc
+	}
+	if len(track.Album.Images) > 0 && track.Album.Images[0].URL != "" {
+		external["image_url"] = track.Album.Images[0].URL
+		external["spotify_image_url"] = track.Album.Images[0].URL
+	}
+	if missingFeatures {
+		external["features_missing"] = "true"
+	}
+	if mb.ID != "" {
+		external["musicbrainz_recording_id"] = mb.ID
+	}
+	if mb.ArtistID != "" {
+		external["musicbrainz_artist_id"] = mb.ArtistID
+	}
+	if mb.ISRC != "" && external["isrc"] == "" {
+		external["isrc"] = mb.ISRC
+	}
+
+	genres := mergeStrings(nil, mb.Genres...)
+	genres = mergeStrings(genres, mb.Tags...)
+
+	return recommendation.Track{
+		ID:          "spotify:track:" + track.ID,
+		Title:       track.Name,
+		Artist:      artist,
+		Album:       track.Album.Name,
+		Genres:      genres,
+		ReleaseDate: track.Album.ReleaseDate,
+		DurationMS:  track.DurationMS,
+		Popularity:  clamp01(float64(track.Popularity) / 100),
+		Explicit:    track.Explicit,
+		Features: recommendation.AudioFeatures{
+			Danceability:     features.Danceability,
+			Energy:           features.Energy,
+			Loudness:         features.Loudness,
+			Speechiness:      features.Speechiness,
+			Acousticness:     features.Acousticness,
+			Instrumentalness: features.Instrumentalness,
+			Liveness:         features.Liveness,
+			Valence:          features.Valence,
+			Tempo:            features.Tempo,
+			TimeSignature:    features.TimeSignature,
+			Key:              features.Key,
+			Mode:             features.Mode,
+		},
+		External:         external,
+		DiscoveryAllowed: true,
+	}
+}
+
+func mergeStrings(values []string, next ...string) []string {
+	seen := make(map[string]struct{}, len(values)+len(next))
+	out := make([]string, 0, len(values)+len(next))
+	for _, value := range append(values, next...) {
+		value = strings.ToLower(strings.TrimSpace(value))
+		if value == "" {
+			continue
+		}
+		if _, ok := seen[value]; ok {
+			continue
+		}
+		seen[value] = struct{}{}
+		out = append(out, value)
+	}
+	return out
+}
+
+func clamp01(value float64) float64 {
+	if value < 0 {
+		return 0
+	}
+	if value > 1 {
+		return 1
+	}
+	return value
+}