feat: backfill duration from musicbrainz (#135)

* feat: backfill durations from musicbrainz

* chore: make request body dump info level

internal/catalog/duration.go

@@ -0,0 +1,84 @@
+package catalog
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/gabehf/koito/internal/db"
+	"github.com/gabehf/koito/internal/logger"
+	"github.com/gabehf/koito/internal/mbz"
+	"github.com/google/uuid"
+)
+
+func BackfillTrackDurationsFromMusicBrainz(
+	ctx context.Context,
+	store db.DB,
+	mbzCaller mbz.MusicBrainzCaller,
+) error {
+	l := logger.FromContext(ctx)
+	l.Info().Msg("BackfillTrackDurationsFromMusicBrainz: Starting backfill of track durations from MusicBrainz")
+
+	var from int32 = 0
+
+	for {
+		tracks, err := store.GetTracksWithNoDurationButHaveMbzID(ctx, from)
+		if err != nil {
+			return fmt.Errorf("BackfillTrackDurationsFromMusicBrainz: failed to fetch tracks for duration backfill: %w", err)
+		}
+
+		// nil, nil means no more results
+		if len(tracks) == 0 {
+			if from == 0 {
+				l.Info().Msg("BackfillTrackDurationsFromMusicBrainz: No tracks need updating. Skipping backfill...")
+			} else {
+				l.Info().Msg("BackfillTrackDurationsFromMusicBrainz: Backfill complete")
+			}
+			return nil
+		}
+
+		for _, track := range tracks {
+			from = track.ID
+
+			if track.MbzID == nil || *track.MbzID == uuid.Nil {
+				continue
+			}
+
+			l.Debug().
+				Str("title", track.Title).
+				Str("mbz_id", track.MbzID.String()).
+				Msg("BackfillTrackDurationsFromMusicBrainz: Backfilling duration from MusicBrainz")
+
+			mbzTrack, err := mbzCaller.GetTrack(ctx, *track.MbzID)
+			if err != nil {
+				l.Err(err).
+					Str("title", track.Title).
+					Msg("BackfillTrackDurationsFromMusicBrainz: Failed to fetch track from MusicBrainz")
+				continue
+			}
+
+			if mbzTrack.LengthMs <= 0 {
+				l.Debug().
+					Str("title", track.Title).
+					Msg("BackfillTrackDurationsFromMusicBrainz: MusicBrainz track has no duration")
+				continue
+			}
+
+			durationSeconds := int32(mbzTrack.LengthMs / 1000)
+
+			err = store.UpdateTrack(ctx, db.UpdateTrackOpts{
+				ID:       track.ID,
+				Duration: durationSeconds,
+			})
+			if err != nil {
+				l.Err(err).
+					Str("title", track.Title).
+					Msg("BackfillTrackDurationsFromMusicBrainz: Failed to update track duration")
+			} else {
+				l.Info().
+					Str("title", track.Title).
+					Int32("duration_seconds", durationSeconds).
+					Msg("BackfillTrackDurationsFromMusicBrainz: Track duration backfilled successfully")
+			}
+		}
+	}
+}