minstrel/internal/db/migrations/0025_library_changes.up.sql

-- Append-only change log for library entities. Every mutation on
-- artists/albums/tracks/likes/playlists/playlist_tracks writes a row
-- in the same transaction as the mutation itself. Powers the delta-sync
-- endpoint — clients pass back the last-seen `id` as a cursor.
--
-- Retention: not capped here. A cursor older than what the table keeps gets
-- the reset path (410).

CREATE TABLE library_changes (
  id BIGSERIAL PRIMARY KEY,
  entity_type TEXT NOT NULL CHECK (entity_type IN (
    'artist', 'album', 'track', 'like_track', 'like_album', 'like_artist',
    'playlist', 'playlist_track'
  )),
  entity_id TEXT NOT NULL,
  op TEXT NOT NULL CHECK (op IN ('upsert', 'delete')),
  changed_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX idx_library_changes_id ON library_changes(id);