-- +goose Up
CREATE TABLE playlists (
  id uuid PRIMARY KEY,
  user_id uuid NOT NULL REFERENCES users(id) ON DELETE CASCADE,
  name text NOT NULL CHECK (char_length(name) BETWEEN 1 AND 120),
  description text NOT NULL DEFAULT '' CHECK (char_length(description) <= 2000),
  revision integer NOT NULL DEFAULT 1,
  created_at timestamptz NOT NULL DEFAULT now(),
  updated_at timestamptz NOT NULL DEFAULT now()
);
CREATE INDEX playlists_owner ON playlists(user_id, updated_at DESC, id);
CREATE TABLE playlist_tracks (
  playlist_id uuid NOT NULL REFERENCES playlists(id) ON DELETE CASCADE,
  track_id uuid NOT NULL REFERENCES tracks(id) ON DELETE CASCADE,
  position integer NOT NULL CHECK (position >= 0),
  PRIMARY KEY (playlist_id, track_id),
  UNIQUE (playlist_id, position)
);
CREATE INDEX playlist_tracks_track ON playlist_tracks(track_id);

-- +goose Down
DROP TABLE playlist_tracks;
DROP TABLE playlists;