-- Playlists
CREATE TABLE playlists (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id uuid NOT NULL REFERENCES auth.users(id) ON DELETE CASCADE,
  name text NOT NULL,
  description text,
  cover_url text,
  is_public boolean NOT NULL DEFAULT true,
  created_at timestamptz NOT NULL DEFAULT now()
);

ALTER TABLE playlists ENABLE ROW LEVEL SECURITY;

CREATE POLICY "Anyone can view public playlists"
  ON playlists FOR SELECT
  USING (is_public = true OR user_id = auth.uid());

CREATE POLICY "Users can manage their own playlists"
  ON playlists FOR ALL
  USING (user_id = auth.uid())
  WITH CHECK (user_id = auth.uid());

-- Playlist items
CREATE TABLE playlist_items (
  id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
  playlist_id uuid NOT NULL REFERENCES playlists(id) ON DELETE CASCADE,
  podcast_id uuid NOT NULL REFERENCES podcasts(id) ON DELETE CASCADE,
  sort_order integer NOT NULL DEFAULT 0,
  added_at timestamptz NOT NULL DEFAULT now(),
  UNIQUE (playlist_id, podcast_id)
);

ALTER TABLE playlist_items ENABLE ROW LEVEL SECURITY;

CREATE POLICY "Anyone can view items of visible playlists"
  ON playlist_items FOR SELECT
  USING (
    EXISTS (
      SELECT 1 FROM playlists
      WHERE playlists.id = playlist_items.playlist_id
      AND (playlists.is_public = true OR playlists.user_id = auth.uid())
    )
  );

CREATE POLICY "Playlist owners can manage items"
  ON playlist_items FOR ALL
  USING (
    EXISTS (
      SELECT 1 FROM playlists
      WHERE playlists.id = playlist_items.playlist_id
      AND playlists.user_id = auth.uid()
    )
  )
  WITH CHECK (
    EXISTS (
      SELECT 1 FROM playlists
      WHERE playlists.id = playlist_items.playlist_id
      AND playlists.user_id = auth.uid()
    )
  );