CREATE TABLE IF NOT EXISTS users (
  id INTEGER PRIMARY KEY,
  email TEXT UNIQUE NOT NULL,
  display_name TEXT NOT NULL,
  password_hash TEXT NOT NULL,
  role TEXT NOT NULL DEFAULT 'user' CHECK(role IN ('user','admin')),
  created_at TEXT NOT NULL DEFAULT (datetime('now'))
);

CREATE TABLE IF NOT EXISTS songs (
  id INTEGER PRIMARY KEY,
  title TEXT NOT NULL,
  artist TEXT NOT NULL,
  album TEXT,
  genre TEXT,
  year INTEGER,
  duration_seconds INTEGER,
  audio_path TEXT NOT NULL,
  cover_path TEXT,
  is_public INTEGER NOT NULL DEFAULT 1,
  uploaded_by INTEGER REFERENCES users(id),
  created_at TEXT NOT NULL DEFAULT (datetime('now'))
);
CREATE INDEX IF NOT EXISTS idx_songs_artist ON songs(artist);
CREATE INDEX IF NOT EXISTS idx_songs_public ON songs(is_public);
CREATE INDEX IF NOT EXISTS idx_songs_created ON songs(created_at DESC);

CREATE TABLE IF NOT EXISTS playlists (
  id INTEGER PRIMARY KEY,
  title TEXT NOT NULL,
  description TEXT,
  cover_path TEXT,
  is_public INTEGER NOT NULL DEFAULT 1,
  created_by INTEGER REFERENCES users(id),
  created_at TEXT NOT NULL DEFAULT (datetime('now'))
);
CREATE INDEX IF NOT EXISTS idx_playlists_public ON playlists(is_public);

CREATE TABLE IF NOT EXISTS playlist_songs (
  playlist_id INTEGER NOT NULL REFERENCES playlists(id) ON DELETE CASCADE,
  song_id INTEGER NOT NULL REFERENCES songs(id) ON DELETE CASCADE,
  position INTEGER NOT NULL,
  PRIMARY KEY (playlist_id, song_id)
);
CREATE INDEX IF NOT EXISTS idx_playlist_songs_order ON playlist_songs(playlist_id, position);