/* Returns true if the game is waiting and userid 
 * has not joined, false otherwise */
export function isWaiting(game, userid) {
  return game.state == "waiting" && game.player1 != userid;
}

/* Lets userid join the given game, throws an error if
 * the game cannot be joined. */
export function joinGame(game, userid) {
  if (!isWaiting(game, userid)) {
    throw Error("Not waiting!");
  }
  if (game.player1 == undefined) {
    game.player1 = userid;
  } else {
    game.player2 = userid;
    game.state = "playing";
  }
}

/* Returns the game state ready to be sent to the client. */
export function toJson(game, userid) {
  // TODO: create a copy of game using structuredClone and
  // set game.myturn=true if the current player is userid.
  return game;
}