import { RCON_CHAT_MESSAGE } from 'squad-server/events/rcon';

function shuffle(array) {
  let currentIndex = array.length;
  let temporaryValue;
  let randomIndex;

  // While there remain elements to shuffle...
  while (currentIndex !== 0) {
    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;

    // And swap it with the current element.
    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }

  return array;
}

export default function(server, options = {}) {
  if (!server)
    throw new Error(
      'TeamRandomizer must be provided with a reference to the server.'
    );

  const command = options.command || '!randomize';
  const commandRegex = new RegExp(`^${command}`, 'i');

  server.on(RCON_CHAT_MESSAGE, info => {
    if (info.chat !== 'ChatAdmin') return;

    const match = info.message.match(commandRegex);
    if (!match) return;

    const players = server.players.slice(0);
    shuffle(players);

    let team = '1';

    for (const player of players) {
      if (player.teamID !== team) {
        server.rcon.execute(`AdminForceTeamChange "${player.steamID}"`);
      }

      team = team === '1' ? '2' : '1';
    }
  });
}