'use strict';

const Multiplayer = (() => {
  let ws = null;
  let asHost = false;
  let gameId = null;
  let myMark = null;
  let myTurn = false;
  let board = Array(9).fill(null);
  let gameOver = false;
  let scores = { you: 0, opponent: 0, draws: 0 };

  function connect(url) {
    return new Promise((resolve, reject) => {
      ws = new WebSocket(url);
      ws.onopen = () => {
        if (asHost) {
          ws.send(JSON.stringify({ type: 'host', id: gameId }));
        } else {
          ws.send(JSON.stringify({ type: 'join', token: gameId }));
        }
        resolve();
      };
      ws.onerror = (e) => {
        App.showToast('Connection failed');
        reject(e);
      };
      ws.onclose = () => {
        if (!gameOver) {
          App.renderStatus('Connection lost', 'normal');
        }
      };
      ws.onmessage = (event) => {
        const msg = JSON.parse(event.data);
        handleMessage(msg);
      };
    });
  }

  function handleMessage(msg) {
    switch (msg.type) {
      case 'joined':
        myMark = msg.mark;
        myTurn = msg.mark === 'X';
        App.setScoreboardLabels(
          myMark === 'X' ? 'You (X)' : 'Opponent (X)',
          myMark === 'O' ? 'You (O)' : 'Opponent (O)'
        );
        App.renderStatus(myTurn ? 'Your turn' : 'Waiting for opponent…', myTurn ? 'normal' : 'thinking');
        break;

      case 'opponent-joined':
        App.showScreen('game');
        App.setScoreboardLabels(
          myMark === 'X' ? 'You (X)' : 'Opponent (X)',
          myMark === 'O' ? 'You (O)' : 'Opponent (O)'
        );
        App.renderStatus('Your turn', 'normal');
        myTurn = true;
        break;

      case 'start':
        board = Array(9).fill(null);
        gameOver = false;
        myMark = msg.mark;
        myTurn = msg.first === myMark;
        App.setScoreboardLabels(
          myMark === 'X' ? 'You (X)' : 'Opponent (X)',
          myMark === 'O' ? 'You (O)' : 'Opponent (O)'
        );
        App.clearBoard();
        App.renderStatus(myTurn ? 'Your turn' : 'Waiting for opponent…', myTurn ? 'normal' : 'thinking');
        break;

      case 'move': {
        board[msg.index] = msg.mark;
        App.renderMark(msg.index, msg.mark);
        if (!gameOver && msg.mark !== myMark) {
          myTurn = !myTurn;
          App.renderStatus(myTurn ? 'Your turn' : 'Opponent is thinking…', myTurn ? 'normal' : 'thinking');
        }
        break;
      }

      case 'end':
        gameOver = true;
        if (msg.winner === 'draw') {
          scores.draws++;
          App.renderStatus("It's a draw", 'normal');
          document.getElementById('board').classList.add('pulse');
        } else {
          const iWon = msg.winner === myMark;
          scores[iWon ? 'you' : 'opponent']++;
          App.renderStatus(iWon ? 'You win!' : 'Opponent wins', 'normal');
          if (!iWon) document.getElementById('board').classList.add('shake');
        }
        App.renderScores(scores);
        if (msg.line) App.drawWinLine(msg.line);
        setTimeout(() => {
          const title = msg.winner === 'draw' ? "It's a Draw" : (msg.winner === myMark ? 'You Win!' : 'Opponent Wins');
          App.showOverlay(title);
          if (msg.winner === myMark) App.burstConfetti();
        }, 600);
        break;

      case 'new-round':
        board = Array(9).fill(null);
        gameOver = false;
        myTurn = msg.first === myMark;
        App.hideOverlay();
        App.clearBoard();
        App.renderStatus(myTurn ? 'Your turn' : 'Waiting for opponent…', myTurn ? 'normal' : 'thinking');
        break;

    case 'opponent-left':
      gameOver = true;
      App.renderStatus('Opponent left', 'error');
      break;

      case 'error':
        App.showToast(msg.message || 'Error');
        break;
    }
  }

  function handleMove(i) {
    if (gameOver || !myTurn || board[i] || myMark === null) return;
    board[i] = myMark;
    App.renderMark(i, myMark);
    ws.send(JSON.stringify({ type: 'move', index: i }));
    myTurn = false;
    App.renderStatus('Waiting for opponent…', 'thinking');
  }

  function newRound() {
    ws.send(JSON.stringify({ type: 'new-round' }));
  }

  function destroy() {
    if (ws) {
      ws.close();
      ws = null;
    }
    myMark = null;
    myTurn = false;
    board = Array(9).fill(null);
    gameOver = false;
    scores = { you: 0, opponent: 0, draws: 0 };
  }

  function init(opts) {
    asHost = opts.asHost;
    gameId = opts.asHost ? opts.id : opts.token;
    const base = location.pathname === '/' ? '' : location.pathname.replace(/\/$/, '');
    const wsUrl = (location.protocol === 'https:' ? 'wss://' : 'ws://') + location.host + base + '/ws';
    connect(wsUrl).catch((err) => {
      console.error('Connection failed:', err);
      App.renderStatus('Connection failed', 'error');
    });
  }

  return { init, handleMove, newRound, destroy };
})();