'use strict';

/* ---------- DOM-referenties ---------- */
const boardCanvas = document.getElementById('canvas-board');
const holdCanvas = document.getElementById('canvas-hold');
const nextCanvas = document.getElementById('canvas-next');

const elScore = document.getElementById('stat-score');
const elLines = document.getElementById('stat-lines');
const elLevel = document.getElementById('stat-level');

const overlay = document.getElementById('overlay');
const overlayTitle = document.getElementById('overlay-title');
const overlaySub = document.getElementById('overlay-sub');
const nameForm = document.getElementById('name-form');
const nameInput = document.getElementById('name-input');
const nameError = document.getElementById('name-error');
const submitBtn = document.getElementById('btn-submit');
const btnPrimary = document.getElementById('btn-primary');
const btnSecondary = document.getElementById('btn-secondary');

const highscoreList = document.getElementById('highscore-list');

const game = new TetrisGame();
game.onUpdate = renderUI;

let gameOverHandled = false;

/* ---------- highscore-opslag in localStorage ---------- */
function loadScores() {
  try {
    const raw = localStorage.getItem(CONSTANTS.HIGHSCORE_KEY);
    const list = raw ? JSON.parse(raw) : [];
    return Array.isArray(list) ? list : [];
  } catch (e) {
    return [];
  }
}

function saveScores(list) {
  try {
    localStorage.setItem(
      CONSTANTS.HIGHSCORE_KEY,
      JSON.stringify(list.slice(0, CONSTANTS.MAX_HIGHSCORES))
    );
  } catch (e) {
    /* opslag niet beschikbaar (bv. private browsing) - negeren */
  }
}

function qualifies(score) {
  if (score <= 0) return false;
  const list = loadScores();
  if (list.length < CONSTANTS.MAX_HIGHSCORES) return true;
  return score > list[list.length - 1].score;
}

function recordScore(name, score, lines, level) {
  const list = loadScores();
  const entry = {
    name: name || 'Speler',
    score,
    lines,
    level,
    date: new Date().toISOString()
  };
  list.push(entry);
  list.sort((a, b) => b.score - a.score || a.date.localeCompare(b.date));
  saveScores(list);
  return list;
}

function escapeHtml(str) {
  return String(str)
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;');
}

function renderHighscores() {
  const list = loadScores();
  highscoreList.innerHTML = '';
  if (list.length === 0) {
    const li = document.createElement('li');
    li.className = 'no-scores';
    li.textContent = 'Nog geen scores - wees de eerste!';
    highscoreList.appendChild(li);
    return;
  }
  list.forEach((entry, i) => {
    const li = document.createElement('li');
    const rank = document.createElement('span');
    rank.className = 'hs-rank';
    rank.textContent = i + 1;
    const name = document.createElement('span');
    name.className = 'hs-name';
    name.textContent = entry.name;
    const score = document.createElement('span');
    score.className = 'hs-score';
    score.textContent = entry.score;
    li.appendChild(rank);
    li.appendChild(name);
    li.appendChild(score);
    highscoreList.appendChild(li);
  });
}

/* ---------- UI-panelen verversen ---------- */
function renderUI() {
  elScore.textContent = game.score;
  elLines.textContent = game.lines;
  elLevel.textContent = game.level;
  drawHold(holdCanvas, game.hold);
  drawNext(nextCanvas, game);
}


/* ---------- overlays (pauze / game over) ---------- */
function setOverlay(title, sub, opts = {}) {
  overlayTitle.textContent = title;
  overlaySub.textContent = sub || '';
  nameForm.classList.toggle('hidden', !opts.showName);
  btnPrimary.textContent = opts.primaryLabel || 'Opnieuw spelen';
  btnSecondary.classList.toggle('hidden', !opts.showSecondary);
  overlay.classList.remove('hidden');
}

function hideOverlay() {
  overlay.classList.add('hidden');
}

function togglePause() {
  if (game.over) return;
  game.paused = !game.paused;
  if (game.paused) {
    setOverlay('PAUZE', 'Druk op P of "Doorgaan" om verder te spelen.', {
      showSecondary: true,
      primaryLabel: 'Opnieuw spelen'
    });
  } else {
    hideOverlay();
  }
}

function restartGame() {
  game.reset();
  game.paused = false;
  gameOverHandled = false;
  nameForm.classList.add('hidden');
  nameError.classList.add('hidden');
  hideOverlay();
  renderUI();
}

function onGameOver() {
  const topTen = qualifies(game.score);
  if (topTen) {
    nameInput.value = localStorage.getItem(CONSTANTS.PLAYER_NAME_KEY) || '';
    setOverlay('GAME OVER', 'Top 10! Voer je naam in:', {
      showName: true,
      primaryLabel: 'Opnieuw spelen'
    });
    nameInput.focus();
  } else {
    setOverlay('GAME OVER', `Score: ${game.score}`, {
      primaryLabel: 'Opnieuw spelen'
    });
  }
  renderHighscores();
}

function handleSubmitScore() {
  const name = nameInput.value.trim();
  if (!name) {
    nameError.classList.remove('hidden');
    nameInput.focus();
    return;
  }
  localStorage.setItem(CONSTANTS.PLAYER_NAME_KEY, name);
  recordScore(name.slice(0, 12), game.score, game.lines, game.level);
  nameForm.classList.add('hidden');
  overlaySub.textContent = 'Score opgeslagen in de highscore-lijst!';
  renderHighscores();
  btnPrimary.focus();
}

/* ---------- game-loop ---------- */
let lastTime = performance.now();

function loop(now) {
  const dt = Math.min((now - lastTime) / 1000, 0.25);
  lastTime = now;

  game.update(dt * 1000);
  drawBoard(boardCanvas, game);
  renderUI();

  if (game.over && !gameOverHandled) {
    gameOverHandled = true;
    onGameOver();
  }

  requestAnimationFrame(loop);
}

/* ---------- toetsenbord ---------- */
const KEYMAP = {
  ArrowLeft: { fn: () => game.move(-1), prevent: true },
  ArrowRight: { fn: () => game.move(1), prevent: true },
  ArrowDown: { fn: () => game.softDrop(), prevent: true },
  ArrowUp: { fn: () => game.rotate(1), prevent: true },
  KeyX: { fn: () => game.rotate(1), prevent: true },
  KeyZ: { fn: () => game.rotate(-1), prevent: false },
  Space: { fn: () => game.hardDrop(), prevent: true },
  KeyC: { fn: () => game.holdPiece(), prevent: false },
  KeyP: { fn: () => togglePause(), prevent: false },
  KeyR: { fn: () => restartGame(), prevent: false }
};

window.addEventListener('keydown', (event) => {
  // typen in het naamveld: alleen Enter voor opslaan
  if (event.target === nameInput) {
    if (event.key === 'Enter') {
      event.preventDefault();
      handleSubmitScore();
    }
    return;
  }

  if (event.key === 'Enter' && !overlay.classList.contains('hidden')) {
    if (game.over) restartGame();
    else if (game.paused) togglePause();
    return;
  }

  const binding = KEYMAP[event.code];
  if (!binding) return;
  if (binding.prevent) event.preventDefault();
  binding.fn();
});

/* ---------- knoppen + touch-controls ---------- */
btnPrimary.addEventListener('click', () => restartGame());
btnSecondary.addEventListener('click', () => {
  if (game.paused) togglePause();
});
submitBtn.addEventListener('click', handleSubmitScore);
// voorkom dat Enter in het naamveld de pagina ververst (default form-submit)
nameForm.addEventListener('submit', (e) => {
  e.preventDefault();
  handleSubmitScore();
});

const ACTION_MAP = {
  rotate: () => game.rotate(1),
  rotateCcw: () => game.rotate(-1),
  hold: () => game.holdPiece(),
  hard: () => game.hardDrop(),
  left: () => game.move(-1),
  right: () => game.move(1),
  drop: () => game.softDrop()
};

document.querySelectorAll('.t-btn').forEach((btn) => {
  btn.addEventListener('click', () => {
    if (ACTION_MAP[btn.dataset.action]) ACTION_MAP[btn.dataset.action]();
  });
});

/* ---------- start ---------- */
renderUI();
renderHighscores();
requestAnimationFrame(loop);