/* TechTacular – IT-Quizduell im Jeopardy-Stil.
   Board kommt aus /api/techtacular/board (ohne Lösung), Prüfung + Score serverseitig. */
(() => {
  'use strict';

  const GAME = 'techtacular';

  const boardEl   = document.getElementById('tt-board');
  const newBtn    = document.getElementById('tt-new');
  const finishBtn = document.getElementById('tt-finish');
  const cancelBtn = document.getElementById('tt-cancel');
  const scoreEl   = document.getElementById('tt-score');
  const answeredEl= document.getElementById('tt-answered');
  const timeEl    = document.getElementById('tt-time');
  const bestEl    = document.getElementById('tt-best');

  const qOverlay  = document.getElementById('tt-question');
  const qCat      = document.getElementById('tt-q-cat');
  const qPoints   = document.getElementById('tt-q-points');
  const qText     = document.getElementById('tt-q-text');
  const qAnswers  = document.getElementById('tt-q-answers');
  const qFeedback = document.getElementById('tt-q-feedback');
  const qNext     = document.getElementById('tt-q-next');

  const resultEl    = document.getElementById('tt-result');
  const resultScore = document.getElementById('tt-result-score');
  const resultMax   = document.getElementById('tt-result-max');
  const resultDetail= document.getElementById('tt-result-detail');
  const resultHigh  = document.getElementById('tt-result-high');
  const againBtn    = document.getElementById('tt-again');

  let board = null;
  let previousIds = [];    // Frage-IDs der Vorrunde -> werden im nächsten Board vermieden
  let tiles = [];          // Tile-Zustände {data, categoryTitle, answered, correct, el}
  let answeredCount = 0;
  let score = 0;
  let seconds = 0;
  let timerId = null;
  let running = false;
  let current = null;      // gerade offene Kachel
  const submitted = [];    // {questionId, answerId} für /finish

  function formatTime(s) {
    return `${Math.floor(s / 60)}:${String(s % 60).padStart(2, '0')}`;
  }

  function startTimer() {
    if (timerId) return;
    timerId = setInterval(() => { seconds++; timeEl.textContent = formatTime(seconds); }, 1000);
  }
  function stopTimer() { clearInterval(timerId); timerId = null; }

  function setIdle(message) {
    boardEl.style.gridTemplateColumns = '';
    boardEl.innerHTML = `<p class="tt-idle">${message}</p>`;
  }

  function updateHud() {
    scoreEl.textContent = String(score);
    answeredEl.textContent = `${answeredCount} / ${tiles.length}`;
  }

  function renderBoard() {
    boardEl.innerHTML = '';
    boardEl.style.gridTemplateColumns = `repeat(${board.categories.length}, 1fr)`;
    tiles = [];

    board.categories.forEach((category) => {
      const col = document.createElement('div');
      col.className = 'tt-col';

      const title = document.createElement('div');
      title.className = 'tt-cat-title';
      title.textContent = category.title;
      col.appendChild(title);

      category.tiles.forEach((tileData) => {
        const tileEl = document.createElement('button');
        tileEl.type = 'button';
        tileEl.className = 'tt-tile';
        tileEl.textContent = String(tileData.points);

        const state = { data: tileData, categoryTitle: category.title, answered: false, correct: false, el: tileEl };
        tileEl.addEventListener('click', () => openTile(state));
        tiles.push(state);
        col.appendChild(tileEl);
      });

      boardEl.appendChild(col);
    });
  }

  function openTile(state) {
    if (!running || state.answered || current) return;
    current = state;

    qCat.textContent = state.categoryTitle;
    qPoints.textContent = String(state.data.points);
    qText.textContent = state.data.text;
    qFeedback.textContent = '';
    qFeedback.className = 'tt-q-feedback';
    qNext.hidden = true;

    qAnswers.innerHTML = '';
    state.data.answers.forEach((answer) => {
      const btn = document.createElement('button');
      btn.type = 'button';
      btn.className = 'tt-answer';
      btn.textContent = `Was ist ${answer.text}?`;
      btn.addEventListener('click', () => chooseAnswer(state, answer.id, btn));
      qAnswers.appendChild(btn);
    });

    qOverlay.hidden = false;
  }

  async function chooseAnswer(state, answerId, btn) {
    if (state.answered) return;
    state.answered = true; // sofort sperren (eine Antwort pro Frage)

    const buttons = Array.from(qAnswers.querySelectorAll('.tt-answer'));
    buttons.forEach((b) => { b.disabled = true; });

    submitted.push({ questionId: state.data.questionId, answerId });

    try {
      const res = await fetch('/api/techtacular/answer', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ questionId: state.data.questionId, answerId })
      });
      const data = await res.json();

      state.correct = data.correct;
      // richtige Antwort grün, eigene falsche rot markieren
      state.data.answers.forEach((answer, i) => {
        if (answer.id === data.correctAnswerId) buttons[i].classList.add('correct');
      });
      if (!data.correct) btn.classList.add('wrong');

      const correctTerm = (state.data.answers.find((a) => a.id === data.correctAnswerId) || {}).text || '';
      if (data.correct) {
        score += data.points;
        qFeedback.textContent = `Richtig! +${data.points}. ${data.explanation || ''}`.trim();
        qFeedback.className = 'tt-q-feedback correct';
      } else {
        qFeedback.textContent = `Falsch – richtig: „Was ist ${correctTerm}?“. ${data.explanation || ''}`.trim();
        qFeedback.className = 'tt-q-feedback wrong';
      }
      updateHud();
    } catch (err) {
      qFeedback.textContent = 'Antwort konnte nicht geprüft werden.';
      qFeedback.className = 'tt-q-feedback wrong';
      console.error(err);
    }

    qNext.hidden = false;
  }

  function closeQuestion() {
    if (!current) return;
    const state = current;
    current = null;
    qOverlay.hidden = true;

    state.el.classList.add('answered', state.correct ? 'correct' : 'wrong');
    state.el.textContent = state.correct ? `✓ ${state.data.points}` : '✗';
    answeredCount++;
    updateHud();

    if (answeredCount === tiles.length) {
      finishGame();
    }
  }

  async function finishGame() {
    if (!running) return;
    running = false;
    stopTimer();
    finishBtn.hidden = true;
    cancelBtn.hidden = true;

    try {
      const res = await fetch('/api/techtacular/finish', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ durationSeconds: seconds, answers: submitted })
      });
      const data = await res.json();
      resultScore.textContent = String(data.score);
      resultMax.textContent = String(data.maxScore);
      resultDetail.textContent =
        `${data.correctCount} von ${data.totalCount} Fragen richtig · ${formatTime(seconds)}`;
      resultHigh.hidden = !data.newHighscore;
      bestEl.textContent = String(data.highscore);
      resultEl.hidden = false;
    } catch (err) {
      console.error('Runde konnte nicht gespeichert werden:', err);
    }
  }

  function cancelGame() {
    if (!running) return;
    if (answeredCount > 0 && !window.confirm(
        'Aktuelle Runde wirklich abbrechen? Sie wird nicht gespeichert.')) {
      return;
    }
    running = false;
    current = null;
    stopTimer();
    qOverlay.hidden = true;
    finishBtn.hidden = true;
    cancelBtn.hidden = true;
    setIdle('Runde abgebrochen – klicke „Neues Spiel“ für ein frisches Board.');
  }

  async function loadStats() {
    try {
      const res = await fetch(`/api/games/${GAME}/stats`);
      if (!res.ok) return;
      const stats = await res.json();
      bestEl.textContent = stats.highscore > 0 ? String(stats.highscore) : '–';
    } catch (err) { /* egal */ }
  }

  async function newGame() {
    stopTimer();
    seconds = 0; score = 0; answeredCount = 0; current = null;
    submitted.length = 0;
    timeEl.textContent = '0:00';
    resultEl.hidden = true;
    qOverlay.hidden = true;

    const excludeParam = previousIds.length ? ('?exclude=' + previousIds.join(',')) : '';
    try {
      const res = await fetch('/api/techtacular/board' + excludeParam);
      if (!res.ok) throw new Error(`HTTP ${res.status}`);
      board = await res.json();
    } catch (err) {
      console.error('Board konnte nicht geladen werden:', err);
      setIdle('Board konnte nicht geladen werden.');
      return;
    }

    if (!board.categories || !board.categories.length) {
      setIdle('Noch keine Kategorien vorhanden. Ein Admin kann sie unter „TechTacular verwalten“ anlegen.');
      return;
    }

    renderBoard();
    previousIds = board.categories.flatMap((c) => c.tiles.map((t) => t.questionId));
    updateHud();
    running = true;
    finishBtn.hidden = false;
    cancelBtn.hidden = false;
    startTimer();
  }

  newBtn.addEventListener('click', newGame);
  againBtn.addEventListener('click', newGame);
  finishBtn.addEventListener('click', finishGame);
  cancelBtn.addEventListener('click', cancelGame);
  qNext.addEventListener('click', closeQuestion);

  loadStats();
  newGame();
})();