import { state } from '../core/state.js';
import { logTts, prefetchAudio, speak, stopAllAudio } from '../services/tts.js';

let autoPlayActive = false;
let autoPlayTimer = null;

export function toggleAutoPlay() {
  if (autoPlayActive) stopAutoPlay();
  else startAutoPlay();
}

export function startAutoPlay() {
  const rows = document.querySelectorAll('.word-table tbody tr[data-word-id]');
  const wordIds = Array.from(rows).map(row => Number.parseInt(row.dataset.wordId, 10));
  if (wordIds.length === 0) return;

  autoPlayActive = true;
  updateAutoPlayBtn();
  prefetchWordListAudio(wordIds);
  playWordSequence(wordIds, 0);
}

export function prefetchWordListAudio(wordIds) {
  const texts = wordIds
    .map(id => state.words.find(word => word.id === id)?.english)
    .filter(Boolean);
  if (!texts.length) return;
  void prefetchAudio(texts, 0.92, { allowCloud: true })
    .catch(error => logTts('word list audio prefetch failed', error));
}

export function playWordSequence(wordIds, index) {
  if (!autoPlayActive || index >= wordIds.length) {
    stopAutoPlay();
    return;
  }

  const word = state.words.find(item => item.id === wordIds[index]);
  if (!word) {
    playWordSequence(wordIds, index + 1);
    return;
  }

  document.querySelectorAll('.word-table tbody tr').forEach(row => row.classList.remove('is-playing'));
  const row = document.querySelector(`tr[data-word-id="${word.id}"]`);
  if (row) {
    row.classList.add('is-playing');
    let shouldScroll = true;
    if (state.autoPlayScrollMode === 'visible') {
      const rect = row.getBoundingClientRect();
      const viewportHeight = window.innerHeight || document.documentElement.clientHeight;
      const header = document.getElementById('mobile-header');
      const topBound = header ? header.getBoundingClientRect().height : 0;
      shouldScroll = rect.top < topBound || rect.bottom > viewportHeight;
    }
    if (shouldScroll) {
      row.scrollIntoView({
        behavior: window.matchMedia('(prefers-reduced-motion: reduce)').matches ? 'auto' : 'smooth',
        block: 'center',
        inline: 'nearest'
      });
    }
  }

  const repeatCount = Math.max(1, state.autoPlayRepeat || 1);
  const repeatDelay = state.autoPlayRepeatDelay || 1000;
  const wordInterval = state.autoPlayInterval || 2500;
  let spoken = 0;

  async function playCurrentWord() {
    if (!autoPlayActive) return;
    await speak(word.english);
    if (!autoPlayActive) return;
    spoken++;
    if (spoken < repeatCount) {
      autoPlayTimer = setTimeout(playCurrentWord, repeatDelay);
    } else {
      autoPlayTimer = setTimeout(() => playWordSequence(wordIds, index + 1), wordInterval);
    }
  }

  void playCurrentWord();
}

export function stopAutoPlay() {
  autoPlayActive = false;
  if (autoPlayTimer) {
    clearTimeout(autoPlayTimer);
    autoPlayTimer = null;
  }
  stopAllAudio();
  document.querySelectorAll('.word-table tbody tr').forEach(row => row.classList.remove('is-playing'));
  updateAutoPlayBtn();
}

export function updateAutoPlayBtn() {
  const button = document.getElementById('auto-play-btn');
  if (!button) return;
  if (autoPlayActive) {
    button.innerHTML = '<i class="fas fa-stop"></i> 停止播放';
    button.className = 'btn btn-error';
  } else {
    button.innerHTML = '<i class="fas fa-play"></i> 自动播放';
    button.className = 'btn btn-secondary';
  }
}