var speechVoices = [];
var speechVoicesLoaded = false;
var speechTimer = null;
var piperFallbackTimer = null;

function refreshSpeechVoices() {
  if (!window.speechSynthesis) return;
  var voices = window.speechSynthesis.getVoices();
  if (voices && voices.length) {
    speechVoices = voices;
    speechVoicesLoaded = true;
  }
  return speechVoices;
}

function pickSpeechVoice(lang) {
  refreshSpeechVoices();
  var target = lang.toLowerCase();
  var exact = speechVoices.find(function(voice) {
    return String(voice.lang || '').toLowerCase() === target;
  });
  if (exact) return exact;
  var prefix = target.split('-')[0];
  return speechVoices.find(function(voice) {
    return String(voice.lang || '').toLowerCase().split('-')[0] === prefix;
  }) || null;
}

function buildSpeechUtterance(text, lang) {
  var utterance = new SpeechSynthesisUtterance(text);
  var langMap = { 'es': 'es-ES', 'en': 'en-US', 'zh': 'zh-CN' };
  utterance.lang = langMap[lang] || lang;
  var voice = pickSpeechVoice(utterance.lang);
  if (voice) utterance.voice = voice;
  utterance.rate = 0.9;
  utterance.pitch = 1;
  return utterance;
}

function doSpeak(text, lang) {
  if (!window.speechSynthesis || !window.SpeechSynthesisUtterance || !text) return;
  window.speechSynthesis.cancel();
  if (speechTimer) clearTimeout(speechTimer);
  var utterance = buildSpeechUtterance(text, lang);
  speechTimer = setTimeout(function() {
    window.speechSynthesis.speak(utterance);
    if (window.speechSynthesis.paused) window.speechSynthesis.resume();
  }, 60);
}

function speakText(text, lang) {
  if (!text) return;
  if (piperFallbackTimer) clearTimeout(piperFallbackTimer);
  if (!window.speechSynthesis || !window.SpeechSynthesisUtterance) {
    playPiperAudio(text, lang);
    return;
  }
  refreshSpeechVoices();
  doSpeak(text, lang);
  window.speechSynthesis.getVoices();
  if (!speechVoicesLoaded) {
    if (piperFallbackTimer) clearTimeout(piperFallbackTimer);
    piperFallbackTimer = setTimeout(function() {
      refreshSpeechVoices();
      if (!speechVoicesLoaded) playPiperAudio(text, lang);
    }, 900);
  }
}

function playPiperAudio(text, lang) {
  if (!text) return;
  fetch('/api/tts', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ text: text, lang: lang || 'es' })
  }).then(function(res) {
    if (!res.ok) throw new Error('tts failed');
    return res.blob();
  }).then(function(blob) {
    var url = URL.createObjectURL(blob);
    var audio = new Audio(url);
    audio.onended = function() { URL.revokeObjectURL(url); };
    audio.play();
  }).catch(function() {});
}

function initSpeech() {
  if (!window.speechSynthesis) return;
  refreshSpeechVoices();
  window.speechSynthesis.onvoiceschanged = function() {
    refreshSpeechVoices();
  };
}

if (document.readyState === 'complete') initSpeech();
else document.addEventListener('DOMContentLoaded', initSpeech);

function warmSpeechVoices() {
  if (!window.speechSynthesis) return;
  window.speechSynthesis.getVoices();
  refreshSpeechVoices();
}

document.addEventListener('touchstart', warmSpeechVoices, { once: true, passive: true });
document.addEventListener('pointerdown', warmSpeechVoices, { once: true, passive: true });