'use strict';

// ── State ──────────────────────────────────────────────
let audioChunks  = [];
let audioBuffer  = null;
let audioBlobUrl = null;
let isPlaying    = false;
let abortCtrl    = null;
let animId       = null;
let analyserNode = null;
let audioCtxViz  = null;

// ── DOM ───────────────────────────────────────────────
const $  = id => document.getElementById(id);
const btnPlay     = $('btnPlay');
const btnStop     = $('btnStop');
const btnDownload = $('btnDownload');
const btnReplay   = $('btnReplay');
const logArea     = $('logArea');
const statusBadge = $('statusBadge');
const progressBar = $('progressBar');
const progressFill= $('progressFill');
const charCount   = $('charCount');
const speedVal    = $('speedVal');
const canvas      = $('waveform');
const canvasCtx   = canvas.getContext('2d');
const nativeAudio = $('nativeAudio');

// ── Persistence: API Key ──────────────────────────────
const LS_KEY = 'mm_tts_apikey';

function saveApiKey() {
  const val = $('apiKey').value.trim();
  if (val) localStorage.setItem(LS_KEY, val);
}

function loadApiKey() {
  const saved = localStorage.getItem(LS_KEY);
  if (saved) $('apiKey').value = saved;
}

// ── Init ───────────────────────────────────────────────
function init() {
  loadApiKey();
  $('speed').addEventListener('input', e => speedVal.textContent = parseFloat(e.target.value).toFixed(2) + 'x');
  $('textInput').addEventListener('input', e => charCount.textContent = e.target.value.length);
  resizeCanvas();
  window.addEventListener('resize', resizeCanvas);
  drawIdle();

  nativeAudio.addEventListener('ended', () => {
    isPlaying = false;
    stopVisualizer();
    setStatus('完成', 'status-done');
    log('✅ 播放完毕', 'info');
    onDone();
  });
  nativeAudio.addEventListener('error', e => {
    log('⚠️ 音频播放错误: ' + (nativeAudio.error && nativeAudio.error.message), 'err');
    isPlaying = false;
    onDone();
  });
  nativeAudio.addEventListener('playing', () => {
    setStatus('播放中', 'status-playing');
    startVisualizer();
  });
}

// ── Canvas ─────────────────────────────────────────────
function resizeCanvas() {
  const dpr = window.devicePixelRatio || 1;
  canvas.width  = canvas.offsetWidth  * dpr;
  canvas.height = canvas.offsetHeight * dpr;
  canvasCtx.scale(dpr, dpr);
}

function drawIdle() {
  const w = canvas.offsetWidth, h = canvas.offsetHeight;
  canvasCtx.clearRect(0, 0, w, h);
  for (let i = 0; i < 72; i++) {
    const x = i * (w / 72 - 1), y = (h - 4) / 2;
    canvasCtx.fillStyle = '#2a2d3a';
    canvasCtx.beginPath();
    canvasCtx.roundRect(x, y, w / 72 - 1, 4, 2);
    canvasCtx.fill();
  }
}

function startVisualizer() {
  if (!audioCtxViz) {
    audioCtxViz = new (window.AudioContext || window.webkitAudioContext)();
  }
  if (!analyserNode) {
    analyserNode = audioCtxViz.createAnalyser();
    analyserNode.fftSize = 256;
  }
  try {
    const track = nativeAudio.captureStream ? nativeAudio.captureStream().getAudioTracks()[0] : null;
    if (track) {
      const src = audioCtxViz.createMediaStreamSource(nativeAudio.captureStream());
      src.connect(analyserNode);
    }
  } catch(e) {}
  drawActive();
}

function drawActive() {
  if (!isPlaying) { drawIdle(); return; }
  const w = canvas.offsetWidth, h = canvas.offsetHeight;
  canvasCtx.clearRect(0, 0, w, h);
  const t = Date.now() / 200;
  for (let i = 0; i < 72; i++) {
    const phase = (i / 72) * Math.PI * 2;
    const v = Math.abs(Math.sin(t + phase)) * 0.7 + 0.1;
    const barH = Math.max(3, v * h * 0.85);
    const x = i * (w / 72 - 1);
    const y = (h - barH) / 2;
    const grad = canvasCtx.createLinearGradient(x, y, x, y + barH);
    grad.addColorStop(0, '#a78bfa'); grad.addColorStop(1, '#7c6af7');
    canvasCtx.fillStyle = grad;
    canvasCtx.beginPath();
    canvasCtx.roundRect(x, y, w / 72 - 1, barH, 2);
    canvasCtx.fill();
  }
  animId = requestAnimationFrame(drawActive);
}

function stopVisualizer() {
  if (animId) { cancelAnimationFrame(animId); animId = null; }
  if (analyserNode) { try { analyserNode.disconnect(); } catch(e){} }
  drawIdle();
}

// ── Logging ────────────────────────────────────────────
function log(msg, type = 'info') {
  const ts = new Date().toLocaleTimeString('zh-CN',{hour12:false});
  const d  = document.createElement('div');
  d.className = 'log-line';
  d.innerHTML = `<span class="log-ts">[${ts}]</span><span class="log-${type}">${esc(msg)}</span>`;
  logArea.appendChild(d);
  logArea.scrollTop = logArea.scrollHeight;
}

function esc(s) { return String(s).replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;'); }
function setStatus(s, cls) { statusBadge.textContent = s; statusBadge.className = 'status-badge ' + cls; }

// ── Audio helpers ─────────────────────────────────────
function stopPlayback() {
  if (isPlaying) {
    nativeAudio.pause();
    nativeAudio.currentTime = 0;
  }
  isPlaying = false;
  stopVisualizer();
}

function mimeOf(fmt) {
  return { mp3:'audio/mpeg', wav:'audio/wav', flac:'audio/flac' }[fmt] || 'audio/mpeg';
}

function hexToBytes(hex) {
  hex = hex.replace(/\s/g, '');
  if (!/^[0-9a-fA-F]*$/.test(hex) || hex.length % 2 !== 0) {
    return new Uint8Array(0);
  }
  const bytes = new Uint8Array(hex.length / 2);
  for (let i = 0; i < bytes.length; i++) {
    bytes[i] = parseInt(hex.substr(i * 2, 2), 16);
  }
  return bytes;
}

function buildBlobUrl(hexChunks, fmt) {
  const allBytes = [];
  for (const hex of hexChunks) {
    const b = hexToBytes(hex);
    if (b.length > 0) allBytes.push(b);
  }
  if (allBytes.length === 0) return null;
  const totalLen = allBytes.reduce((s, b) => s + b.length, 0);
  const combined = new Uint8Array(totalLen);
  let off = 0;
  for (const b of allBytes) { combined.set(b, off); off += b.length; }
  const mime = mimeOf(fmt);
  const blob = new Blob([combined], { type: mime });
  if (audioBlobUrl) URL.revokeObjectURL(audioBlobUrl);
  audioBlobUrl = URL.createObjectURL(blob);
  return audioBlobUrl;
}

function startAudioPlayback(blobUrl) {
  stopPlayback();
  nativeAudio.src = blobUrl;
  nativeAudio.play().then(() => {
    isPlaying = true;
    setStatus('播放中', 'status-playing');
    log('▶️ 开始播放', 'info');
    startVisualizer();
  }).catch(e => {
    log('❌ 播放失败: ' + e.message, 'err');
    onDone();
  });
}

function getAudioBlob() {
  if (!audioChunks.length) return null;
  const allBytes = [];
  for (const hex of audioChunks) {
    const b = hexToBytes(hex);
    if (b.length > 0) allBytes.push(b);
  }
  if (allBytes.length === 0) return null;
  const total = allBytes.reduce((s, b) => s + b.length, 0);
  const combined = new Uint8Array(total);
  let off = 0;
  for (const b of allBytes) { combined.set(b, off); off += b.length; }
  return new Blob([combined], { type: mimeOf($('format').value) });
}

// ── Main synthesis ─────────────────────────────────────
async function startSynthesis() {
  const rawKey = $('apiKey').value.trim();
  const text   = $('textInput').value.trim();

  if (!rawKey) { log('❌ 请先填写 API Key', 'err'); return; }
  if (!text)   { log('❌ 请先填写要转换的文字', 'err'); return; }

  const cleanKey = rawKey.replace(/[^\x20-\x7E]/g, '').trim();
  if (!cleanKey) {
    log('❌ API Key 包含无效字符（仅支持 ASCII），请重新复制粘贴正确的 Key', 'err');
    return;
  }
  if (cleanKey !== rawKey) {
    log('⚠️ API Key 中有不可用字符已自动清除，请确认 Key 正确', 'warn');
  }

  saveApiKey();

  let apiKey = cleanKey.startsWith('Bearer ') ? cleanKey : 'Bearer ' + cleanKey;

  try {
    new Headers({ 'Authorization': apiKey });
  } catch(e) {
    log('❌ API Key 包含非法字符，无法作为 HTTP Header: ' + e.message, 'err');
    return;
  }

  audioChunks = [];
  stopPlayback();
  progressFill.style.width = '0%';
  progressBar.classList.add('active');

  btnPlay.disabled = true; btnStop.disabled = false;
  btnDownload.disabled = true; btnReplay.disabled = true;

  const isStream = $('streamMode').value === 'true';
  log(`🚀 发起 HTTP 请求 (${isStream ? '流式' : '非流式'})`, 'info');
  setStatus('请求中', 'status-connecting');
  abortCtrl = new AbortController();

  const body = {
    model:    $('model').value,
    text,
    stream:   isStream,
    voice_setting: {
      voice_id: $('voiceId').value,
      speed:    parseFloat($('speed').value),
      vol:      parseFloat($('vol').value),
      pitch:    parseInt($('pitch').value),
      ...($('emotion').value ? { emotion: $('emotion').value } : {})
    },
    audio_setting: {
      sample_rate: parseInt($('sampleRate').value),
      bitrate:     128000,
      format:      $('format').value,
      channel:     1
    }
  };

  try {
    const response = await fetch('https://api.minimaxi.com/v1/t2a_v2', {
      method: 'POST',
      headers: {
        'Authorization': apiKey,
        'Content-Type': 'application/json'
      },
      body: JSON.stringify(body),
      signal: abortCtrl.signal
    });

    log(`📡 HTTP ${response.status} ${response.statusText}`, response.ok ? 'info' : 'err');

    if (!response.ok) {
      try {
        const err = await response.json();
        log(`❌ 错误: ${JSON.stringify(err)}`, 'err');
        const sr = err.base_resp || {};
        if (sr.status_code === 1004) log('💡 原因: 鉴权失败，检查 API Key 是否正确', 'warn');
        if (sr.status_code === 1039) log('💡 原因: TPM 触发限流，稍后重试', 'warn');
        if (sr.status_code === 1042) log('💡 原因: 非法字符超过 10%，请精简文本', 'warn');
      } catch {}
      setStatus('失败', 'status-error');
      onDone();
      return;
    }

    if (isStream) {
      setStatus('合成中', 'status-playing');
      await handleStreamResponse(response);
    } else {
      setStatus('合成中', 'status-playing');
      await handleNonStreamResponse(response);
    }
  } catch(e) {
    if (e.name === 'AbortError') {
      log('⏹️ 用户取消', 'warn');
    } else if (e.message && e.message.includes('ISO-8859-1')) {
      log('❌ Header 编码错误：API Key 包含非 ASCII 字符', 'err');
    } else {
      log('❌ 请求异常: ' + e.message, 'err');
      log('🔄 尝试备用接口 api-bj.minimaxi.com...', 'warn');
      try {
        const r2 = await fetch('https://api-bj.minimaxi.com/v1/t2a_v2', {
          method: 'POST',
          headers: { 'Authorization': apiKey, 'Content-Type': 'application/json' },
          body: JSON.stringify(body),
          signal: abortCtrl.signal
        });
        if (r2.ok) {
          if ($('streamMode').value === 'true') await handleStreamResponse(r2);
          else await handleNonStreamResponse(r2);
        } else {
          const err2 = await r2.json().catch(() => ({}));
          log(`❌ 备用接口也失败: ${JSON.stringify(err2)}`, 'err');
          setStatus('失败', 'status-error');
          onDone();
        }
      } catch(e2) {
        log('❌ 备用接口异常: ' + e2.message, 'err');
        setStatus('失败', 'status-error');
        onDone();
      }
    }
  }
}

// ── Stream handler ─────────────────────────────────────
async function handleStreamResponse(response) {
  const reader = response.body.getReader();
  const decoder = new TextDecoder();
  let buffer = '';
  let chunkCount = 0;

  try {
    while (true) {
      const { done, value } = await reader.read();
      if (done) break;

      buffer += decoder.decode(value, { stream: true });
      let nlIdx;
      while ((nlIdx = buffer.indexOf('\n')) !== -1) {
        const line = buffer.slice(0, nlIdx).trim();
        buffer = buffer.slice(nlIdx + 1);
        if (!line || !line.startsWith('data:')) continue;
        const dataStr = line.slice(5).trim();
        if (dataStr === '[DONE]' || dataStr === '') continue;
        try {
          const chunk = JSON.parse(dataStr);
          const baseResp = chunk.base_resp || {};
          if (baseResp.status_code && baseResp.status_code !== 0) {
            log(`❌ 流错误 [${baseResp.status_code}]: ${baseResp.status_msg || ''}`, 'err');
            return;
          }
          if (chunk.data && chunk.data.audio) {
            chunkCount++;
            audioChunks.push(chunk.data.audio);
            progressFill.style.width = Math.min((chunkCount / Math.max(parseInt($('textInput').value.length / 200), 5)) * 95, 95) + '%';
            log(`🔊 #${chunkCount} (${chunk.data.audio.length}B, status=${chunk.data.status})`, 'audio');
            if (chunk.data.status === 2) {
              log('✅ 合成完毕，共 ' + chunkCount + ' 片段', 'info');
            }
          }
          if (chunk.extra_info) {
            const ei = chunk.extra_info;
            log(`📋 音频: ${(ei.audio_length/1000).toFixed(1)}s / ${ei.audio_size}B / ${ei.usage_characters}字符`, 'info');
          }
        } catch(parseErr) {}
      }
    }
  } finally {
    reader.releaseLock();
  }

  if (!audioChunks.length) {
    log('❌ 流接收完毕但无音频数据', 'err');
    setStatus('失败', 'status-error');
    onDone();
    return;
  }

  progressFill.style.width = '98%';
  log('🎵 音频合成完成，开始播放...', 'info');
  const blobUrl = buildBlobUrl(audioChunks, $('format').value);
  startAudioPlayback(blobUrl);
  btnDownload.disabled = false;
  btnReplay.disabled = false;
  onDone();
}

// ── Non-stream handler ─────────────────────────────────
async function handleNonStreamResponse(response) {
  log('📥 接收完整响应...', 'info');
  let json;
  try {
    json = await response.json();
  } catch(e) {
    log('❌ 响应 JSON 解析失败: ' + e.message, 'err');
    log('🔄 尝试作为原始音频处理...', 'warn');
    const bytes = await response.arrayBuffer();
    if (bytes.byteLength > 0) {
      const blob = new Blob([bytes], { type: mimeOf($('format').value) });
      if (audioBlobUrl) URL.revokeObjectURL(audioBlobUrl);
      audioBlobUrl = URL.createObjectURL(blob);
      startAudioPlayback(audioBlobUrl);
      btnDownload.disabled = false;
      btnReplay.disabled = false;
      onDone();
      return;
    }
    setStatus('失败', 'status-error');
    onDone();
    return;
  }

  log('📦 JSON: ' + JSON.stringify(json).slice(0, 400), 'info');
  const baseResp = json.base_resp || {};
  if (baseResp.status_code && baseResp.status_code !== 0) {
    log(`❌ 合成失败 [${baseResp.status_code}]: ${baseResp.status_msg || ''}`, 'err');
    if (baseResp.status_code === 1004) log('💡 提示: 鉴权失败，检查 API Key 是否正确', 'warn');
    setStatus('失败', 'status-error');
    onDone();
    return;
  }
  const audioHex = json.data && json.data.audio;
  if (!audioHex) {
    log('❌ 响应中无 audio 字段', 'err');
    setStatus('失败', 'status-error');
    onDone();
    return;
  }
  audioChunks = [audioHex];
  progressFill.style.width = '90%';
  log('🎵 音频就绪，开始播放...', 'info');
  const blobUrl = buildBlobUrl(audioChunks, $('format').value);
  startAudioPlayback(blobUrl);
  if (json.extra_info) {
    const ei = json.extra_info;
    log(`📋 音频: ${(ei.audio_length/1000).toFixed(1)}s / ${ei.audio_size}B / ${ei.usage_characters}字符`, 'info');
  }
  btnDownload.disabled = false;
  btnReplay.disabled = false;
  onDone();
}

// ── Controls ───────────────────────────────────────────
function stopSynthesis() {
  log('⏹️ 取消请求', 'warn');
  stopPlayback();
  if (abortCtrl) abortCtrl.abort();
  progressFill.style.width = '0%';
  onDone();
}

function onDone() {
  btnPlay.disabled   = false;
  btnStop.disabled  = true;
  setTimeout(() => progressBar.classList.remove('active'), 2000);
}

function replayAudio() {
  if (audioBlobUrl) {
    stopPlayback();
    startAudioPlayback(audioBlobUrl);
  } else {
    log('⚠️ 没有可回放的音频', 'warn');
  }
}

function downloadAudio() {
  const blob = getAudioBlob();
  if (!blob) { log('⚠️ 没有可下载的音频', 'warn'); return; }
  const fmt = $('format').value;
  const a = document.createElement('a');
  a.href   = URL.createObjectURL(blob);
  a.download = `speech_${Date.now()}.${fmt}`;
  a.click();
  URL.revokeObjectURL(a.href);
  log(`💾 已下载: ${a.download} (${(blob.size/1024).toFixed(1)} KB)`, 'info');
}

// auto-init
$('apiKey').addEventListener('blur', saveApiKey);
$('apiKey').addEventListener('keydown', e => {
  if (e.key === 'Enter') { e.preventDefault(); saveApiKey(); $('apiKey').blur(); }
});

init();