const { WebSocket, WebSocketServer } = require('ws');
const url = require('url');
const db = require('../db');
const arkChatService = require('./arkChatService');
const {
  MsgType,
  unmarshal,
  createStartConnectionMessage,
  createStartSessionMessage,
  createAudioMessage,
  createChatTTSTextMessage,
  createChatRAGTextMessage,
} = require('./realtimeDialogProtocol');
const {
  getRuleBasedDirectRouteDecision,
  normalizeTextForSpeech,
  splitTextForSpeech,
  estimateSpeechDurationMs,
  shouldForceKnowledgeRoute,
  resolveReply,
} = require('./realtimeDialogRouting');

const sessions = new Map();

const IDLE_TIMEOUT_MS = 5 * 60 * 1000;

function resetIdleTimer(session) {
  clearTimeout(session.idleTimer);
  session.lastActivityAt = Date.now();
  session.idleTimer = setTimeout(() => {
    session.idleTimer = null;
    console.log(`[NativeVoice] idle timeout (${IDLE_TIMEOUT_MS / 1000}s) session=${session.sessionId}`);
    sendJson(session.client, { type: 'idle_timeout', timeout: IDLE_TIMEOUT_MS });
    setTimeout(() => {
      if (session.client && session.client.readyState === WebSocket.OPEN) {
        session.client.close();
      }
    }, 2000);
  }, IDLE_TIMEOUT_MS);
}

function sendJson(ws, payload) {
  if (ws && ws.readyState === WebSocket.OPEN) {
    ws.send(JSON.stringify(payload));
  }
}

function buildStartSessionPayload(options) {
  return {
    asr: {
      extra: {},
    },
    tts: {
      speaker: options.speaker || process.env.VOLC_S2S_SPEAKER_ID || 'zh_female_vv_jupiter_bigtts',
      audio_config: {
        channel: 1,
        format: 'pcm_s16le',
        sample_rate: 24000,
      },
    },
    dialog: {
      dialog_id: '',
      bot_name: options.botName || '大沃',
      system_role: normalizeTextForSpeech(options.systemRole || '你是大沃，一个德国PM健康事业的智能语音助手。你对PM-FitLine细胞营养素产品、一成系统、招商合作非常熟悉。请优先依据 external_rag 给出的内容回答。无论是闲聊还是引用知识库内容，都要保持一样的说话风格，不要切换成朗读语气。用户进来时请自然地打个招呼，像朋友聊天一样，不要用客服话术。'),
      speaking_style: normalizeTextForSpeech(options.speakingStyle || '说话像朋友聊天一样自然轻松，语气亲切活泼，不要像客服念稿。即使引用知识库内容也要用聊天的语气说出来，不要切换成播音腔或朗读语气。'),
      extra: {
        input_mod: 'audio',
        model: options.modelVersion || 'O',
        strict_audit: false,
        audit_response: '抱歉，这个问题我暂时无法回答。',
      },
    },
  };
}

function parseJsonPayload(message) {
  try {
    return JSON.parse(message.payload.toString('utf8'));
  } catch (error) {
    return null;
  }
}

function extractUserText(jsonPayload) {
  const text = jsonPayload?.text
    || jsonPayload?.content
    || jsonPayload?.results?.[0]?.text
    || jsonPayload?.results?.[0]?.alternatives?.[0]?.text
    || '';
  return String(text || '').trim();
}

function isFinalUserPayload(jsonPayload) {
  if (jsonPayload?.is_final === true) {
    return true;
  }
  if (Array.isArray(jsonPayload?.results)) {
    return jsonPayload.results.some((item) => item && item.is_interim === false);
  }
  return false;
}

function persistUserSpeech(session, text) {
  const cleanText = (text || '').trim();
  if (!cleanText) return false;
  const now = Date.now();
  if (session.lastPersistedUserText === cleanText && now - (session.lastPersistedUserAt || 0) < 5000) {
    return false;
  }
  session.lastPersistedUserText = cleanText;
  session.lastPersistedUserAt = now;
  session.latestUserText = cleanText;
  resetIdleTimer(session);
  db.addMessage(session.sessionId, 'user', cleanText, 'voice_asr').catch((e) => console.warn('[NativeVoice][DB] add user failed:', e.message));
  sendJson(session.client, {
    type: 'subtitle',
    role: 'user',
    text: cleanText,
    isFinal: true,
    sequence: `native_user_${now}`,
  });
  return true;
}

function persistAssistantSpeech(session, text, { source = 'voice_bot', toolName = null, persistToDb = true, meta = null } = {}) {
  const cleanText = (text || '').trim();
  if (!cleanText) return false;
  const now = Date.now();
  if (session.lastPersistedAssistantText === cleanText && now - (session.lastPersistedAssistantAt || 0) < 5000) {
    return false;
  }
  session.lastPersistedAssistantText = cleanText;
  session.lastPersistedAssistantAt = now;
  resetIdleTimer(session);
  if (persistToDb) {
    db.addMessage(session.sessionId, 'assistant', cleanText, source, toolName, meta).catch((e) => console.warn('[NativeVoice][DB] add assistant failed:', e.message));
  }
  sendJson(session.client, {
    type: 'subtitle',
    role: 'assistant',
    text: cleanText,
    isFinal: true,
    source,
    toolName,
    sequence: `native_assistant_${now}`,
  });
  return true;
}

function appendAssistantStream(session, payload) {
  const chunkText = extractUserText(payload);
  if (!chunkText) {
    return '';
  }
  const replyId = payload?.reply_id || '';
  if (replyId && session.assistantStreamReplyId && session.assistantStreamReplyId !== replyId) {
    session.assistantStreamBuffer = '';
  }
  session.assistantStreamReplyId = replyId || session.assistantStreamReplyId || '';
  session.assistantStreamBuffer = `${session.assistantStreamBuffer || ''}${chunkText}`;
  return session.assistantStreamBuffer;
}

function flushAssistantStream(session, { source = 'voice_bot', toolName = null, meta = null } = {}) {
  const fullText = (session.assistantStreamBuffer || '').trim();
  session.assistantStreamBuffer = '';
  session.assistantStreamReplyId = '';
  if (!fullText) {
    return false;
  }
  return persistAssistantSpeech(session, fullText, { source, toolName, meta });
}

async function loadHandoffSummaryForVoice(session) {
  try {
    const history = await db.getHistoryForLLM(session.sessionId, 20);
    if (!history.length) {
      session.handoffSummary = '';
      session.handoffSummaryUsed = false;
      return;
    }
    session.handoffSummary = await arkChatService.summarizeContextForHandoff(history, 3);
    session.handoffSummaryUsed = false;
    console.log(`[NativeVoice] Handoff summary prepared for ${session.sessionId}: ${session.handoffSummary ? 'yes' : 'no'}`);
  } catch (error) {
    session.handoffSummary = '';
    session.handoffSummaryUsed = false;
    console.warn('[NativeVoice] loadHandoffSummaryForVoice failed:', error.message);
  }
}

async function sendSpeechText(session, speechText) {
  const chunks = splitTextForSpeech(speechText);
  if (!chunks.length || !session.upstream || session.upstream.readyState !== WebSocket.OPEN) {
    return;
  }
  console.log(`[NativeVoice] sendSpeechText start session=${session.sessionId} chunks=${chunks.length} textLen=${speechText.length}`);
  session.isSendingChatTTSText = true;
  session.currentTtsType = 'chat_tts_text';
  session.chatTTSUntil = Date.now() + estimateSpeechDurationMs(speechText) + 800;
  clearTimeout(session.chatTTSTimer);
  session.chatTTSTimer = setTimeout(() => {
    session.chatTTSTimer = null;
    if ((session.chatTTSUntil || 0) <= Date.now()) {
      session.isSendingChatTTSText = false;
    }
  }, Math.max(200, session.chatTTSUntil - Date.now() + 50));
  sendJson(session.client, { type: 'tts_reset', ttsType: 'chat_tts_text' });
  for (let index = 0; index < chunks.length; index += 1) {
    const chunk = chunks[index];
    console.log(`[NativeVoice] sendSpeechText chunk session=${session.sessionId} index=${index + 1}/${chunks.length} len=${chunk.length} start=${index === 0} end=false text=${JSON.stringify(chunk.slice(0, 80))}`);
    session.upstream.send(createChatTTSTextMessage(session.sessionId, {
      start: index === 0,
      end: false,
      content: chunk,
    }));
  }
  console.log(`[NativeVoice] sendSpeechText end session=${session.sessionId}`);
  session.upstream.send(createChatTTSTextMessage(session.sessionId, {
    start: false,
    end: true,
    content: '',
  }));
}

 function sendReady(session) {
   if (session.readySent) {
     return;
   }
   session.readySent = true;
   sendJson(session.client, { type: 'ready' });
 }

 function sendGreeting(session) {
  if (session.hasSentGreeting) {
    sendReady(session);
    return;
  }
  session.hasSentGreeting = true;
  const greetingText = session.greetingText || '嗨，你好呀！我是大沃，你的专属智能助手。关于德国PM产品、一成系统、招商合作，随时问我就好～';
  console.log(`[NativeVoice] sendGreeting session=${session.sessionId} text=${JSON.stringify(greetingText.slice(0, 80))}`);
  sendJson(session.client, {
    type: 'subtitle',
    role: 'assistant',
    text: greetingText,
    isFinal: true,
    source: 'voice_bot',
    sequence: `greeting_${Date.now()}`,
  });
  persistAssistantSpeech(session, greetingText, { source: 'voice_bot' });
  clearTimeout(session.greetingTimer);
  clearTimeout(session.readyTimer);
  session.greetingTimer = setTimeout(() => {
    session.greetingTimer = null;
    sendSpeechText(session, greetingText)
      .then(() => {
        session.readyTimer = setTimeout(() => {
          session.readyTimer = null;
          sendReady(session);
        }, Math.max(1200, Math.min(estimateSpeechDurationMs(greetingText) + 300, 8000)));
      })
      .catch((error) => {
        session.hasSentGreeting = false;
        sendReady(session);
        console.warn('[NativeVoice] greeting speech failed:', error.message);
      });
  }, 800);
}

async function sendExternalRag(session, items) {
  if (!session.upstream || session.upstream.readyState !== WebSocket.OPEN) {
    return;
  }
  const ragItems = Array.isArray(items) ? items.filter((item) => item && item.content) : [];
  if (!ragItems.length) {
    return;
  }
  session.upstream.send(createChatRAGTextMessage(session.sessionId, JSON.stringify(ragItems)));
}

async function processReply(session, text) {
  const cleanText = (text || '').trim();
  if (!cleanText) return;
  if (session.processingReply) {
    session.queuedUserText = cleanText;
    console.log(`[NativeVoice] processReply queued(busy) session=${session.sessionId} text=${JSON.stringify(cleanText.slice(0, 80))}`);
    return;
  }
  const now = Date.now();
  if (session.directSpeakUntil && now < session.directSpeakUntil) {
    session.queuedUserText = cleanText;
    console.log(`[NativeVoice] processReply queued(speaking) session=${session.sessionId} waitMs=${session.directSpeakUntil - now} text=${JSON.stringify(cleanText.slice(0, 80))}`);
    return;
  }
  session.processingReply = true;
  sendJson(session.client, { type: 'assistant_pending', active: true });
  const isKnowledgeCandidate = shouldForceKnowledgeRoute(cleanText);
  if (isKnowledgeCandidate) {
    sendJson(session.client, { type: 'tts_reset', reason: 'processing' });
  }
  console.log(`[NativeVoice] processReply start session=${session.sessionId} text=${JSON.stringify(cleanText.slice(0, 120))} blocked=${session.blockUpstreamAudio} kbCandidate=${isKnowledgeCandidate}`);
  try {
    const { delivery, speechText, ragItems, source, toolName, routeDecision, responseMeta } = await resolveReply(session.sessionId, session, cleanText);
    if (delivery === 'upstream_chat') {
      if (isKnowledgeCandidate) {
        console.log(`[NativeVoice] processReply kb-nohit retrigger session=${session.sessionId}`);
        await sendExternalRag(session, [{ title: '用户问题', content: cleanText }]);
      } else {
        session.blockUpstreamAudio = false;
      }
      session.awaitingUpstreamReply = true;
      session.pendingAssistantSource = 'voice_bot';
      session.pendingAssistantToolName = null;
      session.pendingAssistantMeta = responseMeta;
      console.log(`[NativeVoice] processReply handoff session=${session.sessionId} route=${routeDecision?.route || 'unknown'} delivery=upstream_chat`);
      return;
    }
    if (delivery === 'external_rag') {
      if (!session.blockUpstreamAudio) {
        session.blockUpstreamAudio = true;
        sendJson(session.client, { type: 'tts_reset', reason: 'knowledge_hit' });
      }
      session.awaitingUpstreamReply = true;
      session.pendingAssistantSource = source;
      session.pendingAssistantToolName = toolName;
      session.pendingAssistantMeta = responseMeta;
      console.log(`[NativeVoice] processReply handoff session=${session.sessionId} route=${routeDecision?.route || 'unknown'} delivery=external_rag items=${Array.isArray(ragItems) ? ragItems.length : 0}`);
      await sendExternalRag(session, ragItems);
      return;
    }
    if (!speechText) {
      console.log(`[NativeVoice] processReply empty session=${session.sessionId} route=${routeDecision?.route || 'unknown'} delivery=${delivery || 'unknown'}`);
      session.isSendingChatTTSText = false;
      session.chatTTSUntil = 0;
      return;
    }
    console.log(`[NativeVoice] processReply resolved session=${session.sessionId} route=${routeDecision?.route || 'unknown'} delivery=local_rag source=${source} tool=${toolName || 'chat'} speechLen=${speechText.length}`);
    session.awaitingUpstreamReply = true;
    session.pendingAssistantSource = source;
    session.pendingAssistantToolName = toolName;
    session.pendingAssistantMeta = responseMeta;
    await sendExternalRag(session, [{ title: '回复内容', content: speechText }]);
  } catch (error) {
    console.error('[NativeVoice] processReply failed:', error.message);
    sendJson(session.client, { type: 'error', error: error.message });
  } finally {
    session.processingReply = false;
    if (!session.awaitingUpstreamReply) {
      session.blockUpstreamAudio = false;
    }
    if (!session.awaitingUpstreamReply) {
      sendJson(session.client, { type: 'assistant_pending', active: false });
    }
    const pending = session.queuedUserText;
    session.queuedUserText = '';
    if (pending && pending !== cleanText && (!session.directSpeakUntil || Date.now() >= session.directSpeakUntil)) {
      setTimeout(() => {
        session.blockUpstreamAudio = true;
        processReply(session, pending).catch((err) => {
          console.error('[NativeVoice] queued processReply failed:', err.message);
        });
      }, 200);
    } else if (pending && pending !== cleanText) {
      const waitMs = Math.max(200, session.directSpeakUntil - Date.now() + 200);
      clearTimeout(session.queuedReplyTimer);
      session.queuedReplyTimer = setTimeout(() => {
        session.queuedReplyTimer = null;
        const queuedText = session.queuedUserText || pending;
        session.queuedUserText = '';
        session.blockUpstreamAudio = true;
        processReply(session, queuedText).catch((err) => {
          console.error('[NativeVoice] delayed queued processReply failed:', err.message);
        });
      }, waitMs);
    }
  }
}

function handleUpstreamMessage(session, data) {
  let message;
  try {
    message = unmarshal(data);
  } catch (error) {
    console.warn('[NativeVoice] unmarshal failed:', error.message);
    return;
  }

  if (message.type === MsgType.AUDIO_ONLY_SERVER) {
    if (session.blockUpstreamAudio) {
      if (!session._audioBlockLogOnce) {
        session._audioBlockLogOnce = true;
        console.log(`[NativeVoice] audio blocked (blockUpstream) session=${session.sessionId} ttsType=${session.currentTtsType}`);
      }
      return;
    }
    session._audioBlockLogOnce = false;
    if (session.client && session.client.readyState === WebSocket.OPEN) {
      session.client.send(message.payload, { binary: true });
    }
    return;
  }

  const payload = parseJsonPayload(message);
  if (message.type === MsgType.ERROR) {
    console.error(`[NativeVoice] upstream error session=${session.sessionId} code=${message.event} payload=${message.payload.toString('utf8').slice(0, 200)}`);
    sendJson(session.client, { type: 'error', error: message.payload.toString('utf8') });
    return;
  }

  if (message.type !== MsgType.FULL_SERVER) {
    return;
  }

  if (message.event === 150) {
    session.upstreamReady = true;
    console.log(`[NativeVoice] upstream ready session=${session.sessionId}`);
    resetIdleTimer(session);
    sendGreeting(session);
    return;
  }

  if (message.event === 350) {
    session.currentTtsType = payload?.tts_type || '';
    if (payload?.tts_type === 'chat_tts_text' && session.pendingGreetingAck) {
      session.pendingGreetingAck = false;
      clearTimeout(session.greetingAckTimer);
      session.greetingAckTimer = null;
    }
    if (session.blockUpstreamAudio && payload?.tts_type && payload.tts_type !== 'default') {
      session.blockUpstreamAudio = false;
      console.log(`[NativeVoice] unblock audio on ttsType=${payload.tts_type} session=${session.sessionId}`);
    }
    console.log(`[NativeVoice] upstream tts_event session=${session.sessionId} ttsType=${payload?.tts_type || ''}`);
    sendJson(session.client, { type: 'tts_event', payload });
    return;
  }

  const isLocalChatTTSTextActive = !!session.isSendingChatTTSText && (session.chatTTSUntil || 0) > Date.now();

  if (message.event === 351) {
    if (isLocalChatTTSTextActive || session.blockUpstreamAudio) {
      session.assistantStreamBuffer = '';
      session.assistantStreamReplyId = '';
      return;
    }
    const pendingAssistantSource = session.pendingAssistantSource || 'voice_bot';
    const pendingAssistantToolName = session.pendingAssistantToolName || null;
    const pendingAssistantMeta = session.pendingAssistantMeta || null;
    session.awaitingUpstreamReply = false;
    sendJson(session.client, { type: 'assistant_pending', active: false });
    const assistantText = extractUserText(payload);
    if (assistantText) {
      session.assistantStreamBuffer = '';
      session.assistantStreamReplyId = '';
      console.log(`[NativeVoice] upstream assistant session=${session.sessionId} text=${JSON.stringify(assistantText.slice(0, 120))}`);
      persistAssistantSpeech(session, assistantText, {
        source: pendingAssistantSource,
        toolName: pendingAssistantToolName,
        meta: pendingAssistantMeta,
      });
    } else {
      flushAssistantStream(session, {
        source: pendingAssistantSource,
        toolName: pendingAssistantToolName,
        meta: pendingAssistantMeta,
      });
    }
    session.pendingAssistantSource = null;
    session.pendingAssistantToolName = null;
    session.pendingAssistantMeta = null;
    return;
  }

  if (message.event === 550) {
    if (isLocalChatTTSTextActive || session.blockUpstreamAudio) {
      return;
    }
    if (session.awaitingUpstreamReply) {
      session.awaitingUpstreamReply = false;
      sendJson(session.client, { type: 'assistant_pending', active: false });
    }
    const fullText = appendAssistantStream(session, payload);
    if (fullText) {
      console.log(`[NativeVoice] upstream assistant chunk session=${session.sessionId} len=${fullText.length} text=${JSON.stringify(fullText.slice(0, 120))}`);
    }
    return;
  }

  if (message.event === 559) {
    if (isLocalChatTTSTextActive) {
      session.assistantStreamBuffer = '';
      session.assistantStreamReplyId = '';
      return;
    }
    if (session.blockUpstreamAudio) {
      session.assistantStreamBuffer = '';
      session.assistantStreamReplyId = '';
      console.log(`[NativeVoice] blocked response ended (559), keeping block session=${session.sessionId}`);
      return;
    }
    session.awaitingUpstreamReply = false;
    session.blockUpstreamAudio = false;
    sendJson(session.client, { type: 'assistant_pending', active: false });
    flushAssistantStream(session, {
      source: session.pendingAssistantSource || 'voice_bot',
      toolName: session.pendingAssistantToolName || null,
      meta: session.pendingAssistantMeta || null,
    });
    session.pendingAssistantSource = null;
    session.pendingAssistantToolName = null;
    session.pendingAssistantMeta = null;
    return;
  }

  if (message.event === 450 || (message.event === 451 && !isFinalUserPayload(payload))) {
    const text = extractUserText(payload);
    if (text) {
      console.log(`[NativeVoice] upstream partial session=${session.sessionId} text=${JSON.stringify(text.slice(0, 120))}`);
      session.latestUserText = text;
      // 用户开口说话时立即打断 AI 播放
      if (session.directSpeakUntil && Date.now() < session.directSpeakUntil) {
        console.log(`[NativeVoice] user barge-in (partial) session=${session.sessionId}`);
        session.directSpeakUntil = 0;
        session.isSendingChatTTSText = false;
        session.chatTTSUntil = 0;
        clearTimeout(session.chatTTSTimer);
        sendJson(session.client, { type: 'tts_reset', reason: 'user_bargein' });
      } else if (session.isSendingChatTTSText && (session.chatTTSUntil || 0) > Date.now()) {
        console.log(`[NativeVoice] user barge-in chatTTS (partial) session=${session.sessionId}`);
        session.isSendingChatTTSText = false;
        session.chatTTSUntil = 0;
        clearTimeout(session.chatTTSTimer);
        sendJson(session.client, { type: 'tts_reset', reason: 'user_bargein' });
      }
      sendJson(session.client, {
        type: 'subtitle',
        role: 'user',
        text,
        isFinal: false,
        sequence: `native_partial_${Date.now()}`,
      });
    }
    return;
  }

  if (message.event === 459 || (message.event === 451 && isFinalUserPayload(payload))) {
    const finalText = extractUserText(payload) || session.latestUserText || '';
    console.log(`[NativeVoice] upstream final session=${session.sessionId} text=${JSON.stringify(finalText.slice(0, 120))}`);
    if (session.directSpeakUntil && Date.now() < session.directSpeakUntil) {
      console.log(`[NativeVoice] user interrupt during speaking session=${session.sessionId}`);
      session.directSpeakUntil = 0;
      session.isSendingChatTTSText = false;
      session.chatTTSUntil = 0;
      clearTimeout(session.chatTTSTimer);
      sendJson(session.client, { type: 'tts_reset', reason: 'user_bargein' });
    } else if (session.isSendingChatTTSText && (session.chatTTSUntil || 0) > Date.now()) {
      console.log(`[NativeVoice] user interrupt chatTTS during speaking session=${session.sessionId}`);
      session.isSendingChatTTSText = false;
      session.chatTTSUntil = 0;
      clearTimeout(session.chatTTSTimer);
      sendJson(session.client, { type: 'tts_reset', reason: 'user_bargein' });
    }
    if (persistUserSpeech(session, finalText)) {
      session.blockUpstreamAudio = true;
      processReply(session, finalText).catch((error) => {
        console.error('[NativeVoice] processReply error:', error.message);
      });
    }
    return;
  }

  sendJson(session.client, {
    type: 'event',
    event: message.event,
    payload,
  });
}

function attachClientHandlers(session) {
  session.client.on('message', async (raw, isBinary) => {
    if (isBinary) {
      if (session.upstream && session.upstream.readyState === WebSocket.OPEN && session.upstreamReady) {
        session.upstream.send(createAudioMessage(session.sessionId, raw));
      }
      return;
    }

    let parsed;
    try {
      parsed = JSON.parse(raw.toString('utf8'));
    } catch (error) {
      sendJson(session.client, { type: 'error', error: 'invalid client json' });
      return;
    }

    if (parsed.type === 'start') {
      session.botName = parsed.botName || '豆包';
      session.systemRole = parsed.systemRole || '你是一个企业知识库语音助手，请优先依据 external_rag 给出的内容回答。';
      session.speakingStyle = parsed.speakingStyle || '请使用清晰、自然、简洁的口吻。';
      session.speaker = parsed.speaker || process.env.VOLC_S2S_SPEAKER_ID || 'zh_female_vv_jupiter_bigtts';
      session.modelVersion = parsed.modelVersion || 'O';
      session.greetingText = parsed.greetingText || session.greetingText || '嗨，你好呀！我是大沃，你的专属智能助手。关于德国PM产品、一成系统、招商合作，随时问我就好～';
      session.userId = parsed.userId || session.userId || null;
      session.upstream = createUpstreamConnection(session);
      loadHandoffSummaryForVoice(session).catch((error) => {
        console.warn('[NativeVoice] async loadHandoffSummaryForVoice failed:', error.message);
      });
      return;
    }

    if (parsed.type === 'stop') {
      session.client.close();
      return;
    }

    if (parsed.type === 'text' && parsed.text) {
      persistUserSpeech(session, parsed.text);
      processReply(session, parsed.text).catch((error) => {
        console.error('[NativeVoice] text processReply failed:', error.message);
      });
    }
  });

  session.client.on('close', () => {
    clearTimeout(session.chatTTSTimer);
    clearTimeout(session.greetingTimer);
    clearTimeout(session.greetingAckTimer);
    clearTimeout(session.readyTimer);
    clearTimeout(session.idleTimer);
    if (session.upstream && session.upstream.readyState === WebSocket.OPEN) {
      session.upstream.close();
    }
    sessions.delete(session.sessionId);
  });
}

function createUpstreamConnection(session) {
  const upstream = new WebSocket('wss://openspeech.bytedance.com/api/v3/realtime/dialogue', {
    headers: {
      'X-Api-Resource-Id': 'volc.speech.dialog',
      'X-Api-Access-Key': process.env.VOLC_S2S_TOKEN,
      'X-Api-App-Key': process.env.VOLC_DIALOG_APP_KEY || 'PlgvMymc7f3tQnJ6',
      'X-Api-App-ID': process.env.VOLC_S2S_APP_ID,
      'X-Api-Connect-Id': session.sessionId,
    },
  });

  upstream.on('open', () => {
    upstream.send(createStartConnectionMessage());
    upstream.send(createStartSessionMessage(session.sessionId, buildStartSessionPayload(session)));
  });

  upstream.on('message', (data, isBinary) => {
    if (!isBinary && typeof data === 'string') {
      sendJson(session.client, { type: 'server_text', text: data });
      return;
    }
    handleUpstreamMessage(session, Buffer.isBuffer(data) ? data : Buffer.from(data));
  });

  upstream.on('error', (error) => {
    console.error('[NativeVoice] upstream ws error:', error.message);
    sendJson(session.client, { type: 'error', error: `语音服务连接异常: ${error.message}` });
  });

  upstream.on('close', (code) => {
    console.log(`[NativeVoice] upstream closed session=${session.sessionId} code=${code}`);
    session.upstreamReady = false;
    sendJson(session.client, { type: 'upstream_closed', code });
    setTimeout(() => {
      if (session.client && session.client.readyState === WebSocket.OPEN) {
        session.client.close();
      }
    }, 3000);
  });

  return upstream;
}

function createSession(client, sessionId) {
  const session = {
    sessionId,
    client,
    upstream: null,
    upstreamReady: false,
    isSendingChatTTSText: false,
    latestUserText: '',
    queuedUserText: '',
    processingReply: false,
    blockUpstreamAudio: false,
    directSpeakUntil: 0,
    queuedReplyTimer: null,
    lastPersistedAssistantText: '',
    lastPersistedAssistantAt: 0,
    assistantStreamBuffer: '',
    assistantStreamReplyId: '',
    currentTtsType: '',
    botName: '大沃',
    systemRole: '你是大沃，一个德国PM健康事业的智能语音助手。你对PM-FitLine细胞营养素产品、一成系统、招商合作非常熟悉。请优先依据 external_rag 给出的内容回答。用户进来时请自然地打个招呼，像朋友聊天一样，不要用客服话术。',
    speakingStyle: '说话像朋友聊天一样自然轻松，语气亲切活泼，不要像客服念稿。',
    speaker: process.env.VOLC_S2S_SPEAKER_ID || 'zh_female_vv_jupiter_bigtts',
    modelVersion: 'O',
    greetingText: '嗨，你好呀！我是大沃，你的专属智能助手。关于德国PM产品、一成系统、招商合作，随时问我就好～',
    hasSentGreeting: false,
    greetingTimer: null,
    greetingAckTimer: null,
    pendingGreetingAck: false,
    greetingRetryCount: 0,
    readyTimer: null,
    readySent: false,
    handoffSummary: '',
    handoffSummaryUsed: false,
    awaitingUpstreamReply: false,
    pendingAssistantSource: null,
    pendingAssistantToolName: null,
    pendingAssistantMeta: null,
    idleTimer: null,
    lastActivityAt: Date.now(),
  };
  sessions.set(sessionId, session);
  attachClientHandlers(session);
  return session;
}

function setupNativeVoiceGateway(server) {
  const wss = new WebSocketServer({ server, path: '/ws/realtime-dialog' });
  wss.on('connection', async (client, req) => {
    const parsed = url.parse(req.url, true);
    const sessionId = parsed.query?.sessionId;
    if (!sessionId) {
      client.close();
      return;
    }
    const userId = parsed.query?.userId || null;
    const session = createSession(client, sessionId);
    session.userId = userId;
    try {
      await db.createSession(sessionId, userId, 'voice');
    } catch (error) {
      console.warn('[NativeVoice][DB] createSession failed:', error.message);
    }
    sendJson(client, { type: 'connected', sessionId });
  });
  return wss;
}

module.exports = {
  setupNativeVoiceGateway,
};