const express = require('express');
const router = express.Router();
const { v4: uuidv4 } = require('uuid');
const volcengine = require('../services/volcengine');
const VoiceChatConfigBuilder = require('../config/voiceChatConfig');
const ToolExecutor = require('../services/toolExecutor');
const DEFAULT_TOOLS = require('../config/tools');
const db = require('../db');

const activeSessions = new Map();
const completedSessions = new Map();
const roomToBotUserId = new Map();
const roomToHumanUserId = new Map();
const roomToSessionId = new Map();
const roomToTaskId = new Map();
const latestUserSpeech = new Map();
const toolCallBuffers = new Map();

router.get('/config', (req, res) => {
  res.json({
    success: true,
    data: {
      models: [
        { value: '1.2.1.0', label: 'O2.0（推荐，精品音质）' },
        { value: 'O', label: 'O（基础版）' },
        { value: '2.2.0.0', label: 'SC2.0（推荐，声音复刻）' },
        { value: 'SC', label: 'SC（基础版）' },
      ],
      speakers: [
        { value: 'zh_female_vv_jupiter_bigtts', label: 'VV（活泼女声）', series: 'O' },
        { value: 'zh_female_xiaohe_jupiter_bigtts', label: '小禾（甜美女声·台湾口音）', series: 'O' },
        { value: 'zh_male_yunzhou_jupiter_bigtts', label: '云舟（沉稳男声）', series: 'O' },
        { value: 'zh_male_xiaotian_jupiter_bigtts', label: '小天（磁性男声）', series: 'O' },
        { value: 'saturn_common_female_1', label: 'Saturn 女声1', series: 'SC2.0' },
        { value: 'saturn_common_male_1', label: 'Saturn 男声1', series: 'SC2.0' },
        { value: 'ICL_common_female_1', label: 'ICL 女声1', series: 'SC' },
        { value: 'ICL_common_male_1', label: 'ICL 男声1', series: 'SC' },
      ],
      tools: DEFAULT_TOOLS.map((t) => ({
        name: t.function.name,
        description: t.function.description,
      })),
    },
  });
});

router.post('/prepare', async (req, res) => {
  try {
    const { userId } = req.body;
    if (!userId) {
      return res.status(400).json({ success: false, error: 'userId is required' });
    }
    const sessionId = uuidv4();
    const roomId = `room_${sessionId.slice(0, 8)}`;
    const taskId = `task_${sessionId.slice(0, 8)}_${Date.now()}`;
    const rtcToken = volcengine.generateRTCToken(roomId, userId);
    activeSessions.set(sessionId, {
      roomId,
      taskId,
      userId,
      startTime: Date.now(),
      subtitles: [],
      started: false,
    });
    roomToTaskId.set(roomId, taskId);
    roomToSessionId.set(roomId, sessionId);
    console.log(`[Voice] Session prepared: ${sessionId}, room: ${roomId}, user: ${userId}`);
    try { await db.createSession(sessionId, userId, 'voice'); } catch (e) { console.warn('[DB] createSession failed:', e.message); }
    res.json({
      success: true,
      data: {
        sessionId,
        roomId,
        taskId,
        rtcToken,
        rtcAppId: process.env.VOLC_RTC_APP_ID,
      },
    });
  } catch (error) {
    console.error('[Voice] Prepare failed:', error.message);
    res.status(500).json({ success: false, error: error.message });
  }
});

router.post('/start', async (req, res) => {
  let session = null;
  try {
    const {
      sessionId,
      botName,
      systemRole,
      speakingStyle,
      modelVersion,
      speaker,
      enableWebSearch,
      chatHistory,
    } = req.body;
    if (!sessionId) {
      return res.status(400).json({ success: false, error: 'sessionId is required' });
    }
    session = activeSessions.get(sessionId);
    if (!session) {
      return res.status(404).json({ success: false, error: 'Session not found' });
    }
    if (session.started) {
      return res.json({ success: true, data: { message: 'Already started' } });
    }
    let effectiveChatHistory = chatHistory;
    if ((!chatHistory || chatHistory.length === 0) && sessionId) {
      try {
        const dbHistory = await db.getHistoryForLLM(sessionId, 20);
        if (dbHistory.length > 0) {
          effectiveChatHistory = dbHistory;
          console.log(`[Voice] Loaded ${dbHistory.length} messages from DB for session ${sessionId}`);
        }
      } catch (e) { console.warn('[DB] getHistoryForLLM failed:', e.message); }
    }
    console.log(`[Voice] chatHistory: ${effectiveChatHistory ? effectiveChatHistory.length : 'undefined'} messages`);
    const { config, botUserId } = VoiceChatConfigBuilder.build({
      roomId: session.roomId,
      taskId: session.taskId,
      userId: session.userId,
      botName,
      systemRole,
      speakingStyle,
      modelVersion,
      speaker,
      tools: DEFAULT_TOOLS,
      enableWebSearch,
      chatHistory: effectiveChatHistory,
    });
    session.botUserId = botUserId;
    roomToBotUserId.set(session.roomId, botUserId);
    roomToHumanUserId.set(session.roomId, session.userId);
    console.log(`[Voice] room=${session.roomId} botUserId=${botUserId} humanUserId=${session.userId}`);
    const result = await volcengine.startVoiceChat(config);
    session.started = true;
    // 捕获服务端可能分配的不同 TaskId
    const serverTaskId = result?.Result?.TaskId || result?.Result?.task_id;
    if (serverTaskId && serverTaskId !== session.taskId) {
      console.log(`[Voice] Server assigned different TaskId: ${serverTaskId} (ours: ${session.taskId})`);
      roomToTaskId.set(session.roomId, serverTaskId);
      session.taskId = serverTaskId;
    }
    console.log(`[Voice] Session started: ${sessionId}, TaskId=${session.taskId}`);
    res.json({
      success: true,
      data: { startResult: result },
    });
  } catch (error) {
    const detail = error.response?.data || error.message;
    console.error('[Voice] Start failed:', JSON.stringify(detail, null, 2));
    if (session) {
      try {
        await volcengine.stopVoiceChat({
          AppId: process.env.VOLC_RTC_APP_ID,
          RoomId: session.roomId,
          TaskId: session.taskId,
        });
        console.log(`[Voice] Stopped failed session`);
      } catch (stopErr) {
        console.warn('[Voice] Stop failed during error handling:', stopErr.message);
      }
    }
    res.status(500).json({ success: false, error: typeof detail === 'string' ? detail : JSON.stringify(detail) });
  }
});

router.post('/stop', async (req, res) => {
  try {
    const { sessionId } = req.body;
    const session = activeSessions.get(sessionId);
    if (session) {
      await volcengine.stopVoiceChat({
        AppId: process.env.VOLC_RTC_APP_ID,
        RoomId: session.roomId,
        TaskId: session.taskId,
      });
      const duration = Math.floor((Date.now() - session.startTime) / 1000);
      console.log(`[Voice] Session stopped: ${sessionId}, duration: ${duration}s, subtitles: ${session.subtitles.length}`);
      if (session.subtitles.length > 0) {
        completedSessions.set(sessionId, {
          subtitles: session.subtitles,
          duration,
          endTime: Date.now(),
        });
        setTimeout(() => completedSessions.delete(sessionId), 30 * 60 * 1000);
      }
      activeSessions.delete(sessionId);
      roomToTaskId.delete(session.roomId);
      roomToSessionId.delete(session.roomId);
      roomToBotUserId.delete(session.roomId);
      roomToHumanUserId.delete(session.roomId);
      res.json({
        success: true,
        data: {
          duration,
          subtitleCount: session.subtitles.length,
          subtitles: session.subtitles,
        },
      });
    } else {
      res.json({ success: true, data: { message: 'Session not found or already stopped' } });
    }
  } catch (error) {
    console.error('[Voice] Stop failed:', error.message);
    res.status(500).json({ success: false, error: error.message });
  }
});

router.post('/subtitle', (req, res) => {
  try {
    const { sessionId, roomId, text, role, definite, sequence } = req.body;
    const session = activeSessions.get(sessionId);
    if (definite && text) {
      const subtitleRole = role === 'user' ? 'user' : 'assistant';
      if (session) {
        session.subtitles.push({ text, role: subtitleRole, timestamp: Date.now(), sequence });
      }
      const sid = sessionId || (session && roomToSessionId.get(session.roomId));
      if (sid) {
        const source = subtitleRole === 'user' ? 'voice_asr' : 'voice_bot';
        db.addMessage(sid, subtitleRole, text, source).catch(e => console.warn('[DB] addMessage failed:', e.message));
      }
      if (subtitleRole === 'user') {
        const rid = roomId || (session && session.roomId) || '';
        if (rid) {
          latestUserSpeech.set(rid, { text, timestamp: Date.now() });
          console.log(`[Subtitle][user][${rid}] "${text}"`);
        }
      } else {
        console.log(`[Subtitle][assistant] ${text}`);
      }
    }
    res.json({ success: true });
  } catch (error) {
    console.error('[Subtitle] Error:', error.message);
    res.status(500).json({ success: false, error: error.message });
  }
});

router.get('/subtitles/:sessionId', (req, res) => {
  const session = activeSessions.get(req.params.sessionId);
  res.json({
    success: true,
    data: session ? session.subtitles : [],
  });
});

function extractReadableText(chunks) {
  const raw = chunks.join('');
  let decoded = raw;
  try {
    decoded = decoded.replace(/\\\\u([0-9a-fA-F]{4})/g, (_, hex) => {
      return String.fromCharCode(parseInt(hex, 16));
    });
    decoded = decoded.replace(/\\u([0-9a-fA-F]{4})/g, (_, hex) => {
      return String.fromCharCode(parseInt(hex, 16));
    });
  } catch (e) { }
  const chineseChars = decoded.match(/[\u4e00-\u9fff\u3400-\u4dbf]+/g) || [];
  const skipWords = new Set(['id', 'type', 'function', 'name', 'arguments', 'query', 'object', 'string']);
  const englishWords = (decoded.match(/[a-zA-Z]{2,}/g) || [])
    .filter(w => !skipWords.has(w.toLowerCase()));
  const parts = [...chineseChars, ...englishWords];
  const result = parts.join(' ').trim();
  console.log(`[FC] extractReadableText: chinese=[${chineseChars.join(',')}] english=[${englishWords.join(',')}] → "${result}"`);
  return result;
}

let fcCallbackSeq = 0;
router.post('/fc_callback', async (req, res) => {
  try {
    const body = req.body;
    if (!body || typeof body !== 'object' || Object.keys(body).length === 0) {
      console.error('[FC] Empty body');
      return res.status(400).json({ success: false, error: 'Empty body' });
    }
    const { Message, Signature, Type, RoomID, TaskID, TaskType, AppID, AppId, room_id, task_id, roomId, taskId } = body;
    const effectiveRoomId = RoomID || room_id || roomId;
    const effectiveTaskId = TaskID || task_id || taskId;
    const effectiveAppId = AppID || AppId || process.env.VOLC_RTC_APP_ID;
    const seq = body._seq || ++fcCallbackSeq;
    console.log(`[FC] >>> Callback received: seq=${seq} Type="${Type}" Room=${effectiveRoomId} Task=${effectiveTaskId} TaskType=${TaskType}`);
    let msgObj = null;
    try {
      msgObj = typeof Message === 'string' ? JSON.parse(Message) : Message;
    } catch (e) {
      console.error('[FC] Failed to parse Message:', e.message);
      return res.json({ success: true });
    }

    if (Type === 'tool_calls' && Array.isArray(msgObj) && msgObj.length > 0) {
      const tc = msgObj[0];
      const chunkId = tc.id || '';
      const chunkName = tc.function?.name || '';
      const chunkArgs = tc.function?.arguments || '';
      const existing = toolCallBuffers.get(effectiveTaskId);
      
      if (existing && existing.triggered) {
        const userSpeech = latestUserSpeech.get(effectiveRoomId);
        const hasNewInput = userSpeech && (Date.now() - userSpeech.timestamp < 10000);
        if (hasNewInput) {
          console.log(`[FC] [FormatA] New user input detected, clearing cooldown for room=${effectiveRoomId}`);
          toolCallBuffers.delete(effectiveTaskId);
        } else {
          // 扩展 cooldown 到 30 秒，防止 LLM 在 KB 查询期间无限重试
          const cooldownMs = existing.resultSentAt ? 30000 : 15000;
          const elapsed = existing.resultSentAt
            ? (Date.now() - existing.resultSentAt)
            : (Date.now() - existing.createdAt);
          if (elapsed < cooldownMs) {
            console.log(`[FC] [FormatA] Cooldown active (${elapsed}ms < ${cooldownMs}ms), ignoring retry for TaskID=${effectiveTaskId}`);
            res.json({ success: true });
            return;
          }
          console.log(`[FC] [FormatA] Cooldown expired (${elapsed}ms >= ${cooldownMs}ms), allowing new call for TaskID=${effectiveTaskId}`);
          toolCallBuffers.delete(effectiveTaskId);
        }
      }
      
      if (!toolCallBuffers.has(effectiveTaskId)) {
        toolCallBuffers.set(effectiveTaskId, {
          id: '', name: '', chunks: [], triggered: false,
          RoomID: effectiveRoomId, AppID: effectiveAppId, S2STaskID: effectiveTaskId, createdAt: Date.now(), timer: null,
        });
        console.log(`[FC] [FormatA] New buffer created for TaskID=${effectiveTaskId}, room=${effectiveRoomId}`);
      }
      
      const buf = toolCallBuffers.get(effectiveTaskId);
      if (chunkId && !buf.id) buf.id = chunkId;
      if (chunkName && !buf.name) buf.name = chunkName;
      if (chunkArgs) {
        buf.chunks.push({ seq: tc.seq || 0, args: chunkArgs });
      }
      
      res.json({ success: true });
      
      if (buf.timer) clearTimeout(buf.timer);
      buf.timer = setTimeout(async () => {  // 500ms 收集 chunks
        const b = toolCallBuffers.get(effectiveTaskId);
        if (!b || b.triggered) return;
        b.triggered = true;
        const toolName = b.name || 'search_knowledge';
        const sortedChunks = b.chunks.sort((a, b) => a.seq - b.seq);
        const allArgs = sortedChunks.map(c => c.args).join('');
        console.log(`[FC] [FormatA] 500ms timeout, ${b.chunks.length} chunks collected, name="${toolName}"`);

        const s2sTaskId = roomToTaskId.get(b.RoomID) || b.S2STaskID || effectiveTaskId;
        console.log(`[FC] TaskId resolution: roomToTaskId=${roomToTaskId.get(b.RoomID)} callback=${b.S2STaskID} → using=${s2sTaskId}`);
        // 不再单独发 interrupt 命令，ExternalTextToSpeech 的 InterruptMode:1 已包含打断功能

        let parsedArgs = null;
        try {
          parsedArgs = JSON.parse(allArgs);
          console.log(`[FC] [FormatA] JSON.parse succeeded: ${JSON.stringify(parsedArgs)}`);
        } catch (e) {
          const userSpeech = latestUserSpeech.get(b.RoomID);
          if (userSpeech && (Date.now() - userSpeech.timestamp < 30000)) {
            console.log(`[FC] [FormatA] Using ASR user speech: "${userSpeech.text}"`);
            parsedArgs = { query: userSpeech.text };
          } else {
            const extractedText = extractReadableText(b.chunks.map(c => c.args));
            console.log(`[FC] [FormatA] No ASR text, extracted from chunks: "${extractedText}"`);
            parsedArgs = { query: extractedText || '' };
          }
        }

        console.log('[FC] ⚡ Starting KB query (no pre-query interrupt)');
        const kbResult = await ToolExecutor.execute(toolName, parsedArgs);

        try {
          const result = kbResult;
          const resultStr = JSON.stringify(result);
          console.log(`[FC] Tool result (${toolName}): ${resultStr.substring(0, 500)}`);
          let contentText = resultStr;
          try {
            if (result && result.results && Array.isArray(result.results)) {
              contentText = result.results.map(r => r.content || JSON.stringify(r)).join('\n');
            } else if (result && result.error) {
              contentText = result.error;
            } else if (typeof result === 'string') {
              contentText = result;
            }
          } catch (e) { }
          const dbSessionId = roomToSessionId.get(b.RoomID);
          if (dbSessionId) {
            db.addMessage(dbSessionId, 'assistant', contentText, 'voice_tool', toolName)
              .catch(e => console.warn('[DB] addMessage(tool) failed:', e.message));
          }
          console.log(`[FC] Knowledge base content (${contentText.length} chars): ${contentText.substring(0, 200)}${contentText.length > 200 ? '...' : ''}`);
          b.resultSentAt = Date.now();

          // === 策略：只用 Command:function 回传结果给 LLM ===
          // 根因分析：
          //   1. ExternalTextToSpeech 在 S2S 端到端模式下不产生可听见的音频（API返回ok但无声音）
          //   2. ExternalTextToSpeech InterruptMode=1 会打断正在播放的 S2S 回复，导致用户听到中断
          //   3. Command:function 是官方自定义 FC 模式的正确回传方式
          // 流程：Command:function → LLM 收到工具结果 → LLM 生成回复 → S2S 朗读
          const toolCallId = b.id || 'unknown_call_id';
          const functionContent = contentText.length > 1500
            ? contentText.substring(0, 1500) + '……（内容较长，以上为主要部分）'
            : contentText;
          const funcMsg = JSON.stringify({
            ToolCallID: toolCallId,
            Content: functionContent,
          });

          let activeTaskId = s2sTaskId;
          try {
            console.log(`[FC] ★ Sending Command:function (ToolCallID=${toolCallId}, content=${functionContent.length} chars)`);
            await volcengine.updateVoiceChat({
              AppId: effectiveAppId,
              RoomId: b.RoomID,
              TaskId: activeTaskId,
              Command: 'function',
              Message: funcMsg,
            });
            console.log('[FC] ✅ Command:function sent OK → LLM will generate S2S response with KB content');
          } catch (funcErr) {
            console.error('[FC] ✖ Command:function failed:', funcErr.message);
            // 如果正式 TaskId 失败，尝试回调 TaskId
            if (activeTaskId !== b.S2STaskID) {
              try {
                console.log(`[FC] Retrying Command:function with callback TaskID=${b.S2STaskID}`);
                activeTaskId = b.S2STaskID;
                await volcengine.updateVoiceChat({
                  AppId: effectiveAppId,
                  RoomId: b.RoomID,
                  TaskId: activeTaskId,
                  Command: 'function',
                  Message: funcMsg,
                });
                console.log('[FC] ✅ Command:function retry OK');
              } catch (retryErr) {
                console.error('[FC] ✖ Command:function retry also failed:', retryErr.message);
              }
            }
          }
          console.log(`[FC] Final result: Command:function sent (${functionContent.length} chars)`);
        } catch (err) {
          console.error(`[FC] Tool execution failed:`, err.message);
          console.error(`[FC] Error details:`, err);
        }
      }, 500);  // 从1s减到500ms，减少等待
      return;
    }

    if (msgObj && typeof msgObj === 'object' && !Array.isArray(msgObj)) {
      const eventType = msgObj.event_type;
      console.log(`[FC] [FormatB] event_type="${eventType}"`);
      if (eventType === 'function_calling') {
        const funcName = msgObj.function || '';
        const toolCallId = msgObj.tool_call_id || '';
        const responseId = msgObj.response_id || '';
        console.log(`[FC] [Information] FC notification: func=${funcName} toolCallId=${toolCallId} responseId=${responseId}`);
        res.json({ success: true });
        // ExternalTextToSpeech 在 S2S 模式下不产生音频，不再发送安抚语
        // LLM 的 tool_calls 会触发 FormatA 分支执行工具并通过 Command:function 回传结果
        console.log(`[FC] [Information] FC notification received, waiting for tool_calls`);
        return;
      }
    }

    if (msgObj && typeof msgObj === 'object') {
      const asrText = msgObj.text || msgObj.asr_text || msgObj.content ||
                       msgObj.user_text || msgObj.transcript ||
                       (msgObj.data && (msgObj.data.text || msgObj.data.asr_text || msgObj.data.content));
      const role = msgObj.role || msgObj.speaker || msgObj.data?.role || '';
      const isUser = !role || role === 'user' || role === 'human';
      if (asrText && isUser && RoomID) {
        latestUserSpeech.set(RoomID, { text: asrText, timestamp: Date.now() });
        console.log(`[FC] [ConvState] Stored user speech for ${RoomID}: "${asrText}"`);
      }
    }
    res.json({ success: true });
  } catch (error) {
    console.error('[FC] Error:', error.message);
    res.status(500).json({ success: false, error: error.message });
  }
});

router.post('/room_message', (req, res) => {
  try {
    const { roomId, uid, text } = req.body;
    if (!roomId || !text) {
      return res.json({ success: true });
    }
    const jsonStart = text.search(/[\[{]/);
    if (jsonStart < 0) {
      return res.json({ success: true });
    }
    const jsonStr = text.substring(jsonStart);
    let parsed = null;
    try { parsed = JSON.parse(jsonStr); } catch (e) {
      const textMatch = jsonStr.match(/"text"\s*:\s*"([^"]+)"/);
      if (textMatch && textMatch[1]) {
        const extractedText = textMatch[1];
        const userIdMatch = jsonStr.match(/"userId"\s*:\s*"([^"]+)"/);
        const subtitleUserId = userIdMatch ? userIdMatch[1] : '';
        const isUserSpeech = subtitleUserId && !subtitleUserId.startsWith('bot_');
        if (isUserSpeech && extractedText) {
          latestUserSpeech.set(roomId, { text: extractedText, timestamp: Date.now(), source: 'room_regex' });
          console.log(`[RoomMsg] ✅ Stored user speech (regex) for ${roomId}: "${extractedText}"`);
        }
      }
      return res.json({ success: true });
    }
    if (parsed && parsed.data && Array.isArray(parsed.data)) {
      parsed.data.forEach(sub => {
        const subText = sub.text || '';
        const subUserId = sub.userId || sub.user_id || '';
        const isDefinite = sub.definite === true;
        const isUserSpeech = subUserId && !subUserId.startsWith('bot_');
        if (subText && isUserSpeech && isDefinite) {
          latestUserSpeech.set(roomId, { text: subText, timestamp: Date.now(), source: 'room_subtitle' });
          console.log(`[RoomMsg] ✅ Stored user speech for ${roomId}: "${subText}"`);
        }
      });
      res.json({ success: true });
      return;
    }
    if (parsed && typeof parsed === 'object') {
      const asrText = parsed.text || parsed.asr_text || parsed.content ||
                       parsed.user_text || parsed.transcript ||
                       (parsed.data && typeof parsed.data === 'string' ? parsed.data : null);
      const isBot = uid && uid.startsWith('bot_');
      if (asrText && !isBot) {
        latestUserSpeech.set(roomId, { text: asrText, timestamp: Date.now(), source: 'room_object' });
        console.log(`[RoomMsg] ✅ Stored user speech (obj) for ${roomId}: "${asrText}"`);
      }
    }
    res.json({ success: true });
  } catch (error) {
    console.error('[RoomMsg] Error:', error.message);
    res.json({ success: true });
  }
});

router.post('/tool-callback', async (req, res) => {
  console.log('[ToolCallback] Legacy callback received:', JSON.stringify(req.body));
  res.json({ success: true, message: 'deprecated, use fc_callback instead' });
});

router.get('/sessions', (req, res) => {
  const sessions = [];
  for (const [id, session] of activeSessions) {
    sessions.push({
      sessionId: id,
      roomId: session.roomId,
      userId: session.userId,
      duration: Math.floor((Date.now() - session.startTime) / 1000),
      subtitleCount: session.subtitles.length,
    });
  }
  res.json({ success: true, data: sessions });
});

module.exports = router;