require('dotenv').config();
const express = require('express');
const cors = require('cors');
const NodeMediaServer = require('node-media-server');
const childProcess = require('child_process');
const fs = require('fs');
const path = require('path');
const roomsRouter = require('./routes/rooms');
const srsRouter = require('./routes/srs');
const friendsRouter = require('./routes/friends');
const viewHistoryRouter = require('./routes/viewHistory');
const errorHandler = require('./middleware/errorHandler');
const roomStore = require('./store/roomStore');

const app = express();
const PORT = process.env.PORT || 3001;

const startMediaServer = () => {
  const host = process.env.SRS_HOST || 'localhost';
  const rtmpPort = Number(process.env.SRS_RTMP_PORT || 1935);
  const httpPort = Number(process.env.SRS_HTTP_PORT || 8080);
  const rawFfmpegPath = process.env.FFMPEG_PATH;

  const embeddedEnabledRaw = process.env.EMBEDDED_MEDIA_SERVER;
  const embeddedEnabled = embeddedEnabledRaw == null
    ? true
    : !['0', 'false', 'off', 'no'].includes(String(embeddedEnabledRaw).toLowerCase());

  if (!embeddedEnabled) {
    console.log('[Media Server] Embedded NodeMediaServer disabled (EMBEDDED_MEDIA_SERVER=0).');
    return;
  }

  let ffmpegPath = rawFfmpegPath;
  if (!ffmpegPath) {
    try {
      if (process.platform === 'win32') {
        const out = childProcess.execSync('where ffmpeg', { stdio: ['ignore', 'pipe', 'ignore'] });
        const first = String(out || '').split(/\r?\n/).map((s) => s.trim()).filter(Boolean)[0];
        if (first) ffmpegPath = first;
      } else {
        const out = childProcess.execSync('which ffmpeg', { stdio: ['ignore', 'pipe', 'ignore'] });
        const first = String(out || '').split(/\r?\n/).map((s) => s.trim()).filter(Boolean)[0];
        if (first) ffmpegPath = first;
      }
    } catch (_) {
      ffmpegPath = null;
    }
  }

  if (ffmpegPath) {
    const p = String(ffmpegPath).trim().replace(/^"|"$/g, '');
    ffmpegPath = p;
    try {
      if (fs.existsSync(ffmpegPath) && fs.statSync(ffmpegPath).isDirectory()) {
        ffmpegPath = path.join(ffmpegPath, 'ffmpeg.exe');
      }
    } catch (_) {
      ffmpegPath = p;
    }

    if (!fs.existsSync(ffmpegPath)) {
      console.warn(`[Media Server] FFMPEG_PATH set but not found: ${ffmpegPath}`);
      ffmpegPath = null;
    }
  }

  try {
    const nmsConfig = {
      rtmp: {
        port: rtmpPort,
        chunk_size: 60000,
        gop_cache: true,
        ping: 30,
        ping_timeout: 60
      },
      http: {
        port: httpPort,
        mediaroot: './media',
        allow_origin: '*'
      }
    };

    if (ffmpegPath) {
      nmsConfig.trans = {
        ffmpeg: ffmpegPath,
        tasks: [
          {
            app: 'live',
            hls: true,
            hlsFlags: '[hls_time=2:hls_list_size=6:hls_flags=delete_segments]'
          }
        ]
      };
    }

    const nms = new NodeMediaServer(nmsConfig);

    nms.on('prePublish', (id, streamPath) => {
      const parts = String(streamPath || '').split('/').filter(Boolean);
      const streamKey = parts[1];
      if (streamKey) roomStore.setLiveStatus(streamKey, true);
    });

    nms.on('donePublish', (id, streamPath) => {
      const parts = String(streamPath || '').split('/').filter(Boolean);
      const streamKey = parts[1];
      console.log(`[Media Server] 推流结束: streamKey=${streamKey}`);
      // 暂时禁用自动关闭直播，改为手动控制
      // if (streamKey) roomStore.setLiveStatus(streamKey, false);
    });

    nms.run();

    console.log(`Media Server RTMP: rtmp://${host}:${rtmpPort}/live (Stream Key = streamKey)`);
    console.log(`Media Server HTTP-FLV: http://${host}:${httpPort}/live/{streamKey}.flv`);
    if (ffmpegPath) {
      console.log(`Media Server HLS: http://${host}:${httpPort}/live/{streamKey}/index.m3u8`);
      console.log(`[Media Server] Using FFmpeg: ${ffmpegPath}`);
    } else {
      console.log('Media Server HLS disabled (set FFMPEG_PATH to enable HLS)');
    }
  } catch (e) {
    console.error('[Media Server] Failed to start embedded media server:', e.message);
    console.error('[Media Server] If ports 1935/8080 are in use, stop the occupying process or change SRS_RTMP_PORT/SRS_HTTP_PORT.');
  }
};

startMediaServer();

// 中间件
app.use(cors({
  origin: process.env.CLIENT_URL || 'http://localhost:3000',
  credentials: true
}));
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// 路由
app.use('/api/rooms', roomsRouter);
app.use('/api/srs', srsRouter);
app.use('/api/front', friendsRouter);
app.use('/api/front/activity', viewHistoryRouter);

// 健康检查
app.get('/health', (req, res) => {
  res.json({ status: 'ok', timestamp: new Date().toISOString() });
});

// 错误处理
app.use(errorHandler);

// 启动服务
app.listen(PORT, '0.0.0.0', () => {
  console.log(`API 服务运行在 http://localhost:${PORT}`);
  console.log(`API 服务也可通过 http://0.0.0.0:${PORT} 访问（用于 Android 模拟器）`);
  console.log(`SRS RTMP: rtmp://${process.env.SRS_HOST || 'localhost'}:${process.env.SRS_RTMP_PORT || 1935}/live/{streamKey}`);
  console.log(`SRS HTTP: http://${process.env.SRS_HOST || 'localhost'}:${process.env.SRS_HTTP_PORT || 8080}/live/{streamKey}.flv`);
});

module.exports = app;