// Next.js 自定义服务器 + Socket.IO
const { createServer } = require('http');
const { parse } = require('url');
const next = require('next');
const { Server } = require('socket.io');

const dev = process.env.NODE_ENV !== 'production';
const hostname = process.env.HOSTNAME || '0.0.0.0';
const port = parseInt(process.env.PORT || '3000', 10);

const app = next({ dev, hostname, port });
const handle = app.getRequestHandler();

// 读取观影室配置的辅助函数
async function getWatchRoomConfig() {
  const storageType = process.env.NEXT_PUBLIC_STORAGE_TYPE || 'localstorage';

  // 如果使用 localStorage，无法在服务器端读取，返回默认配置（不启用）
  if (storageType === 'localstorage') {
    console.log('[WatchRoom] Using localStorage storage type.');
    // 在 localStorage 模式下，可以通过环境变量控制是否启用观影室
    const enabled = process.env.WATCH_ROOM_ENABLED === 'true';
    console.log(`[WatchRoom] Watch room ${enabled ? 'enabled' : 'disabled'} via environment variable.`);
    return { enabled, serverType: 'internal' };
  }

  try {
    if (storageType === 'redis') {
      // 检查 Redis 配置
      const redisUrl = process.env.REDIS_URL || 'redis://localhost:6379';
      console.log('[WatchRoom] Attempting to read config from Redis...');

      const { createClient } = require('redis');
      const client = createClient({ url: redisUrl });
      await client.connect();

      const configStr = await client.get('admin:config'); // 注意：使用冒号而不是下划线
      await client.disconnect();

      if (configStr) {
        const config = JSON.parse(configStr);
        return config.WatchRoomConfig || { enabled: false, serverType: 'internal' };
      }
    } else if (storageType === 'upstash') {
      // 检查 Upstash 环境变量
      if (!process.env.UPSTASH_REDIS_REST_URL || !process.env.UPSTASH_REDIS_REST_TOKEN) {
        console.log('[WatchRoom] Upstash credentials not configured. Socket.IO disabled by default.');
        return { enabled: false, serverType: 'internal' };
      }

      console.log('[WatchRoom] Attempting to read config from Upstash...');
      const { Redis } = require('@upstash/redis');
      const redis = new Redis({
        url: process.env.UPSTASH_REDIS_REST_URL,
        token: process.env.UPSTASH_REDIS_REST_TOKEN,
      });

      const configStr = await redis.get('admin:config'); // 注意：使用冒号而不是下划线

      if (configStr) {
        const config = typeof configStr === 'string' ? JSON.parse(configStr) : configStr;
        return config.WatchRoomConfig || { enabled: false, serverType: 'internal' };
      }
    } else if (storageType === 'kvrocks') {
      // 检查 Kvrocks 配置
      const kvrocksUrl = process.env.KVROCKS_URL || 'redis://localhost:6666';
      console.log('[WatchRoom] Attempting to read config from Kvrocks...');

      const { createClient } = require('redis');
      const client = createClient({ url: kvrocksUrl });
      await client.connect();

      const configStr = await client.get('admin:config'); // 注意：使用冒号而不是下划线
      await client.disconnect();

      if (configStr) {
        const config = JSON.parse(configStr);
        return config.WatchRoomConfig || { enabled: false, serverType: 'internal' };
      }
    }
  } catch (error) {
    console.error('[WatchRoom] Failed to read config from storage:', error.message);
  }

  // 默认不启用观影室
  console.log('[WatchRoom] No config found or error occurred. Socket.IO disabled by default.');
  return { enabled: false, serverType: 'internal' };
}

// 观影室服务器类
class WatchRoomServer {
  constructor(io) {
    this.io = io;
    this.rooms = new Map();
    this.members = new Map();
    this.socketToRoom = new Map();
    this.roomDeletionTimers = new Map(); // 房间延迟删除定时器
    this.cleanupInterval = null;
    this.setupEventHandlers();
    this.startCleanupTimer();
  }

  setupEventHandlers() {
    this.io.on('connection', (socket) => {
      console.log(`[WatchRoom] Client connected: ${socket.id}`);

      // 创建房间
      socket.on('room:create', (data, callback) => {
        try {
          const roomId = this.generateRoomId();
          const userId = socket.id;
          const ownerToken = this.generateRoomId(); // 生成房主令牌

          const room = {
            id: roomId,
            name: data.name,
            description: data.description,
            password: data.password,
            isPublic: data.isPublic,
            ownerId: userId,
            ownerName: data.userName,
            ownerToken: ownerToken, // 保存房主令牌
            memberCount: 1,
            currentState: null,
            createdAt: Date.now(),
            lastOwnerHeartbeat: Date.now(),
          };

          const member = {
            id: userId,
            name: data.userName,
            isOwner: true,
            lastHeartbeat: Date.now(),
          };

          this.rooms.set(roomId, room);
          this.members.set(roomId, new Map([[userId, member]]));
          this.socketToRoom.set(socket.id, {
            roomId,
            userId,
            userName: data.userName,
            isOwner: true,
          });

          socket.join(roomId);

          console.log(`[WatchRoom] Room created: ${roomId} by ${data.userName}`);
          callback({ success: true, room });
        } catch (error) {
          console.error('[WatchRoom] Error creating room:', error);
          callback({ success: false, error: '创建房间失败' });
        }
      });

      // 加入房间
      socket.on('room:join', (data, callback) => {
        try {
          const room = this.rooms.get(data.roomId);
          if (!room) {
            return callback({ success: false, error: '房间不存在' });
          }

          if (room.password && room.password !== data.password) {
            return callback({ success: false, error: '密码错误' });
          }

          const userId = socket.id;
          let isOwner = false;

          // 检查是否是房主重连（通过 ownerToken 验证）
          if (data.ownerToken && data.ownerToken === room.ownerToken) {
            isOwner = true;
            // 更新房主的 socket.id
            room.ownerId = userId;
            room.lastOwnerHeartbeat = Date.now();
            this.rooms.set(data.roomId, room);
            console.log(`[WatchRoom] Owner ${data.userName} reconnected to room ${data.roomId}`);
          }

          // 取消房间的删除定时器（如果有人重连）
          if (this.roomDeletionTimers.has(data.roomId)) {
            console.log(`[WatchRoom] Cancelling deletion timer for room ${data.roomId}`);
            clearTimeout(this.roomDeletionTimers.get(data.roomId));
            this.roomDeletionTimers.delete(data.roomId);
          }

          const member = {
            id: userId,
            name: data.userName,
            isOwner: isOwner,
            lastHeartbeat: Date.now(),
          };

          const roomMembers = this.members.get(data.roomId);
          if (roomMembers) {
            roomMembers.set(userId, member);
            room.memberCount = roomMembers.size;
            this.rooms.set(data.roomId, room);
          }

          this.socketToRoom.set(socket.id, {
            roomId: data.roomId,
            userId,
            userName: data.userName,
            isOwner: isOwner,
          });

          socket.join(data.roomId);
          socket.to(data.roomId).emit('room:member-joined', member);

          console.log(`[WatchRoom] User ${data.userName} joined room ${data.roomId}${isOwner ? ' (as owner)' : ''}`);

          const members = Array.from(roomMembers?.values() || []);
          callback({ success: true, room, members });
        } catch (error) {
          console.error('[WatchRoom] Error joining room:', error);
          callback({ success: false, error: '加入房间失败' });
        }
      });

      // 离开房间
      socket.on('room:leave', () => {
        this.handleLeaveRoom(socket);
      });

      // 获取房间列表
      socket.on('room:list', (callback) => {
        const publicRooms = Array.from(this.rooms.values()).filter((room) => room.isPublic);
        callback(publicRooms);
      });

      // 播放状态更新（任何成员都可以触发同步）
      socket.on('play:update', (state) => {
        console.log(`[WatchRoom] Received play:update from ${socket.id}:`, state);
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) {
          console.log('[WatchRoom] No room info for socket, ignoring play:update');
          return;
        }

        const room = this.rooms.get(roomInfo.roomId);
        if (room) {
          room.currentState = state;
          this.rooms.set(roomInfo.roomId, room);
          console.log(`[WatchRoom] Broadcasting play:update to room ${roomInfo.roomId} from ${roomInfo.userName}`);
          socket.to(roomInfo.roomId).emit('play:update', state);
        } else {
          console.log('[WatchRoom] Room not found for play:update');
        }
      });

      // 播放进度跳转
      socket.on('play:seek', (currentTime) => {
        console.log(`[WatchRoom] Received play:seek from ${socket.id}:`, currentTime);
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) {
          console.log('[WatchRoom] No room info for socket, ignoring play:seek');
          return;
        }
        console.log(`[WatchRoom] Broadcasting play:seek to room ${roomInfo.roomId}`);
        socket.to(roomInfo.roomId).emit('play:seek', currentTime);
      });

      // 播放
      socket.on('play:play', () => {
        console.log(`[WatchRoom] Received play:play from ${socket.id}`);
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) {
          console.log('[WatchRoom] No room info for socket, ignoring play:play');
          return;
        }
        console.log(`[WatchRoom] Broadcasting play:play to room ${roomInfo.roomId}`);
        socket.to(roomInfo.roomId).emit('play:play');
      });

      // 暂停
      socket.on('play:pause', () => {
        console.log(`[WatchRoom] Received play:pause from ${socket.id}`);
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) {
          console.log('[WatchRoom] No room info for socket, ignoring play:pause');
          return;
        }
        console.log(`[WatchRoom] Broadcasting play:pause to room ${roomInfo.roomId}`);
        socket.to(roomInfo.roomId).emit('play:pause');
      });

      // 切换视频/集数
      socket.on('play:change', (state) => {
        console.log(`[WatchRoom] Received play:change from ${socket.id}:`, state);
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) {
          console.log('[WatchRoom] No room info for socket, ignoring play:change');
          return;
        }
        if (!roomInfo.isOwner) {
          console.log('[WatchRoom] User is not owner, ignoring play:change');
          return;
        }

        const room = this.rooms.get(roomInfo.roomId);
        if (room) {
          room.currentState = state;
          this.rooms.set(roomInfo.roomId, room);
          console.log(`[WatchRoom] Broadcasting play:change to room ${roomInfo.roomId}`);
          socket.to(roomInfo.roomId).emit('play:change', state);
        } else {
          console.log('[WatchRoom] Room not found for play:change');
        }
      });

      // 切换直播频道
      socket.on('live:change', (state) => {
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo || !roomInfo.isOwner) return;

        const room = this.rooms.get(roomInfo.roomId);
        if (room) {
          room.currentState = state;
          this.rooms.set(roomInfo.roomId, room);
          socket.to(roomInfo.roomId).emit('live:change', state);
        }
      });

      // 聊天消息
      socket.on('chat:message', (data) => {
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) return;

        const message = {
          id: this.generateMessageId(),
          userId: roomInfo.userId,
          userName: roomInfo.userName,
          content: data.content,
          type: data.type,
          timestamp: Date.now(),
        };

        this.io.to(roomInfo.roomId).emit('chat:message', message);
      });

      // WebRTC 信令
      socket.on('voice:offer', (data) => {
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) return;
        this.io.to(data.targetUserId).emit('voice:offer', {
          userId: socket.id,
          offer: data.offer,
        });
      });

      socket.on('voice:answer', (data) => {
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) return;
        this.io.to(data.targetUserId).emit('voice:answer', {
          userId: socket.id,
          answer: data.answer,
        });
      });

      socket.on('voice:ice', (data) => {
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) return;
        this.io.to(data.targetUserId).emit('voice:ice', {
          userId: socket.id,
          candidate: data.candidate,
        });
      });

      // 心跳
      socket.on('heartbeat', () => {
        const roomInfo = this.socketToRoom.get(socket.id);
        if (!roomInfo) return;

        const roomMembers = this.members.get(roomInfo.roomId);
        const member = roomMembers?.get(roomInfo.userId);
        if (member) {
          member.lastHeartbeat = Date.now();
          roomMembers?.set(roomInfo.userId, member);
        }

        if (roomInfo.isOwner) {
          const room = this.rooms.get(roomInfo.roomId);
          if (room) {
            room.lastOwnerHeartbeat = Date.now();
            this.rooms.set(roomInfo.roomId, room);
          }
        }
      });

      // 断开连接
      socket.on('disconnect', () => {
        console.log(`[WatchRoom] Client disconnected: ${socket.id}`);
        this.handleLeaveRoom(socket);
      });
    });
  }

  handleLeaveRoom(socket) {
    const roomInfo = this.socketToRoom.get(socket.id);
    if (!roomInfo) return;

    const { roomId, userId, isOwner } = roomInfo;
    const room = this.rooms.get(roomId);
    const roomMembers = this.members.get(roomId);

    if (roomMembers) {
      roomMembers.delete(userId);

      if (room) {
        room.memberCount = roomMembers.size;
        this.rooms.set(roomId, room);
      }

      socket.to(roomId).emit('room:member-left', userId);

      // 如果是房主主动离开，解散房间并踢出所有成员
      if (isOwner) {
        console.log(`[WatchRoom] Owner actively left room ${roomId}, disbanding room`);

        // 通知所有成员房间被解散
        socket.to(roomId).emit('room:deleted', { reason: 'owner_left' });

        // 强制所有成员离开房间
        const members = Array.from(roomMembers.keys());
        members.forEach(memberId => {
          this.socketToRoom.delete(memberId);
        });

        // 立即删除房间（跳过通知，因为上面已经发送了）
        this.deleteRoom(roomId, true);

        // 清除可能存在的删除定时器
        if (this.roomDeletionTimers.has(roomId)) {
          clearTimeout(this.roomDeletionTimers.get(roomId));
          this.roomDeletionTimers.delete(roomId);
        }
      } else {
        // 普通成员离开，房间为空时延迟删除
        if (roomMembers.size === 0) {
          console.log(`[WatchRoom] Room ${roomId} is now empty, will delete in 30 seconds if no one rejoins`);

          const deletionTimer = setTimeout(() => {
            // 再次检查房间是否仍然为空
            const currentRoomMembers = this.members.get(roomId);
            if (currentRoomMembers && currentRoomMembers.size === 0) {
              console.log(`[WatchRoom] Room ${roomId} deletion timer expired, deleting room`);
              this.deleteRoom(roomId);
              this.roomDeletionTimers.delete(roomId);
            }
          }, 30000); // 30秒后删除

          this.roomDeletionTimers.set(roomId, deletionTimer);
        }
      }
    }

    socket.leave(roomId);
    this.socketToRoom.delete(socket.id);
  }

  deleteRoom(roomId, skipNotify = false) {
    console.log(`[WatchRoom] Deleting room ${roomId}`);

    // 如果不跳过通知，则发送 room:deleted 事件
    if (!skipNotify) {
      this.io.to(roomId).emit('room:deleted');
    }

    this.rooms.delete(roomId);
    this.members.delete(roomId);
  }

  startCleanupTimer() {
    this.cleanupInterval = setInterval(() => {
      const now = Date.now();
      const deleteTimeout = 5 * 60 * 1000; // 5分钟 - 删除房间
      const clearStateTimeout = 30 * 1000; // 30秒 - 清除播放状态

      for (const [roomId, room] of this.rooms.entries()) {
        const timeSinceHeartbeat = now - room.lastOwnerHeartbeat;

        // 如果房主心跳超过30秒，清除播放状态
        if (timeSinceHeartbeat > clearStateTimeout && room.currentState !== null) {
          console.log(`[WatchRoom] Room ${roomId} owner inactive for 30s, clearing play state`);
          room.currentState = null;
          this.rooms.set(roomId, room);
          // 通知房间内所有成员状态已清除
          this.io.to(roomId).emit('state:cleared');
        }

        // 检查房主是否超时5分钟 - 删除房间
        if (timeSinceHeartbeat > deleteTimeout) {
          console.log(`[WatchRoom] Room ${roomId} owner timeout, deleting...`);
          this.deleteRoom(roomId);
        }
      }
    }, 10000); // 每10秒检查一次，确保更及时的清理
  }

  generateRoomId() {
    return Math.random().toString(36).substring(2, 8).toUpperCase();
  }

  generateMessageId() {
    return `${Date.now()}-${Math.random().toString(36).substring(2, 9)}`;
  }

  destroy() {
    if (this.cleanupInterval) {
      clearInterval(this.cleanupInterval);
    }

    // 清理所有房间删除定时器
    for (const timer of this.roomDeletionTimers.values()) {
      clearTimeout(timer);
    }
    this.roomDeletionTimers.clear();
  }
}

app.prepare().then(async () => {
  const httpServer = createServer(async (req, res) => {
    try {
      const parsedUrl = parse(req.url, true);
      await handle(req, res, parsedUrl);
    } catch (err) {
      console.error('Error occurred handling', req.url, err);
      res.statusCode = 500;
      res.end('Internal server error');
    }
  });

  // 读取观影室配置
  const watchRoomConfig = await getWatchRoomConfig();
  console.log('[WatchRoom] Config:', watchRoomConfig);

  let watchRoomServer = null;

  // 只在启用观影室且使用内部服务器时初始化 Socket.IO
  if (watchRoomConfig.enabled && watchRoomConfig.serverType === 'internal') {
    console.log('[WatchRoom] Initializing Socket.IO server...');

    // 初始化 Socket.IO
    const io = new Server(httpServer, {
      path: '/socket.io',
      cors: {
        origin: '*',
        methods: ['GET', 'POST'],
      },
    });

    // 初始化观影室服务器
    watchRoomServer = new WatchRoomServer(io);
    console.log('[WatchRoom] Socket.IO server initialized');
  } else {
    if (!watchRoomConfig.enabled) {
      console.log('[WatchRoom] Watch room is disabled');
    } else if (watchRoomConfig.serverType === 'external') {
      console.log('[WatchRoom] Using external watch room server');
    }
  }

  httpServer
    .once('error', (err) => {
      console.error(err);
      process.exit(1);
    })
    .listen(port, () => {
      console.log(`> Ready on http://${hostname}:${port}`);
      if (watchRoomConfig.enabled && watchRoomConfig.serverType === 'internal') {
        console.log(`> Socket.IO ready on ws://${hostname}:${port}`);
      }
    });

  // 优雅关闭
  process.on('SIGINT', () => {
    console.log('\n[Server] Shutting down...');
    if (watchRoomServer) {
      watchRoomServer.destroy();
    }
    httpServer.close(() => {
      console.log('[Server] Server closed');
      process.exit(0);
    });
  });

  process.on('SIGTERM', () => {
    console.log('\n[Server] Shutting down...');
    if (watchRoomServer) {
      watchRoomServer.destroy();
    }
    httpServer.close(() => {
      console.log('[Server] Server closed');
      process.exit(0);
    });
  });
});