const logger = require('../utils/logger');
const { getGameSystem } = require('../systems/GameSystem');
const Player = require('../models/Player');

class SocketHandlers {
  constructor(io) {
    this.io = io;
    this.connectedUsers = new Map(); // userId -> socket.id
    this.userSockets = new Map(); // socket.id -> userId
    
    // Add connection cleanup interval
    this.startConnectionCleanup();
  }
  
  startConnectionCleanup() {
    // Clean up stale connections every 30 seconds
    setInterval(() => {
      this.cleanupStaleConnections();
    }, 30000);
  }
  
  cleanupStaleConnections() {
    logger.info(`[SOCKET HANDLERS] Checking ${this.connectedUsers.size} active connections...`);
    
    for (const [userId, socketId] of this.connectedUsers.entries()) {
      const socket = this.io.sockets.sockets.get(socketId);
      if (!socket || !socket.connected) {
        logger.warn(`[SOCKET HANDLERS] Cleaning up stale connection for user ${userId} (socket: ${socketId})`);
        this.connectedUsers.delete(userId);
        this.userSockets.delete(socketId);
      }
    }
  }

  handleConnection(socket) {
    logger.info(`Client connected: ${socket.id}`);

    // Authentication
    socket.on('authenticate', async (token) => {
      try {
        const jwt = require('jsonwebtoken');
        const decoded = jwt.verify(token, process.env.JWT_SECRET || 'fallback_secret');
        
        const player = await Player.findOne({ userId: decoded.userId });
        if (!player) {
          socket.emit('auth_error', { error: 'Player not found' });
          return;
        }

        // Check if user is already connected from another client
        const existingSocketId = this.connectedUsers.get(decoded.userId);
        if (existingSocketId && existingSocketId !== socket.id) {
          logger.warn(`[SOCKET HANDLERS] User ${decoded.userId} attempting to connect from multiple clients. Disconnecting previous client.`);
          logger.warn(`[SOCKET HANDLERS] Existing socket: ${existingSocketId}, New socket: ${socket.id}`);
          
          // Disconnect the previous client
          const previousSocket = this.io.sockets.sockets.get(existingSocketId);
          if (previousSocket) {
            logger.info(`[SOCKET HANDLERS] Force disconnecting previous socket: ${existingSocketId}`);
            previousSocket.emit('force_disconnect', { 
              reason: 'Another client connected with your account',
              newSocketId: socket.id 
            });
            previousSocket.disconnect(true);
          } else {
            logger.warn(`[SOCKET HANDLERS] Previous socket ${existingSocketId} not found in active connections`);
            // Clean up the stale mapping
            this.connectedUsers.delete(decoded.userId);
            this.userSockets.delete(existingSocketId);
          }
        } else {
          logger.info(`[SOCKET HANDLERS] New connection for user ${decoded.userId} (socket: ${socket.id})`);
        }

        // Store user connection
        this.connectedUsers.set(decoded.userId, socket.id);
        this.userSockets.set(socket.id, decoded.userId);
        
        socket.userId = decoded.userId;
        socket.emit('authenticated', { userId: decoded.userId });
        
        logger.info(`User authenticated: ${decoded.userId} (socket: ${socket.id})`);
        
        // Join user to their current server if any
        if (player.currentServer) {
          socket.join(player.currentServer);
          this.broadcastToServer(player.currentServer, 'user_joined', {
            userId: decoded.userId,
            username: player.username,
            socketId: socket.id
          });
        }
        
      } catch (error) {
        logger.error('Authentication error:', error);
        socket.emit('auth_error', { error: 'Invalid token' });
      }
    });

    // Server management
    socket.on('join_server', async (data) => {
      try {
        if (!socket.userId) {
          socket.emit('error', { error: 'Not authenticated' });
          return;
        }

        const gameSystem = getGameSystem();
        const server = await gameSystem.joinServer(data.serverId, socket.userId);
        
        // Update player's current server
        await Player.findOneAndUpdate(
          { userId: socket.userId },
          { currentServer: data.serverId }
        );
        
        // Join socket room
        socket.join(data.serverId);
        
        socket.emit('server_joined', { server });
        this.broadcastToServer(data.serverId, 'user_joined', {
          userId: socket.userId,
          serverId: data.serverId
        });
        
        logger.info(`User ${socket.userId} joined server ${data.serverId}`);
        
      } catch (error) {
        logger.error('Error joining server:', error);
        socket.emit('error', { error: error.message });
      }
    });

    socket.on('leave_server', async (data) => {
      try {
        if (!socket.userId) {
          socket.emit('error', { error: 'Not authenticated' });
          return;
        }

        const gameSystem = getGameSystem();
        const server = await gameSystem.leaveServer(data.serverId, socket.userId);
        
        // Update player's current server
        await Player.findOneAndUpdate(
          { userId: socket.userId },
          { currentServer: null }
        );
        
        // Leave socket room
        socket.leave(data.serverId);
        
        socket.emit('server_left', { server });
        this.broadcastToServer(data.serverId, 'user_left', {
          userId: socket.userId,
          serverId: data.serverId
        });
        
        logger.info(`User ${socket.userId} left server ${data.serverId}`);
        
      } catch (error) {
        logger.error('Error leaving server:', error);
        socket.emit('error', { error: error.message });
      }
    });

    // Game actions
    socket.on('game_action', async (data) => {
      try {
        if (!socket.userId) {
          socket.emit('error', { error: 'Not authenticated' });
          return;
        }

        const gameSystem = getGameSystem();
        const result = await gameSystem.processGameAction(socket.userId, data);
        
        socket.emit('action_result', { action: data.type, result });
        
        // Broadcast relevant actions to server
        if (data.broadcast && socket.userId) {
          const player = await Player.findOne({ userId: socket.userId });
          if (player && player.currentServer) {
            this.broadcastToServer(player.currentServer, 'user_action', {
              userId: socket.userId,
              username: player.username,
              action: data.type,
              result
            });
          }
        }
        
      } catch (error) {
        logger.error('Error processing game action:', error);
        socket.emit('error', { error: error.message });
      }
    });

    // Chat functionality
    socket.on('send_message', async (data) => {
      try {
        if (!socket.userId) {
          socket.emit('error', { error: 'Not authenticated' });
          return;
        }

        const player = await Player.findOne({ userId: socket.userId });
        if (!player || !player.currentServer) {
          socket.emit('error', { error: 'Not in a server' });
          return;
        }

        const message = {
          userId: socket.userId,
          username: player.username,
          message: data.message,
          timestamp: new Date(),
          type: data.type || 'chat'
        };

        // Broadcast to server
        this.broadcastToServer(player.currentServer, 'new_message', message);
        
        logger.info(`Chat message from ${socket.userId} in server ${player.currentServer}`);
        
      } catch (error) {
        logger.error('Error sending message:', error);
        socket.emit('error', { error: error.message });
      }
    });

    // Real-time updates
    socket.on('request_server_status', async () => {
      try {
        if (!socket.userId) {
          socket.emit('error', { error: 'Not authenticated' });
          return;
        }

        const player = await Player.findOne({ userId: socket.userId });
        if (!player || !player.currentServer) {
          socket.emit('server_status', { server: null });
          return;
        }

        const gameSystem = getGameSystem();
        const server = gameSystem.servers.get(player.currentServer);
        
        if (server) {
          const players = await Player.find({ 
            userId: { $in: server.players } 
          }).select('userId username info.stats.level');

          socket.emit('server_status', {
            server: {
              id: server.id,
              name: server.name,
              currentPlayers: server.players.length,
              maxPlayers: server.maxPlayers,
              players: players.map(p => ({
                userId: p.userId,
                username: p.username,
                level: p.info.stats.level
              }))
            }
          });
        }
        
      } catch (error) {
        logger.error('Error getting server status:', error);
        socket.emit('error', { error: error.message });
      }
    });

    // Disconnection
    socket.on('disconnect', async () => {
      logger.info(`Client disconnected: ${socket.id}`);
      
      const userId = this.userSockets.get(socket.id);
      if (userId) {
        logger.info(`User ${userId} disconnected (socket: ${socket.id})`);
        
        // Remove from tracking maps
        this.connectedUsers.delete(userId);
        this.userSockets.delete(socket.id);
        
        // Update player's online status
        try {
          const player = await Player.findOne({ userId });
          if (player) {
            // Notify server if user was in one
            if (player.currentServer) {
              this.broadcastToServer(player.currentServer, 'user_disconnected', {
                userId,
                username: player.username,
                socketId: socket.id
              });
              
              // Leave the server room
              socket.leave(player.currentServer);
            }
            
            logger.info(`User ${userId} fully disconnected and cleaned up`);
          }
        } catch (error) {
          logger.error(`Error cleaning up user ${userId} on disconnect:`, error);
        }
      } else {
        logger.warn(`Unknown socket ${socket.id} disconnected without user mapping`);
      }
    });
  }

  broadcastToServer(serverId, event, data) {
    this.io.to(serverId).emit(event, data);
  }

  sendToUser(userId, event, data) {
    const socketId = this.connectedUsers.get(userId);
    if (socketId) {
      this.io.to(socketId).emit(event, data);
    }
  }
  
  // Method to check for duplicate accounts
  async checkForDuplicateAccounts() {
    try {
      const Player = require('../models/Player');
      const allPlayers = await Player.find({}, 'userId email username');
      
      const duplicateEmails = [];
      const duplicateUsernames = [];
      const emailMap = new Map();
      const usernameMap = new Map();
      
      allPlayers.forEach(player => {
        if (emailMap.has(player.email)) {
          duplicateEmails.push({
            email: player.email,
            user1: emailMap.get(player.email),
            user2: player.userId
          });
        } else {
          emailMap.set(player.email, player.userId);
        }
        
        if (usernameMap.has(player.username)) {
          duplicateUsernames.push({
            username: player.username,
            user1: usernameMap.get(player.username),
            user2: player.userId
          });
        } else {
          usernameMap.set(player.username, player.userId);
        }
      });
      
      if (duplicateEmails.length > 0) {
        logger.error(`[SOCKET HANDLERS] Found ${duplicateEmails.length} duplicate emails in database:`, duplicateEmails);
      }
      
      if (duplicateUsernames.length > 0) {
        logger.error(`[SOCKET HANDLERS] Found ${duplicateUsernames.length} duplicate usernames in database:`, duplicateUsernames);
      }
      
      logger.info(`[SOCKET HANDLERS] Account check complete: ${allPlayers.length} total players, ${duplicateEmails.length} duplicate emails, ${duplicateUsernames.length} duplicate usernames`);
      
      return {
        totalPlayers: allPlayers.length,
        duplicateEmails,
        duplicateUsernames
      };
    } catch (error) {
      logger.error('[SOCKET HANDLERS] Error checking for duplicate accounts:', error);
      return { error: error.message };
    }
  }
  
  // Method to get connection statistics
  getConnectionStats() {
    return {
      connectedUsers: this.connectedUsers.size,
      userSockets: this.userSockets.size,
      activeSockets: this.io.engine.clientsCount,
      connections: Array.from(this.connectedUsers.entries()).map(([userId, socketId]) => ({
        userId,
        socketId,
        isActive: !!this.io.sockets.sockets.get(socketId)
      }))
    };
  }

  broadcastToAll(event, data) {
    this.io.emit(event, data);
  }

  getConnectedUsers() {
    return Array.from(this.connectedUsers.keys());
  }

  getUserCount() {
    return this.connectedUsers.size;
  }
}

module.exports = SocketHandlers;