import { WebSocket } from "ws";
import { verifyAccessToken } from "./jwt.js";

/**
 * WebSocket Manager
 * Handles WebSocket connections, user mapping, and broadcasting
 */
class WebSocketManager {
  constructor() {
    // Map of steamId -> WebSocket connection
    this.userConnections = new Map();

    // Map of WebSocket -> steamId
    this.socketToUser = new Map();

    // Map of WebSocket -> additional metadata
    this.socketMetadata = new Map();

    // Set to track all connected sockets
    this.allSockets = new Set();
  }

  /**
   * Register a new WebSocket connection
   * @param {WebSocket} socket - The WebSocket connection
   * @param {Object} request - The HTTP request object
   */
  async handleConnection(socket, request) {
    console.log("🔌 New WebSocket connection attempt");

    // Validate socket
    if (!socket || typeof socket.on !== "function") {
      console.error("❌ Invalid WebSocket object received:", typeof socket);
      return;
    }

    // Add to all sockets set
    this.allSockets.add(socket);

    // Set up ping/pong for connection health
    socket.isAlive = true;
    socket.on("pong", () => {
      socket.isAlive = true;
    });

    // Handle authentication
    try {
      const user = await this.authenticateSocket(socket, request);

      if (user) {
        this.mapUserToSocket(user.steamId, socket);
        console.log(
          `✅ WebSocket authenticated for user: ${user.steamId} (${user.username})`
        );

        // Send welcome message
        this.sendToSocket(socket, {
          type: "connected",
          data: {
            steamId: user.steamId,
            username: user.username,
            userId: user.userId,
            timestamp: Date.now(),
          },
        });
      } else {
        console.log("⚠️ WebSocket connection without authentication (public)");
      }
    } catch (error) {
      console.error("❌ WebSocket authentication error:", error.message);
    }

    // Handle incoming messages
    socket.on("message", (data) => {
      this.handleMessage(socket, data);
    });

    // Handle disconnection
    socket.on("close", () => {
      this.handleDisconnection(socket);
    });

    // Handle errors
    socket.on("error", (error) => {
      console.error("❌ WebSocket error:", error);
      this.handleDisconnection(socket);
    });
  }

  /**
   * Authenticate a WebSocket connection
   * @param {WebSocket} socket - The WebSocket connection
   * @param {Object} request - The HTTP request object
   * @returns {Object|null} User object or null if not authenticated
   */
  async authenticateSocket(socket, request) {
    try {
      // Try to get token from query string
      const url = new URL(request.url, `http://${request.headers.host}`);
      const token = url.searchParams.get("token");

      if (!token) {
        // Try to get token from cookie
        const cookies = this.parseCookies(request.headers.cookie || "");
        const cookieToken = cookies.accessToken;

        if (!cookieToken) {
          return null;
        }

        const decoded = verifyAccessToken(cookieToken);
        return decoded;
      }

      const decoded = verifyAccessToken(token);
      return decoded;
    } catch (error) {
      console.error("WebSocket auth error:", error.message);
      return null;
    }
  }

  /**
   * Parse cookie header
   * @param {string} cookieHeader - The cookie header string
   * @returns {Object} Parsed cookies
   */
  parseCookies(cookieHeader) {
    const cookies = {};
    if (!cookieHeader) return cookies;

    cookieHeader.split(";").forEach((cookie) => {
      const parts = cookie.trim().split("=");
      if (parts.length === 2) {
        cookies[parts[0]] = decodeURIComponent(parts[1]);
      }
    });

    return cookies;
  }

  /**
   * Map a user ID to a WebSocket connection
   * @param {string} steamId - The Steam ID
   * @param {WebSocket} socket - The WebSocket connection
   */
  mapUserToSocket(steamId, socket) {
    // Remove old connection if exists
    if (this.userConnections.has(steamId)) {
      const oldSocket = this.userConnections.get(steamId);
      this.handleDisconnection(oldSocket);
    }

    this.userConnections.set(steamId, socket);
    this.socketToUser.set(socket, steamId);
    this.socketMetadata.set(socket, {
      steamId,
      connectedAt: Date.now(),
      lastActivity: Date.now(),
    });
  }

  /**
   * Handle incoming WebSocket messages
   * @param {WebSocket} socket - The WebSocket connection
   * @param {Buffer|string} data - The message data
   */
  handleMessage(socket, data) {
    try {
      const message = JSON.parse(data.toString());
      const steamId = this.socketToUser.get(socket);

      // Update last activity
      const metadata = this.socketMetadata.get(socket);
      if (metadata) {
        metadata.lastActivity = Date.now();
      }

      console.log(`📨 Message from ${steamId || "anonymous"}:`, message.type);

      // Handle ping messages
      if (message.type === "ping") {
        this.sendToSocket(socket, { type: "pong", timestamp: Date.now() });
        return;
      }

      // You can add more message handlers here
      // For now, just log unknown message types
      console.log("Unknown message type:", message.type);
    } catch (error) {
      console.error("❌ Error handling WebSocket message:", error);
    }
  }

  /**
   * Handle WebSocket disconnection
   * @param {WebSocket} socket - The WebSocket connection
   */
  handleDisconnection(socket) {
    const steamId = this.socketToUser.get(socket);

    if (steamId) {
      console.log(`🔌 User ${steamId} disconnected`);
      this.userConnections.delete(steamId);
    }

    this.socketToUser.delete(socket);
    this.socketMetadata.delete(socket);
    this.allSockets.delete(socket);

    try {
      if (socket.readyState === WebSocket.OPEN) {
        socket.close();
      }
    } catch (error) {
      console.error("Error closing socket:", error);
    }
  }

  /**
   * Send a message to a specific socket
   * @param {WebSocket} socket - The WebSocket connection
   * @param {Object} data - The data to send
   */
  sendToSocket(socket, data) {
    if (socket.readyState === WebSocket.OPEN) {
      try {
        socket.send(JSON.stringify(data));
      } catch (error) {
        console.error("❌ Error sending to socket:", error);
      }
    }
  }

  /**
   * Send a message to a specific user by Steam ID
   * @param {string} steamId - The Steam ID
   * @param {Object} data - The data to send
   * @returns {boolean} True if message was sent, false otherwise
   */
  sendToUser(steamId, data) {
    const socket = this.userConnections.get(steamId);
    if (socket) {
      this.sendToSocket(socket, data);
      return true;
    }
    return false;
  }

  /**
   * Broadcast a message to all connected clients
   * @param {Object} data - The data to broadcast
   * @param {Array<string>} excludeSteamIds - Optional array of Steam IDs to exclude
   */
  broadcastToAll(data, excludeSteamIds = []) {
    const message = JSON.stringify(data);
    let sentCount = 0;

    this.allSockets.forEach((socket) => {
      const steamId = this.socketToUser.get(socket);

      // Skip if user is in exclude list
      if (steamId && excludeSteamIds.includes(steamId)) {
        return;
      }

      if (socket.readyState === WebSocket.OPEN) {
        try {
          socket.send(message);
          sentCount++;
        } catch (error) {
          console.error("❌ Error broadcasting to socket:", error);
        }
      }
    });

    console.log(`📡 Broadcast sent to ${sentCount} clients`);
    return sentCount;
  }

  /**
   * Broadcast to authenticated users only
   * @param {Object} data - The data to broadcast
   * @param {Array<string>} excludeSteamIds - Optional array of Steam IDs to exclude
   */
  broadcastToAuthenticated(data, excludeSteamIds = []) {
    const message = JSON.stringify(data);
    let sentCount = 0;

    this.userConnections.forEach((socket, steamId) => {
      // Skip if user is in exclude list
      if (excludeSteamIds.includes(steamId)) {
        return;
      }

      if (socket.readyState === WebSocket.OPEN) {
        try {
          socket.send(message);
          sentCount++;
        } catch (error) {
          console.error("❌ Error broadcasting to user:", error);
        }
      }
    });

    console.log(`📡 Broadcast sent to ${sentCount} authenticated users`);
    return sentCount;
  }

  /**
   * Broadcast a public message (e.g., price updates, new listings)
   * This sends to all clients regardless of authentication
   * @param {string} type - The message type
   * @param {Object} payload - The message payload
   */
  broadcastPublic(type, payload) {
    return this.broadcastToAll({
      type,
      data: payload,
      timestamp: Date.now(),
    });
  }

  /**
   * Check if a user is currently connected
   * @param {string} steamId - The Steam ID
   * @returns {boolean} True if user is connected
   */
  isUserConnected(steamId) {
    return this.userConnections.has(steamId);
  }

  /**
   * Get the number of connected users
   * @returns {number} Number of authenticated users
   */
  getAuthenticatedUserCount() {
    return this.userConnections.size;
  }

  /**
   * Get the total number of connected sockets
   * @returns {number} Total number of sockets
   */
  getTotalSocketCount() {
    return this.allSockets.size;
  }

  /**
   * Get connection metadata for a user
   * @param {string} steamId - The Steam ID
   * @returns {Object|null} Metadata or null if not found
   */
  getUserMetadata(steamId) {
    const socket = this.userConnections.get(steamId);
    if (socket) {
      return this.socketMetadata.get(socket);
    }
    return null;
  }

  /**
   * Start heartbeat interval to check for dead connections
   * @param {number} interval - Interval in milliseconds
   */
  startHeartbeat(interval = 30000) {
    this.heartbeatInterval = setInterval(() => {
      this.allSockets.forEach((socket) => {
        if (socket.isAlive === false) {
          console.log("💀 Terminating dead connection");
          return this.handleDisconnection(socket);
        }

        socket.isAlive = false;
        if (socket.readyState === WebSocket.OPEN) {
          socket.ping();
        }
      });
    }, interval);

    console.log(`💓 WebSocket heartbeat started (${interval}ms)`);
  }

  /**
   * Stop heartbeat interval
   */
  stopHeartbeat() {
    if (this.heartbeatInterval) {
      clearInterval(this.heartbeatInterval);
      console.log("💓 WebSocket heartbeat stopped");
    }
  }

  /**
   * Gracefully close all connections
   */
  closeAll() {
    console.log("🔌 Closing all WebSocket connections...");

    this.allSockets.forEach((socket) => {
      try {
        if (socket.readyState === WebSocket.OPEN) {
          socket.close(1000, "Server shutting down");
        }
      } catch (error) {
        console.error("Error closing socket:", error);
      }
    });

    this.userConnections.clear();
    this.socketToUser.clear();
    this.socketMetadata.clear();
    this.allSockets.clear();
    this.stopHeartbeat();

    console.log("✅ All WebSocket connections closed");
  }
}

// Create and export a singleton instance
export const wsManager = new WebSocketManager();

export default wsManager;