import { useEffect, useRef } from 'react';
import { toast } from 'react-hot-toast'; // Assuming react-hot-toast for notifications
import { useCurrentUser } from './useAuth'; // To get current user and their tenant

/**
 * Custom hook to manage WebSocket connection for real-time notifications.
 */
export const useNotificationWebSocket = () => {
  const wsRef = useRef<WebSocket | null>(null);
  const { data: user } = useCurrentUser(); // Get current user for authentication

  useEffect(() => {
    if (!user || !user.id) {
      // If no user or not authenticated, ensure WebSocket is closed
      if (wsRef.current && wsRef.current.readyState === WebSocket.OPEN) {
        wsRef.current.close();
      }
      return;
    }

    // Determine WebSocket URL dynamically
    const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:';
    // The current host needs to be adjusted if the WebSocket server is on a different subdomain/port
    // For local development, assuming it's on the same host/port as the frontend API
    const wsHost = window.location.host; 
    const wsUrl = `${protocol}//${wsHost}/ws/notifications/`;

    const connectWebSocket = () => {
      wsRef.current = new WebSocket(wsUrl);

      wsRef.current.onopen = () => {
        console.log('Notification WebSocket connected');
      };

      wsRef.current.onmessage = (event) => {
        const data = JSON.parse(event.data);
        console.log('Notification received:', data);
        // Display notification using a toast library
        toast.success(data.message, {
          duration: 5000,
          position: 'top-right',
        });
      };

      wsRef.current.onclose = (event) => {
        console.log('Notification WebSocket disconnected:', event);
        // Attempt to reconnect after a short delay
        setTimeout(() => {
          if (user && user.id) { // Only attempt reconnect if user is still authenticated
            console.log('Attempting to reconnect Notification WebSocket...');
            connectWebSocket();
          }
        }, 3000);
      };

      wsRef.current.onerror = (error) => {
        console.error('Notification WebSocket error:', error);
        wsRef.current?.close();
      };
    };

    connectWebSocket();

    // Clean up WebSocket connection on component unmount or user logout
    return () => {
      if (wsRef.current && wsRef.current.readyState === WebSocket.OPEN) {
        wsRef.current.close();
      }
    };
  }, [user]); // Reconnect if user changes (e.g., login/logout)

  // You can expose functions here to manually send messages if needed
  // For notifications, it's typically server-to-client only
};