'use client';
import { logger } from "@/lib/logger";

import { useEffect, useState } from 'react';
import { useAuthStore } from '@/lib/auth/store';
import { Button } from '@/components/ui/button';

interface SessionTimeoutWarningProps {
  warningTime?: number; // Minutes before token expires to show warning
}

export function SessionTimeoutWarning({ 
  warningTime = 10 // Show warning 10 minutes before expiry
}: SessionTimeoutWarningProps) {
  const { isAuthenticated, token, logout, checkAuth } = useAuthStore();
  const [showWarning, setShowWarning] = useState(false);
  const [timeLeft, setTimeLeft] = useState<number>(0);

  useEffect(() => {
    if (!isAuthenticated || !token) {
      return undefined;
    }

    // Parse JWT to get expiry time
    try {
      const parts = token.split('.');
      if (parts.length !== 3) {
        throw new Error('Invalid token format');
      }

      const payload = JSON.parse(atob(parts[1]));
      if (!payload.exp) {
        logger.warn('Token does not have expiration time');
        return undefined;
      }

      const expiryTime = payload.exp * 1000; // Convert to milliseconds
      const currentTime = Date.now();
      const warningThreshold = warningTime * 60 * 1000; // Convert to milliseconds

      const timeUntilExpiry = expiryTime - currentTime;
      const timeUntilWarning = timeUntilExpiry - warningThreshold;

      if (timeUntilExpiry <= 0) {
        // Token already expired
        logout();
        return undefined;
      }

      if (timeUntilWarning <= 0) {
        // Should show warning immediately
        setShowWarning(true);
        setTimeLeft(Math.ceil(timeUntilExpiry / 1000 / 60)); // Minutes left
        return undefined;
      } else {
        // Set timeout to show warning
        const warningTimeout = setTimeout(() => {
          setShowWarning(true);
          setTimeLeft(warningTime);
        }, timeUntilWarning);

        return () => clearTimeout(warningTimeout);
      }
    } catch (error) {
      logger.error('Error parsing JWT token:', error);
      logout();
      return undefined;
    }
  }, [isAuthenticated, token, warningTime, logout]);

  useEffect(() => {
    if (!showWarning) return undefined;

    const interval = setInterval(() => {
      setTimeLeft((prev) => {
        if (prev <= 1) {
          // Time's up, log out
          logout();
          return 0;
        }
        return prev - 1;
      });
    }, 60000); // Update every minute

    return () => clearInterval(interval);
  }, [showWarning, logout]);

  const handleExtendSession = async () => {
    try {
      await checkAuth(); // This will refresh the user data and validate the token
      setShowWarning(false);
      setTimeLeft(0);
    } catch (error) {
      logger.error('Failed to extend session:', error);
      logout();
    }
  };

  const handleLogoutNow = () => {
    logout();
    setShowWarning(false);
  };

  if (!showWarning) {
    return null;
  }

  return (
    <div className="fixed inset-0 bg-black/50 flex items-center justify-center z-50">
      <div className="bg-white rounded-lg p-6 max-w-md w-full mx-4 shadow-xl">
        <div className="flex items-center gap-2 mb-4">
          <span className="text-yellow-500 text-xl">⚠️</span>
          <h2 className="text-lg font-semibold">Session Expiring Soon</h2>
        </div>
        
        <p className="text-gray-600 mb-6">
          Your session will expire in <strong>{timeLeft} minute{timeLeft !== 1 ? 's' : ''}</strong>.
          Would you like to extend your session?
        </p>
        
        <div className="flex gap-2 justify-end">
          <Button variant="outline" onClick={handleLogoutNow}>
            Logout Now
          </Button>
          <Button onClick={handleExtendSession}>
            Extend Session
          </Button>
        </div>
      </div>
    </div>
  );
}