import React, { useState, useEffect } from 'react';
import { useNavigate, useLocation } from 'react-router-dom';
import { supabase } from '../lib/supabase';
import { KeyRound, Lock, AlertCircle } from 'lucide-react';

export function UpdatePassword() {
  const [password, setPassword] = useState('');
  const [confirmPassword, setConfirmPassword] = useState('');
  const [error, setError] = useState('');
  const [loading, setLoading] = useState(false);
  const navigate = useNavigate();
  const location = useLocation();

  useEffect(() => {
    // Check for error parameters in the URL hash
    const hashParams = new URLSearchParams(location.hash.replace('#', ''));
    const errorCode = hashParams.get('error_code');
    const errorDescription = hashParams.get('error_description');

    if (errorCode === 'otp_expired') {
      setError('Your password reset link has expired. Redirecting to request a new one...');
      setTimeout(() => {
        navigate('/reset-password', { replace: true });
      }, 3000);
      return;
    }

    // Check if we have a valid session
    const checkSession = async () => {
      const { data: { session } } = await supabase.auth.getSession();
      if (!session) {
        setError('Invalid or expired password reset link. Please request a new one.');
        setTimeout(() => {
          navigate('/reset-password', { replace: true });
        }, 3000);
      }
    };

    checkSession();
  }, [navigate, location.hash]);

  const handleUpdatePassword = async (e: React.FormEvent) => {
    e.preventDefault();
    setError('');
    setLoading(true);

    if (password.length < 6) {
      setError('Password must be at least 6 characters long');
      setLoading(false);
      return;
    }

    if (password !== confirmPassword) {
      setError('Passwords do not match');
      setLoading(false);
      return;
    }

    try {
      const { error } = await supabase.auth.updateUser({
        password: password
      });

      if (error) throw error;

      // Show success message before redirecting
      const successMessage = document.createElement('div');
      successMessage.className = 'fixed top-4 right-4 bg-green-500 text-white px-6 py-3 rounded-md shadow-lg z-50';
      successMessage.textContent = 'Password updated successfully!';
      document.body.appendChild(successMessage);

      // Remove the message after 3 seconds
      setTimeout(() => {
        document.body.removeChild(successMessage);
        navigate('/login', { replace: true });
      }, 3000);

    } catch (error: any) {
      if (error.message.includes('auth')) {
        setError('Your password reset link has expired. Please request a new one.');
        setTimeout(() => {
          navigate('/reset-password', { replace: true });
        }, 3000);
      } else {
        setError(error.message);
      }
    } finally {
      setLoading(false);
    }
  };

  return (
    <div className="min-h-[calc(100vh-5rem)] bg-oxford flex items-center justify-center py-12 px-4 sm:px-6 lg:px-8">
      <div className="max-w-md w-full">
        <div className="bg-oxford/50 border border-skyblue/20 p-8 rounded-lg shadow-lg">
          <div className="text-center">
            <div className="flex justify-center">
              <KeyRound className="h-12 w-12 text-skyblue" />
            </div>
            <h2 className="mt-4 text-3xl font-bold text-white">Update Password</h2>
            <p className="mt-2 text-gray-400">Enter your new password</p>
          </div>

          <form onSubmit={handleUpdatePassword} className="mt-8 space-y-6">
            {error && (
              <div className="bg-chili/20 border border-chili text-white p-3 rounded-md text-sm flex items-center gap-2">
                <AlertCircle className="h-4 w-4 flex-shrink-0" />
                <span>{error}</span>
              </div>
            )}

            <div className="space-y-4">
              <div>
                <label htmlFor="password" className="block text-sm font-medium text-gray-300 mb-1">
                  New Password
                </label>
                <div className="relative">
                  <div className="absolute inset-y-0 left-0 pl-3 flex items-center pointer-events-none">
                    <Lock className="h-5 w-5 text-gray-400" />
                  </div>
                  <input
                    id="password"
                    name="password"
                    type="password"
                    required
                    minLength={6}
                    className="block w-full pl-10 pr-3 py-2 border border-skyblue/20 rounded-md leading-5 bg-oxford/50 text-white placeholder-gray-400 focus:outline-none focus:ring-2 focus:ring-skyblue focus:border-skyblue sm:text-sm"
                    placeholder="Enter new password"
                    value={password}
                    onChange={(e) => setPassword(e.target.value)}
                  />
                </div>
                <p className="mt-1 text-sm text-gray-400">Must be at least 6 characters long</p>
              </div>

              <div>
                <label htmlFor="confirmPassword" className="block text-sm font-medium text-gray-300 mb-1">
                  Confirm Password
                </label>
                <div className="relative">
                  <div className="absolute inset-y-0 left-0 pl-3 flex items-center pointer-events-none">
                    <Lock className="h-5 w-5 text-gray-400" />
                  </div>
                  <input
                    id="confirmPassword"
                    name="confirmPassword"
                    type="password"
                    required
                    className="block w-full pl-10 pr-3 py-2 border border-skyblue/20 rounded-md leading-5 bg-oxford/50 text-white placeholder-gray-400 focus:outline-none focus:ring-2 focus:ring-skyblue focus:border-skyblue sm:text-sm"
                    placeholder="Confirm new password"
                    value={confirmPassword}
                    onChange={(e) => setConfirmPassword(e.target.value)}
                  />
                </div>
              </div>
            </div>

            <div>
              <button
                type="submit"
                disabled={loading}
                className="w-full flex justify-center py-2 px-4 border border-transparent rounded-md shadow-sm text-sm font-medium text-white bg-button hover:bg-button/90 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-skyblue transition-colors disabled:opacity-50 disabled:cursor-not-allowed"
              >
                {loading ? 'Updating...' : 'Update Password'}
              </button>
            </div>
          </form>
        </div>
      </div>
    </div>
  );
}