import React, { useState } from 'react';
import { useAuth } from '../contexts/AuthContext';
import { useNavigate, useLocation } from 'react-router-dom';

function LoginForm() {
  const [formData, setFormData] = useState({
    username: '',
    password: ''
  });
  const [error, setError] = useState('');
  const [loading, setLoading] = useState(false);

  const { login } = useAuth();
  const navigate = useNavigate();
  const location = useLocation();

  // Redirect to intended location after login, or to admin dashboard
  const redirectTo = location.state?.from?.pathname || '/admin';

  const handleChange = (e) => {
    const { name, value } = e.target;
    setFormData(prev => ({ ...prev, [name]: value }));
  };

  const handleSubmit = async (e) => {
    e.preventDefault();
    setLoading(true);
    setError('');

    if (!formData.username.trim() || !formData.password) {
      setError('Please enter both username and password');
      setLoading(false);
      return;
    }

    try {
      const result = await login(formData.username.trim(), formData.password);
      
      if (result.success) {
        navigate(redirectTo, { replace: true });
      } else {
        setError(result.error || 'Login failed');
      }
    } catch (err) {
      setError('An unexpected error occurred');
    } finally {
      setLoading(false);
    }
  };

  return (
    <div className="min-h-screen bg-gray-50 flex items-center justify-center py-12 px-4 sm:px-6 lg:px-8">
      <div className="max-w-md w-full space-y-8">
        <div>
          <h2 className="mt-6 text-center text-3xl font-extrabold text-gray-900">
            Sign in to Admin Panel
          </h2>
          <p className="mt-2 text-center text-sm text-gray-600">
            Access the <span className="text-blue-600 font-semibold">Goon</span>Blog admin interface
          </p>
        </div>
        
        <form className="mt-8 space-y-6" onSubmit={handleSubmit}>
          <div className="rounded-md shadow-sm -space-y-px">
            <div>
              <label htmlFor="username" className="sr-only">
                Username
              </label>
              <input
                id="username"
                name="username"
                type="text"
                autoComplete="username"
                required
                value={formData.username}
                onChange={handleChange}
                className="relative block w-full px-3 py-2 border border-gray-300 placeholder-gray-500 text-gray-900 rounded-t-md focus:outline-none focus:ring-blue-500 focus:border-blue-500 focus:z-10 sm:text-sm"
                placeholder="Username"
                disabled={loading}
              />
            </div>
            <div>
              <label htmlFor="password" className="sr-only">
                Password
              </label>
              <input
                id="password"
                name="password"
                type="password"
                autoComplete="current-password"
                required
                value={formData.password}
                onChange={handleChange}
                className="relative block w-full px-3 py-2 border border-gray-300 placeholder-gray-500 text-gray-900 rounded-b-md focus:outline-none focus:ring-blue-500 focus:border-blue-500 focus:z-10 sm:text-sm"
                placeholder="Password"
                disabled={loading}
              />
            </div>
          </div>

          {error && (
            <div className="rounded-md bg-red-50 p-4">
              <div className="flex">
                <div className="flex-shrink-0">
                  <svg className="h-5 w-5 text-red-400" viewBox="0 0 20 20" fill="currentColor">
                    <path fillRule="evenodd" d="M10 18a8 8 0 100-16 8 8 0 000 16zM8.707 7.293a1 1 0 00-1.414 1.414L8.586 10l-1.293 1.293a1 1 0 101.414 1.414L10 11.414l1.293 1.293a1 1 0 001.414-1.414L11.414 10l1.293-1.293a1 1 0 00-1.414-1.414L10 8.586 8.707 7.293z" clipRule="evenodd" />
                  </svg>
                </div>
                <div className="ml-3">
                  <h3 className="text-sm font-medium text-red-800">
                    Error
                  </h3>
                  <div className="mt-1 text-sm text-red-700">
                    {error}
                  </div>
                </div>
              </div>
            </div>
          )}

          <div>
            <button
              type="submit"
              disabled={loading}
              className="group relative w-full flex justify-center py-2 px-4 border border-transparent text-sm font-medium rounded-md text-white bg-blue-600 hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-offset-2 focus:ring-blue-500 disabled:opacity-50 disabled:cursor-not-allowed"
            >
              {loading ? (
                <div className="flex items-center">
                  <div className="animate-spin rounded-full h-4 w-4 border-b-2 border-white mr-2"></div>
                  Signing in...
                </div>
              ) : (
                'Sign in'
              )}
            </button>
          </div>

          <div className="text-center">
            <button
              type="button"
              onClick={() => navigate('/')}
              className="text-sm text-gray-600 hover:text-gray-900"
            >
              ← Back to Blog
            </button>
          </div>
        </form>
      </div>
    </div>
  );
}

export default LoginForm;