import { useState, type FormEvent } from 'react';
import { Navigate } from 'react-router-dom';
import { useAuth } from '../context/AuthContext';
import { ApiError } from '../api/client';

export function LoginPage() {
  const { login, user, needsSetup } = useAuth();
  const [username, setUsername] = useState('');
  const [password, setPassword] = useState('');
  const [error, setError] = useState<string | null>(null);
  const [submitting, setSubmitting] = useState(false);

  if (needsSetup) return <Navigate to="/setup" replace />;
  if (user) return <Navigate to="/" replace />;

  async function handleSubmit(e: FormEvent) {
    e.preventDefault();
    setError(null);
    setSubmitting(true);
    try {
      await login(username, password);
    } catch (err) {
      setError(
        err instanceof ApiError && err.status === 401
          ? 'Invalid username or password.'
          : 'Something went wrong. Please try again.',
      );
    } finally {
      setSubmitting(false);
    }
  }

  return (
    <div className="auth-page">
      <form className="auth-form" onSubmit={handleSubmit}>
        <h1>CityTracker</h1>
        <label>
          Username
          <input
            value={username}
            onChange={(e) => setUsername(e.target.value)}
            autoComplete="username"
            required
            autoFocus
          />
        </label>
        <label>
          Password
          <input
            type="password"
            value={password}
            onChange={(e) => setPassword(e.target.value)}
            autoComplete="current-password"
            required
          />
        </label>
        {error && <p className="form-error">{error}</p>}
        <button type="submit" className="btn btn-primary" disabled={submitting}>
          {submitting ? 'Logging in…' : 'Log in'}
        </button>
      </form>
    </div>
  );
}