'use client';

/**
 * Anmeldeseite (plan.md Abschnitt 11).
 */
import { useState } from 'react';
import { useRouter } from 'next/navigation';
import Link from 'next/link';
import { Button, Card, ErrorMessage, Input, Label } from '@/components/ui/ui';

export default function LoginPage() {
  const router = useRouter();
  const [error, setError] = useState<string | null>(null);
  const [busy, setBusy] = useState(false);

  async function handleSubmit(event: React.FormEvent<HTMLFormElement>) {
    event.preventDefault();
    setBusy(true);
    setError(null);

    const formData = new FormData(event.currentTarget);
    try {
      const response = await fetch('/api/auth/login', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          email: formData.get('email'),
          password: formData.get('password'),
        }),
      });

      if (!response.ok) {
        const data = (await response.json()) as { error?: string };
        setError(data.error ?? 'Anmeldung fehlgeschlagen.');
        return;
      }
      router.push('/dashboard');
      router.refresh();
    } catch {
      setError('Netzwerkfehler. Bitte erneut versuchen.');
    } finally {
      setBusy(false);
    }
  }

  return (
    <main className="mx-auto flex min-h-screen max-w-md flex-col justify-center px-4">
      <h1 className="mb-6 text-center text-2xl font-bold">Anmelden</h1>
      <Card>
        <form onSubmit={handleSubmit} className="space-y-4">
          <ErrorMessage message={error} />
          <div>
            <Label htmlFor="email">E-Mail</Label>
            <Input id="email" name="email" type="email" required autoComplete="email" />
          </div>
          <div>
            <Label htmlFor="password">Passwort</Label>
            <Input
              id="password"
              name="password"
              type="password"
              required
              autoComplete="current-password"
            />
          </div>
          <Button disabled={busy}>{busy ? 'Anmelden …' : 'Anmelden'}</Button>
        </form>
        <div className="mt-4 flex justify-between text-sm">
          <Link href="/register" className="text-slate-700 underline hover:text-slate-900 dark:text-slate-300 dark:hover:text-slate-100">
            Konto erstellen
          </Link>
          <Link href="/forgot-password" className="text-slate-700 underline hover:text-slate-900 dark:text-slate-300 dark:hover:text-slate-100">
            Passwort vergessen?
          </Link>
        </div>
      </Card>
    </main>
  );
}