'use client';

import { useActionState, useState } from 'react';
import { startAuthentication } from '@simplewebauthn/browser';
import { login } from './actions';
import packageJson from '@/package.json';

export default function LoginPage() {
  const [state, loginAction, isPending] = useActionState(login, undefined);
  const [showPassword, setShowPassword] = useState(false);
  const [passkeyBusy, setPasskeyBusy] = useState(false);
  const [passkeyError, setPasskeyError] = useState<string | null>(null);

  async function handlePasskeyLogin() {
    setPasskeyError(null);
    setPasskeyBusy(true);
    try {
      const optRes = await fetch('/api/passkey/authenticate');
      if (!optRes.ok) throw new Error('Optionen konnten nicht geladen werden.');
      const optionsJSON = await optRes.json();

      const response = await startAuthentication({ optionsJSON });

      const verifyRes = await fetch('/api/passkey/authenticate', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ response }),
      });
      if (!verifyRes.ok) {
        const data = await verifyRes.json().catch(() => null);
        throw new Error(data?.error ?? 'Anmeldung mit Passkey fehlgeschlagen.');
      }
      window.location.href = '/';
    } catch (err) {
      // Abbruch durch Nutzer (NotAllowedError) nicht als Fehler anzeigen.
      if (err instanceof Error && err.name === 'NotAllowedError') {
        setPasskeyError(null);
      } else {
        setPasskeyError(err instanceof Error ? err.message : 'Anmeldung mit Passkey fehlgeschlagen.');
      }
    } finally {
      setPasskeyBusy(false);
    }
  }

  const version = packageJson.version;
  const buildDate = process.env.NEXT_PUBLIC_BUILD_DATE || new Date().toLocaleDateString('de-DE', { day: '2-digit', month: '2-digit', year: 'numeric' });

  return (
    <div className="min-h-screen bg-white py-4 px-4">
      <main className="max-w-6xl mx-auto border-2 border-black rounded-lg p-6 bg-[#FFFFDD]">
        <div className="flex justify-between items-center mb-6">
          <h1 className="text-3xl font-bold">Werte - Log</h1>
        </div>

        <div className="flex justify-center py-10">
          <div className="w-full max-w-sm bg-white border border-gray-300 rounded-xl shadow-md p-8">
            <h2 className="text-xl font-semibold text-gray-900 mb-6 text-center">Anmeldung</h2>

            <form action={loginAction} className="space-y-5">
              <div>
                <label
                  htmlFor="username"
                  className="block text-sm font-medium text-gray-700 mb-1"
                >
                  Benutzername
                </label>
                <input
                  id="username"
                  name="username"
                  type="text"
                  required
                  autoComplete="off"
                  className="w-full px-3 py-2 border-2 border-gray-400 rounded-lg bg-white text-gray-900 focus:border-blue-500 focus:outline-none text-sm"
                  placeholder="Benutzername"
                  disabled={isPending}
                />
              </div>

              <div>
                <label
                  htmlFor="password"
                  className="block text-sm font-medium text-gray-700 mb-1"
                >
                  Passwort
                </label>
                <div className="relative">
                  <input
                    id="password"
                    name="password"
                    type={showPassword ? 'text' : 'password'}
                    required
                    autoComplete="new-password"
                    className="w-full px-3 py-2 pr-10 border-2 border-gray-400 rounded-lg bg-white text-gray-900 focus:border-blue-500 focus:outline-none text-sm"
                    placeholder="Passwort"
                    disabled={isPending}
                  />
                  <button
                    type="button"
                    onClick={() => setShowPassword(v => !v)}
                    tabIndex={-1}
                    aria-label={showPassword ? 'Passwort verbergen' : 'Passwort anzeigen'}
                    className="absolute inset-y-0 right-0 px-3 flex items-center text-gray-500 hover:text-gray-800"
                  >
                    {showPassword ? (
                      <svg xmlns="http://www.w3.org/2000/svg" className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M13.875 18.825A10.05 10.05 0 0112 19c-4.478 0-8.268-2.943-9.543-7a9.97 9.97 0 011.563-3.029m5.858.908a3 3 0 114.243 4.243M9.878 9.878l4.242 4.242M9.88 9.88l-3.29-3.29m7.532 7.532l3.29 3.29M3 3l3.59 3.59m0 0A9.953 9.953 0 0112 5c4.478 0 8.268 2.943 9.543 7a10.025 10.025 0 01-4.132 4.411m0 0L21 21" />
                      </svg>
                    ) : (
                      <svg xmlns="http://www.w3.org/2000/svg" className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" />
                        <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M2.458 12C3.732 7.943 7.523 5 12 5c4.478 0 8.268 2.943 9.542 7-1.274 4.057-5.064 7-9.542 7-4.477 0-8.268-2.943-9.542-7z" />
                      </svg>
                    )}
                  </button>
                </div>
              </div>

              {state?.error && (
                <div className="bg-red-50 border border-red-300 text-red-700 px-3 py-2 rounded-lg text-sm">
                  {state.error}
                </div>
              )}

              <button
                type="submit"
                disabled={isPending}
                className="w-full py-2 px-4 bg-[#85B7D7] hover:bg-[#6a9fc5] text-black font-medium rounded-lg transition-colors disabled:opacity-50 disabled:cursor-not-allowed text-sm"
              >
                {isPending ? 'Anmeldung läuft...' : 'Anmelden'}
              </button>
            </form>

            <div className="flex items-center gap-3 my-5">
              <div className="h-px flex-1 bg-gray-200" />
              <span className="text-xs text-gray-400">oder</span>
              <div className="h-px flex-1 bg-gray-200" />
            </div>

            <button
              type="button"
              onClick={handlePasskeyLogin}
              disabled={passkeyBusy}
              className="w-full py-2 px-4 flex items-center justify-center gap-2 border-2 border-gray-400 hover:border-blue-500 text-gray-900 font-medium rounded-lg transition-colors disabled:opacity-50 disabled:cursor-not-allowed text-sm"
            >
              <svg xmlns="http://www.w3.org/2000/svg" className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M15 7a2 2 0 012 2m4 0a6 6 0 01-7.743 5.743L11 17H9v2H7v2H4a1 1 0 01-1-1v-2.586a1 1 0 01.293-.707l5.964-5.964A6 6 0 1121 9z" />
              </svg>
              {passkeyBusy ? 'Anmeldung läuft...' : 'Mit Passkey anmelden'}
            </button>

            {passkeyError && (
              <div className="mt-4 bg-red-50 border border-red-300 text-red-700 px-3 py-2 rounded-lg text-sm">
                {passkeyError}
              </div>
            )}
          </div>
        </div>

        {/* Footer */}
        <footer className="mt-8 flex justify-between items-center text-sm text-gray-600 px-4 ">
          <div>
            <a href="mailto:rxf@gmx.de" className="text-blue-600 hover:underline">
              mailto:rxf@gmx.de
            </a>
          </div>
          <div className="text-right">
            Version {version} - {buildDate}
          </div>
        </footer>        
      </main>
    </div>
  );
}