import 'dart:convert';

import 'package:go_router/go_router.dart';

import '../auth/page.dart';
import '../verification/page.dart';
import 'routes.dart';

GoRouter createAppRouter() => GoRouter(
  // Signup email is an in-memory navigation extra, never browser-history data.
  extraCodec: const _TransientExtras(),
  routes: [
    GoRoute(
      path: '/',
      name: AppRoutes.login,
      builder: (context, state) => const AuthPage(),
    ),
    GoRoute(
      path: '/verification-sent',
      name: AppRoutes.verificationSent,
      builder: (context, state) => VerificationPage(
        email: state.extra is String ? state.extra as String : null,
      ),
    ),
    GoRoute(
      path: '/verify-email',
      name: AppRoutes.verifyEmail,
      builder: (context, state) =>
          VerificationPage(token: state.uri.queryParameters['token'] ?? ''),
    ),
  ],
  // Preserve the existing fallback, and keep the visible URL canonical.
  onException: (context, state, router) => router.goNamed(AppRoutes.login),
);

class _TransientExtras extends Codec<Object?, Object?> {
  const _TransientExtras();
  @override
  Converter<Object?, Object?> get encoder => const _DiscardExtra();
  @override
  Converter<Object?, Object?> get decoder => const _DiscardExtra();
}

class _DiscardExtra extends Converter<Object?, Object?> {
  const _DiscardExtra();
  @override
  Object? convert(Object? input) => null;
}