import 'dart:convert';

import 'package:flutter/widgets.dart';

import 'package:go_router/go_router.dart';

import 'package:sxchnge_wallet/sxchnge_wallet.dart';

import '../auth/page.dart';
import '../destinations/list.dart';
import '../kyc/page.dart';
import '../security/challenge.dart';
import '../verification/page.dart';
import '../workspace/accounts.dart';
import '../workspace/activity.dart';
import '../workspace/limits.dart';
import '../workspace/operation.dart';
import '../workspace/settings.dart';
import '../workspace/shell.dart';
import '../workspace/transfer.dart';
import 'routes.dart';

GoRouter createAppRouter({bool Function()? authenticated}) {
  final topUpKey = GlobalKey<TransferPageState>();
  final exchangeKey = GlobalKey<TransferPageState>();
  final payoutKey = GlobalKey<TransferPageState>();
  final identityKey = GlobalKey<IdentityPageState>();
  return GoRouter(
    redirect: (context, state) {
      if (authenticated == null || authenticated()) return null;
      final path = state.uri.path;
      if (path == '/' ||
          path == '/verify-email' ||
          path == '/verification-sent' ||
          path == '/two-factor') {
        return null;
      }
      return '/';
    },
    // Signup email is an in-memory navigation extra, never browser-history data.
    extraCodec: const _TransientExtras(),
    routes: [
      GoRoute(
        path: '/two-factor',
        redirect: (context, state) =>
            state.extra is FactorRouteRequest ? null : '/',
        builder: (context, state) =>
            FactorRoute(request: state.extra as FactorRouteRequest),
        onExit: (context, state) =>
            state.extra is! FactorRouteRequest ||
            !(state.extra as FactorRouteRequest).provider.busy,
      ),
      ShellRoute(
        builder: (context, state, child) =>
            WorkspaceShell(path: state.uri.path, child: child),
        routes: [
          GoRoute(
            path: '/accounts',
            builder: (context, state) => const AccountsPage(),
            routes: [
              GoRoute(
                path: ':accountId',
                builder: (context, state) =>
                    AccountsPage(accountId: state.pathParameters['accountId']),
              ),
            ],
          ),
          GoRoute(
            path: '/activity',
            builder: (context, state) => const ActivityPage(),
            routes: [
              GoRoute(
                path: ':operationId',
                builder: (context, state) =>
                    OperationPage(id: state.pathParameters['operationId']!),
              ),
            ],
          ),
          GoRoute(
            path: '/limits',
            builder: (context, state) => const LimitsPage(),
          ),
          GoRoute(
            path: '/settings',
            builder: (context, state) => const SettingsPage(),
            routes: [
              GoRoute(
                path: 'payout-methods',
                builder: (context, state) => const DestinationsPage(),
              ),
            ],
          ),
          GoRoute(
            path: '/top-up',
            builder: (context, state) => TransferPage(
              key: topUpKey,
              kind: TransferKind.topUp,
              source: state.extra is String ? state.extra as String : null,
            ),
            onExit: (context, state) async =>
                await topUpKey.currentState?.allowExit() ?? true,
          ),
          GoRoute(
            path: '/exchange',
            builder: (context, state) => TransferPage(
              key: exchangeKey,
              kind: TransferKind.exchange,
              source: state.extra is String ? state.extra as String : null,
            ),
            onExit: (context, state) async =>
                await exchangeKey.currentState?.allowExit() ?? true,
          ),
          GoRoute(
            path: '/payout',
            builder: (context, state) => TransferPage(
              key: payoutKey,
              kind: TransferKind.payout,
              source: state.extra is String ? state.extra as String : null,
            ),
            onExit: (context, state) async =>
                await payoutKey.currentState?.allowExit() ?? true,
          ),
          GoRoute(
            path: '/identity',
            name: AppRoutes.identity,
            builder: (context, state) => IdentityPage(
              key: identityKey,
              onboarding: state.uri.queryParameters['onboarding'] == '1',
            ),
            onExit: (context, state) async =>
                await identityKey.currentState?.allowExit() ?? true,
          ),
        ],
      ),
      GoRoute(
        path: '/',
        name: AppRoutes.login,
        builder: (context, state) => AuthPage(
          email: state.extra is String ? state.extra as String : null,
        ),
      ),
      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;
}