/*
 * Copyright (c) 2024-2026 Fabian Freund.
 *
 * This file is part of WebLibre
 * (see https://weblibre.eu).
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:smooth_page_indicator/smooth_page_indicator.dart';
import 'package:weblibre/core/providers/router.dart';
import 'package:weblibre/features/geckoview/features/browser/domain/services/browser_addon.dart';
import 'package:weblibre/features/onboarding/domain/entities/onboarding_mode.dart';
import 'package:weblibre/features/onboarding/domain/providers.dart';
import 'package:weblibre/features/onboarding/presentation/pages/abstract/i_form_page.dart';
import 'package:weblibre/features/onboarding/presentation/pages/ai_configuration.dart';
import 'package:weblibre/features/onboarding/presentation/pages/default_search.dart';
import 'package:weblibre/features/onboarding/presentation/pages/doh_settings.dart';
import 'package:weblibre/features/onboarding/presentation/pages/permissions.dart';
import 'package:weblibre/features/onboarding/presentation/pages/privacy_hardening.dart';
import 'package:weblibre/features/onboarding/presentation/pages/toolbar_layout.dart';
import 'package:weblibre/features/onboarding/presentation/pages/ublock_opt_in.dart';
import 'package:weblibre/features/onboarding/presentation/pages/welcome.dart';
import 'package:weblibre/features/user/domain/repositories/onboarding.dart';

class OnboardingScreen extends HookConsumerWidget {
  final int currentRevision;
  final int targetRevision;

  const OnboardingScreen({
    super.key,
    required this.currentRevision,
    required this.targetRevision,
  });

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final theme = Theme.of(context);
    final disableAnimations = MediaQuery.disableAnimationsOf(context);

    final pageController = usePageController();
    final eulaAccepted = ref.watch(eulaAcceptedProvider);
    final onboardingMode = ref.watch(onboardingModeProvider);

    final isReturningUser = currentRevision == 2;
    final showDetailedPages =
        isReturningUser || onboardingMode == OnboardingMode.detailed;

    final pages = useMemoized<List<Widget>>(() {
      switch (currentRevision) {
        case 1:
          return [const AiConfigurationPage()];
        default:
          return [
            WelcomePage(isReturningUser: isReturningUser),
            const DefaultSearchPage(),
            if (showDetailedPages) const DohSettingsPage(),
            if (showDetailedPages) const ToolbarLayoutPage(),
            const PrivacyHardeningPage(),
            const AiConfigurationPage(),
            if (showDetailedPages)
              UBlockOptInPage(formKey: GlobalKey<FormState>()),
            PermissionsPage(formKey: GlobalKey<FormState>()),
          ];
      }
    }, [currentRevision, targetRevision, onboardingMode]);

    final lastPage = useRef(pageController.initialPage);
    final currentPage = useState(pageController.initialPage);

    return PopScope(
      canPop: currentPage.value == 0,
      onPopInvokedWithResult: (didPop, _) async {
        if (didPop) return;
        if (disableAnimations) {
          pageController.jumpToPage(currentPage.value - 1);
        } else {
          await pageController.previousPage(
            duration: const Duration(milliseconds: 250),
            curve: Curves.easeInOut,
          );
        }
      },
      child: Scaffold(
        body: SafeArea(
          child: Column(
            children: [
              Expanded(
                child: PageView(
                  controller: pageController,
                  physics: currentPage.value == 0 && !eulaAccepted
                      ? const NeverScrollableScrollPhysics()
                      : null,
                  children: pages,
                  onPageChanged: (value) {
                    if (value > lastPage.value) {
                      if (pages[lastPage.value] case final IFormPage formPage) {
                        formPage.formKey.currentState?.save();
                      }
                    }

                    lastPage.value = value;
                    currentPage.value = value;
                  },
                ),
              ),
              Row(
                children: [
                  Expanded(
                    child: Visibility(
                      visible: currentPage.value > 0,
                      child: TextButton.icon(
                        onPressed: () async {
                          if (disableAnimations) {
                            pageController.jumpToPage(currentPage.value - 1);
                          } else {
                            await pageController.previousPage(
                              duration: const Duration(milliseconds: 250),
                              curve: Curves.easeInOut,
                            );
                          }
                        },
                        icon: const Icon(Icons.chevron_left),
                        label: const Text('Previous'),
                      ),
                    ),
                  ),
                  Expanded(
                    child: Center(
                      child: SmoothPageIndicator(
                        controller: pageController,
                        count: pages.length,
                        effect: WormEffect(
                          activeDotColor: theme.colorScheme.primary,
                          dotHeight: 10.0,
                          dotWidth: 10.0,
                        ),
                      ),
                    ),
                  ),
                  if (currentPage.value < pages.length - 1)
                    Expanded(
                      child: TextButton.icon(
                        onPressed: currentPage.value == 0 && !eulaAccepted
                            ? null
                            : () async {
                                if (disableAnimations) {
                                  pageController.jumpToPage(
                                    currentPage.value + 1,
                                  );
                                } else {
                                  await pageController.nextPage(
                                    duration: const Duration(milliseconds: 250),
                                    curve: Curves.easeInOut,
                                  );
                                }
                              },
                        iconAlignment: IconAlignment.end,
                        icon: const Icon(Icons.chevron_right),
                        label: const Text('Next'),
                      ),
                    )
                  else
                    Expanded(
                      child: TextButton.icon(
                        onPressed: () async {
                          if (pages[currentPage.value]
                              case final IFormPage formPage) {
                            formPage.formKey.currentState?.save();
                          }

                          if (onboardingMode == OnboardingMode.express) {
                            unawaited(
                              ref
                                  .read(browserAddonServiceProvider.notifier)
                                  .install('uBlock0@raymondhill.net'),
                            );
                          }

                          await ref
                              .read(onboardingRepositoryProvider.notifier)
                              .pushRevision(targetRevision);

                          ref.invalidate(routerProvider);
                        },
                        iconAlignment: IconAlignment.end,
                        icon: const Icon(Icons.done),
                        label: const Text('Done'),
                      ),
                    ),
                ],
              ),
            ],
          ),
        ),
      ),
    );
  }
}