/*
 * 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 'package:fast_equatable/fast_equatable.dart';
import 'package:riverpod/riverpod.dart';
import 'package:riverpod_annotation/riverpod_annotation.dart';
import 'package:weblibre/data/models/web_page_info.dart';
import 'package:weblibre/domain/services/generic_website.dart';
import 'package:weblibre/extensions/ref_cache.dart';
import 'package:weblibre/extensions/uri.dart';
import 'package:weblibre/features/geckoview/domain/entities/states/tab.dart';
import 'package:weblibre/features/geckoview/domain/providers/tab_state.dart';
import 'package:weblibre/features/geckoview/features/tabs/data/entities/tab_mode.dart';
import 'package:weblibre/features/geckoview/features/tabs/data/providers.dart';
import 'package:weblibre/features/geckoview/features/tabs/domain/repositories/container.dart';
import 'package:weblibre/features/geckoview/features/tabs/domain/repositories/tab.dart';
import 'package:weblibre/features/proxy/data/proxy_connection.dart';
import 'package:weblibre/features/tor/domain/services/tor_proxy.dart';
import 'package:weblibre/features/user/data/models/proxy_routing_settings.dart';
import 'package:weblibre/features/user/domain/repositories/proxy_routing_settings.dart';

part 'website_title.g.dart';

sealed class _PageInfoProxyAssignment {
  const _PageInfoProxyAssignment();
}

final class _PageInfoDirectAssignment extends _PageInfoProxyAssignment {
  const _PageInfoDirectAssignment();
}

final class _PageInfoExplicitProxyAssignment extends _PageInfoProxyAssignment {
  final ProxyConnectionId proxyConnectionId;

  const _PageInfoExplicitProxyAssignment(this.proxyConnectionId);
}

@Riverpod()
class CompletePageInfo extends _$CompletePageInfo {
  @override
  AsyncValue<WebPageInfo> build(TabState cached) {
    ref.cacheFor(const Duration(minutes: 2));

    if (cached.isPageInfoComplete || !cached.url.isHttpOrHttps) {
      return AsyncData(cached);
    }

    ref.listen(
      fireImmediately: true,
      tabStateProvider(cached.id).select((value) => value?.title),
      (previous, next) {
        if (next != null) {
          final current = stateOrNull?.value ?? cached;
          state = AsyncData(current.copyWith.title(next));
        }
      },
    );

    ref.listen(
      fireImmediately: true,
      tabStateProvider(cached.id).select((value) => value?.favicon),
      (previous, next) {
        if (next != null) {
          final current = stateOrNull?.value ?? cached;
          state = AsyncData(current.copyWith.favicon(next));
        }
      },
    );

    return AsyncData(cached);
  }
}

@Riverpod()
Future<WebPageInfo> pageInfo(
  Ref ref,
  Uri url, {
  required bool isImageRequest,
}) async {
  final link = ref.cacheFor(const Duration(minutes: 2));

  final tabState = ref.read(selectedTabStateProvider);

  int? proxyPort;
  if (tabState?.id != null) {
    final containerData = await ref
        .read(tabDataRepositoryProvider.notifier)
        .getTabContainerData(tabState!.id);

    final proxyRoutingSettings = ref.read(
      proxyRoutingSettingsWithDefaultsProvider,
    );

    final isolatedAssignment = tabState.isolationContextId != null
        ? await _pageInfoAssignmentForIsolationContext(
            ref,
            tabState.isolationContextId!,
          )
        : null;

    final effectiveContainerProxyConnectionId = switch (isolatedAssignment) {
      _PageInfoExplicitProxyAssignment(:final proxyConnectionId) =>
        proxyConnectionId,
      _PageInfoDirectAssignment() => null,
      null => containerData?.metadata.proxyConnectionId,
    };
    final bypassesGlobalProxy =
        isolatedAssignment is _PageInfoDirectAssignment ||
        (isolatedAssignment == null &&
            containerData?.metadata.bypassGlobalProxy == true);
    final usesGlobalRegularTor =
        tabState.tabMode is! PrivateTabMode &&
        effectiveContainerProxyConnectionId == null &&
        !bypassesGlobalProxy &&
        proxyRoutingSettings.regularTabsMode ==
            ProxyRegularTabRoutingMode.all &&
        proxyRoutingSettings.regularTabsProxyConnectionId
            is TorProxyConnectionId;

    if (effectiveContainerProxyConnectionId is TorProxyConnectionId ||
        usesGlobalRegularTor ||
        (tabState.tabMode is PrivateTabMode &&
            proxyRoutingSettings.privateTabsProxyConnectionId
                is TorProxyConnectionId)) {
      proxyPort = await ref.read(
        torProxyServiceProvider.selectAsync((value) => value.socksPort),
      );

      if (proxyPort == null) {
        throw Exception('Could not proxy request');
      }
    }
  }

  final result = await ref
      .watch(genericWebsiteServiceProvider.notifier)
      .fetchPageInfo(
        url: url,
        isImageRequest: isImageRequest,
        proxyPort: proxyPort,
      );

  if (!result.isSuccess) {
    link.close();
  }

  return result.value;
}

Future<_PageInfoProxyAssignment?> _pageInfoAssignmentForIsolationContext(
  Ref ref,
  String contextId,
) async {
  final db = ref.read(tabDatabaseProvider);
  final pairs = await db.tabDao.isolatedContextContainerPairs().get();
  final containerIds = pairs
      .where((pair) => pair.isolationContextId == contextId)
      .map((pair) => pair.containerId)
      .nonNulls
      .toSet();

  if (containerIds.isEmpty) return null;

  final containers = await ref
      .read(containerRepositoryProvider.notifier)
      .getAllContainersWithCount();
  final matchedContainers = containers.where(
    (container) => containerIds.contains(container.id),
  );
  final proxyIds =
      matchedContainers
          .map((container) => container.metadata.proxyConnectionId?.encode())
          .nonNulls
          .toSet()
          .toList()
        ..sort();

  if (proxyIds.isNotEmpty) {
    final proxyConnectionId = ProxyConnectionId.decode(proxyIds.first);
    return proxyConnectionId != null
        ? _PageInfoExplicitProxyAssignment(proxyConnectionId)
        : null;
  }
  final matchedContainerList = matchedContainers.toList();
  if (matchedContainerList.isNotEmpty &&
      matchedContainerList.every(
        (container) => container.metadata.bypassGlobalProxy,
      )) {
    return const _PageInfoDirectAssignment();
  }

  return null;
}

@Riverpod()
AsyncValue<EquatableValue<Set<Uri>?>> websiteFeedProvider(
  Ref ref,
  String tabId,
) {
  final tabState = ref.watch(tabStateProvider(tabId))!;
  final feeds = ref.watch(
    pageInfoProvider(
      tabState.url,
      isImageRequest: false,
    ).select((value) => value.whenData((data) => EquatableValue(data.feeds))),
  );

  return feeds;
}