import 'dart:async';

import 'package:collection/collection.dart';
import 'package:flutter/material.dart';
import 'package:logging/logging.dart';
import "package:photos/core/configuration.dart";
import 'package:photos/core/constants.dart';
import 'package:photos/core/event_bus.dart';
import 'package:photos/events/collection_updated_event.dart';
import 'package:photos/events/local_photos_updated_event.dart';
import 'package:photos/events/user_logged_out_event.dart';
import "package:photos/generated/l10n.dart";
import 'package:photos/models/collection.dart';
import 'package:photos/services/collections_service.dart';
import "package:photos/services/favorites_service.dart";
import "package:photos/ui/collections/button/archived_button.dart";
import "package:photos/ui/collections/button/hidden_button.dart";
import "package:photos/ui/collections/button/trash_button.dart";
import "package:photos/ui/collections/button/uncategorized_button.dart";
import "package:photos/ui/collections/collection_list_page.dart";
import "package:photos/ui/collections/create_new_album_widget.dart";
import "package:photos/ui/collections/device/device_folders_grid_view.dart";
import "package:photos/ui/collections/device/device_folders_vertical_grid_view.dart";
import "package:photos/ui/collections/flex_grid_view.dart";
import 'package:photos/ui/common/loading_widget.dart';
import 'package:photos/ui/components/buttons/icon_button_widget.dart';
import "package:photos/ui/tabs/section_title.dart";
import "package:photos/ui/viewer/actions/delete_empty_albums.dart";
import "package:photos/ui/viewer/gallery/empty_state.dart";
import 'package:photos/utils/local_settings.dart';
import "package:photos/utils/navigation_util.dart";

class UserCollectionsTab extends StatefulWidget {
  const UserCollectionsTab({Key? key}) : super(key: key);

  @override
  State<UserCollectionsTab> createState() => _UserCollectionsTabState();
}

class _UserCollectionsTabState extends State<UserCollectionsTab>
    with AutomaticKeepAliveClientMixin {
  final _logger = Logger((_UserCollectionsTabState).toString());
  late StreamSubscription<LocalPhotosUpdatedEvent> _localFilesSubscription;
  late StreamSubscription<CollectionUpdatedEvent>
      _collectionUpdatesSubscription;
  late StreamSubscription<UserLoggedOutEvent> _loggedOutEvent;
  AlbumSortKey? sortKey;
  String _loadReason = "init";
  final _scrollController = ScrollController();

  static const int _kOnEnteItemLimitCount = 10;
  @override
  void initState() {
    _localFilesSubscription =
        Bus.instance.on<LocalPhotosUpdatedEvent>().listen((event) {
      _loadReason = event.reason;
      setState(() {});
    });
    _collectionUpdatesSubscription =
        Bus.instance.on<CollectionUpdatedEvent>().listen((event) {
      _loadReason = event.reason;
      setState(() {});
    });
    _loggedOutEvent = Bus.instance.on<UserLoggedOutEvent>().listen((event) {
      _loadReason = event.reason;
      setState(() {});
    });
    sortKey = LocalSettings.instance.albumSortKey();
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    super.build(context);
    _logger.info("Building, trigger: $_loadReason");
    return FutureBuilder<List<Collection>>(
      future: _getCollections(),
      builder: (context, snapshot) {
        if (snapshot.hasData) {
          return _getCollectionsGalleryWidget(snapshot.data!);
        } else if (snapshot.hasError) {
          return Text(snapshot.error.toString());
        } else {
          return const EnteLoadingWidget();
        }
      },
    );
  }

  Future<List<Collection>> _getCollections() async {
    final List<Collection> collections =
        CollectionsService.instance.getCollectionsForUI();
    final bool hasFavorites = FavoritesService.instance.hasFavorites();
    late Map<int, int> collectionIDToNewestPhotoTime;
    if (sortKey == AlbumSortKey.newestPhoto) {
      collectionIDToNewestPhotoTime =
          await CollectionsService.instance.getCollectionIDToNewestFileTime();
    }
    collections.sort(
      (first, second) {
        if (sortKey == AlbumSortKey.albumName) {
          return compareAsciiLowerCaseNatural(
            first.displayName,
            second.displayName,
          );
        } else if (sortKey == AlbumSortKey.newestPhoto) {
          return (collectionIDToNewestPhotoTime[second.id] ?? -1 * intMaxValue)
              .compareTo(
            collectionIDToNewestPhotoTime[first.id] ?? -1 * intMaxValue,
          );
        } else {
          return second.updationTime.compareTo(first.updationTime);
        }
      },
    );
    final List<Collection> favorites = [];
    final List<Collection> pinned = [];
    final List<Collection> rest = [];
    for (final collection in collections) {
      if (collection.type == CollectionType.uncategorized ||
          collection.isSharedFilesCollection() ||
          collection.isHidden()) {
        continue;
      }
      if (collection.type == CollectionType.favorites) {
        // Hide fav collection if it's empty
        if (hasFavorites) {
          favorites.add(collection);
        }
      } else if (collection.isPinned) {
        pinned.add(collection);
      } else {
        rest.add(collection);
      }
    }

    return favorites + pinned + rest;
  }

  Widget _getCollectionsGalleryWidget(List<Collection> collections) {
    final TextStyle trashAndHiddenTextStyle =
        Theme.of(context).textTheme.titleMedium!.copyWith(
              color: Theme.of(context)
                  .textTheme
                  .titleMedium!
                  .color!
                  .withOpacity(0.5),
            );

    return CustomScrollView(
      controller: _scrollController,
      slivers: [
        SliverToBoxAdapter(
          child: Hero(
            tag: "OnDeviceAppTitle",
            child: SectionOptions(
              SectionTitle(title: S.of(context).onDevice),
              trailingWidget: IconButtonWidget(
                icon: Icons.chevron_right,
                iconButtonType: IconButtonType.secondary,
                onTap: () {
                  unawaited(
                    routeToPage(
                      context,
                      DeviceFolderVerticalGridView(
                        appTitle: SectionTitle(
                          title: S.of(context).onDevice,
                        ),
                        tag: "OnDeviceAppTitle",
                      ),
                    ),
                  );
                },
              ),
            ),
          ),
        ),
        const SliverToBoxAdapter(child: DeviceFoldersGridView()),
        SliverToBoxAdapter(
          child: SectionOptions(
            SectionTitle(titleWithBrand: getOnEnteSection(context)),
            trailingWidget: _sortMenu(collections),
            padding: const EdgeInsets.only(left: 12, right: 6),
          ),
        ),
        SliverToBoxAdapter(child: DeleteEmptyAlbums(collections ?? [])),
        Configuration.instance.hasConfiguredAccount()
            ? CollectionsFlexiGridViewWidget(
                collections,
                displayLimitCount: _kOnEnteItemLimitCount,
                shrinkWrap: true,
              )
            : const SliverToBoxAdapter(child: EmptyState()),
        collections.length > _kOnEnteItemLimitCount
            ? SliverToBoxAdapter(
                child: GestureDetector(
                  behavior: HitTestBehavior.opaque,
                  onTap: () {
                    unawaited(
                      routeToPage(
                        context,
                        CollectionListPage(
                          collections,
                          appTitle: SectionTitle(
                            titleWithBrand: getOnEnteSection(context),
                          ),
                          initalScrollOffset: _scrollController.offset,
                        ),
                      ),
                    );
                  },
                  child: SectionOptions(
                    SectionTitle(
                      title: S.of(context).viewAll,
                      mutedTitle: true,
                    ),
                    trailingWidget: const IconButtonWidget(
                      icon: Icons.chevron_right,
                      iconButtonType: IconButtonType.secondary,
                    ),
                  ),
                ),
              )
            : const SliverToBoxAdapter(child: SizedBox.shrink()),
        const SliverToBoxAdapter(child: Divider()),
        const SliverToBoxAdapter(child: SizedBox(height: 12)),
        SliverToBoxAdapter(
          child: Padding(
            padding: const EdgeInsets.symmetric(horizontal: 12),
            child: Column(
              children: [
                UnCategorizedCollections(trashAndHiddenTextStyle),
                const SizedBox(height: 12),
                ArchivedCollectionsButton(trashAndHiddenTextStyle),
                const SizedBox(height: 12),
                HiddenCollectionsButtonWidget(trashAndHiddenTextStyle),
                const SizedBox(height: 12),
                TrashSectionButton(trashAndHiddenTextStyle),
              ],
            ),
          ),
        ),
        const SliverToBoxAdapter(child: SizedBox(height: 48)),
      ],
    );
  }

  Widget _sortMenu(List<Collection> collections) {
    Text sortOptionText(AlbumSortKey key) {
      String text = key.toString();
      switch (key) {
        case AlbumSortKey.albumName:
          text = S.of(context).name;
          break;
        case AlbumSortKey.newestPhoto:
          text = S.of(context).newest;
          break;
        case AlbumSortKey.lastUpdated:
          text = S.of(context).lastUpdated;
      }
      return Text(
        text,
        style: Theme.of(context).textTheme.titleMedium!.copyWith(
              fontSize: 14,
              color: Theme.of(context).iconTheme.color!.withOpacity(0.7),
            ),
      );
    }

    return Theme(
      data: Theme.of(context).copyWith(
        highlightColor: Colors.transparent,
        splashColor: Colors.transparent,
      ),
      child: Row(
        children: [
          const CreateNewAlbumIcon(),
          GestureDetector(
            onTapDown: (TapDownDetails details) async {
              final int? selectedValue = await showMenu<int>(
                context: context,
                position: RelativeRect.fromLTRB(
                  details.globalPosition.dx,
                  details.globalPosition.dy,
                  details.globalPosition.dx,
                  details.globalPosition.dy + 50,
                ),
                items: List.generate(AlbumSortKey.values.length, (index) {
                  return PopupMenuItem(
                    value: index,
                    child: sortOptionText(AlbumSortKey.values[index]),
                  );
                }),
              );
              if (selectedValue != null) {
                sortKey = AlbumSortKey.values[selectedValue];
                ;
                await LocalSettings.instance.setAlbumSortKey(sortKey!);
                setState(() {});
              }
            },
            child: const IconButtonWidget(
              icon: Icons.sort_outlined,
              iconButtonType: IconButtonType.secondary,
            ),
          ),
        ],
      ),
    );
  }

  @override
  void dispose() {
    _localFilesSubscription.cancel();
    _collectionUpdatesSubscription.cancel();
    _loggedOutEvent.cancel();
    _scrollController.dispose();
    super.dispose();
  }

  @override
  bool get wantKeepAlive => true;
}