import 'dart:async';
import 'dart:collection';

import 'package:clock/clock.dart';
import 'package:collection/collection.dart';
import 'package:copy_with/copy_with.dart';
import 'package:draggable_scrollbar/draggable_scrollbar.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_staggered_grid_view/flutter_staggered_grid_view.dart';
import 'package:intl/intl.dart';
import 'package:kiwi/kiwi.dart';
import 'package:logging/logging.dart';
import 'package:nc_photos/account.dart';
import 'package:nc_photos/app_localizations.dart';
import 'package:nc_photos/bloc_util.dart';
import 'package:nc_photos/controller/account_controller.dart';
import 'package:nc_photos/controller/account_pref_controller.dart';
import 'package:nc_photos/controller/collections_controller.dart';
import 'package:nc_photos/controller/files_controller.dart';
import 'package:nc_photos/controller/metadata_controller.dart';
import 'package:nc_photos/controller/persons_controller.dart';
import 'package:nc_photos/controller/pref_controller.dart';
import 'package:nc_photos/controller/sync_controller.dart';
import 'package:nc_photos/db/entity_converter.dart';
import 'package:nc_photos/di_container.dart';
import 'package:nc_photos/download_handler.dart';
import 'package:nc_photos/entity/collection.dart';
import 'package:nc_photos/entity/collection/content_provider/memory.dart';
import 'package:nc_photos/entity/file.dart';
import 'package:nc_photos/entity/file_descriptor.dart';
import 'package:nc_photos/entity/file_util.dart' as file_util;
import 'package:nc_photos/event/event.dart';
import 'package:nc_photos/exception_event.dart';
import 'package:nc_photos/flutter_util.dart' as flutter_util;
import 'package:nc_photos/help_utils.dart' as help_util;
import 'package:nc_photos/k.dart' as k;
import 'package:nc_photos/progress_util.dart';
import 'package:nc_photos/remote_storage_util.dart' as remote_storage_util;
import 'package:nc_photos/session_storage.dart';
import 'package:nc_photos/snack_bar_manager.dart';
import 'package:nc_photos/stream_extension.dart';
import 'package:nc_photos/theme.dart';
import 'package:nc_photos/theme/dimension.dart';
import 'package:nc_photos/url_launcher_util.dart';
import 'package:nc_photos/widget/collection_browser.dart';
import 'package:nc_photos/widget/collection_picker.dart';
import 'package:nc_photos/widget/file_sharer_dialog.dart';
import 'package:nc_photos/widget/finger_listener.dart';
import 'package:nc_photos/widget/handler/double_tap_exit_handler.dart';
import 'package:nc_photos/widget/home_app_bar.dart';
import 'package:nc_photos/widget/navigation_bar_blur_filter.dart';
import 'package:nc_photos/widget/network_thumbnail.dart';
import 'package:nc_photos/widget/photo_list_item.dart';
import 'package:nc_photos/widget/photo_list_util.dart' as photo_list_util;
import 'package:nc_photos/widget/selectable_item_list.dart';
import 'package:nc_photos/widget/selection_app_bar.dart';
import 'package:nc_photos/widget/sliver_visualized_scale.dart';
import 'package:nc_photos/widget/viewer.dart';
import 'package:np_async/np_async.dart';
import 'package:np_codegen/np_codegen.dart';
import 'package:np_collection/np_collection.dart';
import 'package:np_common/object_util.dart';
import 'package:np_common/or_null.dart';
import 'package:np_datetime/np_datetime.dart';
import 'package:np_db/np_db.dart';
import 'package:np_platform_util/np_platform_util.dart';
import 'package:np_ui/np_ui.dart';
import 'package:to_string/to_string.dart';
import 'package:visibility_detector/visibility_detector.dart';

part 'home_photos/app_bar.dart';
part 'home_photos/bloc.dart';
part 'home_photos/minimap_view.dart';
part 'home_photos/state_event.dart';
part 'home_photos/type.dart';
part 'home_photos/view.dart';
part 'home_photos2.g.dart';

class HomePhotos2BackToTopEvent {
  const HomePhotos2BackToTopEvent();
}

class HomePhotos2 extends StatelessWidget {
  const HomePhotos2({super.key});

  @override
  Widget build(BuildContext context) {
    final accountController = context.read<AccountController>();
    return BlocProvider(
      create: (_) => _Bloc(
        KiwiContainer().resolve(),
        account: accountController.account,
        filesController: accountController.filesController,
        prefController: context.read(),
        accountPrefController: accountController.accountPrefController,
        collectionsController: accountController.collectionsController,
        syncController: accountController.syncController,
        personsController: accountController.personsController,
        metadataController: accountController.metadataController,
      ),
      child: const _WrappedHomePhotos(),
    );
  }
}

class _WrappedHomePhotos extends StatefulWidget {
  const _WrappedHomePhotos();

  @override
  State<StatefulWidget> createState() => _WrappedHomePhotosState();
}

@npLog
class _WrappedHomePhotosState extends State<_WrappedHomePhotos> {
  @override
  void initState() {
    super.initState();
    _bloc.add(const _LoadItems());
  }

  @override
  Widget build(BuildContext context) {
    final content = VisibilityDetector(
      key: _key,
      onVisibilityChanged: (info) {
        final isVisible = info.visibleFraction >= 0.2;
        if (isVisible != _isVisible) {
          if (mounted) {
            setState(() {
              _isVisible = isVisible;
            });
          }
        }
      },
      child: MultiBlocListener(
        listeners: [
          _BlocListenerT<bool>(
            selector: (state) => state.hasMissingVideoPreview,
            listener: (context, hasMissingVideoPreview) {
              if (hasMissingVideoPreview) {
                if (!context
                        .read<PrefController>()
                        .isDontShowVideoPreviewHintValue &&
                    !SessionStorage().hasShownVideoPreviewHint) {
                  SessionStorage().hasShownVideoPreviewHint = true;
                  showDialog(
                    context: context,
                    builder: (context) => const _VideoPreviewHintDialog(),
                  );
                }
              }
            },
          ),
          _BlocListenerT<ExceptionEvent?>(
            selector: (state) => state.error,
            listener: (context, error) {
              if (error != null && _isVisible == true) {
                if (error.error is _ArchiveFailedError) {
                  SnackBarManager().showSnackBar(SnackBar(
                    content: Text(L10n.global()
                        .archiveSelectedFailureNotification(
                            (error.error as _ArchiveFailedError).count)),
                    duration: k.snackBarDurationNormal,
                  ));
                } else if (error.error is _RemoveFailedError) {
                  SnackBarManager().showSnackBar(SnackBar(
                    content: Text(L10n.global()
                        .deleteSelectedFailureNotification(
                            (error.error as _RemoveFailedError).count)),
                    duration: k.snackBarDurationNormal,
                  ));
                } else {
                  SnackBarManager().showSnackBarForException(error.error);
                }
              }
            },
          ),
        ],
        child: _BlocSelector<bool>(
          selector: (state) =>
              state.files.isEmpty && state.syncProgress != null,
          builder: (context, isInitialSyncing) {
            if (isInitialSyncing) {
              return const _InitialSyncBody();
            } else {
              return Shimmer(
                linearGradient: Theme.of(context).photoGridShimmerGradient,
                child: const _Body(),
              );
            }
          },
        ),
      ),
    );
    if (getRawPlatform() == NpPlatform.android) {
      return WillPopScope(
        onWillPop: () => _onBackButtonPressed(context),
        child: content,
      );
    } else {
      return content;
    }
  }

  Future<bool> _onBackButtonPressed(BuildContext context) async {
    if (context.state.selectedItems.isEmpty) {
      return DoubleTapExitHandler()();
    } else {
      context.addEvent(const _SetSelectedItems(items: {}));
      return false;
    }
  }

  late final _bloc = context.bloc;

  final _key = GlobalKey();
  bool? _isVisible;
}

class _InitialSyncBody extends StatelessWidget {
  const _InitialSyncBody();

  @override
  Widget build(BuildContext context) {
    return CustomScrollView(
      slivers: [
        const _AppBar(),
        _BlocSelector<Progress?>(
          selector: (state) => state.syncProgress,
          builder: (context, syncProgress) {
            return SliverToBoxAdapter(
              child: Padding(
                padding: const EdgeInsets.fromLTRB(16, 56, 16, 0),
                child: Center(
                  child: ConstrainedBox(
                    constraints: BoxConstraints(
                      maxWidth: Theme.of(context).widthLimitedContentMaxWidth,
                    ),
                    child: Column(
                      mainAxisSize: MainAxisSize.min,
                      crossAxisAlignment: CrossAxisAlignment.start,
                      children: [
                        Text(
                          L10n.global().initialSyncMessage,
                          style: Theme.of(context).textTheme.bodyLarge,
                        ),
                        const SizedBox(height: 8),
                        LinearProgressIndicator(
                          value: (syncProgress?.progress ?? 0) == 0
                              ? null
                              : syncProgress!.progress,
                        ),
                        const SizedBox(height: 8),
                        Text(
                          syncProgress?.text ?? "",
                          style: Theme.of(context).textTheme.bodySmall,
                        ),
                      ],
                    ),
                  ),
                ),
              ),
            );
          },
        ),
      ],
    );
  }
}

class _Body extends StatefulWidget {
  const _Body();

  @override
  State<StatefulWidget> createState() => _BodyState();
}

@npLog
class _BodyState extends State<_Body> {
  @override
  void initState() {
    super.initState();
    _onBackToTopListener.begin();
  }

  @override
  void dispose() {
    _onBackToTopListener.end();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return FingerListener(
      onFingerChanged: (finger) {
        setState(() {
          _finger = finger;
        });
      },
      child: GestureDetector(
        onScaleStart: (_) {
          _bloc.add(const _StartScaling());
        },
        onScaleUpdate: (details) {
          _bloc.add(_SetScale(details.scale));
        },
        onScaleEnd: (_) {
          _bloc.add(const _EndScaling());
        },
        child: LayoutBuilder(
          builder: (context, constraints) {
            context.addEvent(_SetLayoutConstraint(
                constraints.maxWidth,
                constraints.maxHeight -
                    MediaQuery.of(context).padding.top -
                    kToolbarHeight -
                    AppDimension.of(context).homeBottomAppBarHeight));
            return _BlocBuilder(
              buildWhen: (previous, current) =>
                  previous.contentListMaxExtent !=
                      current.contentListMaxExtent ||
                  (previous.isEnableMemoryCollection &&
                          previous.memoryCollections.isNotEmpty) !=
                      (current.isEnableMemoryCollection &&
                          current.memoryCollections.isNotEmpty),
              builder: (context, state) {
                final scrollExtent = _getScrollViewExtent(
                  context: context,
                  constraints: constraints,
                  hasMemoryCollection: state.isEnableMemoryCollection &&
                      state.memoryCollections.isNotEmpty,
                  contentListMaxExtent: state.contentListMaxExtent,
                );
                return Stack(
                  children: [
                    DraggableScrollbar.semicircle(
                      controller: _scrollController,
                      overrideMaxScrollExtent: scrollExtent,
                      // status bar + app bar
                      topOffset: _getAppBarExtent(context),
                      bottomOffset:
                          AppDimension.of(context).homeBottomAppBarHeight,
                      labelTextBuilder: (_) => const _ScrollLabel(),
                      labelPadding: const EdgeInsets.symmetric(horizontal: 40),
                      backgroundColor:
                          Theme.of(context).colorScheme.secondaryContainer,
                      foregroundColor:
                          Theme.of(context).colorScheme.onSecondaryContainer,
                      heightScrollThumb: 60,
                      onScrollBegin: () {
                        _bloc.add(const _StartScrolling());
                      },
                      onScrollEnd: () {
                        _bloc.add(const _EndScrolling());
                      },
                      child: ScrollConfiguration(
                        behavior: ScrollConfiguration.of(context)
                            .copyWith(scrollbars: false),
                        child: RefreshIndicator(
                          color: Theme.of(context).colorScheme.secondary,
                          backgroundColor:
                              Theme.of(context).colorScheme.secondaryContainer,
                          onRefresh: () async {
                            _bloc.add(const _RequestRefresh());
                            var hasNotNull = false;
                            await _bloc.stream.firstWhere((s) {
                              if (s.syncProgress != null) {
                                hasNotNull = true;
                              }
                              return hasNotNull && s.syncProgress == null;
                            });
                          },
                          child: Stack(
                            children: [
                              CustomScrollView(
                                controller: _scrollController,
                                physics: _finger >= 2
                                    ? const NeverScrollableScrollPhysics()
                                    : null,
                                slivers: [
                                  _BlocSelector<bool>(
                                    selector: (state) =>
                                        state.selectedItems.isEmpty,
                                    builder: (context, isEmpty) => isEmpty
                                        ? const _AppBar()
                                        : const _SelectionAppBar(),
                                  ),
                                  _BlocBuilder(
                                    buildWhen: (previous, current) =>
                                        (previous.isEnableMemoryCollection &&
                                            previous.memoryCollections
                                                .isNotEmpty) !=
                                        (current.isEnableMemoryCollection &&
                                            current
                                                .memoryCollections.isNotEmpty),
                                    builder: (context, state) {
                                      if (state.isEnableMemoryCollection &&
                                          state.memoryCollections.isNotEmpty) {
                                        return const _MemoryCollectionList();
                                      } else {
                                        return const SliverToBoxAdapter();
                                      }
                                    },
                                  ),
                                  _BlocSelector<double?>(
                                    selector: (state) => state.scale,
                                    builder: (context, scale) =>
                                        SliverTransitionedScale(
                                      scale: scale,
                                      baseSliver: const _ContentList(),
                                      overlaySliver: const _ScalingList(),
                                    ),
                                  ),
                                  SliverToBoxAdapter(
                                    child: SizedBox(
                                      height: AppDimension.of(context)
                                          .homeBottomAppBarHeight,
                                    ),
                                  ),
                                ],
                              ),
                              _BlocSelector<bool>(
                                selector: (state) => state.isScrolling,
                                builder: (context, isScrolling) =>
                                    AnimatedOpacity(
                                  opacity: isScrolling ? 1 : 0,
                                  duration: k.animationDurationNormal,
                                  curve: Curves.fastOutSlowIn,
                                  child: const _MinimapPadding(
                                    child: _MinimapBackground(),
                                  ),
                                ),
                              ),
                            ],
                          ),
                        ),
                      ),
                    ),
                    _BlocSelector<bool>(
                      selector: (state) => state.isScrolling,
                      builder: (context, isScrolling) => AnimatedOpacity(
                        opacity: isScrolling ? 1 : 0,
                        duration: k.animationDurationNormal,
                        curve: Curves.fastOutSlowIn,
                        child: const _MinimapPadding(child: _MinimapView()),
                      ),
                    ),
                    Align(
                      alignment: Alignment.bottomCenter,
                      child: NavigationBarBlurFilter(
                        height: AppDimension.of(context).homeBottomAppBarHeight,
                      ),
                    ),
                  ],
                );
              },
            );
          },
        ),
      ),
    );
  }

  void _onBackToTop(HomePhotos2BackToTopEvent ev) {
    _scrollController.jumpTo(0);
  }

  /// Return the estimated scroll extent of the custom scroll view, or null
  double? _getScrollViewExtent({
    required BuildContext context,
    required BoxConstraints constraints,
    required bool hasMemoryCollection,
    required double? contentListMaxExtent,
  }) {
    if (contentListMaxExtent != null && constraints.hasBoundedHeight) {
      final appBarExtent = _getAppBarExtent(context);
      final bottomAppBarExtent =
          AppDimension.of(context).homeBottomAppBarHeight;
      // final metadataTaskHeaderExtent = _web?.getHeaderHeight() ?? 0;
      final smartAlbumListHeight =
          hasMemoryCollection ? _MemoryCollectionItemView.height : 0;
      // scroll extent = list height - widget viewport height
      // + sliver app bar height + bottom app bar height
      // + metadata task header height + smart album list height
      final scrollExtent = contentListMaxExtent -
          constraints.maxHeight +
          appBarExtent +
          bottomAppBarExtent +
          // metadataTaskHeaderExtent +
          smartAlbumListHeight;
      _log.info("[_getScrollViewExtent] $contentListMaxExtent "
          "- ${constraints.maxHeight} "
          "+ $appBarExtent "
          "+ $bottomAppBarExtent "
          // "+ $metadataTaskHeaderExtent "
          "+ $smartAlbumListHeight "
          "= $scrollExtent");
      return scrollExtent;
    } else {
      return null;
    }
  }

  double _getAppBarExtent(BuildContext context) =>
      MediaQuery.of(context).padding.top + kToolbarHeight;

  late final _bloc = context.bloc;

  final _scrollController = ScrollController();
  var _finger = 0;

  late final _onBackToTopListener =
      AppEventListener<HomePhotos2BackToTopEvent>(_onBackToTop);
}

typedef _BlocBuilder = BlocBuilder<_Bloc, _State>;
// typedef _BlocListener = BlocListener<_Bloc, _State>;
typedef _BlocListenerT<T> = BlocListenerT<_Bloc, _State, T>;
typedef _BlocSelector<T> = BlocSelector<_Bloc, _State, T>;

extension on BuildContext {
  _Bloc get bloc => read<_Bloc>();
  _State get state => bloc.state;
  void addEvent(_Event event) => bloc.add(event);
}

@npLog
// ignore: camel_case_types
class __ {}