import 'dart:math';

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:paperless_api/paperless_api.dart';
import 'package:paperless_mobile/core/bloc/connectivity_cubit.dart';
import 'package:paperless_mobile/extensions/flutter_extensions.dart';
import 'package:paperless_mobile/features/documents/bloc/documents_cubit.dart';
import 'package:paperless_mobile/features/documents/bloc/documents_state.dart';
import 'package:paperless_mobile/features/documents/view/widgets/selection/confirm_delete_saved_view_dialog.dart';
import 'package:paperless_mobile/features/saved_view/cubit/saved_view_cubit.dart';
import 'package:paperless_mobile/features/saved_view/cubit/saved_view_state.dart';
import 'package:paperless_mobile/features/saved_view/view/add_saved_view_page.dart';
import 'package:paperless_mobile/generated/l10n.dart';
import 'package:paperless_mobile/helpers/message_helpers.dart';
import 'package:paperless_mobile/constants.dart';
import 'package:shimmer/shimmer.dart';

class SavedViewSelectionWidget extends StatelessWidget {
  final DocumentFilter currentFilter;
  const SavedViewSelectionWidget({
    Key? key,
    required this.height,
    required this.enabled,
    required this.currentFilter,
  }) : super(key: key);

  final double height;
  final bool enabled;

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<ConnectivityCubit, ConnectivityState>(
      builder: (context, connectivityState) {
        final hasInternetConnection = connectivityState.isConnected;
        return SizedBox(
          height: height,
          child: Column(
            mainAxisAlignment: MainAxisAlignment.start,
            crossAxisAlignment: CrossAxisAlignment.start,
            mainAxisSize: MainAxisSize.min,
            children: [
              BlocBuilder<SavedViewCubit, SavedViewState>(
                builder: (context, state) {
                  if (!state.hasLoaded) {
                    return _buildLoadingWidget(context);
                  }
                  if (state.value.isEmpty) {
                    return Text(S.of(context).savedViewsEmptyStateText);
                  }
                  return SizedBox(
                    height: 38,
                    child: ListView.separated(
                      itemCount: state.value.length,
                      scrollDirection: Axis.horizontal,
                      itemBuilder: (context, index) {
                        final view = state.value.values.elementAt(index);
                        return GestureDetector(
                          onLongPress: hasInternetConnection
                              ? () => _onDelete(context, view)
                              : null,
                          child: BlocBuilder<DocumentsCubit, DocumentsState>(
                            builder: (context, docState) {
                              final view = state.value.values.toList()[index];
                              return FilterChip(
                                label: Text(
                                  view.name,
                                ),
                                selected:
                                    view.id == docState.selectedSavedViewId,
                                onSelected: enabled && hasInternetConnection
                                    ? (isSelected) =>
                                        _onSelected(isSelected, context, view)
                                    : null,
                              );
                            },
                          ),
                        );
                      },
                      separatorBuilder: (context, index) => const SizedBox(
                        width: 4.0,
                      ),
                    ),
                  );
                },
              ),
              BlocBuilder<SavedViewCubit, SavedViewState>(
                builder: (context, state) {
                  return Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      Text(
                        S.of(context).savedViewsLabel,
                        style: Theme.of(context).textTheme.titleSmall,
                      ),
                      BlocBuilder<DocumentsCubit, DocumentsState>(
                        buildWhen: (previous, current) =>
                            previous.filter != current.filter,
                        builder: (context, docState) {
                          return TextButton.icon(
                            icon: const Icon(Icons.add),
                            onPressed: (enabled &&
                                    state.hasLoaded &&
                                    hasInternetConnection)
                                ? () =>
                                    _onCreatePressed(context, docState.filter)
                                : null,
                            label: Text(S.of(context).savedViewCreateNewLabel),
                          );
                        },
                      ),
                    ],
                  );
                },
              ),
            ],
          ).padded(),
        );
      },
    );
  }

  Widget _buildLoadingWidget(BuildContext context) {
    return SizedBox(
      height: 38,
      width: MediaQuery.of(context).size.width,
      child: Shimmer.fromColors(
        baseColor: Theme.of(context).brightness == Brightness.light
            ? Colors.grey[300]!
            : Colors.grey[900]!,
        highlightColor: Theme.of(context).brightness == Brightness.light
            ? Colors.grey[100]!
            : Colors.grey[600]!,
        child: ListView(
          scrollDirection: Axis.horizontal,
          physics: const NeverScrollableScrollPhysics(),
          children: [
            FilterChip(
              label: const SizedBox(width: 32),
              onSelected: (_) {},
            ),
            const SizedBox(width: 4.0),
            FilterChip(
              label: const SizedBox(width: 64),
              onSelected: (_) {},
            ),
            const SizedBox(width: 4.0),
            FilterChip(
              label: const SizedBox(width: 100),
              onSelected: (_) {},
            ),
            const SizedBox(width: 4.0),
            FilterChip(
              label: const SizedBox(width: 32),
              onSelected: (_) {},
            ),
            const SizedBox(width: 4.0),
            FilterChip(
              label: const SizedBox(width: 48),
              onSelected: (_) {},
            ),
          ],
        ),
      ),
    );
  }

  void _onCreatePressed(BuildContext context, DocumentFilter filter) async {
    final newView = await Navigator.of(context).push<SavedView?>(
      MaterialPageRoute(
        builder: (context) => AddSavedViewPage(
          currentFilter: filter,
        ),
      ),
    );
    if (newView != null) {
      try {
        await context.read<SavedViewCubit>().add(newView);
      } on PaperlessServerException catch (error, stackTrace) {
        showErrorMessage(context, error, stackTrace);
      }
    }
  }

  void _onSelected(
    bool selectionIntent,
    BuildContext context,
    SavedView view,
  ) async {
    if (selectionIntent) {
      context.read<DocumentsCubit>().selectView(view.id!);
    } else {
      context.read<DocumentsCubit>().unselectView();
      context.read<DocumentsCubit>().resetFilter();
    }
  }

  void _onDelete(BuildContext context, SavedView view) async {
    {
      final delete = await showDialog<bool>(
            context: context,
            builder: (context) => ConfirmDeleteSavedViewDialog(view: view),
          ) ??
          false;
      if (delete) {
        try {
          context.read<SavedViewCubit>().remove(view);
          if (context.read<DocumentsCubit>().state.selectedSavedViewId ==
              view.id) {
            await context.read<DocumentsCubit>().resetFilter();
          }
        } on PaperlessServerException catch (error, stackTrace) {
          showErrorMessage(context, error, stackTrace);
        }
      }
    }
  }
}