import 'package:auto_route/auto_route.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:remever/common/resources.dart';
import 'package:remever/common/widgets/typography.dart';
import 'package:remever/components/extensions/context.dart';
import 'package:remever/database/database.dart';
import 'package:remever/inject.dart';
import 'package:remever/router.gr.dart';
import 'package:remever/screens/collections/widgets/collection_card.dart';
import 'package:remever/screens/collections/widgets/collections_app_bar.dart';
import 'package:remever/screens/collections/widgets/collections_filters.dart';
import 'package:remever/services/collection/collections_interface.dart';

@RoutePage()
class CollectionScreen extends StatefulWidget {
  const CollectionScreen({super.key});

  @override
  State<CollectionScreen> createState() => _CollectionScreenState();
}

class _CollectionScreenState extends State<CollectionScreen> {
  /// Контроллер скролла для коллекции
  final ScrollController _scrollController = ScrollController();

  /// Показ FAB'а
  bool _showFab = true;

  @override
  void initState() {
    super.initState();
    _initScrollListener();
  }

  @override
  void dispose() {
    _scrollController.dispose();
    super.dispose();
  }

  /// Инициализация слушателя скролла
  void _initScrollListener() {
    _scrollController.addListener(() {
      setState(() {
        _showFab =
            _scrollController.position.userScrollDirection ==
                    ScrollDirection.reverse
                ? false
                : true;
      });
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: AppColors.bg,
      appBar: const CollectionsAppBar(),
      body: _buildMain(context),
      floatingActionButton: AnimatedOpacity(
        opacity: _showFab ? 1.0 : 0.0,
        duration: const Duration(milliseconds: 200),
        child: FloatingActionButton(
          backgroundColor: AppColors.primary,
          onPressed: () => context.pushRoute(CrudCollectionRoute()),
          child: const Icon(Icons.add),
        ),
      ),
    );
  }

  /// Построение основного экрана
  Widget _buildMain(BuildContext context) {
    return Column(
      children: [
        const CollectionsFilters(),
        Expanded(
          child: StreamBuilder<List<Collection>>(
            stream: getIt<CollectionsInterface>().watchCollectionsList(),
            builder: (context, snapshot) {
              if (snapshot.connectionState == ConnectionState.waiting) {
                return const _LoadingList();
              }

              if (snapshot.hasError) {
                return const _ErrorList();
              }

              final collections = snapshot.data;
              if (collections == null || collections.isEmpty) {
                return const _EmptyList();
              }

              return ListView.builder(
                controller: _scrollController,
                itemCount: collections.length,
                padding: const EdgeInsets.symmetric(horizontal: 16).r,
                itemBuilder:
                    (context, index) => Padding(
                      padding: const EdgeInsets.only(bottom: 8).r,
                      child: CollectionCard(collection: collections[index]),
                    ),
              );
            },
          ),
        ),
      ],
    );
  }
}

class _LoadingList extends StatelessWidget {
  const _LoadingList();

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      height: MediaQuery.sizeOf(context).height / 2,
      child: Center(child: CircularProgressIndicator(color: AppColors.primary)),
    );
  }
}

class _ErrorList extends StatelessWidget {
  const _ErrorList();

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      height: MediaQuery.sizeOf(context).height / 2,
      child: Center(
        child: AppTypography('Произошла ошибка при загрузке данных'),
      ),
    );
  }
}

class _EmptyList extends StatelessWidget {
  const _EmptyList();

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      height: MediaQuery.sizeOf(context).height / 2,
      child: Center(child: AppTypography('Нет доступных коллекций')),
    );
  }
}