PMU-PIbd-31-Potapov-N-S/lib/presentation/home_page/home_page.dart

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:pmu/components/debounce.dart';
import 'package:pmu/components/extensions/content_x.dart';
import 'package:pmu/domain/models/card.dart';
import 'package:pmu/presentation/common/svg_objects.dart';
import 'package:pmu/presentation/detail_pages/card_detail_page.dart';
import 'package:pmu/presentation/home_page/bloc/bloc.dart';
import 'package:pmu/presentation/home_page/bloc/events.dart';
import 'package:pmu/presentation/home_page/bloc/state.dart';
import 'package:pmu/presentation/locale/bloc.dart';
import 'package:pmu/presentation/locale/events.dart';
import 'package:pmu/presentation/locale/state.dart';

import '../like/bloc.dart';
import '../like/events.dart';
import '../like/state.dart';

part 'card.dart';

class HomePage extends StatefulWidget {
  const HomePage({super.key});

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  @override
  Widget build(BuildContext context) {
    return const Scaffold(body: _Body());
  }
}

class _Body extends StatefulWidget {
  const _Body();

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

class _BodyState extends State<_Body> {
  final searchController = TextEditingController();
  final scrollController = ScrollController();

  @override
  void initState() {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      context.read<HomeBloc>().add(const HomeLoadDataEvent());
      context.read<LikeBloc>().add(const LoadLikesEvent());
    });

    scrollController.addListener(_onNextPageListener);

    super.initState();
  }

  void _onNextPageListener() {
    if (scrollController.offset >= scrollController.position.maxScrollExtent) {
      // preventing multiple pagination request on multiple swipes
      final bloc = context.read<HomeBloc>();
      if (!bloc.state.isPaginationLoading) {
        bloc.add(HomeLoadDataEvent(
            search: searchController.text,
            pageNumber: bloc.state.data?.pageNumber,
            nextPageNumber: bloc.state.data?.nextPageNumber,
            lastPageNumber: bloc.state.data?.lastPageNumber
        ));
      }
    }
  }

  @override
  void dispose() {
    searchController.dispose();
    scrollController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: EdgeInsets.only(top: MediaQuery
          .of(context)
          .padding
          .top),
      child: Column(
        children: [
          Row(
            children: [
              Expanded(
                flex: 4,
                child: Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: CupertinoSearchTextField(
                    controller: searchController,
                    placeholder: context.locale.search,
                    onChanged: (search) {
                      Debounce.run(() =>
                          context
                              .read<HomeBloc>()
                              .add(HomeLoadDataEvent(search: search)));
                    },
                  ),
                ),
              ),
              GestureDetector(
                onTap: () =>
                    context.read<LocaleBloc>().add(const ChangeLocaleEvent()),
                child: SizedBox.square(
                  dimension: 50,
                  child: Padding(
                    padding: const EdgeInsets.all(12),
                    child: BlocBuilder<LocaleBloc, LocaleState>(
                      builder: (context, state) {
                        return state.currentLocale.languageCode == 'ru'
                            ? const SvgRu()
                            : const SvgUk();
                      },
                    ),
                  ),
                ),
              )
            ],
          ),
          BlocBuilder<HomeBloc, HomeState>(
            builder: (context, state) =>
            state.error != null
                ? Text(
              state.error ?? '',
              style: Theme
                  .of(context)
                  .textTheme
                  .headlineSmall
                  ?.copyWith(color: Colors.red),
            )
                : state.isLoading
                ? const CircularProgressIndicator()
                : BlocBuilder<LikeBloc, LikeState>(
              builder: (context, likeState) {
                return Expanded(
                  child: RefreshIndicator(
                    onRefresh: _onRefresh,
                    child: ListView.builder(
                      controller: scrollController,
                      padding: EdgeInsets.zero,
                      itemCount: state.data?.data?.length ?? 0,
                      itemBuilder: (context, index) {
                        final data = state.data?.data?[index];
                        return data != null
                            ? _Card.fromData(
                          data,
                          onLike: _onLike,
                          isLiked: likeState.likedIds
                              ?.contains(data.id) ==
                              true,
                          onTap: () =>
                              _navToDetails(context, data),
                        )
                            : const SizedBox.shrink();
                      },
                    ),
                  ),
                );
              },
            ),
          ),
          BlocBuilder<HomeBloc, HomeState>(
            builder: (context, state) =>
            state.isPaginationLoading
                ? const CircularProgressIndicator()
                : const SizedBox.shrink(),
          ),
        ],
      ),
    );
  }

  void _onLike(String? id, String title, bool isLiked) {
    if (id != null) {
      context.read<LikeBloc>().add(ChangeLikeEvent(id));
      _showSnackBar(context, title, !isLiked);
    }
  }

  Future<void> _onRefresh() {
    context
        .read<HomeBloc>()
        .add(HomeLoadDataEvent(search: searchController.text));
    return Future.value(null);
  }

  void _navToDetails(BuildContext context, CardData data) {
    Navigator.push(
      context,
      CupertinoPageRoute(builder: (context) => DetailPage(data)),
    );
  }

  void _showSnackBar(BuildContext context, String title, bool isLiked) {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      ScaffoldMessenger.of(context).showSnackBar(SnackBar(
        content: Text(
          '${isLiked ? context.locale.liked : context.locale.disliked } $title',
          style: const TextStyle(
              color: Colors.black45, fontSize: 20, fontWeight: FontWeight.bold),
        ),
        backgroundColor: isLiked ? Colors.green : Colors.red,
        duration: const Duration(seconds: 2),
      ));
    });
  }
}