import 'dart:math';

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:pmu_labworks/components/utils/debounce.dart';
import 'package:pmu_labworks/domain/models/comment.dart';
import 'package:pmu_labworks/domain/models/user.dart';
import 'package:pmu_labworks/view/details_page/details_page.dart';
import 'package:pmu_labworks/view/home_page/bloc/bloc.dart';
import 'package:pmu_labworks/view/home_page/bloc/events.dart';
import 'package:pmu_labworks/view/home_page/bloc/state.dart';

part 'comment.dart';

class HomePage extends StatefulWidget {
  const HomePage({super.key, required this.title});

  final String title;

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

class _HomePageState extends State<HomePage> {
  Color _color = Colors.transparent;

  @override
  void initState() {
    super.initState();
    _color = _generateColor();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: _color,
        title: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Text(widget.title,
                style: const TextStyle(
                  fontSize: 20,
                  fontWeight: FontWeight.bold,
                )),
            const Text(
              'made by Factorino',
              style: TextStyle(
                fontSize: 12,
                fontStyle: FontStyle.italic,
              ),
            ),
          ],
        ),
      ),
      body: const _Body(),
    );
  }

  Color _generateColor() {
    final Random random = Random();
    final int red = (random.nextInt(106) + 150);
    final int green = (random.nextInt(106) + 150);
    final int blue = (random.nextInt(106) + 150);

    return Color.fromARGB(255, red, green, blue);
  }
}

class _Body extends StatefulWidget {
  const _Body();

  @override
  State<_Body> 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());
    });

    scrollController.addListener(_onNextPageListener);

    super.initState();
  }

  @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: [
          Padding(
            padding: const EdgeInsets.all(12),
            child: CupertinoSearchTextField(
              controller: searchController,
              onChanged: (search) {
                Debounce.run(() => context
                    .read<HomeBloc>()
                    .add(HomeLoadDataEvent(search: search)));
              },
            ),
          ),
          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()
                    : 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
                                  ? _Comment.fromData(
                                      data,
                                      onAction:
                                          (nickname, isLiked, isDisliked) =>
                                              _showSnackBar(context, nickname,
                                                  isLiked, isDisliked),
                                      onTap: () => _navToDetails(context, data),
                                    )
                                  : const SizedBox.shrink();
                            },
                          ),
                        ),
                      ),
          ),
          BlocBuilder<HomeBloc, HomeState>(
            builder: (context, state) => state.isPaginationLoading
                ? const CircularProgressIndicator()
                : const SizedBox.shrink(),
          ),
        ],
      ),
    );
  }

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

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

  void _showSnackBar(
      BuildContext context, String nickname, bool isLiked, bool isDisliked) {
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final String action;

      if (isLiked) {
        action = 'liked';
      } else if (isDisliked) {
        action = 'disliked';
      } else {
        action = 'neutralized'; // Состояние без лайков/дизлайков
      }

      ScaffoldMessenger.of(context).showSnackBar(SnackBar(
        content: Text(
          '$nickname\'s comment $action',
          style: Theme.of(context).textTheme.bodyLarge,
        ),
        backgroundColor: Colors.white70,
        duration: const Duration(seconds: 1),
      ));
    });
  }

  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,
          nextPage: bloc.state.data?.nextPage,
        ));
      }
    }
  }
}