import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:gitea_client/cubit/repo_event.dart';
import 'package:gitea_client/model/repository.dart';

import '../cubit/repo_cubit.dart';

class ReposList extends StatefulWidget {
  @override
  _ReposListState createState() => _ReposListState();
}

class _ReposListState extends State<ReposList> {
  final _scrollController = ScrollController();

  @override
  void initState() {
    super.initState();
    _scrollController.addListener(_onScroll);
  }

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<RepoBloc, RepoState>(
      builder: (context, state) {
        switch (state.status) {
          case RepoStatus.failure:
            String error_message = state.error_message!;
            return Center(child: Text('failed to fetch $error_message'));
          case RepoStatus.success:
            if (state.repos.isEmpty) {
              return const Center(child: Text('no repos'));
            }
            if(state.repos.length < 5) {
              context.read<RepoBloc>().add(RepoFetched());
            }
            return ListView.builder(
              itemBuilder: (BuildContext context, int index) {
                return index >= state.repos.length
                    ? BottomLoader()
                    : RepoListItem(repo: state.repos[index]);
              },
              itemCount: state.hasReachedMax
                  ? state.repos.length
                  : state.repos.length + 1,
              controller: _scrollController,
            );
          default:
            return const Center(child: CircularProgressIndicator());
        }
      },
    );
  }

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

  void _onScroll() {
    if (_isBottom) context.read<RepoBloc>().add(RepoFetched());
  }

  bool get _isBottom {
    if (!_scrollController.hasClients) return false;
    final maxScroll = _scrollController.position.maxScrollExtent;
    final currentScroll = _scrollController.offset;
    return currentScroll >= (maxScroll * 0.9);
  }
}

class BottomLoader extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return const Center(
      child: SizedBox(
        height: 24,
        width: 24,
        child: CircularProgressIndicator(strokeWidth: 1.5),
      ),
    );
  }
}

class RepoListItem extends StatelessWidget {
  const RepoListItem({Key? key, required this.repo}) : super(key: key);

  final Repository repo;

  @override
  Widget build(BuildContext context) {
    final textTheme = Theme.of(context).textTheme;

    return Material(
      child: Container(
        color: (repo.private!) ? Colors.yellow[100] : Colors.white,
          child: ListTile(
            leading: (repo.mirror!) ? const Icon(Icons.amp_stories_outlined) : (repo.archived!) ? const Icon(Icons.archive) : const Icon(Icons.book) ,
            title: Text('${repo.owner.username}/${repo.name}'),
            isThreeLine: true,
            subtitle: Column(
              mainAxisAlignment: MainAxisAlignment.start,
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                (repo.description != null) ? Text(repo.description!) : Container(),
                (repo.mirror!) ? Text("Mirror of ${repo.originalUrl!}") : Container()
              ],
            ),
            dense: true,
            onTap: () => Scaffold
                .of(context)
                .showSnackBar(SnackBar(content: Text(repo.fullName!.toString()))),
        ),
      ),
    );
  }
}