Sonnat/lib/features/posts/cubit/posts_cubit.dart

import 'dart:async';
import 'dart:convert';
import 'dart:math';

import 'package:flutter/services.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:sonnat/core/utils/base_cubit_type.dart';
import 'package:sonnat/features/single_post/view_models/post.dart';

class PostsCubit extends Cubit<BaseCubitType<PostsState>> {
  List<Post> allData = [];
  List<Post> postList = [];
  List<Post> searchedList = [];
  bool hasReachedMax = false;
  String _query = '';

  PostsCubit() : super(BaseCubitType(eventName: PostsState.empty));

  void empty() => emit(BaseCubitType(eventName: PostsState.empty));

  Future<void> getData() async {
    if (hasReachedMax) {
      return;
    }
    if (postList.isNotEmpty) {
      emit(BaseCubitType(eventName: PostsState.loadingPagination));
    } else {
      emit(BaseCubitType(eventName: PostsState.loading));
    }
    String data = await rootBundle.loadString('assets/meta/data.json');
    allData = List<Post>.from(
      jsonDecode(data)['posts'].map(
        (post) => Post.fromJson(post).copyWith(DateTime.now().millisecondsSinceEpoch),
      ),
    );
    if (allData.isNotEmpty) {
      List<Post> posts = allData.getRange(postList.length, min(postList.length + 20, allData.length)).toList();
      hasReachedMax = posts.length < 20;
      postList += posts;
      emit(BaseCubitType(eventName: PostsState.data));
    } else {
      emit(BaseCubitType(eventName: PostsState.data));
    }
  }

  Future<void> search({required String query}) async {
    if (query.isEmpty) {
      unawaited(getData());
      _query = '';
      searchedList.clear();
      emit(BaseCubitType(eventName: PostsState.data));
      return;
    }
    if (_query != query) {
      hasReachedMax = false;
      searchedList.clear();
      _query = query;
    }
    if (hasReachedMax) {
      return;
    }
    if (searchedList.isNotEmpty) {
      emit(BaseCubitType(eventName: PostsState.loadingPagination));
    } else {
      emit(BaseCubitType(eventName: PostsState.loading));
    }
    await Future.delayed(Duration(milliseconds: Random().nextInt(1000)));
    String data = await rootBundle.loadString('assets/meta/data.json');
    allData = List<Post>.from(
      jsonDecode(data)['posts'].map(
        (post) => Post.fromJson(post).copyWith(
          DateTime.now().millisecondsSinceEpoch,
        ),
      ),
    );
    if (allData.isNotEmpty) {
      List<Post> posts = allData.where((element) => element.name.contains(query.trim())).toList();
      hasReachedMax = posts.length < 20;
      searchedList += posts;
      emit(BaseCubitType(eventName: PostsState.data));
    } else {
      emit(BaseCubitType(eventName: PostsState.data));
    }
  }

  String get query => _query;

  void clearSearch() {
    unawaited(getData());
    _query = '';
    searchedList.clear();
    emit(BaseCubitType(eventName: PostsState.data));
  }

  Future<void> changeFilter(int index) async {
    emit(BaseCubitType(eventName: PostsState.changeFilterIndex, data: index));
    await Future.delayed(Duration(milliseconds: Random().nextInt(1000)));
    await getData();
  }
}

enum PostsState {
  empty,
  data,
  loading,
  loadingPagination,
  changeFilterIndex,
}