import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:uuid/uuid.dart';

class FoodEntryBloc extends Bloc<FoodEvent, FoodEntryState> {
  FoodEntryBloc(super.initialState) {
    on<FoodEntryEvent>(addFoodEntryToState);
    on<FoodDeletionEvent>(deleteFood);
  }

  void addFoodEntryToState(FoodEntryEvent event, Emitter<FoodEntryState> emit) {
    FoodEntryState newState = FoodEntryState.from(state);
    newState.addEntry(event.entry);
    emit(newState);
  }

  void deleteFood(FoodDeletionEvent event, Emitter<FoodEntryState> emit) {
    state.foodEntries.removeWhere((entry) => entry.id == event.entryID);
    emit(FoodEntryState.from(state));
  }
}

class FoodEvent {}

class FoodEntryEvent extends FoodEvent {
  final FoodEntry entry;
  FoodEntryEvent({required this.entry});
}

class FoodDeletionEvent extends FoodEvent {
  final String entryID;
  FoodDeletionEvent({required this.entryID});
}

class FoodEntryState {
  final List<FoodEntry> foodEntries;

  FoodEntryState({required this.foodEntries});

  factory FoodEntryState.init() {
    return FoodEntryState(foodEntries: []);
  }

  static from(FoodEntryState state) {
    List<FoodEntry> newList = List.from(state.foodEntries);
    return FoodEntryState(foodEntries: newList);
  }

  void addEntry(FoodEntry entry) {
    foodEntries.add(entry);
  }
}

class FoodEntry {
  final String name;
  final double mass;
  final double kcalPerMass;
  final String id;

  FoodEntry({
    required this.name,
    required this.mass,
    required this.kcalPerMass,
  }) : id = const Uuid().v1();
}