import 'package:flutter/material.dart';
import 'package:seshat/data/repositories/bal_repository.dart';
import 'package:seshat/domain/models/bal.dart';
import 'package:seshat/utils/command.dart';
import 'package:seshat/utils/result.dart';

class HomeViewModel extends ChangeNotifier {
  HomeViewModel({required BalRepository balRepository})
    : _balRepository = balRepository {
    load = Command0(_load)..execute();
  }

  final BalRepository _balRepository;

  /*
 * =================
 * =====[ BAL ]=====
 * =================
*/

  /// [List<Bal>] of all [Bal]
  List<Bal> _bals = [];

  /// [List<Bal>] of all [Bal]
  List<Bal> get bals => _bals;

  /// [Bal] currently [BalState.ongoing]
  Bal? _ongoingBal;

  /// [Bal] currently [BalState.ongoing]
  Bal? get ongoingBal => _ongoingBal;

  /// Creates a [Bal] from its [name], [startTime] and [endTime]
  Future<Result<void>> createBal(
    String name,
    DateTime startTime,
    DateTime endTime,
  ) async {
    final result = await _balRepository.addBal(name, startTime, endTime);
    switch (result) {
      case Ok():
        final result2 = await _balRepository.getBals();
        switch (result2) {
          case Ok():
            _bals = result2.value..sort((a, b) => a.compareTo(b));
            break;
          case Error():
            return result2;
        }
        break;
      case Error():
        return result;
    }
    notifyListeners();
    return result;
  }

  /*
 * =================================
 * =====[ COMMAND AND LOADING ]=====
 * =================================
*/

  /// Command to load all necessary data
  late final Command0 load;
  bool isLoaded = false;

  /// Manages loaders
  Future<Result<void>> _load() async {
    final result2 = await _loadBal();
    switch (result2) {
      case Ok():
        isLoaded = true;
        break;
      default:
        break;
    }
    notifyListeners();
    return result2;
  }

  /// Loads data about [Bal]
  Future<Result<void>> _loadBal() async {
    final result = await _balRepository.getBals();
    switch (result) {
      case Ok():
        _bals = result.value..sort((a, b) => a.compareTo(b));
        _ongoingBal = _bals
            .where((bal) => bal.state == BalState.ongoing)
            .firstOrNull;
        break;
      case Error():
        return result;
    }

    return result;
  }
}