/// Coordinates Today Screen Controller state for the FocusFlow Flutter UI.
library;

import 'package:flutter/foundation.dart';
import 'package:scheduler_core/scheduler_core.dart';

import '../models/today_screen_models.dart';

typedef TodayStateReader = Future<ApplicationResult<TodayState>> Function();

sealed class TodayScreenState {
  const TodayScreenState();
}

class TodayScreenLoading extends TodayScreenState {
  const TodayScreenLoading();
}

class TodayScreenReady extends TodayScreenState {
  const TodayScreenReady(this.data);

  final TodayScreenData data;
}

class TodayScreenEmpty extends TodayScreenState {
  const TodayScreenEmpty();
}

class TodayScreenFailure extends TodayScreenState {
  const TodayScreenFailure(this.message);

  final String message;
}

class TodayScreenController extends ChangeNotifier {
  TodayScreenController({required this.read});

  final TodayStateReader read;

  TodayScreenState _state = const TodayScreenLoading();
  TimelineCardModel? _selectedCard;

  TodayScreenState get state => _state;

  TimelineCardModel? get selectedCard => _selectedCard;

  Future<void> load() async {
    _state = const TodayScreenLoading();
    notifyListeners();
    try {
      final result = await read();
      final failure = result.failure;
      if (failure != null) {
        _state = TodayScreenFailure(failure.detailCode ?? failure.code.name);
        notifyListeners();
        return;
      }

      final data = TodayScreenData.fromTodayState(result.requireValue);
      _state = data.cards.isEmpty
          ? const TodayScreenEmpty()
          : TodayScreenReady(data);
      notifyListeners();
    } on Object catch (error) {
      _state = TodayScreenFailure(error.toString());
      notifyListeners();
    }
  }

  void selectCard(TimelineCardModel card) {
    if (!card.isSelectable) {
      return;
    }
    _selectedCard = card;
    notifyListeners();
  }

  void clearSelection() {
    if (_selectedCard == null) {
      return;
    }
    _selectedCard = null;
    notifyListeners();
  }
}