meals/lib/screens/tabs.dart

import 'package:flutter/material.dart';
import 'package:meals/data/dummy_categories.dart';
import 'package:meals/screens/CategoriesScreen.dart';
import 'package:meals/screens/MealsScreen.dart';
import 'package:meals/screens/filters.dart';
import 'package:meals/widgets/main_drawer.dart';

import '../models/Meal.dart';

const kDefaultFilters = {
  Filter.glutenFree: false,
  Filter.lactoseFree: false,
  Filter.veggie: false,
  Filter.vegan: false,
};

class TabsScreen extends StatefulWidget {
  const TabsScreen({Key? key}) : super(key: key);

  @override
  State<TabsScreen> createState() => _TabsScreenState();
}

class _TabsScreenState extends State<TabsScreen> {
  int _selectedPageIndex = 0;
  final List<Meal> _favoriteMeals = [];
  Map<Filter, bool> _selectedFilters = kDefaultFilters;

  void _showInfoMessage(String message) {
    ScaffoldMessenger.of(context).clearSnackBars();
    ScaffoldMessenger.of(context)
        .showSnackBar(SnackBar(content: Text(message)));
  }

  void _selectPage(int index) {
    setState(() {
      _selectedPageIndex = index;
    });
  }

  void _toggleFavoriteMeal(Meal meal) {
    if (_favoriteMeals.contains(meal)) {
      setState(() {
        _favoriteMeals.remove(meal);
      });
      _showInfoMessage('Meal is no longer a favorite');
    } else {
      setState(() {
        _favoriteMeals.add(meal);
        _showInfoMessage('Meal has been added to your favorites');
      });
    }
  }

  void _setScreen(String identifier) async {
    Navigator.of(context).pop();

    switch (identifier) {
      case 'filters':
        final results = await Navigator.of(context)
            .push<Map<Filter, bool>>(MaterialPageRoute(
                builder: (ctx) => FiltersScreen(
                      currentFilters: _selectedFilters,
                    )));
        setState(() {
          _selectedFilters = results ?? kDefaultFilters;
        });
        break;
    }
  }

  @override
  Widget build(BuildContext context) {
    Widget activePage;
    String? activePageTitle;
    final availableMeals = dummyMeals.where((meal) {
      if (_selectedFilters[Filter.glutenFree]! && !meal.isGlutenFree) {
        return false;
      }
      if (_selectedFilters[Filter.lactoseFree]! && !meal.isLactoseFree) {
        return false;
      }
      if (_selectedFilters[Filter.veggie]! && !meal.isVegetarian) {
        return false;
      }
      if (_selectedFilters[Filter.vegan]! && !meal.isVegan) {
        return false;
      }
      return true;
    }).toList();

    switch (_selectedPageIndex) {
      case 1:
        activePageTitle = 'Favorites';
        activePage = MealsScreen(
          meals: _favoriteMeals,
          onToggleFavorite: _toggleFavoriteMeal,
        );
        break;
      default:
        activePageTitle = 'Pick your category';
        activePage = CategoriesScreen(
          availableMeals: availableMeals,
          onToggleFavorite: _toggleFavoriteMeal,
        );
    }

    return Scaffold(
      appBar: AppBar(title: Text(activePageTitle)),
      drawer: MainDrawer(
        onSelectScreen: _setScreen,
      ),
      body: activePage,
      bottomNavigationBar: BottomNavigationBar(
        onTap: _selectPage,
        currentIndex: _selectedPageIndex,
        items: const [
          BottomNavigationBarItem(
              icon: Icon(Icons.set_meal), label: 'Categories'),
          BottomNavigationBarItem(icon: Icon(Icons.star), label: 'Favorites'),
        ],
      ),
    );
  }
}