codelab.dart

import 'package:english_words/english_words.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
        create: (context) => MyAppState(),
        child: MaterialApp(
          title: 'Namer App',
          theme: ThemeData(
            useMaterial3: true,
            colorScheme: ColorScheme.fromSeed(seedColor: Colors.blue),
          ),
          home: const MyHomePage(),
        ));
  }
}

class MyAppState extends ChangeNotifier {
  var current = WordPair.random();

  void getNext() {
    current = WordPair.random();
    notifyListeners();
  }

  var favorites = <WordPair>[];

  void toggleFavorite() {
    if (favorites.contains(current)) {
      favorites.remove(current);
    } else {
      favorites.add(current);
    }

    notifyListeners();
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key});

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  var selectedIndex = 0;

  @override
  Widget build(BuildContext context) {
    Widget page;
    switch (selectedIndex) {
      case 0:
        page = GeneratorPage();
        break;
      case 1:
        page = Favorites();
        break;
      default:
        throw UnimplementedError("No widge for $selectedIndex");
    }
    return LayoutBuilder(
      builder: (context, constraints) {
        return Scaffold(
          body: Row(
            children: [
              SafeArea(
              
                child: NavigationRail(
                  extended: constraints.maxWidth >= 600,
                  destinations: const [
                    NavigationRailDestination(
                      icon: Icon(Icons.home),
                      label: Text('Home'),
                    ),
                    NavigationRailDestination(
                      icon: Icon(Icons.favorite),
                      label: Text('Favorites'),
                    ),
                  ],
                  selectedIndex: selectedIndex,
                  onDestinationSelected: (value) {
                    setState(() {
                      selectedIndex = value;
                    });
                  },
                ),
              ),
              Expanded(
                child: Container(
                  color: Theme.of(context).colorScheme.primaryContainer,
                  child: page,
                ),
              ),
            ],
          ),
        );
      }
    );
  }
}

class Favorites extends StatelessWidget {
  const Favorites({
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    var appState = context.watch<MyAppState>();
    var favorites = appState.favorites;
    return ListView(
      children: [
        Padding(
          padding: const EdgeInsets.all(20),
          child: Text('You have '
                      '${favorites.length} favorits:')
        )
        for (var favorite in favorites)
          ListTile(
            title: Text(favorite.asLowerCase),
            leading: const Icon(Icons.favorite),
          )
      ]
    );
  }
}


class GeneratorPage extends StatelessWidget {
  const GeneratorPage({super.key});

  @override
  Widget build(BuildContext context) {
    var appState = context.watch<MyAppState>();
    var pair = appState.current;

    IconData icon;
    if (appState.favorites.contains(pair)) {
      icon = Icons.favorite;
    } else {
      icon = Icons.favorite_border;
    }

    return Center(
      child: Column(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          BigCard(pair: pair),
          const SizedBox(height: 10),
          Row(
            mainAxisSize: MainAxisSize.min,
            children: [
              ElevatedButton.icon(
                onPressed: () {
                  appState.toggleFavorite();
                },
                icon: Icon(icon),
                label: const Text('Like'),
              ),
              const SizedBox(width: 10),
              ElevatedButton(
                onPressed: () {
                  appState.getNext();
                },
                child: const Text('Next'),
              ),
            ],
          ),
        ],
      ),
    );
  }
}


class BigCard extends StatelessWidget {
  const BigCard({
    super.key,
    required this.pair,
  });

  final WordPair pair;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    final style = theme.textTheme.displayLarge!
        .copyWith(color: theme.colorScheme.onPrimary);

    return Card(
      color: theme.colorScheme.primary,
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Text(
          pair.asLowerCase,
          style: style,
          semanticsLabel: "${pair.first} ${pair.second}",
        ),
      ),
    );
  }
}


class SmallCard extends StatelessWidget {
  const SmallCard({
    super.key,
    required this.pair,
  });

  final WordPair pair;

  @override
  Widget build(BuildContext context) {
    final theme = Theme.of(context);

    final style = theme.textTheme.displaySmall!
        .copyWith(color: theme.colorScheme.onPrimary);

    return Card(
      color: theme.colorScheme.primary,
      child: Padding(
        padding: const EdgeInsets.all(10),
        child: Text(
          pair.asLowerCase,
          style: style,
          semanticsLabel: "${pair.first} ${pair.second}",
        ),
      ),
    );
  }
}