import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      home: const CupertinoHomeScaffold(),
    );
  }
}

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

  void _handleMenuSelection(String value) {
    debugPrint('Menu selection: $value');
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text('Home Page'),
        leading: PopupMenuButton<String>(
          icon: const Icon(Icons.more_vert),
          //tooltip: '', // empty tooltip prevents the crash
          onSelected: _handleMenuSelection,
          itemBuilder:
              (BuildContext context) => [
                const PopupMenuItem<String>(
                  value: 'settings',
                  child: Text('Settings'),
                ),
                const PopupMenuItem<String>(
                  value: 'about',
                  child: Text('About'),
                ),
              ],
        ),
      ),
      body: Center(
        child: TextButton(
          onPressed:
              () => Navigator.push(
                context,
                MaterialPageRoute(
                  builder: (context) => const SimplePage(title: 'Second Page'),
                ),
              ),
          child: const Text('Go to Second Page'),
        ),
      ),
    );
  }
}

class SimplePage extends StatelessWidget {
  const SimplePage({super.key, required this.title});
  final String title;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(title)),
      body: const Center(child: Text('Nothing to see here.')),
    );
  }
}

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

  @override
  CupertinoHomeScaffoldState createState() => CupertinoHomeScaffoldState();
}

class CupertinoHomeScaffoldState extends State<CupertinoHomeScaffold> {
  CupertinoTabController controller = CupertinoTabController();

  @override
  Widget build(BuildContext context) {
    return CupertinoTabScaffold(
      controller: controller,
      tabBar: CupertinoTabBar(
        key: const Key(Keys.tabBar),
        items: TabItem.values.map((ti) => _buildItem(ti)).toList(),
        onTap:
            (index) => setState(() {
              controller.index = index;
            }),
      ),
      tabBuilder: (context, index) {
        final tabItem = TabItem.values[index];
        return CupertinoTabView(
          navigatorKey: navigatorKeys[tabItem],
          builder:
              (context) =>
                  tabItem == TabItem.incidents
                      ? const MyHomePage()
                      : const SimplePage(title: 'Responders'),
        );
      },
    );
  }

  BottomNavigationBarItem _buildItem(TabItem tabItem) {
    final itemData = TabItemData.allTabs[tabItem]!;
    final color =
        controller.index == tabItem.index ? Colors.indigo : Colors.grey;
    return BottomNavigationBarItem(
      icon: Icon(itemData.icon, color: color),
      label: itemData.title,
    );
  }
}

enum TabItem { incidents, responders }

class Keys {
  static const String tabBar = 'tabBar';
  static const String incidentsTab = 'incidentsTab';
  static const String respondersTab = 'respondersTab';
}

final Map<TabItem, GlobalKey<NavigatorState>> navigatorKeys = {
  TabItem.incidents: GlobalKey<NavigatorState>(),
  TabItem.responders: GlobalKey<NavigatorState>(),
};

class TabItemData {
  const TabItemData({
    required this.key,
    required this.title,
    required this.icon,
  });

  final String key;
  final String title;
  final IconData icon;

  static const Map<TabItem, TabItemData> allTabs = {
    TabItem.incidents: TabItemData(
      key: Keys.incidentsTab,
      title: 'Incidents',
      icon: Icons.work,
    ),
    TabItem.responders: TabItemData(
      key: Keys.respondersTab,
      title: 'Responders',
      icon: Icons.person,
    ),
  };
}