SolarAgent/lib/layouts/navigation.dart

import 'package:firebase_messaging/firebase_messaging.dart';
import 'package:flutter/material.dart';
import 'package:goatagent/screens/account.dart';
import 'package:goatagent/screens/dashboard.dart';
import 'package:goatagent/screens/notifications.dart';

class AgentNavigation extends StatefulWidget {
  AgentNavigation({super.key});

  static const items = [
    {'label': 'Dashboard', 'icon': Icon(Icons.home)},
    {'label': 'Notifications', 'icon': Icon(Icons.notifications)},
    {'label': 'Account', 'icon': Icon(Icons.account_circle)},
  ];

  final bottomDestinations = items
      .map((element) => BottomNavigationBarItem(
            icon: element["icon"] as Widget,
            label: element["label"] as String,
          ))
      .toList();
  final railDestinations = items
      .map((element) => NavigationRailDestination(
            icon: element["icon"] as Widget,
            label: Text(element["label"] as String),
          ))
      .toList();

  @override
  State<AgentNavigation> createState() => _AgentNavigationState();
}

class _AgentNavigationState extends State<AgentNavigation> {
  int _view = 0;

  Future<void> initMessage(BuildContext context) async {
    void navigate() {
      setState(() {
        _view = 1;
      });
    }

    RemoteMessage? initialMessage =
        await FirebaseMessaging.instance.getInitialMessage();

    if (initialMessage != null) {
      navigate();
    }

    FirebaseMessaging.onMessageOpenedApp.listen((event) {
      navigate();
    });
  }

  @override
  void initState() {
    super.initState();
    initMessage(context);
  }

  @override
  Widget build(BuildContext context) {
    final isLargeScreen = MediaQuery.of(context).size.width > 640;

    final content = Stack(
      children: [
        Offstage(
          offstage: _view != 0,
          child: const DashboardScreen(),
        ),
        Offstage(
          offstage: _view != 1,
          child: const NotificationScreen(),
        ),
        Offstage(
          offstage: _view != 2,
          child: const AccountScreen(),
        )
      ],
    );

    if (isLargeScreen) {
      return Row(children: <Widget>[
        NavigationRail(
          selectedIndex: _view,
          groupAlignment: 0,
          onDestinationSelected: (int index) {
            setState(() {
              _view = index;
            });
          },
          labelType: NavigationRailLabelType.all,
          destinations: widget.railDestinations,
        ),
        const VerticalDivider(thickness: 1, width: 1),
        Expanded(child: content),
      ]);
    } else {
      return Scaffold(
        body: content,
        bottomNavigationBar: BottomNavigationBar(
          currentIndex: _view,
          showUnselectedLabels: false,
          items: widget.bottomDestinations,
          onTap: (index) {
            setState(() {
              _view = index;
            });
          },
        ),
      );
    }
  }
}