const String appId = "";

void main() => runApp(const MaterialApp(home: MyApp()));

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

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

class _MyAppState extends State {
    String channelName = "";
    String token = "";
    
    int uid = 0; // uid of the local user

    int? _remoteUid; // uid of the remote user
    bool _isJoined = false; // Indicates if the local user has joined the channel
    late RtcEngine agoraEngine; // Agora engine instance

    final GlobalKey scaffoldMessengerKey
    = GlobalKey(); // Global key to access the scaffold

    showMessage(String message) {
        scaffoldMessengerKey.currentState?.showSnackBar(SnackBar(
        content: Text(message),
        ));
    }
}

db.createUser(
// Build UI
@override
Widget build(BuildContext context) {
    return MaterialApp(
    scaffoldMessengerKey: scaffoldMessengerKey,
    home: Scaffold(
        appBar: AppBar(
            title: const Text('Get started with Video Calling'),
        ),
        body: ListView(
            padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 4),
            children: [
            // Container for the local video
            Container(
                height: 240,
                decoration: BoxDecoration(border: Border.all()),
                child: Center(child: _localPreview()),
            ),
            const SizedBox(height: 10),
            //Container for the Remote video
            Container(
                height: 240,
                decoration: BoxDecoration(border: Border.all()),
                child: Center(child: _remoteVideo()),
            ),
            // Button Row
            Row(
                children: [
                Expanded(
                    child: ElevatedButton(
                        onPressed: _isJoined ? null : () => {join()},
                        child: const Text("Join"),
                    ),
                ),
                const SizedBox(width: 10),
                Expanded(
                    child: ElevatedButton(
                        onPressed: _isJoined ? () => {leave()} : null,
                        child: const Text("Leave"),
                    ),
                ),
                ],
            ),
            // Button Row ends
            ],
        )),
    );
}

// Display local video preview
Widget _localPreview() {
    if (_isJoined) {
    return AgoraVideoView(
        controller: VideoViewController(
        rtcEngine: agoraEngine,
        canvas: VideoCanvas(uid: 0),
        ),
    );
    } else {
    return const Text(
        'Join a channel',
        textAlign: TextAlign.center,
    );
    }
}

// Display remote user's video
Widget _remoteVideo() {
    if (_remoteUid != null) {
    return AgoraVideoView(
        controller: VideoViewController.remote(
        rtcEngine: agoraEngine,
        canvas: VideoCanvas(uid: _remoteUid),
        connection: RtcConnection(channelId: channelName),
        ),
    );
    } else {
        String msg = '';
        if (_isJoined) msg = 'Waiting for a remote user to join';
        return Text(
        msg,
        textAlign: TextAlign.center,
    );
    }
}