Android notifications in a xamarin forms app - xamarin.forms

Question

I'm working in a xamarin forms app, and I'm trying to develop an Android notification with two buttons:
In the first one you can write text, and this text must be retrieve to one of the ViewModels.
The second one should open a view of the app.
I have no experience with intents nor Android, and so far I can show the notification with the two buttons:
notification example
The class in charge of showing the notification is LocalNotifications : ILocalNotifications class in the Android solution:
class LocalNotifications : ILocalNotifications
{
const string channelId = "default";
const string channelName = "Default";
const string channelDescription = "The default channel for notifications.";
...
bool channelInitialized = false;
int messageId = 0;
int replyPendingIntentId = 0;
int photoPendingIntentId = 0;
NotificationManager manager;
public event EventHandler NotificationReceived;
public static LocalNotifications Instance { get; private set; }
public LocalNotifications() => Initialize();
public void Initialize()
{
if (Instance == null)
{
CreateNotificationChannel();
Instance = this;
}
}
public void SendNotification(string title, string message)
{
if (!channelInitialized)
{
CreateNotificationChannel();
}
Show(title, message);
}
public void ReceiveNotification(string title, string message)
{
var args = new NotificationEventArgs()
{
Title = title,
Message = message,
};
NotificationReceived?.Invoke(null, args);
}
private static readonly string KEY_TEXT_REPLY = "key_text_reply";
AndroidX.Core.App.RemoteInput remoteEntryInput = new AndroidX.Core.App.RemoteInput.Builder(KEY_TEXT_REPLY)
.SetLabel("Escribir entrada")
.Build();
private Intent replyIntent;
private Intent photoIntent;
public void Show(string title, string message)
{
NotificationCompat.Builder builder = new NotificationCompat.Builder(AndroidApp.Context, channelId)
.SetContentTitle(title)
.SetContentText(message)
.SetLargeIcon(BitmapFactory.DecodeResource(AndroidApp.Context.Resources, Resource.Drawable.abc_ab_share_pack_mtrl_alpha))
.SetSmallIcon(Resource.Drawable.abc_ab_share_pack_mtrl_alpha)
.SetDefaults((int)NotificationDefaults.Sound | (int)NotificationDefaults.Vibrate);
NotificationCompat.Action reply = CreateReplyIntent(title, message);
builder.AddAction(reply);
NotificationCompat.Action image = CreateImageIntent();
builder.AddAction(image);
Notification notification = builder.Build();
manager.Notify(messageId++, notification);
}
NotificationCompat.Action CreateReplyIntent(string title, string message)
{
//replyIntent = new Intent(AndroidApp.Context, typeof(MainActivity));
replyIntent = new Intent();
replyIntent.PutExtra(TitleKey, title);
replyIntent.PutExtra(MessageKey, message);
// Build a PendingIntent for the reply action to trigger.
PendingIntent replyPendingIntent =
PendingIntent.GetBroadcast(AndroidApp.Context, replyPendingIntentId++, replyIntent, PendingIntentFlags.UpdateCurrent);
// Create the reply action and add the remote input.
return new NotificationCompat.Action.Builder(Resource.Drawable.abc_ab_share_pack_mtrl_alpha,
"Escribir entrada", replyPendingIntent)
.AddRemoteInput(remoteEntryInput)
.Build();
}
NotificationCompat.Action CreateImageIntent()
{
//photoIntent = new Intent("android.media.action.IMAGE_CAPTURE");
photoIntent = new Intent(AndroidApp.Context, typeof(MainActivity));
//photoIntent.SetFlags( ActivityFlags.LaunchAdjacent | Intent.FLAG_ACTIVITY_CLEAR_TASK);
// Build a PendingIntent for the reply action to trigger.
PendingIntent phtoPendingIntent = PendingIntent.GetBroadcast(AndroidApp.Context, photoPendingIntentId++, photoIntent, PendingIntentFlags.UpdateCurrent);
return new NotificationCompat.Action.Builder(Resource.Drawable.abc_ab_share_pack_mtrl_alpha,
"Sacar foto", phtoPendingIntent)
.Build();
}
void CreateNotificationChannel()
{
manager = (NotificationManager)AndroidApp.Context.GetSystemService(AndroidApp.NotificationService);
if (Build.VERSION.SdkInt >= BuildVersionCodes.O)
{
var channelNameJava = new Java.Lang.String(channelName);
var channel = new NotificationChannel(channelId, channelNameJava, NotificationImportance.Default)
{
Description = channelDescription
};
manager.CreateNotificationChannel(channel);
}
channelInitialized = true;
}
}
Which a don't get is how/where the app can react to those PendintIntents and how to pass the information from the android solution to the xamarin forms model.