class FirestoreListener
{
    private FirestoreDb db;
    private FirestoreChangeListener listener;

    public FirestoreListener(string projectId)
    {
        // Initialize FirestoreDb instance
        Environment.SetEnvironmentVariable("GOOGLE_APPLICATION_CREDENTIALS", "C:\\Users\\abuba\\source\\repos\\tryingAPI\\tryingAPI\\serviceAccountKey.json"); //google certificate
        db = FirestoreDb.Create(projectId);
    }

    public void ListenToDocument(string collectionName, string documentId)
    {
        DocumentReference docRef = db.Collection(collectionName).Document(documentId);
        listener = docRef.Listen(snapshot =>
        {
            Console.WriteLine("Callback received document snapshot.");
            Console.WriteLine("Document exists? {0}", snapshot.Exists);
            if (snapshot.Exists)
            {
                Console.WriteLine("Document data for {0} document:", snapshot.Id);
                Dictionary<string, object> documentData = snapshot.ToDictionary();
                foreach (KeyValuePair<string, object> pair in documentData)
                {
                    Console.WriteLine("{0}: {1}", pair.Key, pair.Value);
                }
            }
        });
        listener.ListenerTask.Wait(); // Block until the listener is done
    }

    public void stopListener()
    {
        listener.ListenerTask.Dispose();
    }
}

class FirestoreListener
{
    private FirestoreDb db;
    private FirestoreChangeListener listener;

    public FirestoreListener(string projectId)
    {
        // Initialize FirestoreDb instance
        Environment.SetEnvironmentVariable("GOOGLE_APPLICATION_CREDENTIALS", "C:\\Users\\abuba\\source\\repos\\tryingAPI\\tryingAPI\\serviceAccountKey.json"); //google certificate
        db = FirestoreDb.Create(projectId);
    }

    public void ListenToDocument(string collectionName, string documentId)
    {
        DocumentReference docRef = db.Collection(collectionName).Document(documentId);
        listener = docRef.Listen(snapshot =>
        {
            Console.WriteLine("Callback received document snapshot.");
            Console.WriteLine("Document exists? {0}", snapshot.Exists);
            if (snapshot.Exists)
            {
                Console.WriteLine("Document data for {0} document:", snapshot.Id);
                Dictionary<string, object> documentData = snapshot.ToDictionary();
                foreach (KeyValuePair<string, object> pair in documentData)
                {
                    Console.WriteLine("{0}: {1}", pair.Key, pair.Value);
                }
            }
        });
        listener.ListenerTask.Wait(); // Block until the listener is done
    }

    public void stopListener()
    {
        listener.ListenerTask.Dispose();
    }
}