AMessanger-Avalonia-Client/AMessanger/Services/ChatService.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.SignalR.Client;

namespace AMessanger.Services;

public class ChatService
{
    private readonly HubConnection _connection;

    public event Action<string, string>? OnMessageRecieved;
    
    public bool IsConnected { get; private set; } = false;

    public ChatService(string url)
    {
        _connection = new HubConnectionBuilder()
            .WithUrl(url)
            .WithAutomaticReconnect()
            .Build();

        _connection.On<string, string>("ReceiveMessage", (user, message) =>
            OnMessageRecieved?.Invoke(user, message));
    }

    public Task ConnectAsync(CancellationToken cancellationToken = default)
    {
        if (IsConnected)
            return Task.CompletedTask;

        IsConnected = true;
        return _connection.StartAsync(cancellationToken);
    }

    public Task DisconnectAsync(CancellationToken cancellationToken = default)
    {
        if (!IsConnected)
            return Task.CompletedTask;

        IsConnected = false;
        return _connection.StopAsync(cancellationToken);
    }

    public Task SendMessageAsync(string user, string message, CancellationToken cancellationToken = default)
    {
        return _connection.InvokeAsync("SendMessage", user, message, cancellationToken);
    }
}