using RobotNet10.RobotApp.Hubs;

namespace RobotNet10.RobotApp.Services;

/// <summary>
/// Broadcast odometry tới SignalR clients định kỳ (mặc định 10 Hz) để hiển thị realtime
/// </summary>
public class OdometryBroadcastService : IHostedService, IDisposable
{
    private readonly OdometryHubContext _odometryHubContext;
    private readonly ILogger<OdometryBroadcastService> _logger;
    private Timer? _timer;
    private const int BroadcastIntervalMs = 100; // 10 Hz

    public OdometryBroadcastService(OdometryHubContext odometryHubContext, ILogger<OdometryBroadcastService> logger)
    {
        _odometryHubContext = odometryHubContext;
        _logger = logger;
    }

    public Task StartAsync(CancellationToken cancellationToken)
    {
        _timer = new Timer(
            async _ =>
            {
                try
                {
                    await _odometryHubContext.BroadcastOdometryAsync();
                }
                catch (Exception ex)
                {
                    _logger.LogDebug(ex, "Odometry broadcast skipped");
                }
            },
            null,
            TimeSpan.FromMilliseconds(BroadcastIntervalMs),
            TimeSpan.FromMilliseconds(BroadcastIntervalMs));
        _logger.LogInformation("Odometry broadcast started at {Hz} Hz", 1000.0 / BroadcastIntervalMs);
        return Task.CompletedTask;
    }

    public Task StopAsync(CancellationToken cancellationToken)
    {
        _timer?.Change(Timeout.Infinite, 0);
        _logger.LogInformation("Odometry broadcast stopped");
        return Task.CompletedTask;
    }

    public void Dispose()
    {
        _timer?.Dispose();
        GC.SuppressFinalize(this);
    }
}