using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using MxGateway.Server.Configuration;

namespace MxGateway.Server.Sessions;

public sealed class SessionLeaseMonitorHostedService(
    ISessionManager sessionManager,
    IOptions<GatewayOptions> options,
    ILogger<SessionLeaseMonitorHostedService> logger,
    TimeProvider? timeProvider = null) : BackgroundService
{
    private readonly TimeProvider _timeProvider = timeProvider ?? TimeProvider.System;

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        TimeSpan interval = TimeSpan.FromSeconds(Math.Max(1, options.Value.Sessions.LeaseSweepIntervalSeconds));
        using PeriodicTimer timer = new(interval, _timeProvider);

        try
        {
            while (await timer.WaitForNextTickAsync(stoppingToken).ConfigureAwait(false))
            {
                try
                {
                    await sessionManager
                        .CloseExpiredLeasesAsync(_timeProvider.GetUtcNow(), stoppingToken)
                        .ConfigureAwait(false);
                }
                catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
                {
                    return;
                }
                catch (Exception exception)
                {
                    logger.LogWarning(exception, "Session lease sweep failed.");
                }
            }
        }
        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
        {
        }
    }
}