MessageProcessingHealthCheck.cs

using System;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Extensions.Diagnostics.HealthChecks;
using Microsoft.Extensions.Options;
using Motor.Extensions.Hosting.Abstractions;
using Motor.Extensions.Hosting.CloudEvents;

namespace Motor.Extensions.Hosting.HealthChecks;

public class MessageProcessingHealthCheck<TInput> : IHealthCheck where TInput : class
{
    private readonly TimeSpan _maxTimeWithoutAcknowledgedMessage;
    private readonly IBackgroundTaskQueue<MotorCloudEvent<TInput>> _queue;

    public MessageProcessingHealthCheck(IOptions<MessageProcessingOptions> options,
        IBackgroundTaskQueue<MotorCloudEvent<TInput>> queue)
    {
        _maxTimeWithoutAcknowledgedMessage = options.Value.MaxTimeSinceLastProcessedMessage;
        _queue = queue;
    }

    public Task<HealthCheckResult> CheckHealthAsync(HealthCheckContext context,
        CancellationToken token = default)
    {
        if (_queue.ItemCount == 0)
        {
            return Task.FromResult(HealthCheckResult.Healthy());
        }

        return Task.FromResult(DateTimeOffset.UtcNow - _queue.LastDequeuedAt > _maxTimeWithoutAcknowledgedMessage
            ? HealthCheckResult.Unhealthy()
            : HealthCheckResult.Healthy());
    }
}