using OpenHarbor.CQRS.Abstractions;
using System.Diagnostics;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Caching.Memory;
using CH.Dal;
namespace CH.CQRS.Query.Health;
public class HealthQuery
{

}
public class HealthQueryHandler(CHDbContext dbContext, IMemoryCache memoryCache) : IQueryHandler<HealthQuery, HealthQueryResult>
{
  private const string HealthCheckCacheKey = "HealthStatus";
  private const int CacheDurationInSeconds = 60;
  public async Task<HealthQueryResult> HandleAsync(HealthQuery query, CancellationToken cancellationToken = new CancellationToken())
  {
    if (memoryCache.TryGetValue(HealthCheckCacheKey, out var memory))
    {
      return (HealthQueryResult)memory;
    }
    var (databaseStatus, databaseLatency) = await MeasureLatencyAsync(CheckDatabaseHealthAsync);

    var healthCheckResult = new HealthQueryResult
    {
      ApiStatus = true,
      DatabaseStatus = databaseStatus,
      DatabaseLatency = $"{databaseLatency}ms",
    };
    memoryCache.Set(HealthCheckCacheKey, healthCheckResult, TimeSpan.FromSeconds(CacheDurationInSeconds));
    return healthCheckResult;
  }
  public static async Task<(bool isHealthy, long latencyMs)> MeasureLatencyAsync(Func<Task<bool>> healthCheckAction)
  {
    var stopwatch = Stopwatch.StartNew();
    var isHealthy = await healthCheckAction();
    stopwatch.Stop();
    return (isHealthy, stopwatch.ElapsedMilliseconds);
  }
  private async Task<bool> CheckDatabaseHealthAsync()
  {
    try
    {
      await dbContext.Database.ExecuteSqlRawAsync("SELECT 1");
      return true;
    }
    catch
    {
      return false;
    }
  }
}