using System;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Sockeye.Models;

namespace Sockeye.Biz
{

   
    /// <summary>
    /// Check the health of subscribers servers, basically a ping check
    /// trigger notification if any fail the test excessively (some slack for intermittent comm. issues)
    /// </summary>
    internal static class SockBotSubscriptionServerHealthChecks
    {
        private static ILogger log = Sockeye.Util.ApplicationLogging.CreateLogger("SockBotSubscriptionServerHealthChecks");
        private static DateTime lastSweep = DateTime.MinValue;
        private static TimeSpan HEALTHCHECK_EVERY_INTERVAL = new TimeSpan(0, 15, 10);//every 15 minutes roughly
        ////////////////////////////////////////////////////////////////////////////////////////////////
        // DoSweep
        //
        public static async Task DoWorkAsync()
        {
            //This will get triggered roughly every minute, but we don't want to check that frequently
            if (DateTime.UtcNow - lastSweep < HEALTHCHECK_EVERY_INTERVAL)
                return;

            log.LogDebug("Health check starting");
            using (AyContext ct = Sockeye.Util.ServiceProviderProvider.DBContext)
            {
              
  var servers = await ct.SubscriptionServer
                   .AsNoTracking()
                   .Where(z => z.ServerState==  < dtDeleteCutoff && z.JobStatus == jobStatus)
                   .OrderBy(z => z.Created)
                   .ToListAsync();

            }
            lastSweep = DateTime.UtcNow;
        }


        private static async Task sweepAsync(AyContext ct, DateTime dtDeleteCutoff, JobStatus jobStatus)
        {
            //Get the deleteable succeeded jobs list
          

            log.LogDebug($"SweepAsync processing: cutoff={dtDeleteCutoff.ToString()}, for {jobs.Count.ToString()} jobs of status {jobStatus.ToString()}");

            foreach (OpsJob j in jobs)
            {
                try
                {

                    await JobsBiz.RemoveJobAndLogsAsync(j.GId);
                }
                catch (Exception ex)
                {
                    log.LogError(ex, "sweepAsync exception calling JobsBiz.RemoveJobAndLogsAsync");
                    //for now just throw it but this needs to be removed when logging added and better handling 
                    throw;
                }
            }
        }


        /// <summary>
        /// Kill jobs that have been stuck in "running" state for too long
        /// </summary>        
        private static async Task killStuckJobsAsync(AyContext ct, DateTime dtRunningDeadline)
        {
            //Get the deleteable succeeded jobs list
            var jobs = await ct.OpsJob
                   .AsNoTracking()
                   .Where(z => z.Created < dtRunningDeadline && z.JobStatus == JobStatus.Running)
                   .OrderBy(z => z.Created)
                   .ToListAsync();

            log.LogDebug($"killStuckJobsAsync processing: cutoff={dtRunningDeadline.ToString()}, for {jobs.Count.ToString()} jobs of status {JobStatus.Running.ToString()}");

            foreach (OpsJob j in jobs)
            {
                //OPSMETRIC
                await JobsBiz.LogJobAsync(j.GId, "LT:JobFailed LT:TimedOut");
                log.LogError($"Job found job stuck in running status and set to failed: deadline={dtRunningDeadline.ToString()}, jobId={j.GId.ToString()}, jobname={j.Name}, jobtype={j.JobType.ToString()}, jobAType={j.SockType.ToString()}, jobObjectId={j.ObjectId.ToString()}");
                await JobsBiz.UpdateJobStatusAsync(j.GId, JobStatus.Failed);
            }
        }


        private static async Task SweepInternalJobsLogsAsync(AyContext ct, DateTime dtDeleteCutoff)
        {
            //Get the deleteable list (this is for reporting, could easily just do it in one go)
            var logs = await ct.OpsJobLog
                   .AsNoTracking()
                   .Where(z => z.Created < dtDeleteCutoff)
                   .OrderBy(z => z.Created)
                   .ToListAsync();

            log.LogDebug($"SweepInternalJobsLogsAsync processing: cutoff={dtDeleteCutoff.ToString()}, for {logs.Count.ToString()} log entries");

            foreach (OpsJobLog l in logs)
            {
                try
                {
                    await ct.Database.ExecuteSqlInterpolatedAsync($"delete from aopsjoblog where gid = {l.GId}");
                }
                catch (Exception ex)
                {
                    log.LogError(ex, "SweepInternalJobsLogsAsync exception removed old log entries");
                    throw;
                }
            }
        }

        /////////////////////////////////////////////////////////////////////

    }//eoc


}//eons