using System;
using System.Diagnostics;
using System.Threading.Tasks;
using Microsoft.Extensions.Logging;

namespace AyaNova.Util
{

    /// <summary>
    /// Used by reporting system to ensure headless browsers don't hang around in an untimely manner
    /// needed due to bugs in puppeteersharp where it won't close the browser on timeout properly
    /// also zombie process issues in linux etc, this just ensures it's safe
    /// This is triggered when a report is rendered
    /// </summary>
    internal static class ReportProcessorManager
    {
        internal static int ReporterProcessId { get; set; } = -1;
        internal static DateTime Started { get; set; }

        internal async static Task EnsureReporterAvailableAsync(ILogger log)
        {
            Process reportProcess = ReporterProcess();
            if (reportProcess == null)
            {
                return;
            }
            //await it's completion in the specified timeout
            int HardTimeout = ServerBootConfig.AYANOVA_REPORT_RENDERING_TIMEOUT;
            //don't wait forever, hard cap of 3 minutes regardless of setting
            if (HardTimeout > 180000) HardTimeout = 180000;
            bool keepOnWaiting = true;
            while (keepOnWaiting)
            {
                //don't check continually
                await Task.Delay(500);
                //check process is still running
                if (reportProcess?.HasExited == false)
                {
                    //time to kill it?
                    if ((DateTime.UtcNow - Started).TotalMilliseconds > HardTimeout)
                    {
                        log.LogInformation($"Report processor did not complete in {HardTimeout}ms and will be force stopped");
                        reportProcess.Kill();
                        keepOnWaiting = false;
                    }
                }
                else
                {
                    log.LogDebug($"EnsureReporterAvailableAsync Reporter processor completed normally");
                    keepOnWaiting = false;
                }
            };
            ReporterProcessId = -1;
            Started = DateTime.MinValue;
            return;
        }

        internal static void RecordNewReportGeneratorProcess(int processId)
        {
            ReporterProcessId = processId;
            Started = DateTime.UtcNow;
        }

        private static Process ReporterProcess()
        {
            if (ReporterProcessId == -1) return null;
            try
            {
                return Process.GetProcessById(ReporterProcessId);
            }
            catch (ArgumentException)
            {
                return null;//no process available / not running
            }
        }


        /*
                   //Is the report generator (browser) already running?
     if(ReportingProcessCache.ReporterProcess()!=null){
     //there is an existing process in action, let's wait for timeout seconds and kill it if it's still running before proceeding
     //first check to see if it's still actually running or not:
     var process = System.Diagnostics.Process.GetProcessById(ReportingProcessCache.ReporterProcessId);
                         // if (ChromiumProcessID > 0 && process?.HasExited == false)
                         // {
                         //     log.LogError($"Error during render, Chromium process (pid {ChromiumProcessID}) still active, forcing it to stop now");
                         //     process.Kill();
                         // }

     bool keepOnWaiting=true;
     while(keepOnWaiting){
        var v= DateTime.UtcNow-ReportingProcessCache.Started;
        if(v.TotalSeconds> ServerBootConfig.REPORT_RENDERING_OPERATION_TIMEOUT){

        }
     }

     }
        */
    }//eoc
}//eons