//
//  Class:			transmitter
//	Current CLR:	4.0.30319.34209
//	System:			Microsoft Visual Studio 10.0
//	Author:			dani
// 	Created:		7/14/2015 7:39:29 AM
//
//	Copyright (c) 2015 Informatikbüro Daniel Schick. All rights reserved.

using System;
using System.Diagnostics;
using System.IO;
using bsmd.database;
using log4net;

namespace bsmd.hisnord
{
    public class transmitter
    {
        private static readonly ILog _log = LogManager.GetLogger(typeof(transmitter));
        private static int? processId;

        public static bool Transmit()
        {
            string rootDir = Properties.Settings.Default.TransmitterRoot;

            if(processId.HasValue)
            {
                _log.InfoFormat("Transmitter process {0} still running, aborting call", processId);
                return false;
            }

            try
            {

                ProcessStartInfo startInfo = new ProcessStartInfo(Path.Combine(rootDir, Properties.Settings.Default.Transmitter));
                startInfo.WorkingDirectory = rootDir;
                startInfo.RedirectStandardError = true;
                startInfo.RedirectStandardOutput = true;
                startInfo.RedirectStandardInput = false;
                startInfo.UseShellExecute = false;

                using (Process transmitterProcess = new Process())
                {
                    transmitterProcess.Exited += TransmitterProcess_Exited;

                    transmitterProcess.ErrorDataReceived += TransmitterProcess_ErrorDataReceived;
                    transmitterProcess.OutputDataReceived += TransmitterProcess_OutputDataReceived;

                    transmitterProcess.StartInfo = startInfo;
                    transmitterProcess.EnableRaisingEvents = true;
                    transmitterProcess.Start();

                    transmitterProcess.BeginErrorReadLine();
                    transmitterProcess.BeginOutputReadLine();

                    processId = transmitterProcess.Id;

                    // _log.DebugFormat("started {0}", transmitterProcess.ProcessName);
                    int timeout = Properties.Settings.Default.BatchTimeoutMins * 1000 * 60; // convert to ms

                    _log.DebugFormat($"starting transmitter, process ID: {processId}, timeout {timeout} ms.");

                    if (!transmitterProcess.WaitForExit((timeout == 0) ? int.MaxValue : timeout))
                    {
                        _log.Warn($"Transmitter {processId} not exited within {timeout} ms");
                        try
                        {
                            transmitterProcess.Kill();
                            _log.Warn($"Transmitter {processId} killed");
                            processId = null;
                        }
                        catch (Exception e)
                        {
                            _log.Warn($"Killing Transmitter {processId} failed: {e.Message}");
                        }
                    }
                    else
                    {
                        int exitCode = transmitterProcess.ExitCode;
                        if (exitCode != 0)
                        {
                            string errorText = "";
                            switch(exitCode)
                            {
                                case 1: errorText = "Schema violation"; break;
                                case 2:
                                case 3: errorText = "Element must not be null"; break;
                                case 1000: errorText = "Internal error"; break;
                                case 1001: errorText = "Access denied - Login"; break;
                                case 1004: errorText = "Access denied - Internal Configuration"; break;
                                case 1005: errorText = "Internal configuration error"; break;
                                case 2000: errorText = "File not found"; break;
                            }
                            _log.ErrorFormat("Transmitter returned code {0}: {1}", exitCode, errorText);
                        }
                    }
                }
                return true;
            }
            catch (Exception ex)
            {
                _log.Error($"Transmitter failed: {ex.Message}");
                return false;
            }
        }

        private static void TransmitterProcess_OutputDataReceived(object sender, DataReceivedEventArgs e)
        {
            if(!e.Data.IsNullOrEmpty())
                _log.Debug(e.Data);
        }

        private static void TransmitterProcess_ErrorDataReceived(object sender, DataReceivedEventArgs e)
        {
            // Output of STDERR. HIS-Nord seems to be using this for logging, so we do not flag as error.
            if(!e.Data.IsNullOrEmpty())
                _log.Debug(e.Data);
        }

        private static void TransmitterProcess_Exited(object sender, EventArgs e)
        {
            _log.Debug("Transmitter process exited");
            processId = null;
        }

        public static void PurgeOldFiles(int maxAgeDays)
        {
            try
            {
                // "import_done" (= successfully received)
                DirectoryInfo info = new DirectoryInfo(Path.Combine(Properties.Settings.Default.TransmitterRoot, Properties.Settings.Default.AnswerArchiveDir));
                FileInfo[] files = info.GetFiles();
                int cnt = 0;
                foreach (FileInfo file in files)
                {
                    if (file.CreationTime < DateTime.Now.AddDays(-maxAgeDays))
                    {
                        _log.Debug($"deleting {file.Name}");
                        file.Delete();
                        cnt++;
                    }
                }
                _log.Info($"deleted {cnt} files from {Properties.Settings.Default.AnswerArchiveDir}");

                // "archive" (= successfully sent)
                cnt = 0;
                info = new DirectoryInfo(Path.Combine(Properties.Settings.Default.TransmitterRoot, Properties.Settings.Default.OutputArchiveDir));
                files = info.GetFiles();
                foreach (FileInfo file in files)
                {
                    if (file.CreationTime < DateTime.Now.AddDays(-maxAgeDays))
                    {
                        _log.Debug($"deleting {file.Name}");
                        file.Delete();
                        cnt++;
                    }
                }
                _log.Info($"deleted {cnt} files from {Properties.Settings.Default.OutputArchiveDir}");

            }
            catch(Exception ex)
            {
                _log.ErrorFormat("Error trying to delete old files: {0}", ex.Message);
            }
        }
    }
}