// Copyright (c) 2020-present schick Informatik
// Description:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Timers;
using bsmd.email;
using bsmd.database;
using log4net;

namespace bsmd.POService
{
    public partial class POService : ServiceBase
    {

        #region Fields

        private Timer _timer;
        private readonly ILog _log = LogManager.GetLogger(typeof(POService));

        #endregion

        #region Construction

        public POService()
        {
            Directory.SetCurrentDirectory(AppDomain.CurrentDomain.BaseDirectory);
            InitializeComponent();
        }

        #endregion

        #region Start/Stop Service

        protected override void OnStart(string[] args)
        {
            this.EventLog.Source = this.ServiceName;
            this.EventLog.Log = "Application";
            this.Init();
            this.EventLog.WriteEntry("NSW PO Number Service started.", EventLogEntryType.Information);
            System.Reflection.Assembly assembly = System.Reflection.Assembly.GetExecutingAssembly();
            FileVersionInfo fvi = FileVersionInfo.GetVersionInfo(assembly.Location);
            string version = fvi.FileVersion;
            _log.InfoFormat("Starting PO Number Service. v.{0} -------------- ", version);
            this.DoOnce();
        }

        protected override void OnStop()
        {
            this._log.Info("Stopping PO Number Service");
        }

        #endregion

        #region helper

        private void Init()
        {
            this._timer = new Timer
            {
                Interval = Properties.Settings.Default.SleepSeconds * 1000
            };
            this._timer.Elapsed += _timer_Elapsed;
            this._timer.Enabled = true;
        }

        internal void DoOnce()
        {
            this._timer_Elapsed(null, null);
        }

        internal static bool ParsePO(string inputValue)
        {
            bool result = false;

            // Betreffzeile parsen. Ein Beispiel:
            // "WG: PO:8204730095 DEWVNTM-ADELINA D-005E-310120";
            // Hier kann man designen: https://regex101.com/
            const string poPattern = @"PO:(\d+) ([A-Z]+)-(.*?)-(.*?)-(\d{6})";
            Regex poRegex = new Regex(poPattern);
            Match aMatch = poRegex.Match(inputValue);
            if (aMatch.Success)
            {
                string poNummer = aMatch.Groups[1].Captures[0].Value;
                string hafen = aMatch.Groups[2].Captures[0].Value;
                string name = aMatch.Groups[3].Captures[0].Value;
                string irgendwas = aMatch.Groups[4].Captures[0].Value;
                string datumString = aMatch.Groups[5].Captures[0].Value;
                result = true;
            }

            return result;
        }

        #endregion

        private void _timer_Elapsed(object sender, ElapsedEventArgs e)
        {

            if (DBManager.Instance.Connect(Properties.Settings.Default.ConnectionString))
            {

                try
                {
                    string messageId = "";
                    string attachmentLocalPath = null;
                    string mailSender = "";
                    const string receiptSubject = "PO number service INFO";
                    string mailSubject = "";
                    string body = "";

                    using (BSMDPopClient bsmdPopClient = new BSMDPopClient())
                    {
                        if (bsmdPopClient.IsConnected)
                        {
                            // check and download next e-Mail, saving attachment
                            while (bsmdPopClient.ReceiveSingleMailText(out messageId, out mailSender, out mailSubject, out body))
                            {

                                bool readResult = false;
                                string readMessage = "";
                                string receiptText = "";
                                MessageCore messageCore = null;

                                if (attachmentLocalPath == null)
                                {
                                    receiptText = "incoming E-Mail did not contain an Excel attachment!";
                                    _log.WarnFormat(receiptText);
                                }
                                else
                                {
                                    // only a valid sender gets a reply
                                    bool isValidSender = false;
                                    foreach (string aValidSender in Properties.Settings.Default.ValidSender)
                                    {
                                        if (mailSender.Equals(aValidSender, StringComparison.OrdinalIgnoreCase))
                                        {
                                            isValidSender = true;
                                            break;
                                        }
                                    }

                                    if (!isValidSender)
                                    {
                                        receiptText = string.Format("ignored e - mail from illegal sender: {0}", mailSender);
                                        _log.Warn(receiptText);
                                    }
                                    else
                                    {           
                                        try
                                        {
                                            if(!ParsePO(mailSubject))
                                            {

                                            }
                                           

                                            // aus (ungefährem) Datum, Name und Hafen den MessageCore suchen


                                            // PO-Nummer und Schiffs/Anlaufklassifizierung eintragen


                                        }
                                        catch (Exception someException)
                                        {
                                            receiptText = string.Format("Error processing po mail: {0}", someException.Message);
                                            _log.Error(receiptText);
                                        }
                                    }
                                }

                                if (receiptText.Length > 0)
                                {
                                    _log.Debug("sending system info email");
                                    BSMDMail.SendSystemInfo(receiptSubject, receiptText, mailSender);
                                }

                                // remove e-Mail
                                _log.InfoFormat("deleting mail with messageId {0}", messageId);
                                _log.InfoFormat("mail delete {0}", bsmdPopClient.DeleteMessageByMessageId(messageId) ? "successful" : "failed");

                            }
                        }
                    }

                    #region Phase II - Excel Sheets auf Anforderung erzeugen

                    List<MessageCore> excelMessageCoreList = DBManager.Instance.GetMessageCoresForExcelCreate();
                    if (excelMessageCoreList.Count > 0)
                        _log.InfoFormat("{0} excel sheets to create from database", excelMessageCoreList.Count);
                    foreach (MessageCore excelCore in excelMessageCoreList)
                    {
                        // load messages
                        List<Message> messages = DBManager.Instance.GetMessagesForCore(excelCore, DBManager.MessageLoad.ALL);

                        // template

                    }

                    #endregion

                    DBManager.Instance.Disconnect();
                }
                catch (Exception ex)
                {
                    _log.ErrorFormat("Exception occurred: {0}", ex.ToString());
                }
            }
            else
            {
                _log.Error("DB Connection failure");
            }

        }

    }
}