dmdb/model/money/BankTransfer.cs

using System;
using System.Collections.Generic;
using System.Numerics;
using System.Text.RegularExpressions;
using System.Xml.Serialization;

namespace dezentrale.model.money
{
    [XmlType("BankTransfer")]
    public class BankTransfer : MoneyTransfer
    {
        //This resembles an 1:1 data image from CSV entries.
        [XmlElement] public string   AccountInCharge    { get; set; } = "";
        [XmlElement] public DateTime BookingDate        { get; set; }
        [XmlElement] public string   BookingText        { get; set; } = "";
        [XmlElement] public string   CreditorID         { get; set; } = "";
        [XmlElement] public string   MandateReference   { get; set; } = "";
        [XmlElement] public string   ClientReference    { get; set; } = "";

        [XmlElement] public string Sammlerreferenz                  { get; set; } = "";
        [XmlElement] public string LastschriftUrsprungsbetrag       { get; set; } = "";
        [XmlElement] public string AuslagenersatzRuecklastschrift   { get; set; } = "";

        [XmlElement] public string   RecipientOrDebitor { get; set; } = "";
        [XmlElement] public string   IBAN               { get; set; } = "";
        [XmlElement] public string   BIC                { get; set; } = "";
        [XmlElement] public string   Info               { get; set; } = "";

        //During the CSV import process, generated BankTransfer objects will hold CsvFile/Line for later
        //logging into member data / Main log (i.e. it is possible to track a MoneyTransfer from a
        //Member object to a line from a specific csv file)
        [XmlIgnore] public string CsvFile { get; set; } = null;
        [XmlIgnore] public int    CsvLine { get; set; } = 0;

        public BankTransfer() : base() { }
        public BankTransfer(List<string> csvHeadline, List<string> csvEntry, string csvFile = "", int csvLineNumber = 0) : base()
        {
            CsvFile = csvFile;
            CsvLine = csvLineNumber;

            int lc = csvEntry.Count;
            if (lc > csvHeadline.Count) lc = csvHeadline.Count;
            for (int i = 0; i < lc; i++)
            {
                switch (csvHeadline[i])
                {
                    case "Auftragskonto": AccountInCharge = csvEntry[i]; break;
                    case "Buchungstag": BookingDate = DateTime.Parse(csvEntry[i]); break;
                    case "Valutadatum": ValutaDate = DateTime.Parse(csvEntry[i]); break;
                    case "Buchungstext": BookingText = csvEntry[i]; break;
                    case "Verwendungszweck": TransferReason = csvEntry[i]; break;
                    case "Glaeubiger ID": CreditorID = csvEntry[i]; break;
                    case "Mandatsreferenz": MandateReference = csvEntry[i]; break;
                    case "Kundenreferenz (End-to-End)": ClientReference = csvEntry[i]; break;
                    case "Sammlerreferenz": Sammlerreferenz = csvEntry[i]; break;
                    case "Lastschrift Ursprungsbetrag": LastschriftUrsprungsbetrag = csvEntry[i]; break;
                    case "Auslagenersatz Ruecklastschrift": AuslagenersatzRuecklastschrift = csvEntry[i]; break;
                    case "Beguenstigter/Zahlungspflichtiger": RecipientOrDebitor = csvEntry[i]; break;
                    case "Kontonummer/IBAN":
                    case "Kontonummer": IBAN = csvEntry[i].Trim(); break;
                    case "BIC (SWIFT-Code)":
                    case "BLZ": BIC = csvEntry[i].Trim(); break;
                    case "Betrag":
                    {
                        string sAmount = csvEntry[i].Replace(',', '.');
                        float fAmount = float.Parse(sAmount, System.Globalization.CultureInfo.InvariantCulture.NumberFormat);
                        Amount = Convert.ToInt64(fAmount * 100);
                    } break;
                    case "Waehrung": Currency = csvEntry[i]; break;
                    case "Info": Info = csvEntry[i]; break;
                    default:
                        throw new Exception($"invalid csv headline field: \"{csvHeadline[i]}\" csvFile {csvFile} line {csvLineNumber}");
                }
            }
        }

        private const string ibanPattern = "^[A-Z]{2}\\d{2}\\d{8}\\d{10}$";
        public static string IbanRegexAssert(string iban, bool checkPz = true)
        {
            iban = iban.Replace(" ", "").Replace("-", "");
            if (!Regex.IsMatch(iban, ibanPattern))
            {
                throw new FormatException("IBAN format invalid");
            }
            if(checkPz)
            {
                if(!_PzOk(iban))
                {
                    throw new Exception("IBAN checksum error");
                }
            }
            return iban;
        }
        private static int _CCodeToInt(string cCode)
        {
            char[] c = cCode.ToCharArray();
            string ret = String.Format("{0}{1}", c[0] + 10 - 'A', c[1] + 10 - 'A');
            return Convert.ToInt32(ret);
        }
        private static string _CalcPz(string cCode, string blz, string kto)
        {
            //https://www.iban.de/iban-pruefsumme.html
            int cci = _CCodeToInt(cCode);

            string modBaseS = String.Format("{0}{1}{2}00", blz, kto, cci);
            //760909001234567890131400
            BigInteger mod = BigInteger.Parse(modBaseS);
            mod = BigInteger.Remainder(mod, new BigInteger(97));
            string pz = String.Format("{0:D2}", 98 - mod);
            return pz;
        }
        private static string _CalcPz(string iban)
        {
            return _CalcPz(iban.Substring(0, 2), iban.Substring(4, 8), iban.Substring(12,10));
        }
        public static string CalcPz(string iban)
        {
            iban = IbanRegexAssert(iban, false);
            return _CalcPz(iban);
        }
        private static bool _PzOk(string iban)
        {
            return _CalcPz(iban).Equals(iban.Substring(2, 2));
        }
        public static bool PzOk(string iban)
        {
            iban = IbanRegexAssert(iban, false);
            return _PzOk(iban);
        }
        public static string GetKtoFromIban(string iban)
        {
            iban = IbanRegexAssert(iban);
            return iban.Substring(12);
        }
        public static string GetBlzFromIban(string iban)
        {
            iban = IbanRegexAssert(iban);
            return iban.Substring(4, 8);
        }
        public static string GetCCodeFromIban(string iban)
        {
            iban = IbanRegexAssert(iban);
            return iban.Substring(0,2);
        }
        public static string GetIbanFromKtoBlz(string cCode, string blz, string kto)
        {
            //build iban
            string Pz = _CalcPz(cCode, blz, kto);
            string iban = String.Format("{0}{1}{2}{3}", cCode, Pz, blz, kto);

            return IbanRegexAssert(iban);
        }
    }
}