Function to generate code similar to MPESA transaction codes e.g RCE7QMM2G9, SAO9X7099B

main.ts

// Generate voucher number
// using mpesa transaction reference format -> YYMMDDHHmmssNNNN
export function generateVoucherNumber(): string {
  const now = new Date();
  const yearMap = {
    '20': 'A',
    '21': 'B',
    '22': 'C',
    '23': 'D',
    '24': 'E',
    '25': 'F',
    '26': 'G',
    '27': 'H',
    '28': 'I',
    '29': 'J',
    '30': 'K',
    // Add more mappings as needed
  };
  const monthMap = {
    '01': 'A',
    '02': 'B',
    '03': 'C',
    '04': 'D',
    '05': 'E',
    '06': 'F',
    '07': 'G',
    '08': 'H',
    '09': 'I',
    '10': 'J',
    '11': 'K',
    '12': 'L',
  };

  const dayMap = {
    '01': 'A',
    '02': 'B',
    '03': 'C',
    '04': 'D',
    '05': 'E',
    '06': 'F',
    '07': 'G',
    '08': 'H',
    '09': 'I',
    '10': 'J',
    '11': 'K',
    '12': 'L',
    '13': 'M',
    '14': 'N',
    '15': 'O',
    '16': 'P',
    '17': 'Q',
    '18': 'R',
    '19': 'S',
    '20': 'T',
    '21': 'U',
    '22': 'V',
    '23': 'W',
    '24': 'X',
    '25': 'Y',
    '26': 'Z',
    '27': 'a',
    '28': 'b',
    '29': 'c',
    '30': 'd',
    '31': 'e',
  };

  const hourMap = {
    '00': 'A',
    '01': 'B',
    '02': 'C',
    '03': 'D',
    '04': 'E',
    '05': 'F',
    '06': 'G',
    '07': 'H',
    '08': 'I',
    '09': 'J',
    '10': 'K',
    '11': 'L',
    '12': 'M',
    '13': 'N',
    '14': 'O',
    '15': 'P',
    '16': 'Q',
    '17': 'R',
    '18': 'S',
    '19': 'T',
    '20': 'U',
    '21': 'V',
    '22': 'W',
    '23': 'X',
  };

  const year = now.getFullYear().toString().slice(-2);
  const month = String(now.getMonth() + 1).padStart(2, '0');
  const day = String(now.getDate()).padStart(2, '0');
  const hour = String(now.getHours()).padStart(2, '0');
  const minute = String(now.getSeconds()).padStart(2, '0');

  const randomNum = Math.floor(1000 + Math.random() * 9000);

  const yearLetter = yearMap[year] || year;
  const monthLetter = monthMap[month] || month;
  const dayLetter = dayMap[day] || day;
  const hourLetter = hourMap[hour] || hour;

  const transactionRef = `${yearLetter}${monthLetter}${dayLetter}${hourLetter}${minute}${randomNum}`;

  return transactionRef.toUpperCase();
}