@arquetic/billbo/src/JS/control-code/verhoeff.js

Utilities for the national tax billing system of Bolivia

/*
 * Coder & programmer: Luis Sanabria
 * Copyright: (c) Arquetic.org 2019 
 * Date: March, 2019
 * GitHub: https://github.com/aleftos/billbo
 * Summary: Utilities for the national tax billing system of Bolivian country.
 * Description: Verhoeff code generator.
*/

'use strict'

var multiplication = [
  [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 2, 3, 4, 0, 6, 7, 8, 9, 5],
  [2, 3, 4, 0, 1, 7, 8, 9, 5, 6],
  [3, 4, 0, 1, 2, 8, 9, 5, 6, 7],
  [4, 0, 1, 2, 3, 9, 5, 6, 7, 8],
  [5, 9, 8, 7, 6, 0, 4, 3, 2, 1],
  [6, 5, 9, 8, 7, 1, 0, 4, 3, 2],
  [7, 6, 5, 9, 8, 2, 1, 0, 4, 3],
  [8, 7, 6, 5, 9, 3, 2, 1, 0, 4],
  [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
];
var permutation = [
  [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
  [1, 5, 7, 6, 2, 8, 3, 0, 9, 4],
  [5, 8, 0, 3, 7, 9, 6, 1, 4, 2],
  [8, 9, 1, 6, 0, 4, 3, 5, 2, 7],
  [9, 4, 5, 3, 1, 2, 6, 8, 7, 0],
  [4, 2, 8, 6, 5, 7, 3, 9, 0, 1],
  [2, 7, 9, 3, 8, 0, 6, 4, 1, 5],
  [7, 0, 4, 6, 9, 1, 3, 2, 5, 8]	
];
var inverse = [0, 4, 3, 2, 1, 5, 6, 7, 8, 9];

// * converts string or number to an array and inverts it
var invArray = (array) => {   
  if (Object.prototype.toString.call(array) == '[object Number]'){
      array = String(array);
  }
  
  if (Object.prototype.toString.call(array) == '[object String]'){
      array = array.split('').map(Number);
  } 
  return array.reverse();
}

module.exports = {

  // * generates checksum
  genVerhoeff: (array) => {      
    let c = 0;
    let invertedArray = invArray(array);
    for (var i = 0; i < invertedArray.length; i++){
      c = multiplication[c][permutation[((i + 1) % 8)][invertedArray[i]]];
    }
    return inverse[c];
  },
  // * generates checksum
  VerhoeffConcated: (array) => {
    let c = 0;
    let invertedArray = invArray(array);
    for (var i = 0; i < invertedArray.length; i++){
      c = multiplication[c][permutation[((i + 1) % 8)][invertedArray[i]]];
    }
    return array + inverse[c];
  },
  // * validates checksum
  validateVerhoeff: (array) => {
    let c = 0;
    let invertedArray = invArray(array);
    for (var i = 0; i < invertedArray.length; i++){
      c=multiplication[c][permutation[(i % 8)][invertedArray[i]]];
    }
    return (c === 0);
  }
}