cie-calculator-flap/lib/strategies/alg94.js

Easily generate CIE References

'use strict';

var _ = require('underscore');
var CIEStrategy = require('./cie_strategy.js').CIEStrategy;
var CIEUtils = require('./cie_utils.js').CIEUtils;
var cieUtils = new CIEUtils();

var Alg94 = function() {};

Alg94.prototype = new CIEStrategy();
Alg94.prototype = {
  execute: function(input) {

    var validationRules = {
      reference: {length: {min: 1,max: 42}},
      date: {length: {min: 8,max: 8}},
      amount: {length: {min: 1,max: 12}}
    };

    if (!cieUtils.validateInput(input,validationRules )) {
      throw new Error('Longitud invalida');
    }

    return alg94(input.date, input.amount, input.reference);
  }
};

module.exports.Alg94 = Alg94;

var contantLeft = 0;
var yearBase = 2013;
var yearMultiply = 372;
var unitSubtraction = 1;
var monthMultiply = 31;
var digitVerifyConstant = 2;

function alg94(dateExpired, amount, reference){
  var digitVerifyDate = algorithmDate(dateExpired);

  var amountFormat = convertToPounds(amount);

  var digitVerifyAmount = algorithmAmount(amountFormat);
  var reference94 = reference + digitVerifyDate + digitVerifyAmount + digitVerifyConstant;
  var digitVerifyReference = algorithmReference(reference94.toUpperCase());
  reference94 = reference94 + digitVerifyReference;
  return reference94;
}

function convertToPounds(str) {	
	var n = Number.parseFloat(str);
  if(!str || isNaN(n) || n < 0) return 0;
  return n.toFixed(2);
}

function algorithmAmount(data){
  var dataTransform = data.split('.').join("");
  var isPosition = 1
  var mapMultiply = new Map([[1, 7], [2, 3], [3, 1]]);
  var sumData = 0;
  for(var i = dataTransform.length-1; i >= 0; i--) {
    var dataNumber = Number(dataTransform.charAt(i));
    var numberMultiply = 0;
    if(mapMultiply.has(isPosition)){
      numberMultiply = mapMultiply.get(isPosition);
    }else{
      isPosition = 1;
      numberMultiply = mapMultiply.get(isPosition);
    }
    isPosition++;
    var resultMultiply = (numberMultiply * dataNumber);
    sumData += resultMultiply;
  }
  var numberAux = 10;
  var residue = ((sumData % numberAux) + numberAux) % numberAux;

  return residue.toString().charAt(residue.toString().length-1);
}

function algorithmReference(data){
  var dataReplace = data;
  var isPosition = 1
  var mapMultiply = new Map([[1, 11], [2, 13], [3, 17], [4, 19], [5, 23]]);
  var sumData = 0;
  for(var i = dataReplace.length-1; i >= 0; i--) {
    var dataNumber = Number(dataReplace.charAt(i));
    var numberMultiply = 0;
    if(mapMultiply.has(isPosition)){
      numberMultiply = mapMultiply.get(isPosition);
    }else{
      isPosition = 1;
      numberMultiply = mapMultiply.get(isPosition);
    }
    isPosition++;
    var resultMultiply = (numberMultiply * dataNumber);
    sumData += resultMultiply;
  }
  var numberAux = 97;
  var residue = ((sumData % numberAux) + numberAux) % numberAux;
  var digitVerifyReference = residue + 1;

  digitVerifyReference = digitVerifyReference.toString();

  return missingData(2, digitVerifyReference.toString());
}

function algorithmDate(data){
  var dayData = data.substring(0, 2);
  var monthData = data.substring(2, 4);
  var yearData = data.substring(4, 8);

  var yearSubtraction = yearData - yearBase;

  var yearresultMultiply = yearSubtraction * yearMultiply;

  var monthResultSubtraction = Number(monthData) - unitSubtraction;

  var monthResultMultiply = monthResultSubtraction * monthMultiply;

  var dayResultSubtraction = Number(dayData) - unitSubtraction;

  var digitVerifyDate = yearresultMultiply + monthResultMultiply + dayResultSubtraction;

  return missingData(4, digitVerifyDate.toString());
}

function missingData(minLengthMissing, data){
  var missingLeft = minLengthMissing - data.length;
  for (var i = 0; i < missingLeft; i++) {
    data = contantLeft + data;
  }
  return data;
}