boletos-ademitech/lib/utils/math-utils.js

Gerar boletos para vários bancos

const arrayUtils = require('./array-utils');

module.exports.mod = function (value, factors, divider, direction) {

    var reduceSummationTerms = false,
        cumplimentaryToDivider = false;

    if (arguments.length === 1 && typeof value === 'object') {
        factors = value.factors;
        divider = value.divider;
        direction = value.direction;
        reduceSummationTerms = value.reduceSummationTerms;
        cumplimentaryToDivider = value.cumplimentaryToDivider;
        value = value.value;
    }

    if (divider === undefined) {
        divider = 11;
    }

    if (factors === undefined) {
        factors = arrayUtils.series(2, 9);
    }

    if (direction === undefined) {
        direction = 'rightToLeft';
    }

    var reduceMethod = direction === 'leftToRight' ? 'reduce' : 'reduceRight';

    var i = 0;
    var result = value.split('')[reduceMethod](function (last, current) {
        if (i > factors.length - 1) {
            i = 0;
        }

        var total = factors[i++] * parseInt(current, 10);

        const sum = (a, b) => a + b;

        if (reduceSummationTerms) {
            total = total.toString().split('').map(Number).reduce(sum, 0);
        }

        return total + last;
    }, 0) % divider;

    if (cumplimentaryToDivider) {
        result = divider - result;
    }

    return result;
};