base64-format/main.js

Re-format base64 data

/*
    base64-format
*/

"use strict";

var R = require("ramda"),
    escapeRegex = require("escape-string-regexp"),
    segment = require("string-segment"),
    base64Clean = require("base64-clean"),

    variants = require("base64-variants"),

    defaults = R.mixin({
        from: "base64",
        to: "base64",
        clean: true
    }),


    // Make a function-returning-function act like it's curried.
    defer = function (func, value) {
        return (value === undefined) ? func : func(value);
    },


    // Delete non-encoding chars, if appropriate
    clean = function (options) {
        if (!options.clean) {
            return R.identity;
        }
        return base64Clean({ variant: options.from });
    },


    // Reflow lines
    reflow = function (options) {
        var line = variants[options.to].line;
        return R.compose(
            R.join(line.newline), // Join lines together with newline char
            segment(line.width) // Split data into an array of lines
        );
    },


    // Replace `from.keyspace` chars with `to.keyspace` chars
    format = R.curry(function (options, data) {
        var from = variants[options.from].keyspace,
            to = variants[options.to].keyspace;
        R.forEach(function (index) {
            data = R.replace(
                new RegExp(escapeRegex(from[index]), "g"),
                to[index],
                data
            );
        }, R.keys(from));
        return data;
    }),


    main = function (options, data) {
        options = Object.freeze(defaults(options));
        return defer(
            R.compose(
                reflow(options),
                format(options),
                clean(options)
            ),
            data
        );
    };


if (module !== undefined) {
    module.exports = main;
}