import crypto from "crypto";


/**
 * UUID operations.
 *
 * @author n1474335 [n1474335@gmail.com]
 * @copyright Crown Copyright 2016
 * @license Apache-2.0
 *
 * @namespace
 */
const UUID = {

    /**
     * Generate UUID operation.
     *
     * @param {string} input
     * @param {Object[]} args
     * @returns {string}
     */
    runGenerateV4: function(input, args) {
        const buf = new Uint32Array(4).map(() => {
            return crypto.randomBytes(4).readUInt32BE(0, true);
        });
        let i = 0;
        return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(/[xy]/g, function(c) {
            let r = (buf[i >> 3] >> ((i % 8) * 4)) & 0xf,
                v = c === "x" ? r : (r & 0x3 | 0x8);
            i++;
            return v.toString(16);
        });
    }
};

export default UUID;