const crypt = require("crypto");
// const FlakeId = require('flakeid');

module.exports = {
    /**
     * Generates a unique ID
     * @returns {string} 12-character base64 ID
     */
    generateUniqueId: () => crypt.randomBytes(9)
        .toString('base64')
        .replace(/[/+]/g, c => c === '/' ? '_' : '-')
        .slice(0, 12),

    /**
     *
     * @param {number} len How long to set character length
     * @returns alphanumeric string
     */
    random: function random(len) {
        len = len || 64;
        return crypt.randomBytes(len).toString("hex");
    },

    // snowflake: function snowflake() {

    //     const flake = new FlakeId({
    //         mid: 64,
    //         timeOffset: 1431669781,
    //     });

    //     return flake.gen();
    // },

    shortid: function shortid() {
        let str = Buffer.from(crypt.randomUUID()).toString('base64');
        let n = 12;

        return (str.length > n) ? str.substr(0, n - 1) : str
    },

    truncate: function truncate(str, n) {
        return (str.length > n) ? str.substr(0, n - 1) : str;
    },

    randomNum: function (len1) {
        const len2 = len1 || 17;
        const { customAlphabet } = require('nanoid')
        const nanoid = customAlphabet('1234567890', len2)
        return nanoid();
    },

    isJson: function (str) {
        try {
            JSON.parse(str);
        } catch (e) {
            return false;
        }
        return true;
    }
};