cube.js

const fs = require('fs');
const path = require('path');
const pathBaseFile = path.join(__dirname, '../config/database.json');

class Cube {

    constructor(name, description, imageUrl, difficultyLevel) {
        this.name = name;
        this.description = description;
        this.imageUrl = imageUrl;
        this.difficultyLevel = difficultyLevel;
    }

    save() {
        fs.readFile(pathBaseFile, (err, data) => {
            if (err) {
                return console.log(err);
            }

            const cubes = JSON.parse(data);

            this.id = String(cubes.length);

            cubes.push(this);

            fs.writeFile(pathBaseFile, JSON.stringify(cubes), () => {
                console.log('Cubes was successfully saved to database!');
            });
        });
    }

    static find(criteria, cb) {
        if (!cb) {
            cb = criteria;
            criteria = {};
        }
        const { search = null, from = null, to = null } = criteria;
        fs.readFile(pathBaseFile, (err, data) => {
            if (err) {
                return console.log(err);
            }
            const cubes = JSON.parse(data).filter(cube => {
                return (from && to)
                    ? cube.name.toLowerCase().includes(search.toLowerCase()) && cube.difficultyLevel >= Number(from) && cube.difficultyLevel <= Number(to)
                    : search ? cube.name.toLowerCase().includes(search.toLowerCase()) : cube
            })
            cb(cubes);
        });
    }

    static findById(id, cb) {
        this.find({ id }, (cubes) => {
            const cube = cubes.find(cube => cube.id === id);
            cb(cube);
        })
    }
}

module.exports = Cube;