number-munchers/models/multiples.model.js

import BaseModel from './base.model';

const MultiplesModel = Object.create(BaseModel);

MultiplesModel.generate = function(n, level) {
    const multiples = [];
    const nonmultiples = [];
    const target = 19//level + 2;
    const upperLimit = target * 150;

    let tmp;
    while (multiples.length < Math.ceil(n * 4)) {
        tmp = Math.ceil(Math.random() * upperLimit);
        if (tmp % target === 0) {
            multiples.push(tmp);
        }
    }

    while (nonmultiples.length < Math.floor(n * 4)) {
        tmp = Math.ceil(Math.random() * upperLimit);
        if (tmp % target !== 0) {
            nonmultiples.push(tmp);
        }
    }

    return this.buildResults(multiples, nonmultiples, n);
};

MultiplesModel.getTitle = (level) => {
    return `Multiples of ${level + 2}`;
};

MultiplesModel.getError = (value, level) => {
    return `Oops! ${value} is not a multiple of ${level + 2}.`;
};

export default MultiplesModel;