/**
 * A blindtext generator written in JavaScript. It uses a set of latin words to create either a given amount
 * of words or sentences.
 *
 * @author mightyplow
 */

const defaultOptions = {
    minWords: 3,
    maxWords: 9
};

const availableWords = require('./words');
const punctuationMarks = ['.', '!', '?'];

const {
    randomInt,
    capitalize,
    getRandomArrayValue
} = require('./utils');

const getRandomPunctuationMark = getRandomArrayValue.bind(null, punctuationMarks);
const getRandomWord = getRandomArrayValue.bind(null, availableWords);

function createSentence ({ minWords, maxWords }) {
    const numWords = randomInt(minWords, maxWords);
    const sentenceWords = [];

    for (let i = 0, randomWord = ''; i < numWords; i += 1) {
        do {
            randomWord = getRandomWord();
        } while(sentenceWords.includes(randomWord));

        // capitalize first letter when first word of sentence
        // also capitalize when a random number between 0 and 3 is 0 -> just to get more capital letters
        sentenceWords.push(
            (i !== 0 && randomInt(0, 3) > 0)
                ? randomWord
                : capitalize(randomWord)
        );
    }

    return sentenceWords.join(' ') + getRandomPunctuationMark();
}

const Unit = {
    SENTENCE: 'sentence',
    WORD: 'word'
};

const UnitFunction = {
    [Unit.SENTENCE]: createSentence,
    [Unit.WORD]: getRandomWord
};

function createText (num, unit = Unit.WORD, options) {
    if (!UnitFunction.hasOwnProperty(unit)) {
        throw Error('Invalid unit parameter');
    }

    const creatorOptions = Object.assign({}, options, defaultOptions);
    const unitCreator = UnitFunction[unit];
    const texts = [];

    for (let i = 0; i < num; i += 1) {
        texts.push(unitCreator(creatorOptions));
    }

    return texts.join(' ');
}

export {
    createText,
    Unit
};