/**
 * This class repesents phrasebook, which is something like dictionary,
 * but not for words, for all phrases in app. It give functions which 
 * could find and translates phrases.
 */
class phrasebook {

    #collection;

    /**
     * This create new phrasebook, which given collection of phrqses.
     *
     * @param {Map} collection - Collection of phrases to translate from.
     */
    constructor(collection) {
        if (!(collection instanceof Map)) {
            throw new Error("Phrasebook must be indialized with map.");
        }

        this.#collection = collection;
    }

    /**
     * This function translate phrase to lang which coresponds to the 
     * phrasebook. It try to find given phrase in the phrasebook, and 
     * when find it, return that. In the other way, when phrase could
     * not being fount, write warning to the debug console, and return
     * phrase in given not translated form. When phrase in phrasebook
     * is not string, then also return not translated phrase and 
     * report it into developer console.
     * 
     * @param {string} phrase - Phrase to translate.
     * @return {string} Translated phrase.
     */
    get(phrase) {
        if (typeof(phrase) !== "string") {
            throw new Error("Phrase to translate must be string.");
        }

        if (this.#collection.has(phrase)) {
            const translated = this.#collection.get(phrase);
            
            if (typeof(translated) !== "string") {
                console.error("Result for \"" + phrase + "\" is not string.");
                return phrase;
            }

            return translated;
        }

        console.warn("Could not find \"" + phrase + "\" in phrasebook.");

        return phrase;
    }
}

exports.phrasebook = phrasebook;