"use strict";

import {Common} from "../Utils/Common.ecma.js";
import {Check} from "../Utils/Checks.ecma.js";

/**
 * @typedef {import("../Application/AnP.ecma.js").AnP} AnP
 */

/**
 * @class I18NManager
 * @constructor
 * @param {!AnP} anp
 * @returns {void}
 * @access private
 * @static
 */
export const I18NManager = (function(){

    /**
     * @callback simple_callback
     * @returns {void}
     */

    /**
     * @callback continue_callback
     * @param {!boolean} ok 
     * @return {boolean}
     */

    /**
     * @constructs I18NManager
     * @param {!AnP} anp
     * @returns {void}
     * @access private
     * @static
     */
    const I18NManager = function(anp){

        /** @type {!AnP} */
        const self = this, 
              /** @type {Object.<string, Object.<string, string|Array.<string>>>} */
              sentences = {};
        /** @type {boolean} */
        let started = false, 
            /** @type {string} */
            language = "english", 
            /** @type {string} */
            default_language = "english";

        /**
         * @returns {void}
         * @access private
         */
        const constructor = () => {};

        /**
         * @param {?continue_callback} callback 
         * @returns {boolean}
         * @access public
         */
        this.update = (callback = null) => {
            Common.execute_array(["default_i18n_files", "i18n_files", "default_i18n", "i18n"], (key, next) => {
                self.add(anp.settings.get(key), true, next);
            }, callback, true);
        };

        /**
         * @param {?continue_callback} callback 
         * @returns {boolean}
         * @access public
         */
        this.reset = (callback = null) => {

            Common.clear_dictionary(sentences);

            self.update(callback);

        };

        /**
         * @param {?continue_callback} callback 
         * @returns {boolean}
         * @access public
         */
        this.start = (callback = null) => {

            /** @type {continue_callback} */
            const end = ok => Common.execute(callback, ok);

            if(started){
                end(false);
                return false;
            };
            started = true;

            self.update(() => end(true));

            return true;
        };

        /**
         * @param {?continue_callback} callback 
         * @returns {boolean}
         * @access public
         */
        this.close = (callback = null) => {

            /** @type {continue_callback} */
            const end = ok => Common.execute(callback, ok);

            if(!started){
                end(false);
                return false;
            };
            started = false;

            end(true);

            return true;
        };

        /**
         * @param {!(string|Array.<string>)} texts 
         * @param {?(string|Array.<string>)} languages 
         * @returns {string|Array.<string>|null}
         * @access private
         */
        const get_sentence = (texts, languages) => {

            /** @type {Array.<string>} */
            const keys = Common.get_keys(texts);

            if(keys.length){

                /** @type {Array.<string>} */
                const languages_done = [];

                for(let language_key of Common.get_keys(languages).concat(
                    [language, default_language], 
                    Object.keys(sentences)
                )){
                    if(languages_done.includes(language_key))
                        continue;
                    languages_done.push(language_key);
                    if(!sentences[language_key])
                        continue;
                    for(let key of keys)
                        if(sentences[language_key][key] !== undefined)
                            return sentences[language_key][key];
                };

            };
            return Common.get_texts(texts)
            
        };
        
        /**
         * @param {!(string|Array.<string>)} texts 
         * @param {?(Object.<string, any|null>|Array<any|null>)} [subinputs = null] 
         * @param {?(string|Array.<string>)} [languages = null] 
         * @returns {any|null}
         * @access public
         */
        this.get = (texts, inputs = null, languages = null) => {

            /** @type {string|Array.<string>|null} */
            const sentence = get_sentence(texts, languages);

            return Common.string_variables((
                Check.is_array(sentence) ? sentence.join("") : 
            sentence), inputs);
        };

        /**
         * @param {?any} inputs 
         * @param {!boolean} [overwrite = false] 
         * @param {?simple_callback} [callback = null] 
         * @return {void}
         * @access public
         */
        this.add = (inputs, overwrite = false, callback = null) => {
            anp.files.load_json(inputs, data => {
                for(let subinputs of data)
                    Object.entries(subinputs).forEach(([new_language, new_sentences]) => {
                        sentences[new_language] || (sentences[new_language] = {});
                        Check.is_dictionary(new_sentences) && 
                        Object.entries(new_sentences).filter(([key, _]) => !Check.is_mark_key(key)).forEach(([key, sentence]) => {
                            sentences[new_language][key] = sentence;
                        });
                    });
                Common.execute(callback);
            }, true);
        };

        /**
         * @param {!string} new_language 
         * @return {boolean}
         * @access public
         */
        this.change = new_language => {
            if(sentences[new_language] && new_language != language){
                language = new_language;
                return true;
            };
            return false;
        };

        /**
         * @param {!string} check_language 
         * @returns {boolean}
         * @access public
         */
        this.is_language_selected = check_language => language == check_language;

        constructor();

    };

    /** @type {Object.<string, any|null>} */
    I18NManager.DEFAULT_SETTINGS = {};

    return I18NManager;
})();