"use strict";

import {Check} from "./Check.ecma.js";

/**
 * @callback utils_preload_callback
 * @param {?HTMLElement} item 
 * @param {!boolean} asynchronous 
 * @param {!boolean} ok 
 * @returns {void}
 */

/**
 * @callback utils_execute_callback
 * @param {...any} [paramenters] 
 * @returns {any|null}
 */

/**
 * @class
 * @constructor
 * @returns {void}
 * @access public
 * @static
 */
export const Utils = (function(){

    /**
     * @constructs Utils
     * @returns {void}
     * @access private
     * @static
     */
    const Utils = function(){};

    /**
     * @param {!(string|HTMLElement)} selector 
     * @param {!utils_preload_callback} callback 
     * @param {!(Document|HTMLElement)} [root = document] 
     * @param {!number} [timeout = 2000] 
     * @returns {void}
     * @access public
     * @static
     */
    Utils.preload = (selector, callback, root = document, timeout = 2000) => {
        if(!selector)
            callback(null, false, false);
        else if(Check.is_html_object(selector))
            callback(selector, false, true);
        else if(Check.is_string(selector) && (selector = selector.trim())){

            /** @type {HTMLElement|null} */
            let item = null;

            try{
                if(item = root.querySelector(selector)){
                    callback(item, false, true);
                    return;
                };
            }catch(exception){
                callback(null, false, false);
                return;
            };

            /** @type {number} */
            const date = Date.now();
            /** @type {number} */
            let interval = setInterval(() => {
                if(item = root.querySelector(selector)){
                    clearInterval(interval);
                    callback(item, true, true);
                }else if(Date.now() - date > timeout){
                    clearInterval(interval);
                    callback(null, false, true);
                };
            }, 100);

        }else 
            callback(null, false, false);
    };

    /**
     * @param {!utils_execute_callback} callback 
     * @param  {...any} [parameters] 
     * @returns {any|null}
     * @access public
     * @static
     */
    Utils.execute = (callback, ...parameters) => Check.is_function(callback) ? callback(...parameters) : null;

    /**
     * @param {!(string|HTMLElement)} selector 
     * @param {!Object.<string, any|null>} attributes 
     * @param {!(HTMLElement|Document)} [position = document] 
     * @returns {void}
     * @access public
     * @static
     */
    Utils.set_attributes = (selector, attributes, position = document) => {
        (Check.is_string(selector) ? position.querySelectorAll(selector) : [selector]).forEach(item => {
            for(const key in attributes){
                if(/^on_?/i.test(key))
                    item.addEventListener(
                        key.substring(2).replace(/[^a-z]+/g, "").toLowerCase(), 
                        event => Utils.execute(attributes[key], item, event)
                    );
                else 
                    item.setAttribute(key.replace(/_|([A-Z])/g, (_, character) => {
                        return character ? "-" + character.toLowerCase() : "-";
                    }), attributes[key]);
            };
        });
    };

    /**
     * @param {!(string|HTMLElement|Document)} selector 
     * @param {!Array.<[string, Object.<string, any|null>|null, Array.<any>|null]} items 
     * @param {!(HTMLElement|Document)} [position = document] 
     * @returns {Array.<HTMLElement>}
     * @access public
     * @static
     */
    Utils.set_html = (selector, items, position = document) => {

        Check.is_string(selector) && (selector = position.querySelector(selector));

        return items.map(([tag, attributes, childs]) => {

            /** @type {HTMLElement} */
            const item = selector.appendChild(document.createElement(tag));

            attributes && Utils.set_attributes(item, attributes);
            if(!Check.is_null_or_undefined(childs)){
                if(Check.is_string(childs))
                    item.innerHTML = childs;
                else if(Check.is_array(childs))
                    Utils.set_html(item, childs);
            };

            return item;
        });
    };

    Utils.get_keys = keys => (
        Check.is_array(keys) ? keys.reduce((keys, key) => keys.concat(Utils.get_keys(key)), []) : 
        Check.is_key(keys) ? [keys] : 
    []);

    Utils.get_dictionary = (dictionaries, overwrite = false) => (
        Check.is_array(dictionaries) ? dictionaries.reduce((dictionary, item) => (overwrite ? {
            ...dictionary, 
            ...Utils.get_dictionary(item)
        } : {
            ...Utils.get_dictionary(item), 
            ...dictionary
        }), {}) : 
        Check.is_dictionary(dictionaries) ? dictionaries : 
    {});

    Utils.get_value = (keys, inputs, _default = null) => {

        const l = (keys = Utils.get_keys(keys)).length;

        if(l && Object.keys(inputs = Utils.get_dictionary(inputs)).length)
            for(let i = 0; i < l; i ++)
                if(inputs[keys[i]] !== undefined)
                    return inputs[keys[i]];
        return _default;
    };

    Utils.download = (data, mime = "application/octet-stream", name = null) => {
        console.log(data);

        const anchor = document.createElement("a"), 
                date = new Date();

        Utils.set_attributes(anchor, {
            download : name || ("RoutesMaker." + (
                ("0000" + date.getFullYear()).slice(-4) + 
                ("00" + (date.getMonth() + 1)).slice(-2) + 
                ("00" + date.getDate()).slice(-2) + 
                ("00" + date.getHours()).slice(-2) + 
                ("00" + date.getMinutes()).slice(-2) + 
                ("00" + date.getSeconds()).slice(-2)
            ) + ".json"), 
            href : "data:" + mime + ";base64," + btoa(Check.is_string(data) ? data : JSON.stringify(data)), 
            target : "_blank"
        });
        anchor.click();
        anchor.remove();

    };

    Utils.upload = callback => {

        const input = document.createElement("input");

        Utils.set_attributes(input, {
            type : "file", 
            multiple : false, 
            on_change : (item, event) => {

                let loaded = 0;
                const data = [], 
                      l = event.target.files.length, 
                      end = (i, file, string) => {
                          data[i] = {
                              name : file.name, 
                              last_modified_date : file.lastModified, 
                              size : file.size, 
                              mime : file.type, 
                              content : string
                          };
                          if(++ loaded == l){
                              input.remove();
                              Utils.execute(callback, ...data);
                          };
                      };

                [...event.target.files].forEach((file, i) => {

                    const reader = new FileReader();

                    reader.onload = () => {
                        end(i, file, reader.result);
                    };
                    reader.readAsText(file);

                });

            }
        });
        input.click();

    };

    Utils.to_kebab = snake => snake.replace(/_/g, "-");

    /**
     * @param {?string} item 
     * @returns {string|null}
     * @access public
     * @static
     */
    Utils.to_key = item => Check.is_string(item) && (item = item.trim()) ? item.replace(/[^a-z0-9]+/ig, "_") : null;

    return Utils;
})();