import { each, isString, isArray, contains } from 'underscore';
import { Assert } from '../misc/Assert';
import { Logger } from '../misc/Logger';
import { IStringMap } from '../rest/GenericParam';
import { JQueryUtils } from '../utils/JQueryutils';
import { Utils } from '../utils/Utils';
import { DeviceUtils } from './DeviceUtils';

export interface IOffset {
  left: number;
  top: number;
}

/**
 * This is essentially a helper class for dom manipulation.<br/>
 * This is intended to provide some basic functionality normally offered by jQuery.<br/>
 * To minimize the multiple jQuery conflict we have while integrating in various system, we implemented the very small subset that the framework needs.<br/>
 * See {@link $$}, which is a function that wraps this class constructor, for less verbose code.
 */
export class Dom {
  private static CLASS_NAME_REGEX = /-?[_a-zA-Z]+[_a-zA-Z0-9-]*/g;
  private static ONLY_WHITE_SPACE_REGEX = /^\s*$/;
  /**
   * Whether to always register, remove, and trigger events using standard JavaScript rather than attempting to use jQuery first.
   * @type boolean
   */
  public static useNativeJavaScriptEvents = false;

  public el: HTMLElement;

  /**
   * Create a new Dom object with the given HTMLElement
   * @param el The HTMLElement to wrap in a Dom object
   */
  constructor(el: HTMLElement) {
    Assert.exists(el);
    this.el = el;
  }

  private static handlers: WeakMap<(evt: Event, data: any) => void, (e: CustomEvent) => void> = new WeakMap();

  /**
   * Helper function to quickly create an HTMLElement
   * @param type The type of the element (e.g. div, span)
   * @param props The props (id, className, attributes) of the element<br/>
   * Can be either specified in dashed-case strings ('my-attribute') or camelCased keys (myAttribute),
   * the latter of which will automatically get replaced to dash-case.
   * @param innerHTML The contents of the new HTMLElement, either in string form or as another HTMLElement
   */
  static createElement(type: string, props?: Object, ...children: Array<string | HTMLElement | Dom>): HTMLElement {
    const elem: HTMLElement = document.createElement(type);

    for (const key in props) {
      if (key === 'className') {
        elem.className = props['className'];
      } else {
        const attr = key.indexOf('-') !== -1 ? key : Utils.toDashCase(key);
        elem.setAttribute(attr, props[key]);
      }
    }

    each(children, (child: string | HTMLElement | Dom) => {
      if (child instanceof HTMLElement) {
        elem.appendChild(child);
      } else if (isString(child)) {
        elem.innerHTML += child;
      } else if (child instanceof Dom) {
        elem.appendChild(child.el);
      }
    });

    return elem;
  }

  /**
   * Adds the element to the children of the current element
   * @param element The element to append
   * @returns {string}
   */
  public append(element: HTMLElement) {
    this.el.appendChild(element);
  }

  /**
   * Get the css value of the specified property.<br/>
   * @param property The property
   * @returns {string}
   */
  public css(property: string): string {
    if (this.el.style[property]) {
      return this.el.style[property];
    }
    return window.getComputedStyle(this.el).getPropertyValue(property);
  }

  /**
   * Get or set the text content of the HTMLElement.<br/>
   * @param txt Optional. If given, this will set the text content of the element. If not, will return the text content.
   * @returns {string}
   */
  public text(txt?: string): string {
    if (Utils.isUndefined(txt)) {
      return this.el.innerText || this.el.textContent;
    } else {
      if (this.el.innerText != undefined) {
        this.el.innerText = txt;
      } else if (this.el.textContent != undefined) {
        this.el.textContent = txt;
      }
    }
  }

  /**
   * Performant way to transform a NodeList to an array of HTMLElement, for manipulation<br/>
   * http://jsperf.com/nodelist-to-array/72
   * @param nodeList a {NodeList} to convert to an array
   * @returns {HTMLElement[]}
   */
  public static nodeListToArray(nodeList: NodeList): HTMLElement[] {
    let i = nodeList.length;
    const arr: HTMLElement[] = new Array(i);
    while (i--) {
      arr[i] = <HTMLElement>nodeList.item(i);
    }
    return arr;
  }

  /**
   * Focuses on an element.
   * @param preserveScroll Whether or not to scroll the page to the focused element.
   */
  public focus(preserveScroll: boolean) {
    if (DeviceUtils.getDeviceName() === 'IE') {
      const { pageXOffset, pageYOffset } = window;
      this.el.focus();
      if (preserveScroll) {
        window.scrollTo(pageXOffset, pageYOffset);
      }
    } else {
      (this.el as any).focus({ preventScroll: preserveScroll });
    }
  }

  /**
   * Empty (remove all child) from the element;
   */
  public empty(): void {
    while (this.el.firstChild) {
      this.removeChild(this.el.firstChild);
    }
  }

  public removeChild(child: Node) {
    const oldParent = child.parentNode;
    try {
      this.el.removeChild(child);
    } catch (e) {
      if ((e as Error).name !== 'NotFoundError') {
        throw e;
      }
      if (oldParent === child.parentNode) {
        throw e;
      }
    }
  }

  /**
   * Empty the element and all childs from the dom;
   */
  public remove(): void {
    if (this.el.parentNode) {
      this.el.parentNode.removeChild(this.el);
    }
  }

  /**
   * Show the element by setting display to block;
   */
  public show(): void {
    this.el.style.display = 'block';
    $$(this.el).setAttribute('aria-hidden', 'false');
  }

  /**
   * Hide the element;
   */
  public hide(): void {
    this.el.style.display = 'none';
    $$(this.el).setAttribute('aria-hidden', 'true');
  }

  /**
   * Show the element by setting display to an empty string.
   */
  public unhide(): void {
    this.el.style.display = '';
    $$(this.el).setAttribute('aria-hidden', 'false');
  }

  /**
   * Toggle the element visibility.<br/>
   * Optional visible parameter, if specified will set the element visibility
   * @param visible Optional parameter to display or hide the element
   */
  public toggle(visible?: boolean): void {
    if (visible === undefined) {
      if (this.el.style.display == 'block') {
        this.hide();
      } else {
        this.show();
      }
    } else {
      if (visible) {
        this.show();
      } else {
        this.hide();
      }
    }
  }

  /**
   * Tries to determine if an element is "visible", in a generic manner.
   *
   * This is not meant to be a "foolproof" method, but only a superficial "best effort" detection is performed.
   */
  public isVisible() {
    if (this.css('display') === 'none') {
      return false;
    }

    if (this.css('visibility') === 'hidden') {
      return false;
    }

    if (this.hasClass('coveo-tab-disabled')) {
      return false;
    }

    if (this.hasClass('coveo-hidden')) {
      return false;
    }

    if (this.hasClass('coveo-hidden-dependant-facet')) {
      return false;
    }

    return true;
  }

  /**
   * Returns the value of the specified attribute.
   * @param name The name of the attribute
   */
  public getAttribute(name: string): string {
    return this.el.getAttribute(name);
  }

  /**
   * Sets the value of the specified attribute.
   * @param name The name of the attribute
   * @param value The value to set
   */
  public setAttribute(name: string, value: string) {
    this.el.setAttribute(name, value);
  }

  /**
   * Find a child element, given a CSS selector
   * @param selector A CSS selector, can be a .className or #id
   * @returns {HTMLElement}
   */
  public find(selector: string): HTMLElement {
    return <HTMLElement>this.el.querySelector(selector);
  }

  /**
   * Check if the element match the selector.<br/>
   * The selector can be a class, an id or a tag.<br/>
   * Eg : .is('.foo') or .is('#foo') or .is('div').
   */
  public is(selector: string): boolean {
    if (this.el.tagName.toLowerCase() == selector.toLowerCase()) {
      return true;
    }
    if (selector[0] == '.') {
      if (this.hasClass(selector.substr(1))) {
        return true;
      }
    }

    if (selector[0] == '#') {
      if (this.el.getAttribute('id') == selector.substr(1)) {
        return true;
      }
    }

    return false;
  }

  /**
   * Get the first element that matches the classname by testing the element itself and traversing up through its ancestors in the DOM tree.
   *
   * Stops at the body of the document
   * @param className A CSS classname
   */
  public closest(className: string): HTMLElement {
    return this.traverseAncestorForClass(this.el, className);
  }

  /**
   * Get the first element that matches the classname by testing the element itself and traversing up through its ancestors in the DOM tree.
   *
   * Stops at the body of the document
   * @returns {any}
   */
  public parent(className: string): HTMLElement {
    if (this.el.parentElement == undefined) {
      return undefined;
    }
    return this.traverseAncestorForClass(this.el.parentElement, className);
  }

  /**
   *  Get all the ancestors of the current element that match the given className
   *
   *  Return an empty array if none found.
   * @param className
   * @returns {HTMLElement[]}
   */
  public parents(className: string): HTMLElement[] {
    const parentsFound = [];
    let parentFound = this.parent(className);
    while (parentFound) {
      parentsFound.push(parentFound);
      parentFound = new Dom(parentFound).parent(className);
    }
    return parentsFound;
  }

  /**
   * Return all children
   * @returns {HTMLElement[]}
   */
  public children(): HTMLElement[] {
    return Dom.nodeListToArray(this.el.children);
  }

  /**
   * Return all siblings
   * @returns {HTMLElement[]}
   */
  public siblings(selector: string): HTMLElement[] {
    const sibs = [];
    let currentElement = <HTMLElement>this.el.parentNode.firstChild;
    for (; currentElement; currentElement = <HTMLElement>currentElement.nextSibling) {
      if (currentElement != this.el) {
        if (this.matches(currentElement, selector) || !selector) {
          sibs.push(currentElement);
        }
      }
    }
    return sibs;
  }

  private matches(element: HTMLElement, selector: string) {
    const all = document.querySelectorAll(selector);
    for (let i = 0; i < all.length; i++) {
      if (all[i] === element) {
        return true;
      }
    }
    return false;
  }

  /**
   * Find all children that match the given CSS selector
   * @param selector A CSS selector, can be a .className
   * @returns {HTMLElement[]}
   */
  public findAll(selector: string): HTMLElement[] {
    return Dom.nodeListToArray(this.el.querySelectorAll(selector));
  }

  /**
   * Find the child elements using a className
   * @param className Class of the childs elements to find
   * @returns {HTMLElement[]}
   */
  public findClass(className: string): HTMLElement[] {
    if ('getElementsByClassName' in this.el) {
      return Dom.nodeListToArray(this.el.getElementsByClassName(className));
    }
  }

  /**
   * Find an element using an ID
   * @param id ID of the element to find
   * @returns {HTMLElement}
   */
  public findId(id: string): HTMLElement {
    return document.getElementById(id);
  }

  /**
   * Add a class to the element. Takes care of not adding the same class if the element already has it.
   * @param className Classname to add to the element
   */
  public addClass(classNames: string[]): void;
  public addClass(className: string): void;
  public addClass(className: any): void {
    if (isArray(className)) {
      each(className, (name: string) => {
        this.addClass(name);
      });
    } else {
      if (!this.hasClass(className)) {
        if (this.el.className) {
          this.el.className += ' ' + className;
        } else {
          this.el.className = className;
        }
      }
    }
  }

  /**
   * Remove the class on the element. Works even if the element does not possess the class.
   * @param className Classname to remove on the the element
   */
  public removeClass(className: string): void {
    this.el.className = this.el.className.replace(new RegExp(`(^|\\s)${className}(\\s|$)`, 'g'), '$1').trim();
  }

  /**
   * Toggle the class on the element.
   * @param className Classname to toggle
   * @param swtch If true, add the class regardless and if false, remove the class
   */
  public toggleClass(className: string, swtch?: boolean): void {
    if (Utils.isNullOrUndefined(swtch)) {
      if (this.hasClass(className)) {
        this.removeClass(className);
      } else {
        this.addClass(className);
      }
    } else {
      if (swtch) {
        this.addClass(className);
      } else {
        this.removeClass(className);
      }
    }
  }

  /**
   * Sets the inner html of the element
   * @param html The html to set
   */
  public setHtml(html: string) {
    this.el.innerHTML = html;
  }

  /**
   * Return an array with all the classname on the element. Empty array if the element has not classname
   * @returns {any|Array}
   */
  public getClass(): string[] {
    // SVG elements got a className property, but it's not a string, it's an object
    const className = this.getAttribute('class');
    if (className && className.match) {
      return className.match(Dom.CLASS_NAME_REGEX) || [];
    } else {
      return [];
    }
  }

  /**
   * Check if the element has the given class name
   * @param className Classname to verify
   * @returns {boolean}
   */
  public hasClass(className: string): boolean {
    return contains(this.getClass(), className);
  }

  /**
   * Detach the element from the DOM.
   */
  public detach(): void {
    this.el.parentElement && this.el.parentElement.removeChild(this.el);
  }

  /**
   * Insert the current node after the given reference node
   * @param refNode
   */
  public insertAfter(refNode: HTMLElement): void {
    refNode.parentNode && refNode.parentNode.insertBefore(this.el, refNode.nextSibling);
  }

  /**
   * Insert the current node before the given reference node
   * @param refNode
   */
  public insertBefore(refNode: HTMLElement): void {
    refNode.parentNode && refNode.parentNode.insertBefore(this.el, refNode);
  }

  /**
   * Insert the given node as the first child of the current node
   * @param toPrepend
   */
  public prepend(toPrepend: HTMLElement) {
    if (this.el.firstChild) {
      new Dom(toPrepend).insertBefore(<HTMLElement>this.el.firstChild);
    } else {
      this.el.appendChild(toPrepend);
    }
  }

  /**
   * Bind an event handler on the element. Accepts either one (a string) or multiple (Array<String>) event type.<br/>
   * @param types The {string} or {Array<String>} of types on which to bind an event handler
   * @param eventHandle The function to execute when the event is triggered
   */
  public on(types: string[], eventHandle: (evt: Event, data: any) => void): void;
  public on(type: string, eventHandle: (evt: Event, data: any) => void): void;
  public on(type: any, eventHandle: (evt: Event, data: any) => void): void {
    if (isArray(type)) {
      each(type, (t: string) => {
        this.on(t, eventHandle);
      });
    } else {
      const modifiedType = this.processEventTypeToBeJQueryCompatible(type);
      const jq = JQueryUtils.getJQuery();
      if (this.shouldUseJQueryEvent()) {
        jq(this.el).on(modifiedType, eventHandle);
      } else if (this.el.addEventListener) {
        const fn = (e: CustomEvent) => {
          eventHandle(e, e.detail);
        };
        Dom.handlers.set(eventHandle, fn);
        // Mark touch events as passive for performance reasons:
        // https://github.com/WICG/EventListenerOptions/blob/gh-pages/explainer.md
        if (modifiedType && modifiedType.indexOf('touch') != -1) {
          this.el.addEventListener(modifiedType, fn, { passive: true });
        } else {
          this.el.addEventListener(modifiedType, fn, false);
        }
      } else if (this.el['on']) {
        this.el['on']('on' + modifiedType, eventHandle);
      }
    }
  }

  /**
   * Bind an event handler on the element. Accepts either one (a string) or multiple (Array<String>) event type.<br/>
   * The event handler will execute only ONE time.
   * @param types The {string} or {Array<String>} of types on which to bind an event handler
   * @param eventHandle The function to execute when the event is triggered
   */
  public one(types: string[], eventHandle: (evt: Event, args?: any) => void): void;
  public one(type: string, eventHandle: (evt: Event, args?: any) => void): void;
  public one(type: any, eventHandle: (evt: Event, args?: any) => void): void {
    if (isArray(type)) {
      each(type, (t: string) => {
        this.one(t, eventHandle);
      });
    } else {
      const modifiedType = this.processEventTypeToBeJQueryCompatible(type);
      const once = (e: Event, args: any) => {
        this.off(modifiedType, once);
        return eventHandle(e, args);
      };
      this.on(modifiedType, once);
    }
  }

  /**
   * Remove an event handler on the element. Accepts either one (a string) or multiple (Array<String>) event type.<br/>
   * @param types The {string} or {Array<String>} of types on which to remove an event handler
   * @param eventHandle The function to remove on the element
   */
  public off(types: string[], eventHandle: (evt: Event, arg?: any) => void): void;
  public off(type: string, eventHandle: (evt: Event, arg?: any) => void): void;
  public off(type: any, eventHandle: (evt: Event, arg?: any) => void): void {
    if (isArray(type)) {
      each(type, (t: string) => {
        this.off(t, eventHandle);
      });
    } else {
      const modifiedType = this.processEventTypeToBeJQueryCompatible(type);
      const jq = JQueryUtils.getJQuery();
      if (this.shouldUseJQueryEvent()) {
        jq(this.el).off(modifiedType, eventHandle);
      } else if (this.el.removeEventListener) {
        const handler = Dom.handlers.get(eventHandle);
        if (handler) {
          this.el.removeEventListener(modifiedType, handler, false);
        }
      } else if (this.el['off']) {
        this.el['off']('on' + modifiedType, eventHandle);
      }
    }
  }

  /**
   * Trigger an event on the element.
   * @param type The event type to trigger
   * @param data
   */
  public trigger(type: string, data?: { [key: string]: any }): void {
    const modifiedType = this.processEventTypeToBeJQueryCompatible(type);
    if (this.shouldUseJQueryEvent()) {
      JQueryUtils.getJQuery()(this.el).trigger(modifiedType, data);
    } else if (window['CustomEvent'] !== undefined) {
      const event = new CustomEvent(modifiedType, { detail: data, bubbles: true });
      this.el.dispatchEvent(event);
    } else {
      try {
        this.el.dispatchEvent(this.buildIE11CustomEvent(modifiedType, data));
      } catch {
        this.oldBrowserError();
      }
    }
  }

  /**
   * Check if the element is "empty" (has no innerHTML content). Whitespace is considered empty</br>
   * @returns {boolean}
   */
  public isEmpty(): boolean {
    return Dom.ONLY_WHITE_SPACE_REGEX.test(this.el.innerHTML);
  }

  /**
   * Check if the element is not a locked node (`{ toString(): string }`) and thus have base element properties.
   * @returns {boolean}
   */
  public isValid(): boolean {
    return this.el != null && this.el.getAttribute != undefined;
  }

  /**
   * Check if the element is a descendant of parent
   * @param other
   */
  public isDescendant(parent: HTMLElement): boolean {
    let node = this.el.parentNode;
    while (node != null) {
      if (node == parent) {
        return true;
      }
      node = node.parentNode;
    }
    return false;
  }

  /**
   * Replace the current element with the other element, then detach the current element
   * @param otherElem
   */
  public replaceWith(otherElem: HTMLElement): void {
    const parent = this.el.parentNode;
    if (parent) {
      new Dom(otherElem).insertAfter(this.el);
    }
    this.detach();
  }

  // based on http://api.jquery.com/position/
  /**
   * Return the position relative to the offset parent.
   */
  public position(): IOffset {
    const offsetParent = this.offsetParent();
    const offset = this.offset();
    let parentOffset: IOffset = { top: 0, left: 0 };

    if (!$$(offsetParent).is('html')) {
      parentOffset = $$(offsetParent).offset();
    }

    let borderTopWidth = parseInt($$(offsetParent).css('borderTopWidth'));
    let borderLeftWidth = parseInt($$(offsetParent).css('borderLeftWidth'));
    borderTopWidth = isNaN(borderTopWidth) ? 0 : borderTopWidth;
    borderLeftWidth = isNaN(borderLeftWidth) ? 0 : borderLeftWidth;

    parentOffset = {
      top: parentOffset.top + borderTopWidth,
      left: parentOffset.left + borderLeftWidth
    };

    let marginTop = parseInt(this.css('marginTop'));
    let marginLeft = parseInt(this.css('marginLeft'));
    marginTop = isNaN(marginTop) ? 0 : marginTop;
    marginLeft = isNaN(marginLeft) ? 0 : marginLeft;

    return {
      top: offset.top - parentOffset.top - marginTop,
      left: offset.left - parentOffset.left - marginLeft
    };
  }

  // based on https://api.jquery.com/offsetParent/
  /**
   * Returns the offset parent. The offset parent is the closest parent that is positioned.
   * An element is positioned when its position property is not 'static', which is the default.
   */
  public offsetParent(): HTMLElement {
    let offsetParent = this.el.offsetParent;

    while (offsetParent instanceof HTMLElement && $$(offsetParent).css('position') === 'static') {
      // Will break out if it stumbles upon an non-HTMLElement and return documentElement
      offsetParent = (<HTMLElement>offsetParent).offsetParent;
    }

    if (!(offsetParent instanceof HTMLElement)) {
      return document.documentElement;
    }
    return <HTMLElement>offsetParent;
  }

  // based on http://api.jquery.com/offset/
  /**
   * Return the position relative to the document.
   */
  public offset(): IOffset {
    // In <=IE11, calling getBoundingClientRect on a disconnected node throws an error
    if (!this.el.getClientRects().length) {
      return { top: 0, left: 0 };
    }

    const rect = this.el.getBoundingClientRect();

    if (rect.width || rect.height) {
      let doc = this.el.ownerDocument;
      let docElem = doc.documentElement;

      return {
        top: rect.top + window.pageYOffset - docElem.clientTop,
        left: rect.left + window.pageXOffset - docElem.clientLeft
      };
    }
    return rect;
  }

  /**
   * Returns the offset width of the element
   */
  public width(): number {
    return this.el.offsetWidth;
  }

  /**
   * Returns the offset height of the element
   */
  public height(): number {
    return this.el.offsetHeight;
  }

  /**
   * Clone the node
   * @param deep true if the children of the node should also be cloned, or false to clone only the specified node.
   * @returns {Dom}
   */
  public clone(deep = false): Dom {
    return $$(<HTMLElement>this.el.cloneNode(deep));
  }

  /**
   * Determine if an element support a particular native DOM event.
   * @param eventName The event to evaluate. Eg: touchstart, touchend, click, scroll.
   */
  public canHandleEvent(eventName: string): boolean {
    const eventToEvaluate = `on${eventName}`;
    let isSupported = eventToEvaluate in this.el;

    // This is a protection against false negative.
    // Some browser will incorrectly report that the event is not supported at this point
    // To make sure, we need to try and set a fake function as a property on the element,
    // and then check if it got hooked properly as a 'function' or as something else, meaning
    // the property is really not defined on the element.
    if (!isSupported && this.el.setAttribute) {
      this.el.setAttribute(eventToEvaluate, 'return;');
      isSupported = typeof this.el[eventToEvaluate] == 'function';
      this.el.removeAttribute(eventToEvaluate);
    }

    return isSupported;
  }

  private buildIE11CustomEvent(type: string, data?: { [key: string]: any }) {
    const event = document.createEvent('CustomEvent');
    event.initCustomEvent(type, true, true, data);
    return event;
  }

  private shouldUseJQueryEvent() {
    return JQueryUtils.getJQuery() && !Dom.useNativeJavaScriptEvents;
  }

  private processEventTypeToBeJQueryCompatible(event: string): string {
    // From https://api.jquery.com/on/
    // [...]
    // > In addition, the .trigger() method can trigger both standard browser event names and custom event names to call attached handlers. Event names should only contain alphanumerics, underscore, and colon characters.
    if (event) {
      return event.replace(/[^a-zA-Z0-9\:\_]/g, '');
    }
    return event;
  }

  private traverseAncestorForClass(current = this.el, className: string): HTMLElement {
    if (className.indexOf('.') == 0) {
      className = className.substr(1);
    }
    let found = false;
    while (!found) {
      if ($$(current).hasClass(className)) {
        found = true;
      }
      if (current.tagName.toLowerCase() == 'body') {
        break;
      }
      if (current.parentElement == null) {
        break;
      }
      if (!found) {
        current = current.parentElement;
      }
    }
    if (found) {
      return current;
    }
    return undefined;
  }

  private oldBrowserError() {
    new Logger(this).error('CANNOT TRIGGER EVENT FOR OLDER BROWSER');
  }
}

export class Win {
  constructor(public win: Window) {}

  public height(): number {
    return this.win.innerHeight;
  }

  public width(): number {
    return this.win.innerWidth;
  }

  public scrollY(): number {
    return this.supportPageOffset()
      ? this.win.pageYOffset
      : this.isCSS1Compat()
      ? this.win.document.documentElement.scrollTop
      : this.win.document.body.scrollTop;
  }

  public scrollX(): number {
    return this.supportPageOffset()
      ? window.pageXOffset
      : this.isCSS1Compat()
      ? document.documentElement.scrollLeft
      : document.body.scrollLeft;
  }

  private isCSS1Compat() {
    return (this.win.document.compatMode || '') === 'CSS1Compat';
  }

  private supportPageOffset() {
    return this.win.pageXOffset !== undefined;
  }
}

export class Doc {
  constructor(public doc: Document) {}

  public height(): number {
    const body = this.doc.body;
    return Math.max(body.scrollHeight, body.offsetHeight);
  }

  public width(): number {
    const body = this.doc.body;
    return Math.max(body.scrollWidth, body.offsetWidth);
  }
}

/**
 * Convenience wrapper for the {@link Dom} class. Used to do $$(element).<br/>
 * If passed with an argument which is not an HTMLElement, it will call {@link Dom.createElement}.
 * @param el The HTMLElement to wrap in a Dom object
 * @param type See {@link Dom.createElement}
 * @param props See {@link Dom.createElement}
 * @param ...children See {@link Dom.createElement}
 */
export function $$(dom: Dom): Dom;
export function $$(html: HTMLElement): Dom;
export function $$(type: string, props?: IStringMap<any>, ...children: Array<string | HTMLElement | Dom>): Dom;
export function $$(...args: any[]): Dom {
  if (args.length === 1 && args[0] instanceof Dom) {
    return args[0];
  } else if (args.length === 1 && !isString(args[0])) {
    return new Dom(<HTMLElement>args[0]);
  } else {
    return new Dom(Dom.createElement.apply(Dom, args));
  }
}