import HTMLElement from '../html-element/HTMLElement';
import IHTMLElement from '../html-element/IHTMLElement';
import IHTMLFormElement from '../html-form-element/IHTMLFormElement';
import IHTMLLabelElement from './IHTMLLabelElement';

/**
 * HTML Label Element.
 *
 * Reference:
 * https://developer.mozilla.org/en-US/docs/Web/API/HTMLLabelElement.
 */
export default class HTMLLabelElement extends HTMLElement implements IHTMLLabelElement {
	/**
	 * Returns a string containing the ID of the labeled control. This reflects the "for" attribute.
	 *
	 * @returns ID of the labeled control.
	 */
	public get htmlFor(): string {
		const htmlFor = this.getAttributeNS(null, 'for');
		if (htmlFor !== null) {
			return htmlFor;
		}
		return htmlFor !== null ? htmlFor : '';
	}

	/**
	 * Sets a string containing the ID of the labeled control. This reflects the "for" attribute.
	 *
	 * @param htmlFor ID of the labeled control.
	 */
	public set htmlFor(htmlFor: string) {
		this.setAttributeNS(null, 'for', htmlFor);
	}

	/**
	 * Returns an HTML element representing the control with which the label is associated.
	 *
	 * @returns Control element.
	 */
	public get control(): IHTMLElement {
		const htmlFor = this.htmlFor;
		if (htmlFor) {
			return <IHTMLElement>this.ownerDocument.getElementById(htmlFor);
		}
		for (const child of this.children) {
			if (child.tagName === 'INPUT') {
				return <IHTMLElement>child;
			}
		}
		return null;
	}

	/**
	 * Returns the parent form element.
	 *
	 * @returns Form.
	 */
	public get form(): IHTMLFormElement {
		let parent = <IHTMLElement>this.parentNode;
		while (parent && parent.tagName !== 'FORM') {
			parent = <IHTMLElement>parent.parentNode;
		}
		return <IHTMLFormElement>parent;
	}

	/**
	 * Clones a node.
	 *
	 * @override
	 * @param [deep=false] "true" to clone deep.
	 * @returns Cloned node.
	 */
	public cloneNode(deep = false): IHTMLLabelElement {
		return <HTMLLabelElement>super.cloneNode(deep);
	}
}