import * as PropertySymbol from '../../PropertySymbol.js';
import SVGAnimatedEnumeration from '../../svg/SVGAnimatedEnumeration.js';
import SVGAnimatedString from '../../svg/SVGAnimatedString.js';
import SVGAnimatedTransformList from '../../svg/SVGAnimatedTransformList.js';
import SVGGraphicsElement from '../svg-graphics-element/SVGGraphicsElement.js';

/**
 * SVG Gradient Element.
 *
 * @see https://developer.mozilla.org/en-US/docs/Web/API/SVGGradientElement
 */
export default class SVGGradientElement extends SVGGraphicsElement {
	// Public static properties
	public static readonly SVG_SPREADMETHOD_UNKNOWN = 0;
	public static readonly SVG_SPREADMETHOD_PAD = 1;
	public static readonly SVG_SPREADMETHOD_REFLECT = 2;
	public static readonly SVG_SPREADMETHOD_REPEAT = 3;

	// Internal properties
	public [PropertySymbol.href]: SVGAnimatedString | null = null;
	public [PropertySymbol.gradientUnits]: SVGAnimatedEnumeration | null = null;
	public [PropertySymbol.gradientTransform]: SVGAnimatedTransformList | null = null;
	public [PropertySymbol.spreadMethod]: SVGAnimatedEnumeration | null = null;

	/**
	 * Returns href.
	 *
	 * @returns Href.
	 */
	public get href(): SVGAnimatedString {
		if (!this[PropertySymbol.href]) {
			this[PropertySymbol.href] = new SVGAnimatedString(
				PropertySymbol.illegalConstructor,
				this[PropertySymbol.window],
				{
					getAttribute: () => this.getAttribute('href'),
					setAttribute: (value) => this.setAttribute('href', value)
				}
			);
		}
		return this[PropertySymbol.href];
	}

	/**
	 * Returns gradient units.
	 *
	 * @returns Gradient units.
	 */
	public get gradientUnits(): SVGAnimatedEnumeration {
		if (!this[PropertySymbol.gradientUnits]) {
			this[PropertySymbol.gradientUnits] = new SVGAnimatedEnumeration(
				PropertySymbol.illegalConstructor,
				this[PropertySymbol.window],
				{
					getAttribute: () => this.getAttribute('gradientUnits'),
					setAttribute: (value) => this.setAttribute('gradientUnits', value),
					values: ['userSpaceOnUse', 'objectBoundingBox'],
					defaultValue: 'objectBoundingBox'
				}
			);
		}
		return this[PropertySymbol.gradientUnits];
	}

	/**
	 * Returns gradient transform.
	 *
	 * @returns Gradient transform.
	 */
	public get gradientTransform(): SVGAnimatedTransformList {
		if (!this[PropertySymbol.gradientTransform]) {
			this[PropertySymbol.gradientTransform] = new SVGAnimatedTransformList(
				PropertySymbol.illegalConstructor,
				this[PropertySymbol.window],
				{
					getAttribute: () => this.getAttribute('gradientTransform'),
					setAttribute: (value) => this.setAttribute('gradientTransform', value)
				}
			);
		}
		return this[PropertySymbol.gradientTransform];
	}

	/**
	 * Returns spread method.
	 *
	 * @returns Spread method.
	 */
	public get spreadMethod(): SVGAnimatedEnumeration {
		if (!this[PropertySymbol.spreadMethod]) {
			this[PropertySymbol.spreadMethod] = new SVGAnimatedEnumeration(
				PropertySymbol.illegalConstructor,
				this[PropertySymbol.window],
				{
					getAttribute: () => this.getAttribute('spreadMethod'),
					setAttribute: (value) => this.setAttribute('spreadMethod', value),
					values: ['pad', 'reflect', 'repeat'],
					defaultValue: 'pad'
				}
			);
		}
		return this[PropertySymbol.spreadMethod];
	}
}