/**
 * Adds css classes to a given element only if these classes are not already
 * present. Keeps a record of css classes which actually have been added.
 * This way, they can also be removed in a way which keeps the original classes
 * set by the user.
 * Most useful in attached() and detached() handlers.
 */
export class AttributeManager {
	constructor(private element: Element) { }

	colorClasses = ["accent", "primary"];
	addedClasses: string[] = [];
	addedAttributes: any = {};

	addAttributes(attrs) {
		let keys = Object.keys(attrs);
		keys.forEach(k => {
			if (!this.element.getAttribute(k)) {
				this.addedAttributes[k] = attrs[k];
				this.element.setAttribute(k, attrs[k]);
			} else if (this.element.getAttribute(k) !== attrs[k]) {
				this.element.setAttribute(k, attrs[k]);
			}
		});
	}

	removeAttributes(attrs) {
		if (typeof attrs === "string") {
			attrs = [attrs];
		}
		attrs.forEach(a => {
			if (this.element.getAttribute(a) && !!this.addedAttributes[a]) {
				this.element.removeAttribute(a);
				this.addedAttributes[a] = null;
				delete this.addedAttributes[a];
			}
		});
	}

	addClasses(classes) {
		if (typeof classes === "string") {
			classes = [classes];
		}
		classes.forEach(c => {
			let classListHasColor = this.colorClasses.filter(cc => this.element.classList.contains(cc)).length > 0;
			if (this.colorClasses.indexOf(c) > -1 && classListHasColor) {
				//
			} else {
				if (!this.element.classList.contains(c)) {
					this.addedClasses.push(c);
					this.element.classList.add(c);
				}
			}
		});
	}

	removeClasses(classes) {
		if (typeof classes === "string") {
			classes = [classes];
		}
		classes.forEach(c => {
			if (this.element.classList.contains(c) && this.addedClasses.indexOf(c) > -1) {
				this.element.classList.remove(c);
				this.addedClasses.splice(this.addedClasses.indexOf(c), 1);
			}
		});
	}
}