export function ready(fn) {
	document.addEventListener('DOMContentLoaded', (e) => {
		fn();
	}, false);
}

export function closest(el, fn) {
	if (!el) {
		return null;
	}
	while (el) {
		if (fn(el)) {
			return el;
		}
		el = el.parentNode
	}
	return null;
}

export function withClass(className) {
	const els = document.getElementsByClassName(className);
	const arr = [];

	for (let i = 0; i < els.length; i++) {
		arr.push(els.item(i));
	}
	return arr;
}

export function firstChild(el, fn) {
	if (!el) {
		return null;
	}

	for (const child of el.childNodes) {
		if (child.nodeName === '#text') {
			continue;
		}
		if (fn(child)) {
			return child;
		}
	}
	return null;
}

export function next(el, fn) {
	if (!el) {
		return null;
	}
	el = el.nextSibling;
	while (el) {
		if (fn(el)) {
			return el;
		}
		el = el.nextSibling;
	}
	return null;
}

export function previous(el, fn) {
	if (!el) {
		return null;
	}
	el = el.previousSibling;
	while (el) {
		if (fn(el)) {
			return el;
		}
		el = el.previousSibling;
	}
	return null;
}