import type { OnPageTransitionEndAsync, PageContext } from "vike/types";

import { buildPublicUrl } from "@/buildPublicUrl";
import NProgress from "nprogress";

export const onPageTransitionEnd: OnPageTransitionEndAsync = async (
	pageContext,
) => {
	NProgress.done();
	NProgress.remove();

	updateCanonicalTag(pageContext);
};

const updateCanonicalTag = (pageContext: PageContext) => {
	const canonicalTag = findOrCreateCanonicalTag();
	const canonicalUrl = buildPublicUrl(
		pageContext,
		pageContext.urlParsed.pathname,
	);

	canonicalTag.href = canonicalUrl;
};

const findOrCreateCanonicalTag = () => {
	const head = document.head;
	let canonicalTag: HTMLLinkElement | null = head.querySelector(
		"link[rel=canonical]",
	);
	if (canonicalTag) return canonicalTag;

	canonicalTag = document.createElement("link");
	canonicalTag.rel = "canonical";

	document.head.appendChild(canonicalTag);

	return canonicalTag;
};