"use strict";

const cheerio = require("cheerio");

const rewriteCssUrls = require("./rewrite-css-urls");

module.exports = function (body, rewriteUrl) {

	function patchAttribute(elements, attribute) {
		elements.get().forEach((element) => {
			let $element = $(element);

			let value = $element.attr(attribute);
			if (value != null) {
				$element.attr(attribute, rewriteUrl(value));
			}
		});
	}

	function removeAttribute(elements, attribute) {
		elements.get().forEach((element) => {
			let $element = $(element);

			$element.removeAttr(attribute);
		});
	}

	let $ = cheerio.load(body);

	patchAttribute($("a"), "href");
	patchAttribute($("img"), "src"); /* FIXME: Responsive versions? */
	patchAttribute($("link"), "href");
	patchAttribute($("script"), "src");
	patchAttribute($("form"), "action");
	patchAttribute($("iframe"), "src");
	patchAttribute($("source"), "src");

	/* NOTE: The below is necessary because we're rewriting the contents of CSS and potentially JS files, intentionally. TODO: In the future, just to be safe, we should actually verify the received content against the hashes first, before trying to forward the content to the user. */
	removeAttribute($("link"), "integrity");
	removeAttribute($("script"), "integrity");

	$("style").get().forEach((element) => {
		let $element = $(element);

		$element.text(rewriteCssUrls($element.text(), rewriteUrl));
	});

	$("*[style]").get().forEach((element) => {
		let $element = $(element);

		$element.attr("style", rewriteCssUrls($element.attr("style"), rewriteUrl));
	});

	return $.html();
};