/** @file Url normalize module. */
import { COMMON_TRACKING_QUERY_PARAMS } from "../defaults.ts";

export interface NormalizeUrlOptions {
	stripTrackingParams?: boolean;
	stripFragment?: boolean;
	trimTrailingSlash?: boolean;
}

const TRACKING_PARAMS = new Set(COMMON_TRACKING_QUERY_PARAMS.map((param) => param.toLowerCase()));

export function normalizeUrl(input: string | URL, options: NormalizeUrlOptions = {}): string {
	const { stripTrackingParams = true, stripFragment = true, trimTrailingSlash = true } = options;
	const url = new URL(input.toString());

	url.protocol = url.protocol.toLowerCase();
	url.hostname = url.hostname.toLowerCase();

	if (isDefaultPort(url.protocol, url.port)) {
		url.port = "";
	}

	if (stripFragment) {
		url.hash = "";
	}

	const sortedParams = [...url.searchParams.entries()]
		.filter(([key]) => !stripTrackingParams || !TRACKING_PARAMS.has(key.toLowerCase()))
		.toSorted(([leftKey, leftValue], [rightKey, rightValue]) => {
			const keyOrder = leftKey.localeCompare(rightKey);
			return keyOrder === 0 ? leftValue.localeCompare(rightValue) : keyOrder;
		});
	url.search = "";
	for (const [key, value] of sortedParams) {
		url.searchParams.append(key, value);
	}

	if (trimTrailingSlash && url.pathname.length > 1) {
		url.pathname = url.pathname.replace(/\/+$/u, "") || "/";
	}

	return url.toString();
}

function isDefaultPort(protocol: string, port: string): boolean {
	return (protocol === "http:" && port === "80") || (protocol === "https:" && port === "443");
}