Hydrilla

/**

 * SPDX-License-Identifier: CC0-1.0

 *

 * Library to convert youtube.com URLs to yewtu.be URLs.

 *

 * Copyright (C) 2021 Wojtek Kosior <koszko@koszko.org>

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the CC0 1.0 Universal License as published by

 * the Creative Commons Corporation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * CC0 1.0 Universal License for more details.

 */

function decode_query_options(url)

{

    const query_options = {};

    const match = /^[^?]*\?(.*)/.exec(url);

    if (!match)

	return query_options;

    for (const opt of match[1].split("&")) {

	const [key, val] =

	      /^([^=]*)=?(.*)/.exec(opt).splice(1, 2).map(decodeURIComponent);

	query_options[key] = val;

    }

    return query_options;

}

function encode_query_options(query_options)

{

    return Object.entries(query_options)

	.map(ar => ar.map(encodeURIComponent).join("=")).join("&");

}

function make_yewtube_url(youtube_url)

{

    const query_options = decode_query_options(youtube_url);

    let endpoint = "";

    const match = /^(?:(?:https?:)?\/\/)?[^/]*\/([^?]*)/.exec(youtube_url);

    if (match)

	endpoint = match[1];

    if (/^embed\//.test(query_options.v))

	endpoint = query_options.v;

    if (/^embed\/.+/.test(endpoint))

	delete query_options.v;

    const encoded_options = encode_query_options(query_options);

    return `https://yewtu.be/${endpoint}?${encoded_options}`;

}