/*
	GoToSocial
	Copyright (C) GoToSocial Authors admin@gotosocial.org
	SPDX-License-Identifier: AGPL-3.0-or-later

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.

	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
	GNU Affero General Public License for more details.

	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

const isValidDomain = require("is-valid-domain");
const psl = require("psl");

function isValidDomainBlock(domain) {
	return isValidDomain(domain, {
		/* 
			Wildcard prefix *. can be stripped since it's equivalent to not having it,
			but wildcard anywhere else in the domain is not handled by the backend so it's invalid.
		*/
		wildcard: false,
		allowUnicode: true
	});
}

/* 
	Still can't think of a better function name for this,
	but we're checking a domain against the Public Suffix List <https://publicsuffix.org/>
	to see if we should suggest removing subdomain(s) since they're likely owned/ran by the same party
	social.example.com -> suggests example.com
*/
function hasBetterScope(domain) {
	const lookup = psl.get(domain);
	if (lookup && lookup != domain) {
		return lookup;
	} else {
		return false;
	}
}

module.exports = { isValidDomainBlock, hasBetterScope };