<?php

define('SOA_VALUES', [
	'ttl' => 10800,
	'email' => CONF['ns']['public_soa_email'],
	'refresh' => 10800,
	'retry' => 3600,
	'expire' => 3628800,
	'negative' => 10800,
]);

define('MIN_TTL', 300);
define('DEFAULT_TTL', 10800);
define('MAX_TTL', 1728000);

define('ALLOWED_TYPES', ['AAAA', 'A', 'TXT', 'SRV', 'MX', 'SVCB', 'HTTPS', 'NS', 'DS', 'CAA', 'CNAME', 'DNAME', 'LOC', 'SSHFP', 'TLSA']);

define('ZONE_MAX_CHARACTERS', 10000);

function nsCommonRequirements() {
	return (isset($_POST['action'])
		AND isset($_POST['zone'])
		AND isset($_POST['ttl-value'])
		AND isset($_POST['ttl-multiplier'])
		AND isset($_SESSION['id'])
	);
}

function nsParseCommonRequirements() {
	nsCheckZonePossession($_POST['zone']);

	if (($_POST['subdomain'] === '') OR ($_POST['subdomain'] === '@'))
		$values['domain'] = $_POST['zone'];
	else
		$values['domain'] = formatAbsoluteDomain(formatEndWithDot($_POST['subdomain']) . $_POST['zone']);

	$values['ttl'] = $_POST['ttl-value'] * $_POST['ttl-multiplier'];

	if ($values['ttl'] < MIN_TTL)
		output(403, sprintf(_('TTLs shorter than %s seconds are forbidden.'), MIN_TTL));
	if ($values['ttl'] > MAX_TTL)
		output(403, sprintf(_('TTLs longer than %s seconds are forbidden.'), MAX_TTL));

	return $values;
}

function nsListUserZones() {
	if (isset($_SESSION['id']))
		return query('select', 'zones', ['username' => $_SESSION['id']], 'zone');
	return [];
}

function nsCheckZonePossession($zone) {
	checkAbsoluteDomainFormat($zone);

	if (!in_array($zone, nsListUserZones(), true))
		output(403, 'You don\'t own this zone on the name server.');
}

function nsDeleteZone($zone) {
	// Remove from Knot configuration
	knotcConfExec(["unset 'zone[$zone]'"]);

	// Remove Knot zone file
	if (unlink(CONF['ns']['knot_zones_path'] . '/' . $zone . 'zone') !== true)
		output(500, 'Failed to remove Knot zone file.');

	// Remove Knot related data
	exec(CONF['dns']['knotc_path'] . ' zone-purge ' . $zone);

	// Remove from database
	query('delete', 'zones', [
		'zone' => $zone,
		'username' => $_SESSION['id'],
	]);
}