<?php

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

const MIN_TTL = 300;
const DEFAULT_TTL = 10800;
const MAX_TTL = 1728000;

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

const ZONE_MAX_CHARACTERS = 10000;

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

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

	$values['ttl'] = intval($_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(): array {
	if (isset($_SESSION['id']))
		return query('select', 'zones', ['username' => $_SESSION['id']], 'zone');
	return [];
}

function nsCheckZonePossession(string $zone): void {
	checkAbsoluteDomainFormat($zone);

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

function nsDeleteZone(string $zone, string $user_id): void {
	// Remove from Knot configuration
	knotcConfExec([['conf-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
	exescape([
		CONF['dns']['knotc_path'],
		'--blocking',
		'--timeout',
		'3',
		'--force',
		'--',
		'zone-purge',
		$zone,
		'+orphan',
	], result_code: $code);
	if ($code !== 0)
		output(500, 'Failed to purge zone data.');

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