<?php declare(strict_types=1);

$el_nb = count($_POST['syncs']);
if ($el_nb < 1 OR $el_nb > 8)
	output(403, 'Wrong elements number.');

foreach ($_POST['syncs'] as $i => &$sync) {
	if (($sync['source'] ?? '') === '') {
		unset($_POST['syncs'][$i]);
		continue;
	}
	$sync['source'] = formatAbsoluteDomain($sync['source']);
	nsCheckZonePossession($sync['destination']);
}
$new_syncs = array_values($_POST['syncs']);

$new_destinations = array_column($new_syncs, 'destination');
if (count($new_destinations) !== count(array_unique($new_destinations)))
	output(403, _('Multiple source domains can\'t be applied to the same target domain.'));

rateLimit();

$current_syncs = query('select', 'ns-syncs', ['username' => $_SESSION['id']], ['source', 'destination']);

try {
	foreach ($new_syncs as $new_sync)
		if (!in_array($new_sync, $current_syncs))
			nsSync($new_sync['source'], $new_sync['destination']);
} catch (KdigException | NoDnssecException $e) {
	output(403, $e->getMessage() . LF);
}

try {
	DB->beginTransaction();

	foreach ($current_syncs as $current_sync) // Deletions
		if (!in_array($current_sync, $new_syncs))
			query('delete', 'ns-syncs', [
				'username' => $_SESSION['id'],
				'source' => $current_sync['source'],
				'destination' => $current_sync['destination'],
			]);
	foreach ($new_syncs as $new_sync) // Adds
		if (!in_array($new_sync, $current_syncs))
			insert('ns-syncs', [
				'username' => $_SESSION['id'],
				'source' => $new_sync['source'],
				'destination' => $new_sync['destination'],
			]);

	DB->commit();
} catch (Exception $e) {
	DB->rollback();
	output(500, 'Database error.', [$e->getMessage()]);
}

output(200, _('Synchronized records updated.'));