<?php

authorize();

$CollageID = $_POST['collageid'];
if (!is_number($CollageID)) {
	error(404);
}

$DB->query("SELECT UserID, CategoryID FROM collages WHERE ID='$CollageID'");
list($UserID, $CategoryID) = $DB->next_record();
if ($CategoryID == 0 && $UserID != $LoggedUser['ID'] && !check_perms('site_collages_delete')) {
	error(403);
}
if ($CategoryID != array_search(ARTIST_COLLAGE, $CollageCats)) {
	error(403);
}

$ArtistID = $_POST['artistid'];
if (!is_number($ArtistID)) {
	error(404);
}

if ($_POST['submit'] == 'Remove') {
	$DB->query("DELETE FROM collages_artists WHERE CollageID='$CollageID' AND ArtistID='$ArtistID'");
	$Rows = $DB->affected_rows();
	$DB->query("UPDATE collages SET NumTorrents=NumTorrents-$Rows WHERE ID='$CollageID'");
	$Cache->delete_value('artists_collages_'.$ArtistID);
	$Cache->delete_value('artists_collages_personal_'.$ArtistID);
} elseif (isset($_POST['drag_drop_collage_sort_order'])) {

	@parse_str($_POST['drag_drop_collage_sort_order'], $Series);
	$Series = @array_shift($Series);
	if (is_array($Series)) {
		$SQL = array();
		foreach ($Series as $Sort => $ArtistID) {
			if (is_number($Sort) && is_number($ArtistID)) {
				$Sort = ($Sort + 1) * 10;
				$SQL[] = sprintf('(%d, %d, %d)', $ArtistID, $Sort, $CollageID);
			}
		}

		$SQL = 'INSERT INTO collages_artists (ArtistID, Sort, CollageID) VALUES '
			. implode(', ', $SQL)
			. ' ON DUPLICATE KEY UPDATE Sort = VALUES (Sort)';

		$DB->query($SQL);
	}

} else {
	$Sort = $_POST['sort'];
	if (!is_number($Sort)) {
		error(404);
	}
	$DB->query("
		UPDATE collages_artists
		SET Sort='$Sort'
		WHERE CollageID='$CollageID'
			AND ArtistID='$ArtistID'");
}

$Cache->delete_value('collage_'.$CollageID);
header('Location: collages.php?action=manage_artists&collageid='.$CollageID);