<?
authorize();

if (!check_perms('torrents_edit')) { error(403); }
if (!empty($_POST['newartistid']) && !empty($_POST['newartistname'])) {
	error("Please enter either an artist id OR an artist name.");
}
$ArtistID = (int)$_POST['artistid'];
$NewArtistID = (int)$_POST['newartistid'];
$NewArtistName = $_POST['newartistname'];


if (!is_number($ArtistID) || !$ArtistID) {
	error('Please select a valid artist to change.');
}
if (empty($NewArtistName) && (!$NewArtistID || !is_number($NewArtistID))) {
	error('Please enter a valid artist ID number or a valid artist name.');
}

$DB->query("SELECT Name FROM artists_group WHERE ArtistID = $ArtistID LIMIT 1");
if(!(list($ArtistName) = $DB->next_record())) {
	error('An error has occured.');
}

if ($NewArtistID > 0) {
	// Make sure that's a real artist id number, and grab the name
	$DB->query("SELECT Name FROM artists_group WHERE ArtistID = $NewArtistID LIMIT 1");	
	if(!(list($NewArtistName) = $DB->next_record())) {
		error('Please enter a valid artist ID number.');
	}
} else {
	// Didn't give an ID, so try to grab based on the name
	$DB->query("SELECT ArtistID FROM artists_alias WHERE Name = '".db_string($NewArtistName)."' LIMIT 1");	
	if(!(list($NewArtistID) = $DB->next_record())) {
		error('No artist by that name was found.');
	}
}

if ($ArtistID == $NewArtistID) {
	error("You cannot merge an artist with himself.");
}
if (isset($_POST['confirm'])) {
	// Get the information for the cache update
	$DB->query("SELECT DISTINCT GroupID FROM torrents_artists WHERE ArtistID = $ArtistID");
	$Groups = $DB->collect('GroupID');
	$DB->query("SELECT DISTINCT RequestID FROM requests_artists WHERE ArtistID = $ArtistID");
	$Requests = $DB->collect('RequestID');
	$DB->query("SELECT DISTINCT UserID FROM bookmarks_artists WHERE ArtistID = $ArtistID");
	$BookmarkUsers = $DB->collect('UserID');
	$DB->query("SELECT DISTINCT ct.CollageID
				FROM collages_torrents AS ct
				JOIN torrents_artists AS ta ON ta.GroupID = ct.GroupID
				WHERE ta.ArtistID = $ArtistID");
	$Collages = $DB->collect('CollageID');

	// And the info to avoid double-listing an artist if it and the target are on the same group
	$DB->query("SELECT DISTINCT GroupID FROM torrents_artists WHERE ArtistID = $NewArtistID");
	$NewArtistGroups = $DB->collect('GroupID');
	$NewArtistGroups[] = '0';
	$NewArtistGroups = implode(',',$NewArtistGroups);
	
	$DB->query("SELECT DISTINCT RequestID FROM requests_artists WHERE ArtistID = $NewArtistID");
	$NewArtistRequests = $DB->collect('RequestID');
	$NewArtistRequests[] = '0';
	$NewArtistRequests = implode(',',$NewArtistRequests);
	
	$DB->query("SELECT DISTINCT UserID from bookmarks_artists WHERE ArtistID = $NewArtistID");
	$NewArtistBookmarks = $DB->collect('UserID');
	$NewArtistBookmarks[] = '0';
	$NewArtistBookmarks = implode(',',$NewArtistBookmarks);				
	
	// Merge all of this artist's aliases onto the new artist
	$DB->query("UPDATE artists_alias SET ArtistID = $NewArtistID WHERE ArtistID = $ArtistID");
	
	// Update the torrent groups, requests, and bookmarks
	$DB->query("UPDATE IGNORE torrents_artists SET ArtistID = $NewArtistID
				WHERE ArtistID = $ArtistID 
				  AND GroupID NOT IN ($NewArtistGroups)");
	$DB->query("DELETE FROM torrents_artists WHERE ArtistID = $ArtistID");
	$DB->query("UPDATE IGNORE requests_artists SET ArtistID = $NewArtistID
				WHERE ArtistID = $ArtistID
				  AND RequestID NOT IN ($NewArtistRequests)");
	$DB->query("DELETE FROM requests_artists WHERE ArtistID = $ArtistID");
	$DB->query("UPDATE IGNORE bookmarks_artists SET ArtistID = $NewArtistID
				WHERE ArtistID = $ArtistID
				  AND UserID NOT IN ($NewArtistBookmarks)");
	$DB->query("DELETE FROM bookmarks_artists WHERE ArtistID = $ArtistID");
	
	// Cache clearing
	if(!empty($Groups)) {
		foreach($Groups as $GroupID) {
			$Cache->delete_value('groups_artists_'.$GroupID);
			update_hash($GroupID);
		}
	}
	if(!empty($Requests)) {
		foreach($Requests as $RequestID) {
			$Cache->delete_value('request_artist_'.$RequestID);
			update_sphinx_requests($RequestID);
		}
	}
	if(!empty($BookmarkUsers)) {
		foreach($BookmarkUsers as $UserID) {
			$Cache->delete_value('notify_artists_'.$UserID);
		}
	}
	if(!empty($Collages)) {
		foreach($Collages as $CollageID) {
			$Cache->delete_value('collage_'.$CollageID);
		}
	}

	$Cache->delete_value('artist_'.$ArtistID);
	$Cache->delete_value('artist_'.$NewArtistID);

	// Delete the old artist
	$DB->query("DELETE FROM artists_group WHERE ArtistID = $ArtistID");

	write_log("The artist ".$ArtistID." (".$ArtistName.") was made into a non-redirecting alias of artist ".$NewArtistID." (".$NewArtistName.") by user ".$LoggedUser['ID']." (".$LoggedUser['Username'].")");

	header("Location: artist.php?action=edit&artistid=$NewArtistID");
} else {
	show_header('Merging Artists');
?>
	<h2>Confirm merge</h2>
	<form action="artist.php" method="post">
		<input type="hidden" name="action" value="change_artistid" />
		<input type="hidden" name="auth" value="<?=$LoggedUser['AuthKey']?>" />
		<input type="hidden" name="artistid" value="<?=$ArtistID?>" />
		<input type="hidden" name="newartistid" value="<?=$NewArtistID?>" />
		<input type="hidden" name="confirm" value="1" />
		<div style="text-align: center;">
			<p>Please confirm that you wish to make <a href="artist.php?id=<?=$ArtistID?>"><?=display_str($ArtistName)?> (<?=$ArtistID?>)</a> into a non-redirecting alias of <a href="artist.php?id=<?=$NewArtistID?>"><?=display_str($NewArtistName)?> (<?=$NewArtistID?>)</a>.</p>
			<br>
			<input type="submit" value="Confirm" />
		</div>
	</form>
<?
	show_footer();
}
?>