Gazelle/sections/forums/delete.php

<?
authorize();
// Quick SQL injection check
if(!isset($_GET['postid']) || !is_number($_GET['postid'])) { error(0); }
$PostID = $_GET['postid'];

// Make sure they are moderators
if(!check_perms('site_admin_forums')) {
	error(403);
}

// Get topicid, forumid, number of pages
$DB->query("SELECT 
	DISTINCT
	TopicID,
	ForumID,
	CEIL(
		(SELECT COUNT(ID) 
		FROM forums_posts 
		WHERE TopicID=p.TopicID)/".POSTS_PER_PAGE."
	) AS Pages,
	CEIL(
		(SELECT COUNT(ID) 
		FROM forums_posts 
		WHERE ID<'$PostID'
		AND TopicID=p.TopicID)/".POSTS_PER_PAGE."
	) AS Page
	FROM forums_posts AS p
	JOIN forums_topics AS t ON t.ID=p.TopicID
	WHERE p.TopicID=(SELECT TopicID FROM forums_posts WHERE ID='$PostID')");
list($TopicID, $ForumID, $Pages, $Page) = $DB->next_record();

// $Pages = number of pages in the thread
// $Page = which page the post is on
// These are set for cache clearing.

$DB->query("DELETE FROM forums_posts WHERE ID='$PostID'");

$DB->query("SELECT MAX(ID) FROM forums_posts WHERE TopicID='$TopicID'");
list($LastID) = $DB->next_record();
$DB->query("UPDATE forums AS f, forums_topics AS t SET f.NumPosts=f.NumPosts-1, t.NumPosts=t.NumPosts-1 WHERE f.ID='$ForumID' AND t.ID='$TopicID'");

if($LastID < $PostID) { // Last post in a topic was removed
	$DB->query("SELECT p.AuthorID, u.Username, p.AddedTime FROM forums_posts AS p LEFT JOIN users_main AS u ON u.ID = p.AuthorID WHERE p.ID='$LastID'");
	list($LastAuthorID, $LastAuthorName, $LastTime) = $DB->next_record();
	$DB->query("UPDATE forums_topics SET LastPostID='$LastID', LastPostAuthorID='$LastAuthorID', LastPostTime='$LastTime' WHERE ID='$TopicID'");
	$DB->query("SELECT
		t.ID, t.Title, t.LastPostID, t.LastPostTime, t.LastPostAuthorID, u.Username
		FROM forums_topics AS t
		LEFT JOIN users_main AS u ON u.ID = t.LastPostAuthorID
		WHERE ForumID='$ForumID' AND t.ID<>'$TopicID'
		ORDER BY LastPostID DESC LIMIT 1");
	list($LastTopicID, $LastTopicTitle, $LastTopicPostID, $LastTopicPostTime, $LastTopicAuthorID, $LastTopicAuthorName) = $DB->next_record(MYSQLI_BOTH, false);

	if($LastID < $LastTopicPostID) { // Topic is no longer the most recent in its forum
		$DB->query("UPDATE forums SET LastPostTopicID='$LastTopicID', LastPostID='$LastTopicPostID', LastPostAuthorID='$LastTopicAuthorID', LastPostTime='$LastTopicPostTime' WHERE ID='$ForumID' AND LastPostTopicID='$TopicID'");
		$UpdateArrayForums = array(
			'NumPosts' => '-1',
			'LastPostID' => $LastTopicPostID,
			'LastPostAuthorID' => $LastTopicAuthorID,
			'LastPostTime' => $LastTopicPostTime,
			'LastPostTopicID' => $LastTopicID,
			'Title' => $LastTopicTitle);
	} else { // Topic is still the most recent in its forum
		$DB->query("UPDATE forums SET LastPostID='$LastID', LastPostAuthorID='$LastAuthorID', LastPostTime='$LastTime' WHERE ID='$ForumID' AND LastPostTopicID='$TopicID'");
		$UpdateArrayForums = array(
			'NumPosts' => '-1',
			'LastPostID' => $LastID,
			'LastPostAuthorID' => $LastAuthorID,
			'LastPostTime' => $LastTime);
	}
	$UpdateArrayThread = array('Posts' => '-1', 'LastPostAuthorID' => $LastAuthorID);
} else {
	$UpdateArrayForums = array('NumPosts' => '-1');
	$UpdateArrayThread = array('Posts' => '-1');
}

//We need to clear all subsequential catalogues as they've all been bumped with the absence of this post
$ThisCatalogue = floor((POSTS_PER_PAGE*$Page-POSTS_PER_PAGE)/THREAD_CATALOGUE);
$LastCatalogue = floor((POSTS_PER_PAGE*$Pages-POSTS_PER_PAGE)/THREAD_CATALOGUE);
for($i=$ThisCatalogue;$i<=$LastCatalogue;$i++) {
	$Cache->delete('thread_'.$TopicID.'_catalogue_'.$i);
}

$Cache->begin_transaction('thread_'.$TopicID.'_info');
$Cache->update_row(false, $UpdateArrayThread);
$Cache->commit_transaction();

$Cache->begin_transaction('forums_list');
$Cache->update_row($ForumID, $UpdateArrayForums);
$Cache->commit_transaction();

$Cache->delete('forums_'.$ForumID);
?>