ops-Gazelle/app/Manager/Subscription.php

<?php

namespace Gazelle\Manager;

use Gazelle\ForumThread;

class Subscription extends \Gazelle\Base {
    /**
     * For all subscribers of a forum thread or artist/collage/request/torrent comments, clear
     *   - subscription cache
     *   - quote notification
     * @param string $Page 'forums', 'artist', 'collages', 'requests' or 'torrents'
     * @param int $PageID, ID of the above
     * @return int total number of cache expiries
     */
    public function flushPage(string $Page, int $PageID): int {
        $qid = self::$db->get_query_id();
        if ($Page === 'forums') {
            self::$db->prepared_query('
                SELECT UserID FROM users_subscriptions WHERE TopicID = ?
                ', $PageID
            );
        } else {
            self::$db->prepared_query('
                SELECT UserID FROM users_subscriptions_comments WHERE Page = ?  AND PageID = ?
                ', $Page, $PageID
            );
        }

        $list = self::$db->collect('UserID');
        $affected = count($list);
        self::$cache->delete_multi(array_map(fn($id) => "subscriptions_user_new_$id", $list));

        self::$db->prepared_query('
            SELECT UserID FROM users_notify_quoted WHERE Page = ?  AND PageID = ?
            ', $Page, $PageID
        );
        $list = self::$db->collect('UserID');

        foreach ($list as $userId) {
            new \Gazelle\User\Quote(new \Gazelle\User($userId))->flush();
        }

        self::$db->set_query_id($qid);
        return $affected + count($list);
    }

    /**
     * For all subscribers of a forum thread, clear
     *   - subscription cache
     *   - quote notification
     * @return int total number of cache expiries
     */
    public function flushThread(ForumThread $thread): int {
        self::$db->prepared_query('
            SELECT UserID FROM users_subscriptions WHERE TopicID = ?
            ', $thread->id
        );
        $list = self::$db->collect('UserID');
        $affected = count($list);
        self::$cache->delete_multi(
            array_map(
                fn ($id) => "subscriptions_user_new_$id",
                $list
            )
        );

        self::$db->prepared_query("
            SELECT UserID FROM users_notify_quoted WHERE Page = ?  AND PageID = ?
            ", 'forums', $thread->id
        );
        foreach (self::$db->collect('UserID') as $userId) {
            ++$affected;
            new \Gazelle\User\Quote(new \Gazelle\User($userId))->flush();
        }
        return $affected;
    }

    /**
     * Move all $Page subscriptions from $OldPageID to $NewPageID (for example when merging torrent groups).
     * @param string $Page 'artist', 'collages', 'requests' or 'torrents'
     */
    public function move(string $Page, int $OldPageID, ?int $NewPageID): int {
        if ($NewPageID !== null) {
            self::$db->prepared_query('
                UPDATE IGNORE users_subscriptions_comments SET
                    PageID = ?
                WHERE Page = ?
                    AND PageID = ?
                ', $NewPageID, $Page, $OldPageID
            );
            // last read handling
            // 1) update all rows that have no key collisions (i.e. users that haven't previously read both pages or if there are only comments on one page)
            self::$db->prepared_query('
                UPDATE IGNORE users_comments_last_read SET
                    PageID = ?
                WHERE Page = ?
                    AND PageID = ?
                ', $NewPageID, $Page, $OldPageID
            );
            // 2) get all last read records with key collisions (i.e. there are records for one user for both PageIDs)
            self::$db->prepared_query('
                SELECT UserID, min(PostID)
                FROM users_comments_last_read
                WHERE Page = ?
                    AND PageID IN (?, ?)
                GROUP BY UserID
                HAVING count(1) = 2
                ', $Page, $OldPageID, $NewPageID
            );
            $Results = self::$db->to_array(false, MYSQLI_NUM);
            // 3) update rows for those people found in 2) to the earlier post
            foreach ($Results as $Result) {
                self::$db->prepared_query('
                    UPDATE users_comments_last_read SET
                        PostID = ?
                    WHERE Page = ?
                        AND PageID = ?
                        AND UserID = ?
                    ', $Result[1], $Page, $NewPageID, $Result[0]
                );
            }
        }
        self::$db->prepared_query('
            DELETE FROM users_subscriptions_comments
            WHERE Page = ?
                AND PageID = ?
            ', $Page, $OldPageID
        );
        self::$db->prepared_query('
            DELETE FROM users_comments_last_read
            WHERE Page = ?
                AND PageID = ?
            ', $Page, $OldPageID
        );
        return $this->flushPage($Page, $OldPageID);
    }

    /**
     * Move all forum subscriptions from $source to $target (for example when merging torrent groups).
     */
    public function moveThread(ForumThread $source, ?ForumThread $target): int {
        if ($target !== null) {
            self::$db->prepared_query('
                UPDATE IGNORE users_subscriptions SET
                    TopicID = ?
                WHERE TopicID = ?
                ', $target->id, $source->id
            );
            // explanation see below
            self::$db->prepared_query('
                UPDATE IGNORE forums_last_read_topics SET
                    TopicID = ?
                WHERE TopicID = ?
                ', $target->id, $source->id
            );
            self::$db->prepared_query('
                SELECT UserID   AS user_id,
                    min(PostID) AS first
                FROM forums_last_read_topics
                WHERE TopicID IN (?, ?)
                GROUP BY UserID
                HAVING COUNT(*) = 2
                ', $target->id, $source->id
            );
            foreach (self::$db->to_array(false, MYSQLI_ASSOC) as $row) {
                self::$db->prepared_query('
                    UPDATE forums_last_read_topics SET
                        PostID = ?
                    WHERE TopicID = ?
                        AND UserID = ?
                    ', $row['first'], $target->id, $row['user_id']
                );
            }
        }
        self::$db->prepared_query('
            DELETE FROM users_subscriptions WHERE TopicID = ?
            ', $source->id
        );
        self::$db->prepared_query("
            DELETE FROM forums_last_read_topics WHERE TopicID = ?
            ", $source->id
        );
        return $this->flushThread($source);
    }
}