Gazelle/classes/comments.class.php

<?php

class Comments
{
    /*
     * For all functions:
     * $Page = 'artist', 'collages', 'requests' or 'torrents'
     * $PageID = ArtistID, CollageID, RequestID or GroupID, respectively
     */

    /**
     * Post a comment on an artist, request or torrent page.
     * @param string $Page
     * @param int $PageID
     * @param string $Body
     * @return int ID of the new comment
     */
    public static function post($Page, $PageID, $Body)
    {
        $QueryID = G::$DB->get_query_id();
        G::$DB->query("
        SELECT
        CEIL(
          (
            SELECT COUNT(ID) + 1
            FROM comments
            WHERE Page = '$Page'
            AND PageID = $PageID
            ) / " . TORRENT_COMMENTS_PER_PAGE . "
          ) AS Pages");
        list($Pages) = G::$DB->next_record();

        G::$DB->query("
        INSERT INTO comments (Page, PageID, AuthorID, AddedTime, Body)
        VALUES ('$Page', $PageID, " . G::$LoggedUser['ID'] . ", NOW(), '" . db_string($Body) . "')");
        $PostID = G::$DB->inserted_id();

        $CatalogueID = floor((TORRENT_COMMENTS_PER_PAGE * $Pages - TORRENT_COMMENTS_PER_PAGE) / THREAD_CATALOGUE);
        G::$Cache->delete_value($Page.'_comments_'.$PageID.'_catalogue_'.$CatalogueID);
        G::$Cache->delete_value($Page.'_comments_'.$PageID);

        Subscriptions::flush_subscriptions($Page, $PageID);
        Subscriptions::quote_notify($Body, $PostID, $Page, $PageID);

        G::$DB->set_query_id($QueryID);
        return $PostID;
    }

    /**
     * Edit a comment
     * @param int $PostID
     * @param string $NewBody
     * @param bool $SendPM If true, send a PM to the author of the comment informing him about the edit
     *
     * todo: Move permission check out of here/remove hardcoded error(404)
     */
    public static function edit($PostID, $NewBody, $SendPM = false)
    {
        $QueryID = G::$DB->get_query_id();

        G::$DB->query("
        SELECT
          Body,
          AuthorID,
          Page,
          PageID,
          AddedTime
        FROM comments
          WHERE ID = $PostID");
        if (!G::$DB->has_results()) {
            return false;
        }
        list($OldBody, $AuthorID, $Page, $PageID, $AddedTime) = G::$DB->next_record();

        if (G::$LoggedUser['ID'] != $AuthorID && !check_perms('site_moderate_forums')) {
            return false;
        }

        G::$DB->query("
        SELECT CEIL(COUNT(ID) / " . TORRENT_COMMENTS_PER_PAGE . ") AS Page
        FROM comments
          WHERE Page = '$Page'
          AND PageID = $PageID
          AND ID <= $PostID");
        list($CommPage) = G::$DB->next_record();

        // Perform the update
        G::$DB->query("
        UPDATE comments
        SET
          Body = '" . db_string($NewBody) . "',
          EditedUserID = " . G::$LoggedUser['ID'] . ",
          EditedTime = NOW()
        WHERE ID = $PostID");

        // Update the cache
        $CatalogueID = floor((TORRENT_COMMENTS_PER_PAGE * $CommPage - TORRENT_COMMENTS_PER_PAGE) / THREAD_CATALOGUE);
        G::$Cache->delete_value($Page . '_comments_' . $PageID . '_catalogue_' . $CatalogueID);

        if ($Page == 'collages') {
            // On collages, we also need to clear the collage key (collage_$CollageID), because it has the comments in it... (why??)
            G::$Cache->delete_value('collage_' . $PageID);
        }

        G::$DB->query("
        INSERT INTO comments_edits (Page, PostID, EditUser, EditTime, Body)
        VALUES ('$Page', $PostID, " . G::$LoggedUser['ID'] . ", NOW(), '" . db_string($OldBody) . "')");

        G::$DB->set_query_id($QueryID);

        if ($SendPM && G::$LoggedUser['ID'] != $AuthorID) {
            // Send a PM to the user to notify them of the edit
            $PMSubject = "Your comment #$PostID has been edited";
            $PMurl = site_url()."comments.php?action=jump&postid=$PostID";
            $ProfLink = '[url='.site_url().'user.php?id='.G::$LoggedUser['ID'].']'.G::$LoggedUser['Username'].'[/url]';
            $PMBody = "One of your comments has been edited by $ProfLink: [url]{$PMurl}[/url]";
            Misc::send_pm($AuthorID, 0, $PMSubject, $PMBody);
        }

        return true; // todo: This should reflect whether or not the update was actually successful, e.g., by checking G::$DB->affected_rows after the UPDATE query
    }

    /**
     * Delete a comment
     * @param int $PostID
     */
    public static function delete($PostID)
    {
        $QueryID = G::$DB->get_query_id();
        // Get page, pageid
        G::$DB->query("SELECT Page, PageID FROM comments WHERE ID = $PostID");
        if (!G::$DB->has_results()) {
            // no such comment?
            G::$DB->set_query_id($QueryID);
            return false;
        }
        list($Page, $PageID) = G::$DB->next_record();

        // Get number of pages
        G::$DB->query("
        SELECT
          CEIL(COUNT(ID) / " . TORRENT_COMMENTS_PER_PAGE . ") AS Pages,
          CEIL(SUM(IF(ID <= $PostID, 1, 0)) / " . TORRENT_COMMENTS_PER_PAGE . ") AS Page
        FROM comments
          WHERE Page = '$Page'
          AND PageID = $PageID
        GROUP BY PageID");

        if (!G::$DB->has_results()) {
            // The comment $PostID was probably not posted on $Page
            G::$DB->set_query_id($QueryID);
            return false;
        }
        list($CommPages, $CommPage) = G::$DB->next_record();

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

        G::$DB->query("
        DELETE FROM comments
          WHERE ID = $PostID");

        G::$DB->query("
        DELETE FROM comments_edits
          WHERE Page = '$Page'
          AND PostID = $PostID");

        G::$DB->query("
        DELETE FROM users_notify_quoted
          WHERE Page = '$Page'
          AND PostID = $PostID");

        Subscriptions::flush_subscriptions($Page, $PageID);
        Subscriptions::flush_quote_notifications($Page, $PageID);

        // We need to clear all subsequential catalogues as they've all been bumped with the absence of this post
        $ThisCatalogue = floor((TORRENT_COMMENTS_PER_PAGE * $CommPage - TORRENT_COMMENTS_PER_PAGE) / THREAD_CATALOGUE);
        $LastCatalogue = floor((TORRENT_COMMENTS_PER_PAGE * $CommPages - TORRENT_COMMENTS_PER_PAGE) / THREAD_CATALOGUE);
        for ($i = $ThisCatalogue; $i <= $LastCatalogue; ++$i) {
            G::$Cache->delete_value($Page . '_comments_' . $PageID . '_catalogue_' . $i);
        }

        G::$Cache->delete_value($Page . '_comments_' . $PageID);
        if ($Page === 'collages') {
            // On collages, we also need to clear the collage key (collage_$CollageID), because it has the comments in it... (why??)
            G::$Cache->delete_value("collage_$PageID");
        }

        G::$DB->set_query_id($QueryID);
        return true;
    }

    /**
     * Get the URL to a comment, already knowing the Page and PostID
     * @param string $Page
     * @param int $PageID
     * @param int $PostID
     * @return string|bool The URL to the comment or false on error
     */
    public static function get_url($Page, $PageID, $PostID = null)
    {
        $Post = (!empty($PostID) ? "&postid=$PostID#post$PostID" : '');
        switch ($Page) {
        case 'artist':
            return "artist.php?id=$PageID$Post";
        case 'collages':
            return "collages.php?action=comments&collageid=$PageID$Post";
        case 'requests':
            return "requests.php?action=view&id=$PageID$Post";
        case 'torrents':
            return "torrents.php?id=$PageID$Post";
        default:
            return false;
        }
    }

    /**
     * Get the URL to a comment
     * @param int $PostID
     * @return string|bool The URL to the comment or false on error
     */
    public static function get_url_query($PostID)
    {
        $QueryID = G::$DB->get_query_id();
        G::$DB->query("
        SELECT Page, PageID
        FROM comments
          WHERE ID = $PostID");

        if (!G::$DB->has_results()) {
            error(404);
        }

        list($Page, $PageID) = G::$DB->next_record();
        G::$DB->set_query_id($QueryID);

        return self::get_url($Page, $PageID, $PostID);
    }

    /**
     * Load a page's comments. This takes care of `postid` and (indirectly) `page` parameters passed in $_GET.
     * Quote notifications and last read are also handled here, unless $HandleSubscriptions = false is passed.
     * @param string $Page
     * @param int $PageID
     * @param bool $HandleSubscriptions Whether or not to handle subscriptions (last read & quote notifications)
     * @return array ($NumComments, $Page, $Thread, $LastRead)
     *     $NumComments: the total number of comments on this artist/request/torrent group
     *     $Page: the page we're currently on
     *     $Thread: an array of all posts on this page
     *     $LastRead: ID of the last comment read by the current user in this thread;
     *                will be false if $HandleSubscriptions == false or if there are no comments on this page
     */
    public static function load($Page, $PageID, $HandleSubscriptions = true)
    {
        $QueryID = G::$DB->get_query_id();

        // Get the total number of comments
        $NumComments = G::$Cache->get_value($Page."_comments_$PageID");
        if ($NumComments === false) {
            G::$DB->query("
            SELECT COUNT(ID)
            FROM comments
              WHERE Page = '$Page'
              AND PageID = $PageID");
            list($NumComments) = G::$DB->next_record();
            G::$Cache->cache_value($Page."_comments_$PageID", $NumComments, 0);
        }

        // If a postid was passed, we need to determine which page that comment is on.
        // Format::page_limit handles a potential $_GET['page']
        if (isset($_GET['postid']) && is_number($_GET['postid']) && $NumComments > TORRENT_COMMENTS_PER_PAGE) {
            G::$DB->query("
            SELECT COUNT(ID)
            FROM comments
              WHERE Page = '$Page'
              AND PageID = $PageID
              AND ID <= $_GET[postid]");

            list($PostNum) = G::$DB->next_record();
            list($CommPage, $Limit) = Format::page_limit(TORRENT_COMMENTS_PER_PAGE, $PostNum);
        } else {
            list($CommPage, $Limit) = Format::page_limit(TORRENT_COMMENTS_PER_PAGE, $NumComments);
        }

        // Get the cache catalogue
        $CatalogueID = floor((TORRENT_COMMENTS_PER_PAGE * $CommPage - TORRENT_COMMENTS_PER_PAGE) / THREAD_CATALOGUE);

        // Cache catalogue from which the page is selected, allows block caches and future ability to specify posts per page
        $Catalogue = G::$Cache->get_value($Page.'_comments_'.$PageID.'_catalogue_'.$CatalogueID);
        if ($Catalogue === false) {
            $CatalogueLimit = $CatalogueID * THREAD_CATALOGUE . ', ' . THREAD_CATALOGUE;
            G::$DB->query("
            SELECT
              c.ID,
              c.AuthorID,
              c.AddedTime,
              c.Body,
              c.EditedUserID,
              c.EditedTime,
              u.Username
            FROM comments AS c
              LEFT JOIN users_main AS u ON u.ID = c.EditedUserID
              WHERE c.Page = '$Page'
              AND c.PageID = $PageID
            ORDER BY c.ID
              LIMIT $CatalogueLimit");

            $Catalogue = G::$DB->to_array(false, MYSQLI_ASSOC);
            G::$Cache->cache_value($Page.'_comments_'.$PageID.'_catalogue_'.$CatalogueID, $Catalogue, 0);
        }

        // This is a hybrid to reduce the catalogue down to the page elements: We use the page limit % catalogue
        $Thread = array_slice($Catalogue, ((TORRENT_COMMENTS_PER_PAGE * $CommPage - TORRENT_COMMENTS_PER_PAGE) % THREAD_CATALOGUE), TORRENT_COMMENTS_PER_PAGE, true);

        if ($HandleSubscriptions && count($Thread) > 0) {
            // Quote notifications
            $LastPost = end($Thread);
            $LastPost = $LastPost['ID'];
            $FirstPost = reset($Thread);
            $FirstPost = $FirstPost['ID'];

            G::$DB->query("
            UPDATE users_notify_quoted
            SET UnRead = false
              WHERE UserID = " . G::$LoggedUser['ID'] . "
              AND Page = '$Page'
              AND PageID = $PageID
              AND PostID >= $FirstPost
              AND PostID <= $LastPost");

            if (G::$DB->affected_rows()) {
                G::$Cache->delete_value('notify_quoted_' . G::$LoggedUser['ID']);
            }

            // Last read
            G::$DB->query("
            SELECT PostID
            FROM users_comments_last_read
              WHERE UserID = " . G::$LoggedUser['ID'] . "
              AND Page = '$Page'
              AND PageID = $PageID");

            list($LastRead) = G::$DB->next_record();
            if ($LastRead < $LastPost) {
                G::$DB->query("
                INSERT INTO users_comments_last_read
                  (UserID, Page, PageID, PostID)
                VALUES
                  (" . G::$LoggedUser['ID'] . ", '$Page', $PageID, $LastPost)
                ON DUPLICATE KEY UPDATE
                  PostID = $LastPost");
                G::$Cache->delete_value('subscriptions_user_new_' . G::$LoggedUser['ID']);
            }
        } else {
            $LastRead = false;
        }

        G::$DB->set_query_id($QueryID);
        return array($NumComments, $CommPage, $Thread, $LastRead);
    }

    /**
     * Merges all comments from $Page/$PageID into $Page/$TargetPageID. This also takes care of quote notifications, subscriptions and cache.
     * @param type $Page
     * @param type $PageID
     * @param type $TargetPageID
     */
    public static function merge($Page, $PageID, $TargetPageID)
    {
        $QueryID = G::$DB->get_query_id();

        G::$DB->query("
        UPDATE comments
        SET PageID = $TargetPageID
          WHERE Page = '$Page'
          AND PageID = $PageID");

        // quote notifications
        G::$DB->query("
        UPDATE users_notify_quoted
        SET PageID = $TargetPageID
          WHERE Page = '$Page'
          AND PageID = $PageID");

        // comment subscriptions
        Subscriptions::move_subscriptions($Page, $PageID, $TargetPageID);

        // cache (we need to clear all comment catalogues)
        G::$DB->query("
        SELECT
          CEIL(COUNT(ID) / " . TORRENT_COMMENTS_PER_PAGE . ") AS Pages
        FROM comments
          WHERE Page = '$Page'
          AND PageID = $TargetPageID
        GROUP BY PageID");

        list($CommPages) = G::$DB->next_record();
        $LastCatalogue = floor((TORRENT_COMMENTS_PER_PAGE * $CommPages - TORRENT_COMMENTS_PER_PAGE) / THREAD_CATALOGUE);
        
        for ($i = 0; $i <= $LastCatalogue; ++$i) {
            G::$Cache->delete_value($Page . "_comments_$TargetPageID" . "_catalogue_$i");
        }

        G::$Cache->delete_value($Page."_comments_$TargetPageID");
        G::$DB->set_query_id($QueryID);
    }

    /**
     * Delete all comments on $Page/$PageID (deals with quote notifications and subscriptions as well)
     * @param string $Page
     * @param int $PageID
     * @return boolean
     */
    public static function delete_page($Page, $PageID)
    {
        $QueryID = G::$DB->get_query_id();

        // get number of pages
        G::$DB->query("
        SELECT
          CEIL(COUNT(ID) / " . TORRENT_COMMENTS_PER_PAGE . ") AS Pages
        FROM comments
          WHERE Page = '$Page'
          AND PageID = $PageID
        GROUP BY PageID");

        if (!G::$DB->has_results()) {
            return false;
        }
        list($CommPages) = G::$DB->next_record();

        // Delete comments
        G::$DB->query("
        DELETE FROM comments
          WHERE Page = '$Page'
          AND PageID = $PageID");

        // Delete quote notifications
        Subscriptions::flush_quote_notifications($Page, $PageID);
        G::$DB->query("
        DELETE FROM users_notify_quoted
          WHERE Page = '$Page'
          AND PageID = $PageID");

        // Deal with subscriptions
        Subscriptions::move_subscriptions($Page, $PageID, null);

        // Clear cache
        $LastCatalogue = floor((TORRENT_COMMENTS_PER_PAGE * $CommPages - TORRENT_COMMENTS_PER_PAGE) / THREAD_CATALOGUE);
        for ($i = 0; $i <= $LastCatalogue; ++$i) {
            G::$Cache->delete_value($Page . '_comments_' . $PageID . '_catalogue_' . $i);
        }

        G::$Cache->delete_value($Page.'_comments_'.$PageID);
        G::$DB->set_query_id($QueryID);

        return true;
    }
}