fembooru/ext/relatationships/main.php

<?php
/**
 * Name: Post Relationships
 * Author: Angus Johnston <admin@codeanimu.net>
 * License: GPLv2
 * Description: Allow posts to have relationships (parent/child).
 */

class Relationships extends Extension
{
    protected $db_support = ['mysql', 'pgsql'];

    public function onInitExt(InitExtEvent $event)
    {
        global $config, $database;

        // Create the database tables
        if ($config->get_int("ext_relationships_version") < 1) {
            $database->execute("ALTER TABLE images ADD parent_id INT");
            $database->execute($database->scoreql_to_sql("ALTER TABLE images ADD has_children SCORE_BOOL DEFAULT SCORE_BOOL_N NOT NULL"));
            $database->execute("CREATE INDEX images__parent_id ON images(parent_id)");

            $config->set_int("ext_relationships_version", 1);
            log_info("relationships", "extension installed");
        }
        if ($config->get_int("ext_relationships_version") < 2) {
            $database->execute("CREATE INDEX images__has_children ON images(has_children)");

            $config->set_int("ext_relationships_version", 2);
            log_info("relationships", "extension updated");
        }
    }

    public function onImageInfoSet(ImageInfoSetEvent $event)
    {
        if (isset($_POST['tag_edit__tags']) ? !preg_match('/parent[=|:]/', $_POST["tag_edit__tags"]) : true) { //Ignore tag_edit__parent if tags contain parent metatag
            if (isset($_POST["tag_edit__parent"]) ? ctype_digit($_POST["tag_edit__parent"]) : false) {
                $this->set_parent($event->image->id, (int) $_POST["tag_edit__parent"]);
            } else {
                $this->remove_parent($event->image->id);
            }
        }
    }

    public function onDisplayingImage(DisplayingImageEvent $event)
    {
        $this->theme->relationship_info($event->image);
    }

    public function onSearchTermParse(SearchTermParseEvent $event)
    {
        $matches = [];
        if (preg_match("/^parent[=|:]([0-9]+|any|none)$/", $event->term, $matches)) {
            $parentID = $matches[1];

            if (preg_match("/^(any|none)$/", $parentID)) {
                $not = ($parentID == "any" ? "NOT" : "");
                $event->add_querylet(new Querylet("images.parent_id IS $not NULL"));
            } else {
                $event->add_querylet(new Querylet("images.parent_id = :pid", ["pid"=>$parentID]));
            }
        } elseif (preg_match("/^child[=|:](any|none)$/", $event->term, $matches)) {
            $not = ($matches[1] == "any" ? "=" : "!=");
            $event->add_querylet(new Querylet("images.has_children $not TRUE"));
        }
    }

    public function onTagTermParse(TagTermParseEvent $event)
    {
        $matches = [];

        if (preg_match("/^parent[=|:]([0-9]+|none)$/", $event->term, $matches) && $event->parse) {
            $parentID = $matches[1];

            if ($parentID == "none" || $parentID == "0") {
                $this->remove_parent($event->id);
            } else {
                $this->set_parent($event->id, $parentID);
            }
        } elseif (preg_match("/^child[=|:]([0-9]+)$/", $event->term, $matches) && $event->parse) {
            $childID = $matches[1];

            $this->set_child($event->id, $childID);
        }

        if (!empty($matches)) {
            $event->metatag = true;
        }
    }

    public function onImageInfoBoxBuilding(ImageInfoBoxBuildingEvent $event)
    {
        $event->add_part($this->theme->get_parent_editor_html($event->image), 45);
    }

    public function onImageDeletion(ImageDeletionEvent $event)
    {
        global $database;

        if (bool_escape($event->image->has_children)) {
            $database->execute("UPDATE images SET parent_id = NULL WHERE parent_id = :iid", ["iid"=>$event->image->id]);
        }

        if ($event->image->parent_id !== null) {
            $database->execute("UPDATE images SET has_children = (SELECT * FROM (SELECT CASE WHEN (COUNT(*) - 1) > 0 THEN 1 ELSE 0 END FROM images WHERE parent_id = :pid) AS sub)
								WHERE id = :pid", ["pid"=>$event->image->parent_id]);
        }
    }

    private function set_parent(int $imageID, int $parentID)
    {
        global $database;

        if ($database->get_row("SELECT 1 FROM images WHERE id = :pid", ["pid"=>$parentID])) {
            $database->execute("UPDATE images SET parent_id = :pid WHERE id = :iid", ["pid"=>$parentID, "iid"=>$imageID]);
            $database->execute("UPDATE images SET has_children = TRUE WHERE id = :pid", ["pid"=>$parentID]);
        }
    }

    private function set_child(int $parentID, int $childID)
    {
        global $database;

        if ($database->get_row("SELECT 1 FROM images WHERE id = :cid", ["cid"=>$childID])) {
            $database->execute("UPDATE images SET parent_id = :pid WHERE id = :cid", ["cid"=>$childID, "pid"=>$parentID]);
            $database->execute("UPDATE images SET has_children = TRUE WHERE id = :pid", ["pid"=>$parentID]);
        }
    }

    private function remove_parent(int $imageID)
    {
        global $database;
        $parentID = $database->get_one("SELECT parent_id FROM images WHERE id = :iid", ["iid"=>$imageID]);

        if ($parentID) {
            $database->execute("UPDATE images SET parent_id = NULL WHERE id = :iid", ["iid"=>$imageID]);
            $database->execute("UPDATE images SET has_children = (SELECT * FROM (SELECT CASE WHEN COUNT(*) > 0 THEN 1 ELSE 0 END FROM images WHERE parent_id = :pid) AS sub)
								WHERE id = :pid", ["pid"=>$parentID]);
        }
    }
}