<?php

class Tags {
    
    function __construct() {
    }

    function getTagRelations($obj_id, $obj_type) {
        global $TeKe;
        $tags = array();
        $res = query_rows("SELECT * FROM ". DB_PREFIX . "tag_relations WHERE object=".$obj_id." AND object_type='".$obj_type."'");
        foreach($res as $tag) {
            $tag_obj = $TeKe->plugin->loadType("tag", $tag->tag);
            $tag_id = $tag_obj->getId();
            $tags [$tag_id]= $tag_obj->getName();
        }
        return $tags;
    }

    function addNewTagRelations($tags, $obj_id, $obj_type) {
        global $TeKe;
        foreach ($tags as $tag) {
            $tag = trim($tag);
            if ($tag == "") {
                continue;
            }
            $obj = $TeKe->plugin->loadType("tag", $tag);
            if ($obj->getId()) {
                $tag_id = $obj->getId();
            } else {
                $tag_id = $obj->build(array("name"=>$tag));
            }
            $this->addTagRelation($tag_id, $obj_id, $obj_type);
        }
    }

    function addTagRelation($tag_id, $obj_id, $obj_type) {
        $insert = query_insert("INSERT INTO " . DB_PREFIX . "tag_relations (tag, object, object_type) values (".$tag_id.", ".$obj_id.", '".$obj_type."')");
    }

    function deleteOldTagRelations($tags, $obj_id, $obj_type) {
        foreach ($tags as $tag_id => $tag) {
            $this->deleteTagRelation($tag_id, $obj_id, $obj_type);
        }   
    }   
    
    function deleteTagRelation($tag_id, $obj_id, $obj_type) {
        global $TeKe;
        $res = query("DELETE FROM ". DB_PREFIX . "tag_relations WHERE tag=${tag_id} AND object=${obj_id} AND object_type='${obj_type}'");
        $existing_tag_relations = query_rows("SELECT * FROM ". DB_PREFIX . "tag_relations WHERE tag=".$tag_id);
        if (count($existing_tag_relations) == 0) {
            $tag_obj = $TeKe->plugin->loadType("tag", $tag_id);
            $tag_obj->delete();
        }
    }

}
?>