<?php
class TagService {
	var $db;
	var $tablename;

	function &getInstance(&$db) {
		static $instance;
		if (!isset($instance))
		$instance =& new TagService($db);
		return $instance;
	}

	function TagService(&$db) {
		$this->db =& $db;
		$this->tablename = $GLOBALS['tableprefix'] .'tags';
	}

	function getDescription($tag, $uId) {
		$query = 'SELECT tag, uId, tDescription';
		$query.= ' FROM '.$this->getTableName();
		$query.= ' WHERE tag = "'.$tag.'"';
		$query.= ' AND uId = "'.$uId.'"';

		if (!($dbresult = & $this->db->sql_query($query))) {
			message_die(GENERAL_ERROR, 'Could not get tag description', '', __LINE__, __FILE__, $query, $this->db);
			return false;
		}

		if ($row =& $this->db->sql_fetchrow($dbresult)) {
			return $row;
		} else {
			return array('tDescription'=>'');
		}
	}
	
	function existsDescription($tag, $uId) {
			$query = 'SELECT tag, uId, tDescription';
		$query.= ' FROM '.$this->getTableName();
		$query.= ' WHERE tag = "'.$tag.'"';
		$query.= ' AND uId = "'.$uId.'"';

		if (!($dbresult = & $this->db->sql_query($query))) {
			message_die(GENERAL_ERROR, 'Could not get tag description', '', __LINE__, __FILE__, $query, $this->db);
			return false;
		}

		if ($row =& $this->db->sql_fetchrow($dbresult)) {
			return true;
		} else {
			return false;
		}
	}

	function getAllDescriptions($tag) {
		$query = 'SELECT tag, uId, tDescription';
		$query.= ' FROM '.$this->getTableName();
		$query.= ' WHERE tag = "'.$tag.'"';

		if (!($dbresult = & $this->db->sql_query($query))) {
			message_die(GENERAL_ERROR, 'Could not get tag description', '', __LINE__, __FILE__, $query, $this->db);
			return false;
		}

		return $this->db->sql_fetchrowset($dbresult);
	}

	function updateDescription($tag, $uId, $desc) {
		if($this->existsDescription($tag, $uId)) {
			$query = 'UPDATE '.$this->getTableName();
			$query.= ' SET tDescription="'.$this->db->sql_escape($desc).'"';
			$query.= ' WHERE tag="'.$tag.'" AND uId="'.$uId.'"';
		} else {
			$values = array('tag'=>$tag, 'uId'=>$uId, 'tDescription'=>$desc);
			$query = 'INSERT INTO '. $this->getTableName() .' '. $this->db->sql_build_array('INSERT', $values);
		}

		$this->db->sql_transaction('begin');
		if (!($dbresult = & $this->db->sql_query($query))) {
			$this->db->sql_transaction('rollback');
			message_die(GENERAL_ERROR, 'Could not delete bookmarks', '', __LINE__, __FILE__, $query, $this->db);
			return false;
		}
		$this->db->sql_transaction('commit');
		return true;
	}

	function renameTag($uId, $oldName, $newName) {
		$newname = $this->normalize($newname);
		
		$query = 'UPDATE `'. $this->getTableName() .'`';
		$query.= ' SET tag="'.$newName.'"';
		$query.= ' WHERE tag="'.$oldName.'"';
		$query.= ' AND uId="'.$uId.'"';
		$this->db->sql_query($query);
		return true;
	}
	
	/* normalize the input tags which could be a string or an array*/
	function normalize($tags) {
		//clean tags from strange characters
		$tags = str_replace(array('"', '\'', '/'), "_", $tags);
		
		//normalize
		if(!is_array($tags)) {
			$tags = strtolower(trim($tags));
		} else {
			for($i=0; $i<count($tags); $i++) {
				$tags[$i] = strtolower(trim($tags[$i])); 
			}
		}
		return $tags;
	}

	function deleteAll() {
		$query = 'TRUNCATE TABLE `'. $this->getTableName() .'`';
		$this->db->sql_query($query);
	}

	// Properties
	function getTableName()       { return $this->tablename; }
	function setTableName($value) { $this->tablename = $value; }
}
?>