class Database
{
	protected $_connect  = null;
	protected $error = null; 
	private static $_instance =  null;   
   
	final private function __wakeup(){}
	final private function __clone() {}
	
	public static function get(){
	   if(!extension_loaded('pdo')){
			throw new Exception('PDO не работает');
			die();
	   }else{
			if ( self::$_instance[ANCHOR] == null )
				self::$_instance[ANCHOR] = new self();     
			}
			return self::$_instance[ANCHOR];
   } 
   
	private function __construct(){
		try{
				 $params = array(
					PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
				 );
				 if (DB_DRIVER == 'mysql') {
					$params[PDO::MYSQL_ATTR_INIT_COMMAND] = "SET NAMES '".CHARACTER."'";
				 }
				$params[PDO::ATTR_PERSISTENT] = true;
				$this->_connect = new PDO(DB_DRIVER.':host='.DB_HOST.';dbname='.DB_NAME.';charset='.CHARACTER, DB_USER, DB_PASS, $params);
				$this->_connect->exec('SET NAMES '.CHARACTER );
				$this->_connect->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
				$this->_connect->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
				$this->_connect->query( 'SET character_set_connection = '.CHARACTER.';' );
				$this->_connect->query( 'SET character_set_client = ' . CHARACTER . ';' );
				$this->_connect->query( 'SET character_set_results = ' . CHARACTER . ';' );
				$this->_connect->query('SET NAMES '.CHARACTER);
		}catch (PDOException $e){
			   throw new Exception('Mysql error'.$e->getMessage());
			   die();
		}
		return $this->_connect;
   }
   
	public function prepare($sql, $values){
		$sth = $this->db->prepare($sql);
		$sth->execute($values);
	}
	
	private static function where($where_array){
	   /* 
		  $where_array=Array('id'=>Array(
										'comparison'=>'=',
										'value'=>'1'
										 ),
							 'condition'=>Array('0'=>'')
		  );
		  
		  $where_array['id']['comparison']='=';
		  $where_array['id']['value']='1';
		  $where_array['condition'][]='';
		  
		  $where_array=Array(
								'id'=>Array(
									'comparison'=>'=',
									'value'=>'1'
								),
								'name'=>Array(
									'comparison'=>'=',
									'value'=>'Roman'
								),
								'famaly'=>Array(
									'comparison'=>'=',
									'value'=>'Gaevoy'
								),
								'condition'=>Array(
									'0'=>' AND',
									'1'=>' AND',
									'2'=>''
								)
		  );  
		  $where_array['id']['comparison']='=';
		  $where_array['id']['value']='1';
		  $where_array['condition'][]='AND';
		  $where_array['name']['comparison']='=';
		  $where_array['name']['value']='Roman';
		  $where_array['condition'][]='AND';
		  $where_array['famaly']['comparison']='=';
		  $where_array['famaly']['value']='Gaevoy;
		  $where_array['condition'][]='';
			 */
		  if(is_array($where_array)){
	   $i=0;
	   $where = Array('sql' => null, 'condition' => null);
	  foreach ($where_array as $key => $value){ 
		  if($key !='condition'){
			$where['sql'] = $where['sql'].''.$key.''.$value['comparison'].' :'.$key.''.$where['condition'][$i++];
			$where['execute'][':'.$key] = self::get()->quote($value['value']);
		  }
	  }
		  }else{
		   $where['sql'] =  $where_array;     
		  }
	  return $where; 
	}
	
	public function quote($quote){
	   $quote = $this->_connect->quote($quote);   
	 return $quote;    
   }
 
	public function select($table, $fields='*', $where=null, $order=null , $limit=null, $rsql=false) {
		if($table == null) $table = "*";
		if($fields == null) $fields = "*";
		if($order != null) $order = "ORDER BY ".$order."";
		if($limit != null) $limit = "LIMIT ".$limit."";
		if($where != null){
			$where = self::where($where);
			$where_sql ='WHERE  '.$where['sql']; 
			$where_execute =$where['execute'];  
		}else{
		  $where_sql = null;
		  $where_execute = null;  
		}
		$sql ="SELECT $fields from ".PREF."$table $where_sql $order $limit";
			if($rsql == true){
				return Array('sql'=>$sql,'where_execute'=>$where_execute);
			}
		$query =  $this->_connect->prepare($sql);
		if($where != null){
			foreach ($where_execute as $key => $value){
				$query->bindValue($key, $value);
			}
		$query->execute($where_execute);
		}
		if ($query->fetchColumn() > 0) {
			return $query->fetch(PDO::FETCH_ASSOC);
		}else{
			return false;   
		}
	}
	
	public function selectall($table, $fields='*', $where=null, $order=null , $limit=null, $rsql=false) {
		if($table == null) $table = "*";
		if($fields == null) $fields = "*";
		if($order != null) $order = "ORDER BY ".$order."";
		if($limit != null) $limit = "LIMIT ".$limit."";
		if($where != null){
			$where = self::where($where);
			$where_sql ='WHERE  '.$where['sql']; 
			$where_execute =$where['execute'];  
		}else{
		  $where_sql = null;
		  $where_execute = null;  
		} 
		$sql="SELECT $fields from ".PREF."$table $where_sql $order $limit";
		if($rsql == true){
			return Array('sql'=>$sql,'where_execute'=>$where_execute);
		}
		$query =  $this->_connect->prepare($sql);
		if($where != null){
			foreach ($where_execute as $key => $value){
				$query->bindValue($key, $value);
			}
		$query->execute($where_execute);
		}
				$query->execute($where_execute);
		if ($query->fetchColumn() > 0) {
			return $query->fetchAll(PDO::FETCH_ASSOC);
		}else{
			return false;   
		}
	}  
	
	public function insert($table, $values, $rsql=false) { 
	  foreach ($values as $key => $value){
		  if($key == 'changed'){
				$valuesq[$key] ="NOW()";
			}else{
				$valuesq[$key] =self::quote ($value);
			}
		}
		$sql = "INSERT INTO  ".PREF."$table  (".(implode(",",array_keys($valuesq))).")VALUES('".(implode("','",$valuesq))."')";
		if($rsql == true){
			return $sql;
		} 
		$query =  $this->_connect->prepare($sql);
		foreach ($valuesq as $key => $value){
			$query->bindValue(':' . $key, $value);
		} 
		$query->execute($valuesq);
		
		return $query->rowCount();
	}

	public function update($table, $values, $where= null, $rsql=false) {
		foreach ($values as $key => $value){
			if($key == 'changed'){
				$preupdate[] = $key." = NOW()";
			}else{
				$preupdate[] = $key." = '".self::quote($value)."'";
			}
		}
		$update = implode("','",$preupdate);
		$where = self::where($where); 
		$sql ="UPDATE  ".PREF."$table SET ".$update." ".$where['sql'].""; 
		if($rsql == true){
			return $sql;
		}         
		$query =  $this->_connect->prepare($sql); 
	   
		foreach ($where['execute'] as $key => $value){
			$query->bindValue($key, $value);
		}
		foreach ($values as $key => $value){
			$query->bindValue(':' . $key, $value);
		}
		
		 $query->execute($values);
		 
		 return $query->rowCount();
	} 
	
	public function delete($table, $where, $rsql=false) {
		$where = self::where($where);
		$sql = "DELETE FROM  ".PREF."$table ".$where['sql']."";
		if($rsql == true){
			return $sql;
		}     
		$query =  $this->_connect->prepare($sql);
		foreach ($where['execute'] as $key => $value){
			$query->bindValue($key, $value);
			   }
		$query->execute($where['execute']);
		
		return $query->rowCount();
	}
			
}