<?php
	
	class DB {
	
			private static $instance;
			private static $con;
			private static $customError;		
	
			public static function init($host, $user, $pass, $db) {
	
				if(!isset(self::$instance)) {
	
					try {
						self::$instance = new PDO('mysql:host='.$host.';dbname='.$db, $user, $pass);
						self::$instance->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
						self::$con = true;
					}
					catch (PDOException $e) {
						
						self::$customError = $e->getMessage();
						self::$con = false;
					}
				}
			}
			
			public static function isConnected() {
				
				return self::$con;	
			}
	
			public static function query($query, $params = array()) {
				
				try {
					$params = !is_array($params) ? array($params) : $params;
					$data = array();
					$is_select = strtoupper(substr($query,0,6)) == "SELECT" ? true : false;
					
					if(count($params) > 0) {
						
						$stmt = self::$instance->prepare($query);
						
						if(!$stmt)
						{
							return false;	
						}
						
						$stmt->execute($params);			
						
						if($is_select)
							$data = $stmt->fetchAll(PDO::FETCH_ASSOC);
						else {
							$data = true;	
						}
						
						$stmt->closeCursor();
					}
					else {
		
						$res = self::$instance->query($query);
		
						if(!$res)
						{					
							return false;	
						}
						else if($is_select)
						{
							foreach($res as $row)
								$data[] = $row;
						}
						else
						{
							$data = true;	
						}
					}
					
					self::$customError = "";
					
					return $data;
				}
				catch(Exception $e) {
					
					self::setError($e->getMessage());
					return false;	
				}
			}
			
			public static function getError() {
				
				if(strlen(self::$customError) > 0)
				{
					return self::$customError;
				}
				else
				{
					$err = self::$instance->errorInfo();	
					return $err[count($err)-1];
				}
			}
			
			public static function setError($e) {
				
				self::$customError = $e;	
			}
		}