<?php

/**
 * PDO class wrapper
 */
class DB
{
	private $user = DB_USER;
	private $pass = DB_PASS;
	private $host = DB_HOST;
	private $dbname = DB_NAME;

	private $dbh;
	private $error;

	private $stmt;

	public function __construct()
	{
		// Database Source Name
		$dsn = 'mysql:host=' . $this->host . ';dbname=' . $this->dbname;

		$options = array(
			PDO::ATTR_PERSISTENT	=> true,
			PDO::ATTR_ERRMODE		=> PDO::ERRMODE_EXCEPTION
		);

		try {
			$this->dbh = new PDO($dsn, $this->user, $this->pass, $options);
		} catch (PDOException $e) {
			$this->error = $e->getMessage();
		}
	}

	public function query($query)
	{
		$this->stmt = $this->dbh->prepare($query);
	}

	public function bind($param, $value, $type=null)
	{
		if (is_null($type)) {
			switch (true) {
				case is_int($value):
					$type = PDO::PARAM_INT;
					break;

				case is_bool($type):
					$type = PDO::PARAM_BOOL;
					break;

				case is_null($value):
					$type = PDO::PARAM_NULL;
					break;

				default:
					$type = PDO::PARAM_STR;
					break;
			}
		}
		$this->stmt->bindValue($param, $value, $type);
	}

	public function execute()
	{
		return $this->stmt->execute();
	}

	public function resultSet()
	{
		$this->execute();
		return $this->stmt->fetchAll(PDO::FETCH_ASSOC);
	}

	public function single()
	{
		$this->execute();
		return $this->stmt->fetch(PDO::FETCH_ASSOC);
	}

	public function rowCount()
	{
		return $this->stmt->rowCount();
	}

	public function lastInsertId()
	{
		return $this->dbh->lastInsertId();
	}

	public function beginTransaction()
	{
		return $this->dbh->beginTransaction();
	}

	public function endTransaction()
	{
		return $this->dbh->commit();
	}

	public function cancelTransaction()
	{
		return $this->dbh->rollBack();
	}
}