<?php

/*
 * SITE : Classes & PHP
 * TITRE : PHP4 - Design pattern bridge
 * AUTEUR : Antoine DESSAIGNE
 *
 */

header('Content-Type: text/plain');

Class DatabaseManager
{
	var $impl;

	function DatabaseManager()
	{
		$this->impl = null;
	}

	function setImplementor(&$impl)
	{
		if (!is_object($impl) || !is_a($impl, 'Database'))
			return false;

		$this->impl =& $impl;
		return true;
	}

	function connect($host, $user, $pass, $base)
	{
		if (!$this->impl)
			return false;
		return $this->impl->connect($host, $user, $pass, $base);
	}

	function query($sql)
	{
		if (!$this->impl)
			return array();
		return $this->impl->query($sql);
	}
}

Class Database
{
	function connect($host, $user, $pass, $base) { return false; }
	function query($sql) { return array(); }
}

Class MySQL extends Database
{
	var $_id;

	function connect($host, $user, $pass, $base)
	{
		$this->_id = @mysql_connect($host, $user, $pass);
		if (!$this->_id)
			return false;
		return @mysql_select_db($base, $this->_id);
	}

	function query($sql)
	{
		$tab = array();
		$res = @mysql_query($sql, $this->_id);
		if (!$res)
			return array();
		while ($row = @mysql_fetch_assoc($res))
			$tab[] = $row;
		@mysql_free_result($res);
		return $tab;
	}
}

Class PostgreSQL extends Database
{
	var $_id;

	function connect($host, $user, $pass, $base)
	{
		$this->_id = @pg_connect('host='.$host.' dbname='.$base.' user='.$user.' password='.$pass);
		if (!$this->_id)
			return false;
		return true;
	}

	function query($sql)
	{
		$tab = array();
		$res = @pg_query($this->_id, $sql);
		if (!$res)
			return array();
		while ($row = @pg_fetch_assoc($res))
			$tab[] = $row;
		@pg_free_result($res);
		return $tab;
	}
}

$mgr =& new DatabaseManager();
$impl =& new MySQL();
$mgr->setImplementor($impl);
echo $mgr->connect('localhost', 'root', '', 'mysql') ? 'Connecté !' : 'Non connecté !';

?>