Http to Https direct using PHP

Http to Https direct  using PHP with  www Extension 

<?php
$protocol = $_SERVER['HTTPS'] == 'on' ? 'https' : 'http';
if ($_SERVER["SERVER_PORT"] != "80")
{
$pageURL= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
}
else
{
$pageURL= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
}

if($protocol!='https' || strpos($pageURL,'www') === false)
{
$protocol='https';

if (strpos($pageURL,'www') === false)
{
$www='www.' ;
}
$url=$protocol.'://'.$www.$pageURL;
header("Location: ".$url."");
exit();
}