<?php
$apiKey = "41A4485DDA5F97E5E31B8BC05EC091E4";
$steam=$_GET['stid'];
$info = "";
if (empty($steam)) {
    $info="ERR_EMPTY";
} else if (preg_match('/^STEAM_0:[01]:[0-9]{2,12}$/', $steam)) {

    $steam64 = st32to64($steam);
    $jsonURL =  $steam64;
    $steam32 = $steam;

} else if (preg_match('/^http:\/\/steamcommunity.com\/profiles\/\d{17}$/', $steam)) {

    preg_match('/^http:\/\/steamcommunity.com\/profiles\/(\d{17})$/', $steam,$steam);

    $steam32 = st64to32($steam[1]);
    $jsonURL =  $steam[1];

}
else if (preg_match('/^\d{17}$/', $steam)) {

    $steam32 = st64to32($steam);
    $jsonURL =  $steam;

} else {
    if(empty($info)){
        $info='ERR_NOT_VALID';
    }
}
function st32to64($steam_id)
{
    list( , $m1, $m2) = explode(':', $steam_id, 3);
    list($steam_cid, ) = explode('.', bcadd((((int) $m2 * 2) + $m1), '76561197960265728'), 2);
    return $steam_cid;
}
function st64to32($steam_cid)
{
    $id = array('STEAM_0');
    $id[1] = substr($steam_cid, -1, 1) % 2 == 0 ? 0 : 1;
    $id[2] = bcsub($steam_cid, '76561197960265728');
    if(bccomp($id[2], '0') != 1)
    {
        return false;
    }
    $id[2] = bcsub($id[2], $id[1]);
    list($id[2], ) = explode('.', bcdiv($id[2], 2), 2);
    return implode(':', $id);
}
if($jsonURL){
    $json = file_get_contents("http://api.steampowered.com/ISteamUser/GetPlayerSummaries/v0002/?key=$apiKey&steamids=$jsonURL&format=json");
    $json = json_decode($json,true);
    $userdata = $json['response']['players'][0];
    if(empty($userdata)){
        if(empty($info)){
            $info='ERR_PROFILE_NOT_FOUND';
        }
    }
}
if(empty($info)){
    $info='VALID';
}
echo $info;
?>