Antispammer

function checkAntispam(){
    $antiSpamTime = 2; //How fast does to connections have to be to be considered spam?
    $antiSpamMaxScore = 1; //Number of times you can spam untill getting temporaly banned
    $antiSpamMultiplier = 5; //Set a multiplier to figure out ban time. Ban time is calculated like this: bantime=multiplier*number of bans
    $jsonfile = "./antispam.json"; //Data file for storing
    $json = NULL;
    try{
        $json = file_get_contents($jsonfile);
        $json = json_decode($json, true);
        if(isset($json[$_SERVER['REMOTE_ADDR']])){
            //We have seen the user before
            if($json[$_SERVER['REMOTE_ADDR']]["blockedUntil"] > time()){ // User is banned
                return false;
            }
            if(time()-$json[$_SERVER['REMOTE_ADDR']]["lastConnect"] < $antiSpamTime){ //If user has connected within x seconds again, then increment spamscore
                $json[$_SERVER['REMOTE_ADDR']]["spamScore"] += 1;
                $json[$_SERVER['REMOTE_ADDR']]["lastConnect"] = time();
            }else{ //Hvis ikke, så ingen spamscore.
                $json[$_SERVER['REMOTE_ADDR']]["lastConnect"] = time();
                $json[$_SERVER['REMOTE_ADDR']]["spamScore"] = 0;
                if($json[$_SERVER['REMOTE_ADDR']]["banCount"] > $antiSpamMaxScore){
                    $json[$_SERVER['REMOTE_ADDR']]["banCount"] = $antiSpamMaxScore; //Max score!
                }
            }
            if($json[$_SERVER['REMOTE_ADDR']]["spamScore"] >= $antiSpamMaxScore){ //Brugerens spamscore er for høj
                $json[$_SERVER['REMOTE_ADDR']]["banCount"] = $json[$_SERVER['REMOTE_ADDR']]["banCount"] + 1;
                $json[$_SERVER['REMOTE_ADDR']]["blockedUntil"] = time()+$antiSpamMultiplier * $json[$_SERVER['REMOTE_ADDR']]["banCount"];
            }
        }else{
            //New user
            $json[$_SERVER['REMOTE_ADDR']]["lastConnect"] = time();
            $json[$_SERVER['REMOTE_ADDR']]["spamScore"] = 0;
            $json[$_SERVER['REMOTE_ADDR']]["blockedUntil"] = 0;
            $json[$_SERVER['REMOTE_ADDR']]["banCount"] = 0;
        }

        $f = fopen($jsonfile, "w");
        fwrite($f, json_encode($json));
        fclose($f);
    }catch(Exception $e){
        $f = fopen($jsonfile, "w");
        fwrite($f, json_encode($json));
        fclose($f);
    }
    return true;
}