<?php

function descramble($strLine) {
  $strLine = strtoupper($strLine);
  $strOutput = "";
  for($j=0; $j<strlen($strLine); $j+=2) {
    if(!($strLine{$j}>='A' && $strLine{$j}<'Q') ||
       !($strLine{$j+1}>='A' && $strLine{$j+1}<'Q')) {
      break;
    }
    $cc = ~((ord($strLine{$j})-ord('A')) + (ord($strLine{$j+1})-ord('A'))*0x10);
    $strOutput .= chr($cc);
  }
  return $strOutput;
}

$nParam = -1;
$bNewUser = true;
$strAffID = "[s-f]";
$nDaysInstalled = -1;

if (isset($_GET["aaa"])) {
  $strInput = descramble($_GET["aaa"]);
  $aMatch = array();
  if (preg_match("/\&p=(.)\&/", $strInput, $aMatch)) {
    $nParam = $aMatch[1];
    $bNewUser = (($aMatch[1] & 4)!=0);
  }
  if (preg_match("/\&p=(.):([^:]*):([^&]*)\&/", $strInput, $aMatch)) {
    $nParam = $aMatch[1];
    $bNewUser = (($aMatch[1] & 4)!=0);
    $strAffID = $aMatch[2];
    $nDaysInstalled = $aMatch[3];
  }
}
if ($strAffID!="[s-f]") {
  if (!preg_match("/^\w{5}$/", $strAffID)) {
    $strAffID = "[s-f]";
  }
}

$strPageContents = @file_get_contents(($bNewUser ? "welcome-new.html" : "welcome-existing.html"));
if (!$strPageContents && !$bNewUser) {
  $strPageContents = @file_get_contents("welcome-new.html");
}
if ($strAffID != "[s-f]") {
  $strAffIDInsert = @file_get_contents("../affinsert-$strAffID.html");
  if (!$strAffIDInsert) {
    $strAffIDInsert = "";
  }
} else {
  $strAffIDInsert = "";
}

echo str_replace(
  "<!-- AffID code -->", 
  "<!-- nParam=" . $nParam . " AffID=". $strAffID . " nDays=" . $nDaysInstalled . " -->\n"  . $strAffIDInsert, 
  $strPageContents);

?>