<?PHP

  $TLV_SNACs = array (
    0x0001 => array (0x0005, 0x0012, 0x001E),
    0x0002 => array (0x0003, 0x0004, 0x0009, 0x000F),
    0x0003 => array (0x0003),
    0x0006 => array (0x0002),
    0x0007 => array (0x0002, 0x0004, 0x0008, 0x0009),
    0x0008 => array (0x0002),
    0x0009 => array (0x0003),
    0x000A => array (0x0003),
    0x000B => array (0x0003),
    0x000D => array (0x0009),
    0x0013 => array (0x0003),
    0x0015 => array (0x0002, 0x0003),
    0x0017 => array (0x0002, 0x0003, 0x0004, 0x0005, 0x0006, 0x0007),
  );
  
  $Printables = utf8_decode ("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890 ,;.:-_#'+*~·@ł€¶ŧ←↓→øþ¨æßðđŋħjĸł˝^`«»¢“”nµ²³¼½¬{[]}\¸'`!\"§\$%&/()=?");
  
  function dumpData ($Data, $Prefix = "", $Return = false) {
    global $Printables;
    
    $buf = "";
    $line = "";
    
    for ($i = 0; $i < strlen ($Data); $i++) {
      $m = $i % 16;
      
      if ($m == 0)
        $buf .= $Prefix;
      
      $n = ord ($Data [$i]);
      $c = dechex ($n);
      $line .= $Data [$i];
      
      $buf .= ($n < 16 ? "0" : "") . $c . " ";
      
      if ($m == 15) {
        $buf .= "  ";
        
        for ($p = 0; $p < strlen ($line); $p++) {
          $c = $line [$p];
          
          if (strpos ($Printables, $c) === false)
            $buf .= ".";
          else
            $buf .= utf8_encode ($c);
        }
        
        $buf .= "\n";
        $line = "";
      }
    }
    
    if ($i % 16 != 15)
      $buf .= "\n";
    
    if ($Return)
      return $buf;
    
    print $buf;
  }
  
  function flapDebug ($Flap, $Socket = null, $Read = true, $DebugInfo = "") {
    global $TLV_SNACs;
    
    // Retrive information about our socket
    $IP = "";
    $Port = 0;
    
    if (is_resource ($Socket))
      socket_getpeername ($Socket, $IP, $Port);
    
    // Output FLAP Header
    if ($DebugInfo != "")
      $DebugInfo .= " ";
    
    print $DebugInfo;
    
    if ($Read)
      print "Reading FLAP" . ($IP != "" ? " from $IP:$Port" : "");
    else
      print "Writing FLAP" . ($IP != "" ? " to $IP:$Port" : "");
    
    print "\n" . $DebugInfo . "Channel " . $Flap ["Channel"] . " / Sequence " . $Flap ["Sequence"] . " / Length " . $Flap ["Length"] . " (" . strlen ($Flap ["Payload"]) . ")\n" . $DebugInfo . "\n";
    
    // Handle SNACs on Channel 2
    if ($Flap ["Channel"] == 2) {
      $SNAC = flapReadSNAC ($Flap);
      
      print $DebugInfo . "SNAC Family 0x" . dechex ($SNAC ["Family"]) . " / Subtype 0x" . dechex ($SNAC ["Subtype"]) . " / " .
              "Flags 0x" . dechex ($SNAC ["Flags"]) . " / Sequence 0x" . dechex ($SNAC ["Sequence"]) . "\n" .
            $DebugInfo . "\n";
      
      // Check for TLVs in SNAC
      if (isset ($TLV_SNACs [$SNAC ["Family"]]) && in_array ($SNAC ["Subtype"], $TLV_SNACs [$SNAC ["Family"]]))
        $hasTLV = true;
      else
        $hasTLV = false; # TODO: Try to autodetect TLV-SNACs here
      
      if ($hasTLV) {
        $Flap ["Length"] = 0;
        $Items = flapTreatTLV ($SNAC);
        
        foreach ($Items as $Item) {
          print $DebugInfo . "TLV Type 0x" . dechex ($Item ["Type"]) . " / Length " . $Item ["Length"] . "\n";
          
          dumpData ($Item ["Payload"], $DebugInfo);
          
          print $DebugInfo . "\n";
        }
      
      // Dirty hack :D
      } else {
        $Flap = $SNAC;
        $Flap ["Length"] = strlen ($SNAC ["Payload"]);
      }
    }
    
    // Output payload
    if ($Flap ["Length"] > 0)
      dumpData ($Flap ["Payload"], $DebugInfo);
      
    print "\n";
  }
  
  function flapRead ($Socket, $Debug = false, $DebugInfo = "") {
    // Read magic packet from stream
    $C = chr (0x2A);
    
    while (($c = socket_read ($Socket, 1, PHP_BINARY_READ)) && ($c != $C)) {
      if ($c == "")
        break;
      
      usleep (1);
    }
    
    // Check if read was successfull
    if ($c != $C) {
      unsetSocketContext ($Socket);
      
      return false;
    }
    
    // Read FLAP-Header from stream
    $Header = socket_read ($Socket, 5, PHP_BINARY_READ);
    
    // Parse the header
    $Info = array (
      "Channel"  => ord ($Header [0]),
      "Sequence" => (ord ($Header [1]) << 8) + ord ($Header [2]),
      "Length"   => (ord ($Header [3]) << 8) + ord ($Header [4]),
      "Payload"  => "",
    );
    
    // Read payload
    if ($Info ["Length"] > 0) {
      while (strlen ($Info ["Payload"]) < $Info ["Length"])
        $Info ["Payload"] .= socket_read ($Socket, $Info ["Length"] - strlen ($Info ["Payload"]), PHP_BINARY_READ);
      
      if (($l = strlen ($Info ["Payload"])) != $Info ["Length"])
        print "WARNING: Read " . $l . " bytes instead of " . $Info ["Length"] . "\n\n";
    }
    
    // Debug this packet
    if ($Debug)
      flapDebug ($Info, $Socket, true, $DebugInfo);
    
    return $Info;
  }
  
  function writeFlap ($Socket, $Data, $Debug = false, $DebugInfo = "") {
    // Prepare FLAP Payload
    if ($Data ["Length"] > 0) {
      $Payload = substr ($Data ["Payload"], 0, $Data ["Length"]);
      
      if (($l = strlen ($Payload)) < $Data ["Length"])
        $Payload .= str_repeat (chr (0), $Data ["Length"] - $l);
    } else
      $Payload = "";
    
    if ($Debug)
      flapDebug ($Data, $Socket, false, $DebugInfo);
    
    // Write everything to stream
    return @socket_write (
      $Socket,
      chr (0x2A) .
      chr ($Data ["Channel"]) .
      chr (($Data ["Sequence"] & 0xFF00) >> 8) . chr ($Data ["Sequence"] & 0xFF) .
      chr (($Data ["Length"]   & 0xFF00) >> 8) . chr ($Data ["Length"]   & 0xFF) .
      $Payload
    );
  }
  
  function flapTreatTLV ($Flap) {
    $Payload = $Flap ["Payload"];
    $Items = array ();
    
    while (strlen ($Payload) > 0) {
      $Type   = (ord ($Payload [0]) << 8) + ord ($Payload [1]);
      $Length = (ord ($Payload [2]) << 8) + ord ($Payload [3]);
      
      if ($Length > 0)
        $Data = substr ($Payload, 4, $Length);
      else
        $Data = "";
      
      $Items [] = array (
        "Type"    => $Type,
        "Length"  => $Length,
        "Payload" => $Data,
      );
      
      $Payload = substr ($Payload, $Length + 4);
    }
    
    return $Items;
  }
  
  function flapReadSNAC ($Flap) {
    if ($Flap ["Channel"] != 2)
      return false;
    
    $Payload = $Flap ["Payload"];
    
    $Family  = (ord ($Payload [0]) <<  8) +  ord ($Payload [1]);
    $Subtype = (ord ($Payload [2]) <<  8) +  ord ($Payload [3]);
    $Flags   = (ord ($Payload [4]) <<  8) +  ord ($Payload [5]);
    $Request = (ord ($Payload [6]) << 24) + (ord ($Payload [7]) << 16) +
               (ord ($Payload [8]) <<  8) +  ord ($Payload [9]);
    
    $Payload = substr ($Payload, 10);
    
    return array (
      "Family"  => $Family,
      "Subtype" => $Subtype,
      "Flags"   => $Flags,
      "Request" => $Request,
      "Payload" => $Payload,
    );
  }
  
  function flapRewriteSNAC ($FLAP, $SNAC) {
    $FLAP ["Payload"] =
      chr (($SNAC ["Family"]  & 0xFF00) >> 8) . chr ($SNAC ["Family"]  & 0xFF) .
      chr (($SNAC ["Subtype"] & 0xFF00) >> 8) . chr ($SNAC ["Subtype"] & 0xFF) .       
      chr (($SNAC ["Flags"]   & 0xFF00) >> 8) . chr ($SNAC ["Flags"]   & 0xFF) .       
      chr (($SNAC ["Request"] & 0xFF000000) >> 24) . chr (($SNAC ["Request"] & 0x00FF0000) >> 16) .
      chr (($SNAC ["Request"] & 0x0000FF00) >>  8) . chr  ($SNAC ["Request"] & 0x000000FF) .
      $SNAC ["Payload"];
    
    $FLAP ["Length"] = strlen ($FLAP ["Payload"]);
    
    return $FLAP;
  }
  
  function flapRewriteTLV ($FLAP, $Items) {
    $FLAP ["Payload"] = "";
    
    foreach ($Items as $Item) {
      if ($Item ["Length"] > 0) {
        $Payload = $Item ["Payload"];
        
        if (($l = strlen ($Payload)) < $Item ["Length"])
          $Payload .= str_repeat (chr (0), $Item ["Length"] - $l);
      } else
        $Payload = "";
      
      $FLAP ["Payload"] .=
        chr (($Item ["Type"]   & 0xFF00) >> 8) . chr ($Item ["Type"]   & 0xFF) .
        chr (($Item ["Length"] & 0xFF00) >> 8) . chr ($Item ["Length"] & 0xFF) .
        $Payload;
    }
  
    $FLAP ["Length"] = strlen ($FLAP ["Payload"]);
    
    return $FLAP;
  }

?>