#define LOG_MODULE PacketLogModuleMplsLayer

#include "MplsLayer.h"

#include "IPv4Layer.h"

#include "IPv6Layer.h"

#include "PayloadLayer.h"

#include "Logger.h"

#include <sstream>

#include "EndianPortable.h"

namespace pcpp

{

  MplsLayer::MplsLayer(uint32_t mplsLabel, uint8_t ttl, uint8_t experimentalUseValue, bool bottomOfStack)

  {

    allocData(sizeof(mpls_header));

    m_Protocol = MPLS;

    setMplsLabel(mplsLabel);

    setTTL(ttl);

    setExperimentalUseValue(experimentalUseValue);

    setBottomOfStack(bottomOfStack);

  }

  bool MplsLayer::isBottomOfStack() const

  {

    return (getMplsHeader()->misc & 0x01);

  }

  void MplsLayer::setBottomOfStack(bool val)

  {

    if (!val)

      getMplsHeader()->misc &= 0xFE;

    else

      getMplsHeader()->misc |= 0x1;

  }

  uint8_t MplsLayer::getExperimentalUseValue() const

  {

    return ((getMplsHeader()->misc & 0x0E) >> 1);

  }

  bool MplsLayer::setExperimentalUseValue(uint8_t val)

  {

    // exp value is only 3 bits

    if (val > 7)

    {

      PCPP_LOG_ERROR("Set ExperimentalUse value got an illegal value: " << (int)val

                                                                        << ". Value must be lower than 8");

      return false;

    }

    mpls_header* hdr = getMplsHeader();

    // clear the 3 exp bits

    hdr->misc &= 0xF1;

    // move the 3 bits to their place

    val = val << 1;

    hdr->misc |= val;

    return true;

  }

  uint32_t MplsLayer::getMplsLabel() const

  {

    return (htobe16(getMplsHeader()->hiLabel) << 4) | ((getMplsHeader()->misc & 0xF0) >> 4);

  }

  bool MplsLayer::setMplsLabel(uint32_t label)

  {

    if (label > 0xFFFFF)

    {

      PCPP_LOG_ERROR(

          "MPLS label mustn't exceed 20 bits which is the value 0xffff. Got a parameter with the value 0x"

          << std::hex << label);

      return false;

    }

    mpls_header* hdr = getMplsHeader();

    // clear the 4 label bits in misc field

    hdr->misc &= 0x0F;

    // take the last nibble of the label value and move this nibble to its place in misc

    uint8_t miscVal = (label & 0x0F) << 4;

    // update misc field

    hdr->misc |= miscVal;

    // get rid of the nibble that went to misc

    label = label >> 4;

    // set the high 2 bytes of the label

    hdr->hiLabel = (uint16_t)htobe16(label);

    return true;

  }

  void MplsLayer::parseNextLayer()

  {

    size_t headerLen = getHeaderLen();

    if (m_DataLen < headerLen + 1)

      return;

    uint8_t* payload = m_Data + sizeof(mpls_header);

    size_t payloadLen = m_DataLen - sizeof(mpls_header);

    if (!isBottomOfStack())

    {

      constructNextLayer<MplsLayer>(payload, payloadLen);

      return;

    }

    uint8_t nextNibble = (*((uint8_t*)(m_Data + headerLen)) & 0xF0) >> 4;

    switch (nextNibble)

    {

    case 4:

      tryConstructNextLayerWithFallback<IPv4Layer, PayloadLayer>(payload, payloadLen);

      break;

    case 6:

      tryConstructNextLayerWithFallback<IPv6Layer, PayloadLayer>(payload, payloadLen);

      break;

    default:

      constructNextLayer<PayloadLayer>(payload, payloadLen);

    }

  }

  void MplsLayer::computeCalculateFields()

  {

    Layer* nextLayer = getNextLayer();

    if (nextLayer != nullptr)

    {

      setBottomOfStack((nextLayer->getProtocol() != MPLS));

    }

  }

  std::string MplsLayer::toString() const

  {

    std::ostringstream labelStream;

    labelStream << getMplsLabel();

    std::ostringstream expStream;

    expStream << (int)getExperimentalUseValue();

    std::ostringstream ttlStream;

    ttlStream << (int)getTTL();

    std::string bottomOfStack = isBottomOfStack() ? "true" : "false";

    return "MPLS Layer, Label: " + labelStream.str() + ", Exp: " + expStream.str() + ", TTL: " + ttlStream.str() +

           ", Bottom of stack: " + bottomOfStack;

  }

}  // namespace pcpp