// ======================================================================
// \title  FilePacket.hpp
// \author bocchino
// \brief  hpp file for FilePacket
//
// \copyright
// Copyright 2009-2016, by the California Institute of Technology.
// ALL RIGHTS RESERVED.  United States Government Sponsorship
// acknowledged.
//
// ======================================================================

#ifndef Fw_FilePacket_HPP
#define Fw_FilePacket_HPP

#include <CFDP/Checksum/Checksum.hpp>
#include <Fw/Buffer/Buffer.hpp>
#include <FpConfig.hpp>
#include <Fw/Types/SerialBuffer.hpp>
#include <Fw/Types/Serializable.hpp>

namespace Fw {

  //! \class FilePacket
  //! \brief A file packet
  //!
  union FilePacket {

    public:

      // ----------------------------------------------------------------------
      // Types
      // ----------------------------------------------------------------------

      //! Packet type
      typedef enum {
        T_START = 0,
        T_DATA = 1,
        T_END = 2,
        T_CANCEL = 3,
        T_NONE = 255
      } Type;

      //! The type of a path name
      class PathName {

          friend union FilePacket;

        public:

          //! The maximum length of a path name
          enum { MAX_LENGTH = 255 };

        public:

          //! The length
          U8 length;

          //! Pointer to the path value
          const char *value;

        public:

          //! Initialize a PathName
          void initialize(
              const char *const value //! The path value
          );

          //! Compute the buffer size needed to hold this PathName
          U32 bufferSize() const;

        PRIVATE:

          //! Initialize this PathName from a SerialBuffer
          SerializeStatus fromSerialBuffer(SerialBuffer& serialBuffer);

          //! Write this PathName to a SerialBuffer
          SerializeStatus toSerialBuffer(SerialBuffer& serialBuffer) const;

      };

      //! The type of a packet header
      class Header {

          friend union FilePacket;

        public:

          //! The packet type
          Type type;

          //! The sequence index
          U32 sequenceIndex;

          //! Header size
          enum { HEADERSIZE = sizeof(U8) + sizeof(U32) };

        PRIVATE:

          //! Initialize a file packet header
          void initialize(
              const Type type, //!< The packet type
              const U32 sequenceIndex //!< The sequence index
          );

          //! Compute the buffer size needed to hold this Header
          U32 bufferSize() const;

          //! Initialize this Header from a SerialBuffer
          SerializeStatus fromSerialBuffer(SerialBuffer& serialBuffer);

          //! Write this Header to a SerialBuffer
          SerializeStatus toSerialBuffer(SerialBuffer& serialBuffer) const;

      };

      //! The type of a start packet
      struct StartPacket {

          friend union FilePacket;

        public:

          //! The packet header
          Header header;

          //! The file size
          U32 fileSize;

          //! The source path
          PathName sourcePath;

          //! The destination path
          PathName destinationPath;

        public:

          //! Initialize a StartPacket with sequence number 0
          void initialize(
              const U32 fileSize, //!< The file size
              const char *const sourcePath, //!< The source path
              const char *const destinationPath //!< The destination path
          );

          //! Compute the buffer size needed to hold this StartPacket
          U32 bufferSize() const;

          //! Convert this StartPacket to a Buffer
          SerializeStatus toBuffer(Buffer& buffer) const;

        PRIVATE:

          //! Initialize this StartPacket from a SerialBuffer
          SerializeStatus fromSerialBuffer(SerialBuffer& serialBuffer);

          //! Write this StartPacket to a SerialBuffer
          SerializeStatus toSerialBuffer(SerialBuffer& serialBuffer) const;

      };

      //! The type of a data packet
      class DataPacket {

          friend union FilePacket;

        public:

          //! The packet header
          Header header;

          //! The byte offset of the packet data into the destination file
          U32 byteOffset;

          //! The size of the file data in the packet
          U16 dataSize;

          //! Pointer to the file data
          const U8 *data;

          //! header size
          enum { HEADERSIZE = Header::HEADERSIZE +
              sizeof(U32) +
              sizeof(U16) };


        public:

          //! Initialize a data packet
          void initialize(
              const U32 sequenceIndex, //!< The sequence index
              const U32 byteOffset, //!< The byte offset
              const U16 dataSize, //!< The data size
              const U8 *const data //!< The file data
          );

          //! Compute the buffer size needed to hold this DataPacket
          U32 bufferSize() const;

          //! Convert this DataPacket to a Buffer
          SerializeStatus toBuffer(Buffer& buffer) const;

        PRIVATE:

          //! Initialize this DataPacket from a SerialBuffer
          SerializeStatus fromSerialBuffer(SerialBuffer& serialBuffer);

          //! Compute the fixed-length data size of a StartPacket
          U32 fixedLengthSize() const;

          //! Write this DataPacket to a SerialBuffer
          SerializeStatus toSerialBuffer(SerialBuffer& serialBuffer) const;

      };

      //! The type of an end packet
      class EndPacket {

          friend union FilePacket;

        public:

          //! The packet header
          Header header;

          //! Set the checksum
          void setChecksum(const CFDP::Checksum& checksum);

          //! Get the checksum
          void getChecksum(CFDP::Checksum& checksum) const;

          //! Compute the buffer size needed to hold this EndPacket
          U32 bufferSize() const;

          //! Convert this EndPacket to a Buffer
          SerializeStatus toBuffer(Buffer& buffer) const;

        public:

          //! Initialize an end packet
          void initialize(
              const U32 sequenceIndex, //!< The sequence index
              const CFDP::Checksum& checksum //!< The checksum
          );

        PRIVATE:

          //! The checksum
          U32 checksumValue;

          //! Initialize this EndPacket from a SerialBuffer
          SerializeStatus fromSerialBuffer(SerialBuffer& serialBuffer);

          //! Write this EndPacket to a SerialBuffer
          SerializeStatus toSerialBuffer(SerialBuffer& serialBuffer) const;

      };

      //! The type of a cancel packet
      class CancelPacket {

          friend union FilePacket;

        public:

          //! The packet header
          Header header;

        public:

          //! Initialize a cancel packet
          void initialize(
              const U32 sequenceIndex //!< The sequence index
          );

          //! Compute the buffer size needed to hold this CancelPacket
          U32 bufferSize() const;

          //! Convert this CancelPacket to a Buffer
          SerializeStatus toBuffer(Buffer& buffer) const;

        PRIVATE:

          //! Initialize this CancelPacket from a SerialBuffer
          SerializeStatus fromSerialBuffer(SerialBuffer& serialBuffer);

      };

    public:

      // ----------------------------------------------------------------------
      // Constructor
      // ----------------------------------------------------------------------

      FilePacket() { this->header.type = T_NONE; }

    public:

      // ----------------------------------------------------------------------
      // Public instance methods
      // ----------------------------------------------------------------------

      //! Initialize this from a Buffer
      //!
      SerializeStatus fromBuffer(const Buffer& buffer);

      //! Get this as a Header
      //!
      const Header& asHeader() const;

      //! Get this as a StartPacket
      //!
      const StartPacket& asStartPacket() const;

      //! Get this as a DataPacket
      //!
      const DataPacket& asDataPacket() const;

      //! Get this as an EndPacket
      //!
      const EndPacket& asEndPacket() const;

      //! Get this as a CancelPacket
      //!
      const CancelPacket& asCancelPacket() const;

      //! Initialize this with a StartPacket
      //!
      void fromStartPacket(const StartPacket& startPacket);

      //! Initialize this with a DataPacket
      //!
      void fromDataPacket(const DataPacket& dataPacket);

      //! Initialize this with an EndPacket
      //!
      void fromEndPacket(const EndPacket& endPacket);

      //! Initialize this with a CancelPacket
      //!
      void fromCancelPacket(const CancelPacket& cancelPacket);

      //! Get the buffer size needed to hold this FilePacket
      //!
      U32 bufferSize() const;

      //! Convert this FilePacket to a Buffer
      //!
      SerializeStatus toBuffer(Buffer& buffer) const;

    PRIVATE:

      // ----------------------------------------------------------------------
      // Private methods
      // ----------------------------------------------------------------------

      //! Initialize this from a SerialBuffer
      //!
      SerializeStatus fromSerialBuffer(SerialBuffer& serialBuffer);

    PRIVATE:

      // ----------------------------------------------------------------------
      // Private data
      // ----------------------------------------------------------------------

      //! this, seen as a header
      //!
      Header header;

      //! this, seen as a Start packet
      //!
      StartPacket startPacket;

      //! this, seen as a Data packet
      //!
      DataPacket dataPacket;

      //! this, seen as an End packet
      //!
      EndPacket endPacket;

      //! this, seen as a Cancel packet
      //!
      CancelPacket cancelPacket;

  };

}

#endif