/*=========================================================================

  Program:   DICOMParser
  Module:    DICOMSource.h
  Language:  C++

  Copyright (c) 2003 Matt Turek
  All rights reserved.
  See Copyright.txt for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

#ifndef __DICOMSOURCE_H_
#define __DICOMSOURCE_H_

#ifdef _MSC_VER
#pragma warning(disable : 4514)
#pragma warning(push, 3)
#endif

#include <cstring>
#include <fstream>
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string>

#include "DICOMConfig.h"
#include "DICOMTypes.h"

namespace DICOMPARSER_NAMESPACE
{
//
// Abstraction of a DICOM data source used by the DICOMParser.
//
class DICOM_EXPORT DICOMSource
{
public:
  DICOMSource();
  virtual ~DICOMSource();

  //
  // Return the position in the source
  //
  virtual long Tell() = 0;

  //
  // Move to a particular position in the source.
  //
  virtual void SkipToPos(long) = 0;

  //
  // Return the size of the source.
  //
  virtual long GetSize() = 0;

  //
  // Skip a number of bytes.
  //
  virtual void Skip(long) = 0;

  //
  // Skip to the beginning of the source.
  //
  virtual void SkipToStart() = 0;

  //
  // Read data of length len.
  //
  virtual void Read(void* data, long len) = 0;

  //
  // Read a double byte of data.
  //
  virtual doublebyte ReadDoubleByte();
  virtual doublebyte ReadDoubleByteAsLittleEndian();

  //
  // Read a quadbyte of data.
  //
  virtual quadbyte ReadQuadByte();

  //
  // Read nbytes of data up to 4 bytes.
  //
  virtual quadbyte ReadNBytes(int len);

  //
  // Read a float an ascii.
  //
  virtual float ReadAsciiFloat(int len);

  //
  // Read an int as ascii.
  //
  virtual int ReadAsciiInt(int len);

  //
  // Read an array of ascii characters.
  //
  virtual char* ReadAsciiCharArray(int len);

  //
  // Convert the data to signed long.
  //
  static long ReturnAsSignedLong(unsigned char* data, bool)
  {
    return *(reinterpret_cast<quadbyte*>(data));
  }

  //
  // Convert the data to unsigned long.
  //
  static ulong ReturnAsUnsignedLong(unsigned char* data, bool)
  {
    return *(reinterpret_cast<ulong*>(data));
  }

  //
  // Convert data to unsigned short.
  //
  static ushort ReturnAsUnsignedShort(unsigned char* data, bool)
  {
    return *(reinterpret_cast<doublebyte*>(data));
  }

  //
  // Convert data to signed short.
  //
  static short int ReturnAsSignedShort(unsigned char* data, bool)
  {
    return *(reinterpret_cast<short int*>(data));
  }

  //
  // Convert data to int.
  //
  static int ReturnAsInteger(unsigned char* data, bool)
  {
    return static_cast<int>(atoi((const char*)data));
  }

  static float ReturnAsFloat(unsigned char* data, bool)
  {
    return static_cast<float>(atof((const char*)data));
  }

  bool GetPlatformIsBigEndian() { return PlatformIsBigEndian; }

  void SetPlatformIsBigEndian(bool v) { this->PlatformIsBigEndian = v; }

  //
  // Swap the bytes in an array of unsigned shorts.
  //
  static void swapShorts(ushort* ip, ushort* op, int count)
  {
    while (count)
    {
      *op++ = swapShort(*ip++);
      count--;
    }
  }

  //
  // Swap the bytes in an array of unsigned longs.
  //
  static void swapLongs(ulong* ip, ulong* op, int count)
  {
    while (count)
    {
      *op++ = swapLong(*ip++);
      count--;
    }
  }

  //
  // Swap the bytes in an unsigned short.
  //
  static ushort swapShort(ushort v) { return ushort((v << 8) | (v >> 8)); }

  //
  // Swap the bytes in an unsigned long.
  //
  static ulong swapLong(ulong v)
  {
    return ulong((v << 24) | ((v << 8) & 0x00ff0000) | ((v >> 8) & 0x0000ff00) | (v >> 24));
  }

  const char* GetPlatformEndian() { return this->PlatformEndian; }

protected:
  DICOMSource(const DICOMSource&);
  void operator=(const DICOMSource&);

  //
  // Flag for swaping bytes.
  //
  bool PlatformIsBigEndian;

  //
  // Platform endianness
  //
  const char* PlatformEndian;

private:
};
} // namespace DICOMPARSER_NAMESPACE
#ifdef _MSC_VER
#pragma warning(pop)
#endif

#endif // __DICOMSOURCE_H_