// Copyright (c) 1994 James Clark

// See the file COPYING for copying permission.

#include "splib.h"

#include "IdentityCodingSystem.h"

#include <limits.h>

#ifdef SP_NAMESPACE

namespace SP_NAMESPACE {

#endif

class IdentityDecoder : public Decoder {

public:

  size_t decode(Char *to, const char *from, size_t fromLen,

		const char **rest);

  Boolean convertOffset(unsigned long &offset) const;

};

class IdentityEncoder : public RecoveringEncoder {

public:

  IdentityEncoder();

  void output(const Char *, size_t, OutputByteStream *);

};

IdentityCodingSystem::IdentityCodingSystem()

{

}

Decoder *IdentityCodingSystem::makeDecoder() const

{

  return new IdentityDecoder;

}

Encoder *IdentityCodingSystem::makeEncoder() const

{

  return new IdentityEncoder;

}

Boolean IdentityCodingSystem::isIdentity() const

{

  return 1;

}

size_t IdentityDecoder::decode(Char *to, const char *from, size_t fromLen,

			       const char **rest)

{

  if (sizeof(Char) == sizeof(char) && from == (char *)to) {

    *rest = from + fromLen;

    return fromLen;

  }

  for (size_t n = fromLen; n > 0; n--)

    *to++ = (unsigned char)*from++; // zero extend

  *rest = from;

  return fromLen;

}

Boolean IdentityDecoder::convertOffset(unsigned long &) const

{

  return true;

}

IdentityEncoder::IdentityEncoder()

{

}

void IdentityEncoder::output(const Char *s, size_t n, OutputByteStream *sb)

{

  if (sizeof(Char) != sizeof(char)) {

    for (size_t i = 0; i < n; i++) {

      Char c = s[i];

      if (c > UCHAR_MAX)

	handleUnencodable(c, sb);

      else

	sb->sputc((unsigned char)c);

    }

  }

  else

    sb->sputn((const char *)s, n);

}

#ifdef SP_NAMESPACE

}

#endif