// Copyright (c) 1997 James Clark

// See the file COPYING for copying permission.

#include "splib.h"

#ifdef SP_MULTI_BYTE

#include "Big5CodingSystem.h"

#ifdef SP_NAMESPACE

namespace SP_NAMESPACE {

#endif

class Big5Decoder : public Decoder {

public:

  Big5Decoder() { }

  size_t decode(Char *, const char *, size_t, const char **);

private:

};

class Big5Encoder : public Encoder {

public:

  Big5Encoder() { }

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

};

Decoder *Big5CodingSystem::makeDecoder() const

{

  return new Big5Decoder;

}

Encoder *Big5CodingSystem::makeEncoder() const

{

  return new Big5Encoder;

}

size_t Big5Decoder::decode(Char *to, const char *s,

			   size_t slen, const char **rest)

{

  Char *start = to;

  const unsigned char *us = (const unsigned char *)s;

  while (slen > 0) {

    if (!(*us & 0x80)) {

      *to++ = *us++;

      slen--;

    }

    else {

      if (slen < 2)

	break;

      slen -= 2;

      unsigned short n = *us++ << 8;

      n |= *us++;

      *to++ = n;

    }

  }

  *rest = (const char *)us;

  return to - start;

}

void Big5Encoder::output(const Char *s, size_t n, OutputByteStream *sb)

{

  for (; n > 0; s++, n--) {

    Char c = *s;

    if (c < 0x80)

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

    else if (c & 0x8000) {

      sb->sputc((unsigned char)(c >> 8));

      sb->sputc((unsigned char)(c & 0xff));

    }

    else

      handleUnencodable(c, sb);

  }

}

#ifdef SP_NAMESPACE

}

#endif

#else /* not SP_MULTI_BYTE */

#ifndef __GNUG__

static char non_empty_translation_unit;	// sigh

#endif

#endif /* not SP_MULTI_BYTE */