/*
   Convertors for Shift_JIS

   Name: Shift_JIS  (preferred MIME name)
   MIBenum: 17
   Source: A Microsoft code that extends csHalfWidthKatakana to include 
           kanji by adding a second byte when the value of the first 
           byte is in the ranges 81-9F or E0-EF.
   Alias: MS_Kanji 
   Alias: csShiftJIS
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include "xlocale.h"
#include "xwchar.h"

int _SJIS_init __P((_LocaleInfo *loc, const char *encoding));
static void   _SJIS_stateinit __P((mbstate_t *));
static int    _SJIS_mbsinit   __P((const mbstate_t *));
static size_t _SJIS_mbrtowc __P((wchar_t*, const char*, size_t, mbstate_t *));
static size_t _SJIS_wcrtomb __P((char *, wchar_t, mbstate_t *));

int
_SJIS_init(loc, encoding)
	 _LocaleInfo *loc;
	 const char *encoding;
{
	if (!strcasecmp(encoding, "Shift_JIS") ||
		!strcasecmp(encoding, "MS_Kanji")) {
		loc->mbcurmax  = 2;
		loc->stateinit = _SJIS_stateinit;
		loc->mbsinit   = _SJIS_mbsinit;
		loc->mbrtowc   = _SJIS_mbrtowc;
		loc->wcrtomb   = _SJIS_wcrtomb;
		return 0;
	} else
		return -1;
}

static void
_SJIS_stateinit(state)
	 mbstate_t *state;
{
}

static int
_SJIS_mbsinit(state)
	 const mbstate_t *state;
{
	return 1;
}

/* Shift_JISコードの1 byte code診断マクロ */
#if 0
#define issjis1(c) (((c) > 0x80 && (c) <= 0x9f) \
        || ((c) >= 0xe0 && (c) <= 0xef))
#else
#define issjis1(c) ((unsigned)((c) ^ 0x20) - 0xa1 < 0x3c)
#endif

/* Shift_JISコードの2 byte code診断マクロ */
#define issjis2(c) ((c) >= 0x40 && (c) <= 0xfc)

/* Shift_JISコードのカナコード診断マクロ */
#define issjis_kana(c) ((c) > 0xa0 && (c) <= 0xdf)

static size_t
_SJIS_mbrtowc(pwc, s, len, mbs)
	 wchar_t *pwc;
	 const char *s;
	 size_t len;
	 mbstate_t *mbs;
{
	u_char *in = (u_char *)s;
	int c, c2;
	wchar_t wc;

	if (s == NULL) {			/* initial state */
/*		_SJIS_stateinit(mbs);	*/
		return 0; 				/* Shift_Jis has no states */
	}
	
	if (len < 1)
		return -1;

	if (c=*in++,issjis1(c)) { 	/* kanji */
		c2 = *in++;
		if (len < 2 || !issjis2(c2)) {
			fprintf(stderr, "bad code!\n");
			return -1;	/* bad code */
		} else if (c2 < 0x9f) {
			c = ((c - (c < 0xa0 ? 0x70 : 0xb0)) << 1) -1;
			c2 -= (c2 > 0x7f ? 0x20 : 0x1f);
		} else {
			c = ((c - (c < 0xa0 ? 0x70 : 0xb0)) << 1);
			c2 -= 0x7e;
		}
		wc = HEAD_JISX0208 | ((c&0x7f)<<8)  | (c2&0x7f);
	} else if (issjis_kana(c)) {	/* kana */
		wc = HEAD_JISX0201 | (c & 0x7f);
	} else
		wc = c;

	if (pwc)
		*pwc = wc;

	return ((const char*)in - s);	/* return length */
}

static size_t
_SJIS_wcrtomb(s, wc, wcs)
	 char *s;
	 wchar_t wc;
	 mbstate_t *wcs;
{
	return 1;
}