#include "StdAfx.h"
#include "Japanese.h"

//
// CP932: Shift-JIS (Japan Industry Standard)
//

#define MACRO_IsLeadByte(c) ((0x81 <= (c) && (c) <= 0x9f) || ((0xe0 <= (c)) && (c) <= 0xfc))
#define MACRO_IsTailByte(c) ((0x40 <= (c) && (c) <= 0x7e) || (0x80 <= (c) && (c) <= 0xfc))

BOOL ShiftJIS_IsLeadByte( const char chByte )
{
	const unsigned char byByte = (const unsigned char) chByte;

	return MACRO_IsLeadByte( byByte );
}

BOOL ShiftJIS_IsTrailByte( const char chByte )
{
	const unsigned char byByte = (const unsigned char) chByte;

	return MACRO_IsTailByte( byByte );
}

int ShiftJIS_StringCompareCI( LPCSTR szStringLeft, LPCSTR szStringRight, size_t sizeLength )
{
	const unsigned char* uszString1 = (const unsigned char*) szStringLeft;
	const unsigned char* uszString2 = (const unsigned char*) szStringRight;
	unsigned short c1, c2;

	if( sizeLength == 0 )
		return 0;
	while( sizeLength-- ) {
		c1 = *uszString1++;
		if( MACRO_IsLeadByte(c1) ) {
			if( sizeLength == 0 ) {
				c1 = 0;
				c2 = MACRO_IsLeadByte( *uszString2 ) ? 0 : *uszString2;
				goto test;
			}
			if( *uszString1 == '\0' )
				c1 = 0;
			else {
				c1 = ((c1 << 8) | *uszString1++);
			}
		} else
			c1 = tolower(c1);

		c2 = *uszString2++;
		if( MACRO_IsLeadByte(c2) ) {
			if( sizeLength == 0 ) {
				c2 = 0;
				goto test;
			}
			sizeLength--;
			if( *uszString2 == '\0' )
				c2 = 0;
			else {
				c2 = ((c2 << 8) | *uszString2++);
			}
		} else
			c2 = tolower(c2);
test:
        if (c1 != c2)
            return( (c1 > c2) ? 1 : -1);

        if (c1 == 0)
            return(0);
	}
	return 0;
}