/**
 * hanyupinyin.c
 *
 * Copyright (c) 2005, 2006
 *	libchewing Core Team. See ChangeLog for details.
 *
 * See the file "COPYING" for information on usage and redistribution
 * of this file.
 */

/* @(#)hanyupinyin.c
 */

#include <stdio.h>
#include <string.h>
#include "hanyupinyin.h"
#include "hash.h"
#include "private.h"
#include "plat_mmap.h"

#define PINYIN_TAB_NAME "pinyin.tab"
/* */
#define CHEWING_DATADIR "/Library/OpenVanilla/0.7.2/Modules/OVIMSpaceChewing03"
/*
  according to XCIN bims_pinyin.cin
 */
static keymap* keytable;
static int INIT_FLAG = 0;
static int N_TOTAL = 0;

static void FreeMap()
{
	if (keytable)
		free(keytable);
}

void InitMap()
{
	int i;
	FILE *fd;
	INIT_FLAG = 1;
	if ( getenv( "HOME" ) ) {
		char *filedir = strcat( getenv( "HOME" ), CHEWING_HASH_PATH );
		char *filepath = strcat( filedir, PINYIN_TAB_NAME );

		if (access(filepath, R_OK) == 0) {
			/* Use user-defined tables */
			fd = fopen( filepath, "r" );
		}
		else {
			/* Failback */
			fd = fopen( CHEWING_DATADIR PLAT_SEPARATOR PINYIN_TAB_NAME, "r" );
		}
	}
	else {
		/* Failback */
		fd = fopen( CHEWING_DATADIR PLAT_SEPARATOR PINYIN_TAB_NAME, "r" );
	}

	if ( fd ) {
		addTerminateService( FreeMap );
		fscanf( fd, "%d", &N_TOTAL );
		keytable = ALC( keymap, N_TOTAL );
		for ( i = 0; i < N_TOTAL - 1; i++ ) {
			memset( &keytable[i], 0, sizeof(keymap) );
			fscanf( fd, "%s %s",
					keytable[ i ].pinyin,
					keytable[ i ].zuin );
		}
		fclose( fd );
		return;
	}
		
}

static int compkey( const void *k1, const void *k2 )
{
	keymap *key1 = (keymap *) k1;
	keymap *key2 = (keymap *) k2;
	return strcmp( key1->pinyin, key2->pinyin );
}

/**
 * Map pinyin key-sequence to Zuin key-sequence.
 * Caller should allocate char zuin[4].
 * 
 * Non-Zero: Fail to fully convert
 * 
 * @retval 0 Success
 */
int HanyuPinYinToZuin( char *pinyinKeySeq, char *zuinKeySeq )
{
	if ( ! INIT_FLAG )
		InitMap();
	/*
	 * pinyinKeySeq[] should have at most 6 letters (Shuang)
	 * zuinKeySeq[] has at most 3 letters.
	 */
	keymap key, *res;
	strcpy( key.pinyin, pinyinKeySeq );

	DEBUG_CHECKPOINT();
	res = bsearch( &key, keytable, N_TOTAL, sizeof(keymap), compkey );
	if ( res != NULL )
		strcpy( zuinKeySeq, res->zuin );
	else
		zuinKeySeq = strdup( "" );
	return 0;
}