/*-
 * Copyright (c) 1995 Alex Tatmanjants <alex@elvisti.kiev.ua>
 *		at Electronni Visti IA, Kiev, Ukraine.
 *			All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#define _GNU_SOURCE
#include <sys/cdefs.h>

#include "namespace.h"
#include "rune.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include "sysexits.h"
#include "un-namespace.h"

#include "collate.h"

extern char *_PathLocale;
int __collate_load_error = 1;
int __collate_substitute_nontrivial;
char __collate_version[STR_LEN];
u_char __collate_substitute_table[UCHAR_MAX + 1][STR_LEN];
struct __collate_st_char_pri __collate_char_pri_table[UCHAR_MAX + 1];
struct __collate_st_chain_pri __collate_chain_pri_table[TABLE_SIZE];

#define FREAD(a, b, c, d) \
	do { \
		if (fread(a, b, c, d) != c) { \
			fclose(d); \
			return -1; \
		} \
	} while(0)

void __collate_err(int ex, const char *f);

int
__collate_load_tables(char *encoding)
{
	char buf[PATH_MAX];
	FILE *fp;
	int i, save_load_error;

	save_load_error = __collate_load_error;
	__collate_load_error = 1;
	if (!encoding) {
		__collate_load_error = save_load_error;
		return -1;
	}
	if (!strcmp(encoding, "C") || !strcmp(encoding, "POSIX"))
		return 0;
	if (!_PathLocale) {
		__collate_load_error = save_load_error;
		return -1;
	}
	/* Range checking not needed, encoding has fixed size */
	(void) strcpy(buf, _PathLocale);
	(void) strcat(buf, "/");
	(void) strcat(buf, encoding);
	(void) strcat(buf, "/LC_COLLATE");
	if ((fp = fopen(buf, "r")) == NULL) {
		__collate_load_error = save_load_error;
		return -1;
	}
	FREAD(__collate_version, sizeof(__collate_version), 1, fp);
	if (strcmp(__collate_version, COLLATE_VERSION) != 0) {
		fclose(fp);
		return -1;
	}
	FREAD(__collate_substitute_table, sizeof(__collate_substitute_table),
	      1, fp);
	FREAD(__collate_char_pri_table, sizeof(__collate_char_pri_table), 1,
	      fp);
	FREAD(__collate_chain_pri_table, sizeof(__collate_chain_pri_table), 1,
	      fp);
	fclose(fp);
	__collate_load_error = 0;
	
	__collate_substitute_nontrivial = 0;
	for (i = 0; i < UCHAR_MAX + 1; i++) {
		if (__collate_substitute_table[i][0] != i ||
		    __collate_substitute_table[i][1] != 0) {
			__collate_substitute_nontrivial = 1;
			break;
		}
	}

	return 0;
}

u_char *
__collate_substitute(const u_char *s)
{
	int dest_len, len, nlen;
	int delta = strlen((const char *) s);
	u_char *dest_str = NULL;

	if(s == NULL || *s == '\0')
		return __collate_strdup((u_char *) "");
	delta += delta / 8;
	dest_str = (u_char *) malloc(dest_len = delta);
	if(dest_str == NULL)
		__collate_err(EX_OSERR, __FUNCTION__);
	len = 0;
	while(*s) {
		nlen = len + strlen((const char *)
				    __collate_substitute_table[*s]);
		if (dest_len <= nlen) {
			dest_str = reallocf(dest_str, dest_len = nlen + delta);
			if(dest_str == NULL)
				__collate_err(EX_OSERR, __FUNCTION__);
		}
		strcpy((char *) dest_str + len,
		       (const char *) __collate_substitute_table[*s++]);
		len = nlen;
	}
	return dest_str;
}

void
__collate_lookup(const u_char *t,
                 int *len,
                 int *prim,
                 int *sec)
{
	struct __collate_st_chain_pri *p2;

	*len = 1;
	*prim = *sec = 0;
	for(p2 = __collate_chain_pri_table; p2->str[0]; p2++) {
		if(strncmp((const char *) t, (const char *) p2->str,
			   strlen((const char *) p2->str)) == 0) {
			*len = strlen((const char *) p2->str);
			*prim = p2->prim;
			*sec = p2->sec;
			return;
		}
	}
	*prim = __collate_char_pri_table[*t].prim;
	*sec = __collate_char_pri_table[*t].sec;
}

u_char *
__collate_strdup(u_char *s)
{
	u_char *t = (u_char *) strdup((const char *) s);

	if (t == NULL)
		__collate_err(EX_OSERR, __FUNCTION__);
	return t;
}

void
__collate_err(int ex, const char *f)
{
	const char *s;
	int serrno = errno;

	/* Be careful to change write counts if you change the strings */
	write(STDERR_FILENO, "collate_error: ", 15);
	write(STDERR_FILENO, f, strlen(f));
	write(STDERR_FILENO, ": ", 2);
	s = strerror(serrno);
	write(STDERR_FILENO, s, strlen(s));
	write(STDERR_FILENO, "\n", 1);
	exit(ex);
}

#ifdef COLLATE_DEBUG
void
__collate_print_tables()
{
	int i;
	struct __collate_st_chain_pri *p2;

	printf("Substitute table:\n");
	for (i = 0; i < UCHAR_MAX + 1; i++)
	    if (i != *__collate_substitute_table[i])
		printf("\t'%c' --> \"%s\"\n", i,
		       __collate_substitute_table[i]);
	printf("Chain priority table:\n");
	for (p2 = __collate_chain_pri_table; p2->str[0]; p2++)
		printf("\t\"%s\" : %d %d\n\n", p2->str, p2->prim, p2->sec);
	printf("Char priority table:\n");
	for (i = 0; i < UCHAR_MAX + 1; i++)
		printf("\t'%c' : %d %d\n", i, __collate_char_pri_table[i].prim,
		       __collate_char_pri_table[i].sec);
}
#endif
