/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is the Netscape Portable Runtime (NSPR).
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998-2000
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */


/*

Copyright 1987, 1988 by the Student Information Processing Board
	of the Massachusetts Institute of Technology

Permission to use, copy, modify, and distribute this software
and its documentation for any purpose and without fee is
hereby granted, provided that the above copyright notice
appear in all copies and that both that copyright notice and
this permission notice appear in supporting documentation,
and that the names of M.I.T. and the M.I.T. S.I.P.B. not be
used in advertising or publicity pertaining to distribution
of the software without specific, written prior permission.
M.I.T. and the M.I.T. S.I.P.B. make no representations about
the suitability of this software for any purpose.  It is
provided "as is" without express or implied warranty.

*/

#include <string.h>
#ifdef SUNOS4
#include "md/sunos4.h"  /* for strerror */
#endif
#include <assert.h>
#include <errno.h>
#include "prmem.h"
#include "prerror.h"

#define	ERRCODE_RANGE	8	/* # of bits to shift table number */
#define	BITS_PER_CHAR	6	/* # bits to shift per character in name */

#ifdef NEED_SYS_ERRLIST
extern char const * const sys_errlist[];
extern const int sys_nerr;
#endif

/* List of error tables */
struct PRErrorTableList {
    struct PRErrorTableList *next;
    const struct PRErrorTable *table;
    struct PRErrorCallbackTablePrivate *table_private;
};
static struct PRErrorTableList * Table_List = (struct PRErrorTableList *) NULL;

/* Supported languages */
static const char * default_languages[] = { "i-default", "en", 0 };
static const char * const * callback_languages = default_languages;

/* Callback info */
static struct PRErrorCallbackPrivate *callback_private = 0;
static PRErrorCallbackLookupFn *callback_lookup = 0;
static PRErrorCallbackNewTableFn *callback_newtable = 0;


static const char char_set[] =
	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_";

static const char *
error_table_name (PRErrorCode num)
{
    static char buf[6];	/* only used if internal code problems exist */

    long ch;
    int i;
    char *p;

    /* num = aa aaa abb bbb bcc ccc cdd ddd d?? ??? ??? */
    p = buf;
    num >>= ERRCODE_RANGE;
    /* num = ?? ??? ??? aaa aaa bbb bbb ccc ccc ddd ddd */
    num &= 077777777;
    /* num = 00 000 000 aaa aaa bbb bbb ccc ccc ddd ddd */
    for (i = 4; i >= 0; i--) {
	ch = (num >> BITS_PER_CHAR * i) & ((1 << BITS_PER_CHAR) - 1);
	if (ch != 0)
	    *p++ = char_set[ch-1];
    }
    *p = '\0';
    return(buf);
}

PR_IMPLEMENT(const char *)
PR_ErrorToString(PRErrorCode code, PRLanguageCode language)
{
    /* static buffer only used if code is using inconsistent error message
     * numbers, so just ignore the possible thread contention
     */
    static char buffer[25];

    const char *msg;
    int offset;
    PRErrorCode table_num;
    struct PRErrorTableList *et;
    int started = 0;
    char *cp;

    for (et = Table_List; et; et = et->next) {
	if (et->table->base <= code &&
	    et->table->base + et->table->n_msgs > code) {
	    /* This is the right table */
	    if (callback_lookup) {
		msg = callback_lookup(code, language, et->table,
		    callback_private, et->table_private);
		if (msg) return msg;
	    }
    
	    return(et->table->msgs[code - et->table->base].en_text);
	}
    }

    if (code >= 0 && code < 256) {
	return strerror(code);
    }

    offset = (int) (code & ((1<<ERRCODE_RANGE)-1));
    table_num = code - offset;
    strcpy (buffer, "Unknown code ");
    if (table_num) {
	strcat(buffer, error_table_name (table_num));
	strcat(buffer, " ");
    }
    for (cp = buffer; *cp; cp++)
	;
    if (offset >= 100) {
	*cp++ = (char)('0' + offset / 100);
	offset %= 100;
	started++;
    }
    if (started || offset >= 10) {
	*cp++ = (char)('0' + offset / 10);
	offset %= 10;
    }
    *cp++ = (char)('0' + offset);
    *cp = '\0';
    return(buffer);
}

PR_IMPLEMENT(const char *)
PR_ErrorToName(PRErrorCode code)
{
    struct PRErrorTableList *et;

    for (et = Table_List; et; et = et->next) {
	if (et->table->base <= code &&
	    et->table->base + et->table->n_msgs > code) {
	    /* This is the right table */
	    return(et->table->msgs[code - et->table->base].name);
	}
    }

    return 0;
}

PR_IMPLEMENT(const char * const *)
PR_ErrorLanguages(void)
{
    return callback_languages;
}

PR_IMPLEMENT(PRErrorCode)
PR_ErrorInstallTable(const struct PRErrorTable *table)
{
    struct PRErrorTableList * new_et;

    new_et = (struct PRErrorTableList *)
					PR_Malloc(sizeof(struct PRErrorTableList));
    if (!new_et)
	return errno;	/* oops */
    new_et->table = table;
    if (callback_newtable) {
	new_et->table_private = callback_newtable(table, callback_private);
    } else {
	new_et->table_private = 0;
    }
    new_et->next = Table_List;
    Table_List = new_et;
    return 0;
}

PR_IMPLEMENT(void)
PR_ErrorInstallCallback(const char * const * languages,
		       PRErrorCallbackLookupFn *lookup, 
		       PRErrorCallbackNewTableFn *newtable,
		       struct PRErrorCallbackPrivate *cb_private)
{
    struct PRErrorTableList *et;

    assert(strcmp(languages[0], "i-default") == 0);
    assert(strcmp(languages[1], "en") == 0);
    
    callback_languages = languages;
    callback_lookup = lookup;
    callback_newtable = newtable;
    callback_private = cb_private;

    if (callback_newtable) {
	for (et = Table_List; et; et = et->next) {
	    et->table_private = callback_newtable(et->table, callback_private);
	}
    }
}