/* Copyright (C) 2001, Ghostgum Software Pty Ltd.  All rights reserved.
  
  This program is free software; you can redistribute it and/or modify it
  under the terms of the GNU General Public License as published by the
  Free Software Foundation; either version 2 of the License, or (at your
  option) any later version.

  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License along
  with this program; if not, write to the Free Software Foundation, Inc.,
  59 Temple Place, Suite 330, Boston, MA, 02111-1307.

*/

/*$Id: dwreg.c,v 1.1.2.2.2.1 2003/01/17 00:49:00 giles Exp $ */
/* MS Windows registry values */

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>		/* for getenv */
#include <string.h>
#include "gscdefs.h"		/* for gs_productfamily and gs_revision */

/* We store registry named values under the key 
 * "Software\\GNU Ghostscript"
 * where "GNU Ghostscript" is actually gs_productfamily.
 * Either HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER will be used.
 */
int
win_registry_key(char *buf, int len)
{
    const char *software = "Software";
    if (strlen(software) + 1 + strlen(gs_productfamily) >= len)
	return -1;

   strcpy(buf, software);
   strcat(buf, "\\");
   strcat(buf, gs_productfamily);
   return 0;
}

/*
 * Get a named registry value from HKCU.
 * name, ptr, plen and return values are the same as in gp_getenv();
 */
int 
win_get_reg_value(const char *name, char *ptr, int *plen)
{
    HKEY hkey;
    DWORD cbData, keytype;
    BYTE b;
    LONG rc;
    BYTE *bptr = (BYTE *)ptr;
    char key[256];

    win_registry_key(key, sizeof(key));
    if (RegOpenKeyEx(HKEY_CURRENT_USER, key, 0, KEY_READ, &hkey)
	== ERROR_SUCCESS) {
	keytype = REG_SZ;
	cbData = *plen;
	if (bptr == (char *)NULL)
	    bptr = &b;	/* Registry API won't return ERROR_MORE_DATA */
			/* if ptr is NULL */
	rc = RegQueryValueEx(hkey, (char *)name, 0, &keytype, bptr, &cbData);
	RegCloseKey(hkey);
	if (rc == ERROR_SUCCESS) {
	    *plen = cbData;
	    return 0;	/* found environment variable and copied it */
	} else if (rc == ERROR_MORE_DATA) {
	    /* buffer wasn't large enough */
	    *plen = cbData;
	    return -1;
	}
    }
    return 1;	/* not found */
}

/*
 * Set a named registry value under HKCU.
 * name = name of named value
 * str = value of named value
 * Returns 0 on success.
 */
int 
win_set_reg_value(const char *name, const char *value)
{
    HKEY hkey;
    LONG rc;
    char key[256];
    DWORD dwDisposition;

    win_registry_key(key, sizeof(key));
    rc = RegOpenKeyEx(HKEY_CURRENT_USER, key, 0, KEY_WRITE, &hkey);
    if (rc != ERROR_SUCCESS)
	rc = RegCreateKeyEx(HKEY_CURRENT_USER, key, 0, "", 0,
	    KEY_ALL_ACCESS, NULL, &hkey, &dwDisposition);
    if (rc == ERROR_SUCCESS) {
	rc = RegSetValueEx(hkey, name, 0, REG_SZ, 
		(CONST BYTE *)value, strlen(value)+1);
	RegCloseKey(hkey);
    }

    return rc == ERROR_SUCCESS ? 0 : -1;
}