/* Copyright (C) 2001-2006 Artifex Software, Inc.
   All Rights Reserved.
  
   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied, modified
   or distributed except as expressly authorized under the terms of that
   license.  Refer to licensing information at http://www.artifex.com/
   or contact Artifex Software, Inc.,  7 Mt. Lassen Drive - Suite A-134,
   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
*/

/* $Id: gp_wgetv.c 8022 2007-06-05 22:23:38Z giles $ */
/* MS Windows implementation of gp_getenv */

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

/* prototypes */
int gp_getenv_registry(HKEY hkeyroot, const char *key, const char *name, 
    char *ptr, int *plen);

/* ------ Environment variables ------ */

/* Get the value of an environment variable.  See gp.h for details. */
int 
gp_getenv(const char *name, char *ptr, int *plen)
{
    const char *str = getenv(name);

    if (str) {
	int len = strlen(str);

	if (len < *plen) {
	    /* string fits */
	    strcpy(ptr, str);
	    *plen = len + 1;
	    return 0;
	}
	/* string doesn't fit */
	*plen = len + 1;
	return -1;
    }
    /* environment variable was not found */

#ifdef __WIN32__
    {
	/* If using Win32, look in the registry for a value with
	 * the given name.  The registry value will be under the key
	 * HKEY_CURRENT_USER\Software\GPL Ghostscript\N.NN
	 * or if that fails under the key
	 * HKEY_LOCAL_MACHINE\Software\GPL Ghostscript\N.NN
	 * where "GPL Ghostscript" is actually gs_productfamily
	 * and N.NN is obtained from gs_revision.
	 */
	DWORD version = GetVersion();

	if (!(((HIWORD(version) & 0x8000) != 0)
	      && ((HIWORD(version) & 0x4000) == 0))) {
	    /* not Win32s */
	    int code;
	    char key[256];
	    char dotversion[16];
	    
	    sprintf(dotversion, "%d.%02d", (int)(gs_revision / 100),
		    (int)(gs_revision % 100));
	    sprintf(key, "Software\\%s\\%s", gs_productfamily, dotversion);

	    code = gp_getenv_registry(HKEY_CURRENT_USER, key, name, ptr, plen);
	    if ( code <= 0 )
		return code;	/* found it */

	    code = gp_getenv_registry(HKEY_LOCAL_MACHINE, key, name, ptr, plen);
	    if ( code <= 0 )
		return code;	/* found it */
	}
    }
#endif

    /* nothing found at all */

    if (*plen > 0)
	*ptr = 0;
    *plen = 1;
    return 1;
}


/*
 * Get a named registry value.
 * Key = hkeyroot\\key, named value = name.
 * name, ptr, plen and return values are the same as in gp_getenv();
 */

int 
gp_getenv_registry(HKEY hkeyroot, const char *key, const char *name, 
    char *ptr, int *plen)
{
    HKEY hkey;
    DWORD cbData, keytype;
    BYTE b;
    LONG rc;
    BYTE *bptr = (BYTE *)ptr;

    if (RegOpenKeyEx(hkeyroot, 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 */
}
