/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*************************************************************************
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 * 
 * Copyright 2000, 2010 Oracle and/or its affiliates.
 *
 * OpenOffice.org - a multi-platform office productivity suite
 *
 * This file is part of OpenOffice.org.
 *
 * OpenOffice.org is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * only, as published by the Free Software Foundation.
 *
 * OpenOffice.org 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 Lesser General Public License version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenOffice.org.  If not, see
 * <http://www.openoffice.org/license.html>
 * for a copy of the LGPLv3 License.
 *
 ************************************************************************/

#include "precompiled_cppuhelper.hxx"
#include "sal/config.h"

#include <stdlib.h>
#include <string.h>

#if defined WNT

#define WIN32_LEAN_AND_MEAN
#include <windows.h>

/*
 * Gets the installation path from the Windows Registry for the specified
 * registry key.
 *
 * @param hroot       open handle to predefined root registry key
 * @param subKeyName  name of the subkey to open
 *
 * @return the installation path or NULL, if no installation was found or
 *         if an error occurred
 */
static char* getPathFromRegistryKey( HKEY hroot, const char* subKeyName )
{
    HKEY hkey;
    DWORD type;
    char* data = NULL;
    DWORD size;

    /* open the specified registry key */
    if ( RegOpenKeyEx( hroot, subKeyName, 0, KEY_READ, &hkey ) != ERROR_SUCCESS )
    {
        return NULL;
    }

    /* find the type and size of the default value */
    if ( RegQueryValueEx( hkey, NULL, NULL, &type, NULL, &size) != ERROR_SUCCESS )
    {
        RegCloseKey( hkey );
        return NULL;
    }

    /* get memory to hold the default value */
    data = (char*) malloc( size );

    /* read the default value */
    if ( RegQueryValueEx( hkey, NULL, NULL, &type, (LPBYTE) data, &size ) != ERROR_SUCCESS )
    {
        RegCloseKey( hkey );
        return NULL;
    }

    /* release registry key handle */
    RegCloseKey( hkey );

    return data;
}

/*
 * Gets the installation path from the Windows Registry.
 *
 * @return the installation path or NULL, if no installation was found or
 *         if an error occurred
 */
static char* platformSpecific()
{
    const char* SUBKEYNAME = "Software\\LibreOffice\\UNO\\InstallPath";

    char* path = NULL;
    
    /* read the key's default value from HKEY_CURRENT_USER */
    path = getPathFromRegistryKey( HKEY_CURRENT_USER, SUBKEYNAME );

    if ( path == NULL )
    {
        /* read the key's default value from HKEY_LOCAL_MACHINE */
        path = getPathFromRegistryKey( HKEY_LOCAL_MACHINE, SUBKEYNAME );
    }

    return path;
}

#else

#include <unistd.h>
#include <limits.h>

/*     
 * Gets the installation path from the PATH environment variable.
 *
 * <p>An installation is found, if the executable 'soffice' or a symbolic link
 * is in one of the directories listed in the PATH environment variable.</p>
 *
 * @return the installation path or NULL, if no installation was found or 
 *         if an error occurred
 */
static char* platformSpecific()
{
    const int SEPARATOR = '/';
    const char* PATHSEPARATOR = ":";
    const char* PATHVARNAME = "PATH";
    const char* APPENDIX = "/libreoffice";

    char* path = NULL;
    char* env = NULL;
    char* str = NULL;
    char* dir = NULL;
    char* file = NULL;
    char* resolved = NULL;
    char* sep = NULL;

    char buffer[PATH_MAX];
    int pos;

    /* get the value of the PATH environment variable */
    env = getenv( PATHVARNAME );
    str = (char*) malloc( strlen( env ) + 1 );
    strcpy( str, env );

    /* get the tokens separated by ':' */
    dir = strtok( str, PATHSEPARATOR );

    while ( dir )
    {
        /* construct soffice file path */
        file = (char*) malloc( strlen( dir ) + strlen( APPENDIX ) + 1 );
        strcpy( file, dir );
        strcat( file, APPENDIX );

        /* check existence of soffice file */
        if ( !access( file, F_OK ) )
        {
            /* resolve symbolic link */
            resolved = realpath( file, buffer );

            if ( resolved != NULL )
            {
                /* get path to program directory */
                sep = strrchr( resolved, SEPARATOR );

                if ( sep != NULL )
                {
                    pos = sep - resolved;
                    path = (char*) malloc( pos + 1 );
                    strncpy( path, resolved, pos );
                    path[ pos ] = '\0';
                    free( file );
                    break;
                }
            }
        }

        dir = strtok( NULL, PATHSEPARATOR );
        free( file );
    }

    free( str );

    return path;
}

#endif

char const* cppuhelper_detail_findSofficePath()
{
    const char* UNOPATHVARNAME = "UNO_PATH";

    char* path = NULL;

    /* get the installation path from the UNO_PATH environment variable */
    path = getenv( UNOPATHVARNAME );

    if (!path || !path[0])
        path = platformSpecific();

    return path;
}

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