/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
*    provided with the Original Code and Modifications, and is also
*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
*    ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
*    NON-INFRINGEMENT. Please see the License for the specific language
*    governing rights and limitations under the License.
*
*  ========================================================================
*
* Description:  Implementation for putenv().
*
****************************************************************************/


#include "variety.h"
#include "widechar.h"
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <mbstring.h>
#include <errno.h>
#ifdef __NT__
    #include <windows.h>
    #include "libwin32.h"
#endif
#include "liballoc.h"
#include "rtdata.h"
#include "seterrno.h"
#ifdef __WIDECHAR__
    #include "wenviron.h"
    #include <wctype.h>
#endif
#ifdef __RDOS__
    #include <rdos.h>
#endif


extern int __putenv( const char *env_string );
extern int __wputenv( const wchar_t *env_string );


// _wpetenv and putenv are implemented this way so that each can call the
// other without having the other call it, which would call the other, and
// so on, making bad things happen.  This inter-calling is necessary to keep
// the wide and MBCS environments consistent.  Also, with this method
// __create_wide_environment can call __wputenv, without having the function
// it calls call __create_wide_environment, causing similar bad things.
_WCRTLINK int __F_NAME(putenv,_wputenv)( const CHAR_TYPE *env_string )
{
#ifndef __UNIX__
#ifdef __WIDECHAR__
    char                *otherStr;
    const size_t        charsize = sizeof(wchar_t);
    const size_t        fact = MB_CUR_MAX;
#else
    wchar_t             *otherStr;
    const size_t        charsize = MB_CUR_MAX;
    const size_t        fact = 1;
#endif
    size_t              otherStrLen;
    int                 rc;
#endif
#ifdef __NT__
    CHAR_TYPE           *name;
    CHAR_TYPE           *value;
    CHAR_TYPE           *p;
    size_t              len;
    BOOL                osRc;
#endif
#ifdef __RDOS__
    CHAR_TYPE           *name;
    CHAR_TYPE           *value;
    CHAR_TYPE           *p;
    size_t              len;
    int                 handle;
#endif

    /*** Update the process environment if using Win32 ***/
#if defined(__NT__) || defined(__RDOS__) 
    /*** Validate the input string ***/
    p = __F_NAME(_mbschr,wcschr)( env_string, STRING( '=' ) );
    if( p == NULL ) return( -1 );           /* must have form name=value */
    if( p == env_string ) return( -1 );     /* must have form name=value */

    /*** Extract the variable name ***/
    len = p - env_string;
    name = lib_malloc( (len + 1) * CHARSIZE );
    if( name == NULL ) return( -1 );
    memcpy( name, env_string, len * CHARSIZE );
    name[len] = NULLCHAR;

    /*** Extract the new value, if any ***/
    p++;                                    /* point past the '=' */
    len = __F_NAME(_mbslen,wcslen)( p );
    if( len != 0 ) {
        value = lib_malloc( (len + 1) * CHARSIZE );
        if( value == NULL ) {
            lib_free( name );
            return( -1 );
        }
        memcpy( value, p, len * CHARSIZE );
        value[len] = NULLCHAR;
    } else {
        value = NULL;               /* don't need a buffer to delete */
    }

#ifdef __NT__
    /*** Tell the OS about the change ***/
    #ifdef __WIDECHAR__
        osRc = __lib_SetEnvironmentVariableW( name, value );
    #else
        osRc = SetEnvironmentVariableA( name, value );
    #endif
#endif

#ifdef __RDOS__
    handle = RdosOpenProcessEnv();
    RdosDeleteEnvVar( handle, name );
    RdosAddEnvVar( handle, name, value );
    RdosCloseEnv( handle );        

#endif
    
    lib_free( name );
    lib_free( value );

#ifndef __RDOS__
    if( osRc == FALSE ) {
        if( value == NULL ) {
            // we couldn't find the envvar but since we are deleting it,
            // the putenv() is successful
            return( 0 );
        }
        return( -1 );
    }
#endif
    
#endif

    /*** Update the (__WIDECHAR__ ? wide : MBCS) environment ***/
#ifdef __WIDECHAR__
    if( _RWD_wenviron == NULL )  __create_wide_environment();
#endif

#ifdef __UNIX__
    return( __F_NAME(__putenv,__wputenv)( env_string ) );
#else
    if( __F_NAME(__putenv,__wputenv)( env_string ) != 0 ) return( -1 );

    /*** Update the other environment ***/
    #ifndef __WIDECHAR__
        if( _RWD_wenviron == NULL ) return( 0 );    // _wenviron uninitialized
    #endif
    otherStrLen = __F_NAME(_mbslen,wcslen)( env_string ) + 1;
    otherStr = lib_malloc( otherStrLen * charsize );
    if( otherStr == NULL ) {
        __set_errno( ENOMEM );
        return( -1 );
    }
    if( __F_NAME(mbstowcs,wcstombs)( otherStr, env_string, otherStrLen * fact ) == -1 ) {
        lib_free( otherStr );
        __set_errno( ERANGE );
        return( -1 );
    }
#ifdef __RDOS__
    rc = 0;
#else    
    rc = __F_NAME(__wputenv,__putenv)( otherStr );
#endif    
    return( rc );
#endif
}


#ifndef __NETWARE__
static int findenv( const CHAR_TYPE *env_string, int delete_var )
{
    CHAR_TYPE           **envp, **tmp_envp;
    const CHAR_TYPE     *p1, *p2, *env_str;
    int                 index1;
#ifndef __WIDECHAR__
    int                 index2;
    char                *envm;
#endif

    for( envp = __F_NAME(_RWD_environ,_RWD_wenviron); p1 = *envp; ++envp ) {
        for( p2 = env_string; *p2; ++p1, ++p2 ) {
#if defined(__UNIX__)
            if( *p1 != *p2 ) break;
#else
            /* case independent search */
            #ifdef __WIDECHAR__
                if( towupper( *p1 ) != towupper( *p2 ) ) break;
            #else
                if( toupper( *p1 ) != toupper( *p2 ) ) break;
            #endif
#endif
            if( *p1 == STRING( '=' ) ) {
                index1 = envp - __F_NAME(_RWD_environ,_RWD_wenviron);
                if( delete_var ) {
                    env_str = *envp;
                    tmp_envp = envp;        /* delete entry */
                    for( ; *tmp_envp; ++tmp_envp ) {
                        *tmp_envp = *(tmp_envp + 1);
                    }
                    #ifdef __WIDECHAR__
                        lib_free( (void *)env_str );
                    #else
                        if( _RWD_env_mask != NULL ) {
                            if( _RWD_env_mask[ index1 ] != 0 ) {
                                lib_free( (void *)env_str );
                            }
                            envm = (char *)(tmp_envp);
                            index2 = tmp_envp - _RWD_environ;
                            memmove( envm, _RWD_env_mask, index2 * sizeof(char) );
                            _RWD_env_mask = envm;
                            for( ; index1 < index2; index1++ ) {
                                envm[ index1 ] = envm[ index1 + 1 ];
                            }
                        }
                    #endif
                    return( 0 );            /* pretend it wasn't found */
                } else {
                    return( index1 + 1 );   /* return index origin 1 */
                }
            }
        }
    }
    return( __F_NAME(_RWD_environ,_RWD_wenviron) - envp );  /* not found */
}
#endif


int __F_NAME(__putenv,__wputenv)( const CHAR_TYPE *env_string )
{
#ifdef __NETWARE__

    env_string = env_string;
    return( -1 );

#else

    const CHAR_TYPE     **envp;
    int                 index;
    const CHAR_TYPE     *p;
    int                 delete_var;

    if( env_string == NULL ) return( -1 );
    if( *env_string != NULLCHAR ) { // handle =NAME=STRING
        for( p = env_string + 1; *p; ++p ) {    // (used under NT)
            if( *p == STRING( '=' ) ) break;
        }
    }
    if( *p == NULLCHAR )  return( -1 ); /* <name> with no '=' is illegal */
    delete_var = ( p[ 1 ] == NULLCHAR );
    envp = (const CHAR_TYPE **)__F_NAME(_RWD_environ,_RWD_wenviron);
    if( envp == NULL ) {
        if( delete_var ) return( 0 );
        #ifdef __WIDECHAR__
            envp = lib_malloc( 2 * sizeof(CHAR_TYPE *) );
        #else
            envp = lib_malloc( 2 * sizeof(CHAR_TYPE *) + sizeof(char) );
        #endif
        if( envp == NULL ) return( -1 );
        envp[ 0 ] = NULL;                   /* fill in below */
        envp[ 1 ] = NULL;
        __F_NAME(_RWD_environ,_RWD_wenviron) = (CHAR_TYPE **)envp;
        #ifndef __WIDECHAR__
            _RWD_env_mask = (char *)&envp[ 2 ];
        #endif
        index = 0;
    } else {
        index = findenv( env_string, delete_var );
        if( delete_var ) return( 0 );
        if( index <= 0 ) {                  /* name not found */
            index = - index;
            #ifdef __WIDECHAR__
                /* wide environment doesn't use alloc'd mask */
                envp = lib_realloc( envp, (index + 2) * sizeof(CHAR_TYPE *) );
                if( envp == NULL ) return( -1 );
                memcpy( envp, _RWD_wenviron, index * sizeof(CHAR_TYPE *) );
            #else
                if( _RWD_env_mask == NULL ) {
                    envp = lib_malloc( (index + 2) * sizeof(CHAR_TYPE *) +
                                   (index + 1) * sizeof(char) );
                    if( envp == NULL ) return( -1 );
                    memcpy( envp, _RWD_environ, index * sizeof(CHAR_TYPE *) );
                    _RWD_env_mask = (char *)&envp[ index + 2 ];
                    memset( _RWD_env_mask, 0, (index + 1) * sizeof(char) );
                } else {
                    envp = lib_realloc( envp, (index + 2) * sizeof(CHAR_TYPE *)
                                            + (index + 1) * sizeof(char) );
                    if( envp == NULL ) return( -1 );
                    memmove( &envp[ index + 2 ], _RWD_env_mask,
                                index * sizeof(char) );
                    _RWD_env_mask = (char *)&envp[ index + 2 ];
                }
            #endif
            envp[ index + 1 ] = NULL;
            __F_NAME(_RWD_environ,_RWD_wenviron) = (CHAR_TYPE **) envp;
        } else {                            /* name found */
            index--;
        }
    }
    envp[ index ] = env_string;
    #ifndef __WIDECHAR__
        _RWD_env_mask[ index ] = 0;     /* indicate not alloc'd */
    #endif
    return( 0 );
#endif
}
