/***
*stat64.c - get file status
*
*       Copyright (c) 1998-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       defines _stat64() - get file status
*
*Revision History:
*       06-02-98  GJF   Created.
*       11-10-99  GB    Made changes so as to take care of DST.
*
*******************************************************************************/

#include <cruntime.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <ctype.h>
#include <msdos.h>
#include <oscalls.h>
#include <string.h>
#include <internal.h>
#include <stdlib.h>
#include <direct.h>
#include <mbstring.h>
#include <tchar.h>


#define ISSLASH(a)  ((a) == _T('\\') || (a) == _T('/'))


/*
 * Number of 100 nanosecond units from 1/1/1601 to 1/1/1970
 */
#define EPOCH_BIAS  116444736000000000i64


#ifdef  _UNICODE
#define __tdtoxmode __wdtoxmode
#else   /* ndef _UNICODE */
#define __tdtoxmode __dtoxmode
#endif  /* _UNICODE */


/*
 * Local routine which returns true if the argument is a UNC name
 * specifying the root name of a share, such as '\\server\share\'.
 */

static int IsRootUNCName(const _TSCHAR *path);

extern unsigned short __cdecl __tdtoxmode(int, const _TSCHAR *);


/***
*int _stat64(name, buf) - get file status info
*
*Purpose:
*       _stat64 obtains information about the file and stores it in the
*       structure pointed to by buf.
*
*       Note: Unlike _stat, _stat64 uses the UTC time values returned in
*       WIN32_FIND_DATA struct. This means the time values will always be
*       correct on NTFS, but may be wrong on FAT file systems for file times
*       whose DST state is different from the current DST state (this an NT
*       bug).
*
*Entry:
*       _TSCHAR *name -    pathname of given file
*       struct _stat *buffer - pointer to buffer to store info in
*
*Exit:
*       fills in structure pointed to by buffer
*       returns 0 if successful
*       returns -1 and sets errno if unsuccessful
*
*Exceptions:
*
*******************************************************************************/

int __cdecl _tstat64 (
        REG1 const _TSCHAR *name,
        REG2 struct __stat64 *buf
        )
{
        _TSCHAR *  path;
        _TSCHAR    pathbuf[ _MAX_PATH ];
        int drive;          /* A: = 1, B: = 2, etc. */
        HANDLE findhandle;
        WIN32_FIND_DATA findbuf;

        /* Don't allow wildcards to be interpreted by system */

#ifdef  _UNICODE
        if (wcspbrk(name, L"?*")) {
#else
        if (_mbspbrk(name, "?*")) {
#endif
            errno = ENOENT;
            _doserrno = E_nofile;
            return(-1);
        }

        /* Try to get disk from name.  If none, get current disk.  */

        if (name[1] == _T(':')){
            if ( *name && !name[2] ){
                errno = ENOENT;             /* return an error if name is   */
                _doserrno = E_nofile;       /* just drive letter then colon */
                return( -1 );
            }
            drive = _totlower(*name) - _T('a') + 1;
        }
        else
            drive = _getdrive();

        /* Call Find Match File */
        findhandle = FindFirstFile((_TSCHAR *)name, &findbuf);
        if ( findhandle == INVALID_HANDLE_VALUE ) {
#ifdef  _UNICODE
            if ( !( wcspbrk(name, L"./\\") &&
#else
            if ( !( _mbspbrk(name, "./\\") &&
#endif
                 (path = _tfullpath( pathbuf, name, _MAX_PATH )) &&
                 /* root dir. ('C:\') or UNC root dir. ('\\server\share\') */
                 ((_tcslen( path ) == 3) || IsRootUNCName(path)) &&
                 (GetDriveType( path ) > 1) ) ) 
            {
                errno = ENOENT;
                _doserrno = E_nofile;
                return( -1 );
            }

            /*
             * Root directories (such as C:\ or \\server\share\ are fabricated.
             */

            findbuf.dwFileAttributes = A_D;
            findbuf.nFileSizeHigh = 0;
            findbuf.nFileSizeLow = 0;
            findbuf.cFileName[0] = _T('\0');

            buf->st_mtime = __loctotime64_t(1980,1,1,0,0,0, -1);
            buf->st_atime = buf->st_mtime;
            buf->st_ctime = buf->st_mtime;
        }
        else {
            SYSTEMTIME SystemTime;
            FILETIME LocalFTime;

            if ( !FileTimeToLocalFileTime( &findbuf.ftLastWriteTime, 
                                           &LocalFTime )            ||
                 !FileTimeToSystemTime( &LocalFTime, &SystemTime ) )
            {
                _dosmaperr( GetLastError() );
                FindClose( findhandle );
                return( -1 );
            }

            buf->st_mtime = __loctotime64_t( SystemTime.wYear,
                                           SystemTime.wMonth,
                                           SystemTime.wDay,
                                           SystemTime.wHour,
                                           SystemTime.wMinute,
                                           SystemTime.wSecond,
                                           -1 );

            if ( findbuf.ftLastAccessTime.dwLowDateTime ||
                 findbuf.ftLastAccessTime.dwHighDateTime )
            {
                if ( !FileTimeToLocalFileTime( &findbuf.ftLastAccessTime,
                                               &LocalFTime )                ||
                     !FileTimeToSystemTime( &LocalFTime, &SystemTime ) )
                {
                    _dosmaperr( GetLastError() );
                    FindClose( findhandle );
                    return( -1 );
                }

                buf->st_atime = __loctotime64_t( SystemTime.wYear,
                                               SystemTime.wMonth,
                                               SystemTime.wDay,
                                               SystemTime.wHour,
                                               SystemTime.wMinute,
                                               SystemTime.wSecond,
                                               -1 );
            } else
                buf->st_atime = buf->st_mtime ;

            if ( findbuf.ftCreationTime.dwLowDateTime ||
                 findbuf.ftCreationTime.dwHighDateTime )
            {
                if ( !FileTimeToLocalFileTime( &findbuf.ftCreationTime,
                                               &LocalFTime )                ||
                     !FileTimeToSystemTime( &LocalFTime, &SystemTime ) )
                {
                    _dosmaperr( GetLastError() );
                    FindClose( findhandle );
                    return( -1 );
                }

                buf->st_ctime = __loctotime64_t( SystemTime.wYear,
                                               SystemTime.wMonth,
                                               SystemTime.wDay,
                                               SystemTime.wHour,
                                               SystemTime.wMinute,
                                               SystemTime.wSecond,
                                               -1 );
            } else
                buf->st_ctime = buf->st_mtime ;

            FindClose(findhandle);
        }

        /* Fill in buf */

        buf->st_mode = __tdtoxmode(findbuf.dwFileAttributes, name);
        buf->st_nlink = 1;
        buf->st_size = ((__int64)(findbuf.nFileSizeHigh)) * (0x100000000i64) +
                        (__int64)(findbuf.nFileSizeLow);

        /* now set the common fields */

        buf->st_uid = buf->st_gid = buf->st_ino = 0;

        buf->st_rdev = buf->st_dev = (_dev_t)(drive - 1); /* A=0, B=1, etc. */

        return(0);
}


/*
 * IsRootUNCName - returns TRUE if the argument is a UNC name specifying
 *      a root share.  That is, if it is of the form \\server\share\.
 *      This routine will also return true if the argument is of the
 *      form \\server\share (no trailing slash) but Win32 currently
 *      does not like that form.
 *
 *      Forward slashes ('/') may be used instead of backslashes ('\').
 */

static int IsRootUNCName(const _TSCHAR *path)
{
        /*
         * If a root UNC name, path will start with 2 (but not 3) slashes
         */

        if ( ( _tcslen ( path ) >= 5 ) /* minimum string is "//x/y" */
             && ISSLASH(path[0]) && ISSLASH(path[1]))
        {
            const _TSCHAR * p = path + 2 ;

            /*
             * find the slash between the server name and share name
             */
            while ( * ++ p )
                if ( ISSLASH(*p) )
                    break ;

            if ( *p && p[1] )
            {
                /*
                 * is there a further slash?
                 */
                while ( * ++ p )
                    if ( ISSLASH(*p) )
                        break ;

                /*
                 * just final slash (or no final slash)
                 */
                if ( !*p || !p[1])
                    return 1;
            }
        }

        return 0 ;
}