/***************************************************************
  SYS-OPEN.C

       This file contains Linux/i386/ILP32 implementation of
       __cpu_sys_open().

       PART OF : CPU - library .

       USAGE   : Internal only .

       Copyright (C) 2026  by Andrew V.Kosteltsev.
       All Rights Reserved.
 ***************************************************************/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>

#include <libmcpu.h>
#include <cpu-sysdeps.h>


static int
__cpu_open_flags( __mpu_uint64_t flags, int *host_flags )
{
  int  f = 0;

  if( !host_flags ) return( __MCPU_EINVAL );
  if( flags & ~(__mpu_uint64_t)__CPU_O_SUPPORTED ) return( __MCPU_EINVAL );

  switch( flags & __CPU_O_ACCMODE )
  {
  case __CPU_O_RDONLY: f |= O_RDONLY; break;
  case __CPU_O_WRONLY: f |= O_WRONLY; break;
  case __CPU_O_RDWR:   f |= O_RDWR;   break;
  default: return( __MCPU_EINVAL );
  }

  if( flags & __CPU_O_CREAT )    f |= O_CREAT;
  if( flags & __CPU_O_EXCL )     f |= O_EXCL;
  if( flags & __CPU_O_NOCTTY )   f |= O_NOCTTY;
  if( flags & __CPU_O_TRUNC )    f |= O_TRUNC;
  if( flags & __CPU_O_APPEND )   f |= O_APPEND;
  if( flags & __CPU_O_NONBLOCK ) f |= O_NONBLOCK;

  *host_flags = f;
  return( 0 );

} /* End of __cpu_open_flags() */


static int
__cpu_open_mode( __mpu_uint64_t mode, mode_t *host_mode )
{
  mode_t  m = 0;

  if( !host_mode ) return( __MCPU_EINVAL );
  if( mode & ~(__mpu_uint64_t)__CPU_S_SUPPORTED ) return( __MCPU_EINVAL );

  if( mode & __CPU_S_ISUID ) m |= S_ISUID;
  if( mode & __CPU_S_ISGID ) m |= S_ISGID;
#ifdef S_ISVTX
  if( mode & __CPU_S_ISVTX ) m |= S_ISVTX;
#endif
  if( mode & __CPU_S_IRUSR ) m |= S_IRUSR;
  if( mode & __CPU_S_IWUSR ) m |= S_IWUSR;
  if( mode & __CPU_S_IXUSR ) m |= S_IXUSR;
  if( mode & __CPU_S_IRGRP ) m |= S_IRGRP;
  if( mode & __CPU_S_IWGRP ) m |= S_IWGRP;
  if( mode & __CPU_S_IXGRP ) m |= S_IXGRP;
  if( mode & __CPU_S_IROTH ) m |= S_IROTH;
  if( mode & __CPU_S_IWOTH ) m |= S_IWOTH;
  if( mode & __CPU_S_IXOTH ) m |= S_IXOTH;

  *host_mode = m;
  return( 0 );

} /* End of __cpu_open_mode() */


__mpu_int64_t
__cpu_sys_open( int dirfd, const char *path, __mpu_uint64_t flags,
                __mpu_uint64_t mode )
{
  mode_t  host_mode = 0;
  int     host_flags;
  int     error;
  int     fd;

  if( !path ) return( -(__mpu_int64_t)__MCPU_EFAULT );

  error = __cpu_open_flags( flags, &host_flags );
  if( error ) return( -(__mpu_int64_t)error );

  if( flags & __CPU_O_CREAT )
  {
    error = __cpu_open_mode( mode, &host_mode );
    if( error ) return( -(__mpu_int64_t)error );
    fd = openat( dirfd, path, host_flags, host_mode );
  }
  else
  {
    if( mode != 0 ) return( -(__mpu_int64_t)__MCPU_EINVAL );
    fd = openat( dirfd, path, host_flags );
  }

  if( fd < 0 ) return( -(__mpu_int64_t)__cpu_errno_from_host( errno ) );
  return( (__mpu_int64_t)fd );

} /* End of __cpu_sys_open() */