/*      $NetBSD: file.c,v 1.9 2024/08/18 20:47:24 christos Exp $        */


/**
* \file file.c
*
* Handle options that have file names for arguments.
*
* @addtogroup autoopts
* @{
*/
/*
*  This file is part of AutoOpts, a companion to AutoGen.
*  AutoOpts is free software.
*  AutoOpts is Copyright (C) 1992-2018 by Bruce Korb - all rights reserved
*
*  AutoOpts is available under any one of two licenses.  The license
*  in use must be one of these two and the choice is under the control
*  of the user of the license.
*
*   The GNU Lesser General Public License, version 3 or later
*      See the files "COPYING.lgplv3" and "COPYING.gplv3"
*
*   The Modified Berkeley Software Distribution License
*      See the file "COPYING.mbsd"
*
*  These files have the following sha256 sums:
*
*  8584710e9b04216a394078dc156b781d0b47e1729104d666658aecef8ee32e95  COPYING.gplv3
*  4379e7444a0e2ce2b12dd6f5a52a27a4d02d39d247901d3285c88cf0d37f477b  COPYING.lgplv3
*  13aa749a5b0a454917a944ed8fffc530b784f5ead522b1aacaf4ec8aa55a6239  COPYING.mbsd
*/

/**
*  Make sure the directory containing the subject file exists and that
*  the file exists or does not exist, per the option requirements.
*
* @param ftype file existence type flags
* @param pOpts program option descriptor
* @param pOD   the option descriptor
*/
static void
check_existence(teOptFileType ftype, tOptions * pOpts, tOptDesc * pOD)
{
   char const * fname = pOD->optArg.argString;
   struct stat sb;

   errno = 0;

   switch (ftype & FTYPE_MODE_EXIST_MASK) {
   case FTYPE_MODE_MUST_NOT_EXIST:
       if ((stat(fname, &sb) == 0) || (errno != ENOENT)) {
           if (errno == 0)
               errno = EINVAL;
           fserr_exit(pOpts->pzProgName, "stat", fname);
           /* NOTREACHED */
       }
       /* FALLTHROUGH */

   default:
   case FTYPE_MODE_MAY_EXIST:
   {
       char * p = strrchr(fname, DIRCH);
       size_t l;

       if (p == NULL)
           /*
            *  The file may or may not exist and its directory is ".".
            *  Assume that "." exists.
            */
           break;

       l = (size_t)(p - fname);
       p = AGALOC(l + 1, "fname");
       memcpy(p, fname, l);
       p[l] = NUL;

       if ((stat(p, &sb) != 0) || (errno = EINVAL, ! S_ISDIR(sb.st_mode)))
           fserr_exit(pOpts->pzProgName, "stat", p);
           /* NOTREACHED */

       AGFREE(p);
       break;
   }

   case FTYPE_MODE_MUST_EXIST:
       if (  (stat(fname, &sb) != 0)
          || (errno = EINVAL, ! S_ISREG(sb.st_mode))  )
           fserr_exit(pOpts->pzProgName, "stat", fname);
           /* NOTREACHED */

       break;
   }
}

/**
*  Open the specified file with open(2) and save the FD.
*
* @param pOpts program option descriptor
* @param pOD   the option descriptor
* @param mode  the open mode (uses int flags value)
*/
static void
open_file_fd(tOptions * pOpts, tOptDesc * pOD, tuFileMode mode)
{
   int fd = open(pOD->optArg.argString, mode.file_flags);
   if (fd < 0)
       fserr_exit(pOpts->pzProgName, "open", pOD->optArg.argString);
       /* NOTREACHED */

   if ((pOD->fOptState & OPTST_ALLOC_ARG) != 0)
       pOD->optCookie = VOIDP(pOD->optArg.argString);
   else
       AGDUPSTR(pOD->optCookie, pOD->optArg.argString, "file name");

   pOD->optArg.argFd = fd;
   pOD->fOptState &= ~OPTST_ALLOC_ARG;
}

/**
*  Open the specified file with open(2) and save the FD.
*
* @param pOpts program option descriptor
* @param pOD   the option descriptor
* @param mode  the open mode (uses "char *" mode value)
*/
static void
fopen_file_fp(tOptions * pOpts, tOptDesc * pOD, tuFileMode mode)
{
   FILE * fp = fopen(pOD->optArg.argString, mode.file_mode);
   if (fp == NULL)
       fserr_exit(pOpts->pzProgName, "fopen", pOD->optArg.argString);
       /* NOTREACHED */

   if ((pOD->fOptState & OPTST_ALLOC_ARG) != 0)
       pOD->optCookie = VOIDP(pOD->optArg.argString);
   else
       AGDUPSTR(pOD->optCookie, pOD->optArg.argString, "file name");

   pOD->optArg.argFp = fp;
   pOD->fOptState &= ~OPTST_ALLOC_ARG;
}

/*=export_func  optionFileCheck
* private:
*
* what:  Decipher a boolean value
* arg:   + tOptions *    + pOpts    + program options descriptor  +
* arg:   + tOptDesc *    + pOptDesc + the descriptor for this arg +
* arg:   + teOptFileType + ftype    + File handling type          +
* arg:   + tuFileMode    + mode     + file open mode (if needed)  +
*
* doc:
*   Make sure the named file conforms with the file type mode.
*   The mode specifies if the file must exist, must not exist or may
*   (or may not) exist.  The mode may also specify opening the
*   file: don't, open just the descriptor (fd), or open as a stream
*   (FILE * pointer).
=*/
void
optionFileCheck(tOptions * pOpts, tOptDesc * pOD,
               teOptFileType ftype, tuFileMode mode)
{
   if (pOpts <= OPTPROC_EMIT_LIMIT) {
       if (pOpts != OPTPROC_EMIT_USAGE)
           return;

       switch (ftype & FTYPE_MODE_EXIST_MASK) {
       case FTYPE_MODE_MUST_NOT_EXIST:
           fputs(zFileCannotExist + tab_skip_ct, option_usage_fp);
           break;

       case FTYPE_MODE_MUST_EXIST:
           fputs(zFileMustExist + tab_skip_ct, option_usage_fp);
           break;
       }
       return;
   }

   if ((pOD->fOptState & OPTST_RESET) != 0) {
       if (pOD->optCookie != NULL)
           AGFREE(pOD->optCookie);
       return;
   }

   check_existence(ftype, pOpts, pOD);

   switch (ftype & FTYPE_MODE_OPEN_MASK) {
   default:
   case FTYPE_MODE_NO_OPEN:  break;
   case FTYPE_MODE_OPEN_FD:  open_file_fd( pOpts, pOD, mode); break;
   case FTYPE_MODE_FOPEN_FP: fopen_file_fp(pOpts, pOD, mode); break;
   }
}

/** @}
*
* Local Variables:
* mode: C
* c-file-style: "stroustrup"
* indent-tabs-mode: nil
* End:
* end of autoopts/file.c */