/* work.c
   Routines to read command files.

   Copyright (C) 1991, 1992, 1993, 1995 Ian Lance Taylor

   This file is part of the Taylor UUCP package.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   This program 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
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

   The author of the program may be contacted at ian@airs.com or
   c/o Cygnus Support, 48 Grove Street, Somerville, MA 02144.
   */

#include "uucp.h"

#if USE_RCS_ID
const char work_rcsid[] = "$Id: work.c,v 1.20 1995/06/30 21:35:14 ian Rel $";
#endif

#include "uudefs.h"
#include "uuconf.h"
#include "system.h"
#include "sysdep.h"

#include <ctype.h>
#include <errno.h>

#if HAVE_OPENDIR
#if HAVE_DIRENT_H
#include <dirent.h>
#else /* ! HAVE_DIRENT_H */
#include <sys/dir.h>
#define dirent direct
#endif /* ! HAVE_DIRENT_H */
#endif /* HAVE_OPENDIR */

/* Local functions.  */

static char *zswork_directory P((const char *zsystem));
static boolean fswork_file P((const char *zsystem, const char *zfile,
			      char *pbgrade));
static int iswork_cmp P((constpointer pkey, constpointer pdatum));

/* These functions can support multiple actions going on at once.
   This allows the UUCP package to send and receive multiple files at
   the same time.  */

/* To avoid wasting a lot of time scanning the spool directory, which
   might cause the remote system to time out, we limit each scan to
   pick up at most a certain number of files.  */
#define COMMANDS_PER_SCAN (200)

/* The ssfilename structure holds the name of a work file, as well as
   its grade.  */

struct ssfilename
{
  char *zfile;
  char bgrade;
  /* Some compiler may need this, and it won't normally hurt.  */
  char bdummy;
};

/* The ssfile structure holds a command file name and all the lines
   read in from that command file.  The union within the ssline
   structure initially holds a line from the file and then holds a
   pointer back to the ssfile structure; a pointer to this union is
   used as a sequence pointer.  The ztemp entry of the ssline
   structure holds the name of a temporary file to delete, if any.  */

#define CFILELINES (10)

struct ssline
{
  char *zline;
  struct ssfile *qfile;
  char *ztemp;
};

struct ssfile
{
  char *zfile;
  char bgrade;
  /* bdummy is needed for some buggy compilers.  */
  char bdummy;
  int clines;
  int cdid;
  struct ssline aslines[CFILELINES];
};

/* Static variables for the work scan.  */

static struct ssfilename *asSwork_files;
static size_t cSwork_files;
static size_t iSwork_file;
static struct ssfile *qSwork_file;

/* Given a system name, return a directory to search for work.  */

static char *
zswork_directory (zsystem)
     const char *zsystem;
{
#if SPOOLDIR_V2
  return zbufcpy (".");
#endif /* SPOOLDIR_V2 */
#if SPOOLDIR_BSD42 || SPOOLDIR_BSD43
  return zbufcpy ("C.");
#endif /* SPOOLDIR_BSD42 || SPOOLDIR_BSD43 */
#if SPOOLDIR_HDB || SPOOLDIR_SVR4
  return zbufcpy (zsystem);
#endif /* SPOOLDIR_HDB || SPOOLDIR_SVR4 */
#if SPOOLDIR_ULTRIX
  return zsappend3 ("sys",
		    (fsultrix_has_spool (zsystem)
		     ? zsystem
		     : "DEFAULT"),
		    "C.");
#endif /* SPOOLDIR_ULTRIX */
#if SPOOLDIR_TAYLOR
  return zsysdep_in_dir (zsystem, "C.");
#endif /* SPOOLDIR_TAYLOR */
}

/* See whether a file name from the directory returned by
   zswork_directory is really a command for a particular system.
   Return the command grade.  */

/*ARGSUSED*/
static boolean
fswork_file (zsystem, zfile, pbgrade)
     const char *zsystem;
     const char *zfile;
     char *pbgrade;
{
#if SPOOLDIR_V2 || SPOOLDIR_BSD42 || SPOOLDIR_BSD43 || SPOOLDIR_ULTRIX
  int cfilesys, csys;

  /* The file name should be C.ssssssgqqqq, where g is exactly one
     letter and qqqq is exactly four numbers.  The system name may be
     truncated to six or seven characters.  The system name of the
     file must match the system name we're looking for, since there
     could be work files for several systems in one directory.  */
  if (zfile[0] != 'C' || zfile[1] != '.')
    return FALSE;
  csys = strlen (zsystem);
  cfilesys = strlen (zfile) - 7;
  if (csys != cfilesys
      && (csys < 6 || (cfilesys != 6 && cfilesys != 7)))
    return FALSE;
  *pbgrade = zfile[cfilesys + 2];
  return strncmp (zfile + 2, zsystem, cfilesys) == 0;
#endif /* V2 || BSD42 || BSD43 || ULTRIX */
#if SPOOLDIR_HDB || SPOOLDIR_SVR4
  int clen;

  /* The HDB file name should be C.ssssssgqqqq where g is exactly one
     letter and qqqq is exactly four numbers or letters.  We don't
     check the system name, because it is guaranteed by the directory
     we are looking in and some versions of uucp set it to the local
     system rather than the remote one.  I'm not sure of the exact
     format of the SVR4 file name, but it does not include the grade
     at all.  */
  if (zfile[0] != 'C' || zfile[1] != '.')
    return FALSE;
  clen = strlen (zfile);
  if (clen < 7)
    return FALSE;
#if ! SPOOLDIR_SVR4
  *pbgrade = zfile[clen - 5];
#endif
  return TRUE;
#endif /* SPOOLDIR_HDB || SPOOLDIR_SVR4 */
#if SPOOLDIR_TAYLOR
  /* We don't keep the system name in the file name, since that
     forces truncation.  Our file names are always C.gqqqq.  */
  *pbgrade = zfile[2];
  return (zfile[0] == 'C'
	  && zfile[1] == '.'
	  && zfile[2] != '\0');
#endif /* SPOOLDIR_TAYLOR */
}

/* A comparison function to look through the list of file names.  */

static int
iswork_cmp (pkey, pdatum)
     constpointer pkey;
     constpointer pdatum;
{
  const struct ssfilename *qkey = (const struct ssfilename *) pkey;
  const struct ssfilename *qdatum = (const struct ssfilename *) pdatum;

  return strcmp (qkey->zfile, qdatum->zfile);
}

/* See whether there is any work to do for a particular system.  */

boolean
fsysdep_has_work (qsys)
     const struct uuconf_system *qsys;
{
  char *zdir;
  DIR *qdir;
  struct dirent *qentry;
#if SPOOLDIR_SVR4
  DIR *qgdir;
  struct dirent *qgentry;
#endif

  zdir = zswork_directory (qsys->uuconf_zname);
  if (zdir == NULL)
    return FALSE;
  qdir = opendir ((char *) zdir);
  if (qdir == NULL)
    {
      ubuffree (zdir);
      return FALSE;
    }

#if SPOOLDIR_SVR4
  qgdir = qdir;
  while ((qgentry = readdir (qgdir)) != NULL)
    {
      char *zsub;

      if (qgentry->d_name[0] == '.'
	  || qgentry->d_name[1] != '\0')
	continue;
      zsub = zsysdep_in_dir (zdir, qgentry->d_name);
      qdir = opendir (zsub);
      ubuffree (zsub);
      if (qdir == NULL)
	continue;
#endif

      while ((qentry = readdir (qdir)) != NULL)
	{
	  char bgrade;

	  if (fswork_file (qsys->uuconf_zname, qentry->d_name, &bgrade))
	    {
	      closedir (qdir);
#if SPOOLDIR_SVR4
	      closedir (qgdir);
#endif
	      ubuffree (zdir);
	      return TRUE;
	    }
	}

#if SPOOLDIR_SVR4
      closedir (qdir);
    }
  qdir = qgdir;
#endif

  closedir (qdir);
  ubuffree (zdir);
  return FALSE;
}

/* Initialize the work scan.  We have to read all the files in the
   work directory, so that we can sort them by work grade.  The bgrade
   argument is the minimum grade to consider.  We don't want to return
   files that we have already considered; usysdep_get_work_free will
   clear the data out when we are done with the system.  This returns
   FALSE on error.  */

#define CWORKFILES (10)

boolean
fsysdep_get_work_init (qsys, bgrade)
     const struct uuconf_system *qsys;
     int bgrade;
{
  char *zdir;
  DIR *qdir;
  struct dirent *qentry;
  size_t chad;
  size_t callocated;
#if SPOOLDIR_SVR4
  DIR *qgdir;
  struct dirent *qgentry;
#endif

  zdir = zswork_directory (qsys->uuconf_zname);
  if (zdir == NULL)
    return FALSE;

  qdir = opendir (zdir);
  if (qdir == NULL)
    {
      boolean fret;

      if (errno == ENOENT)
	fret = TRUE;
      else
	{
	  ulog (LOG_ERROR, "opendir (%s): %s", zdir, strerror (errno));
	  fret = FALSE;
	}
      ubuffree (zdir);
      return fret;
    }

  chad = cSwork_files;
  callocated = cSwork_files;

  /* Sort the files we already know about so that we can check the new
     ones with bsearch.  It would be faster to use a hash table, and
     the code should be probably be changed.  The sort done at the end
     of this function does not suffice because it only includes the
     files added last time, and does not sort the entire array.  Some
     (bad) qsort implementations are very slow when given a sorted
     array, which causes particularly bad effects here.  */
  if (chad > 0)
    qsort ((pointer) asSwork_files, chad, sizeof (struct ssfilename),
	   iswork_cmp);

#if SPOOLDIR_SVR4
  qgdir = qdir;
  while ((qgentry = readdir (qgdir)) != NULL)
    {
      char *zsub;

      if (qgentry->d_name[0] == '.'
	  || qgentry->d_name[1] != '\0'
	  || UUCONF_GRADE_CMP (bgrade, qgentry->d_name[0]) < 0)
	continue;
      zsub = zsysdep_in_dir (zdir, qgentry->d_name);
      qdir = opendir (zsub);
      if (qdir == NULL)
	{
	  if (errno != ENOTDIR && errno != ENOENT)
	    {
	      ulog (LOG_ERROR, "opendir (%s): %s", zsub,
		    strerror (errno));
	      ubuffree (zsub);
	      return FALSE;
	    }
	  ubuffree (zsub);
	  continue;
	}
      ubuffree (zsub);
#endif

      while ((qentry = readdir (qdir)) != NULL)
	{
	  char bfilegrade;
	  char *zname;
	  struct ssfilename slook;

#if ! SPOOLDIR_SVR4
	  zname = zbufcpy (qentry->d_name);
#else
	  zname = zsysdep_in_dir (qgentry->d_name, qentry->d_name);
	  bfilegrade = qgentry->d_name[0];
#endif

	  slook.zfile = zname;
	  if (! fswork_file (qsys->uuconf_zname, qentry->d_name,
			     &bfilegrade)
	      || UUCONF_GRADE_CMP (bgrade, bfilegrade) < 0
	      || (asSwork_files != NULL
		  && bsearch ((pointer) &slook,
			      (pointer) asSwork_files,
			      chad, sizeof (struct ssfilename),
			      iswork_cmp) != NULL))
	    ubuffree (zname);
	  else
	    {
	      DEBUG_MESSAGE1 (DEBUG_SPOOLDIR,
			      "fsysdep_get_work_init: Found %s",
			      zname);

	      if (cSwork_files >= callocated)
		{
		  callocated += CWORKFILES;
		  asSwork_files =
		    ((struct ssfilename *)
		     xrealloc ((pointer) asSwork_files,
			       (callocated * sizeof (struct ssfilename))));
		}

	      asSwork_files[cSwork_files].zfile = zname;
	      asSwork_files[cSwork_files].bgrade = bfilegrade;
	      ++cSwork_files;
	      if (cSwork_files - chad > COMMANDS_PER_SCAN)
		break;
	    }
	}

#if SPOOLDIR_SVR4
      closedir (qdir);
      if (cSwork_files - chad > COMMANDS_PER_SCAN)
	break;
    }
  qdir = qgdir;
#endif

  closedir (qdir);
  ubuffree (zdir);

  /* Sorting the files alphabetically will get the grades in the
     right order, since all the file prefixes are the same.  */
  if (cSwork_files > iSwork_file)
    qsort ((pointer) (asSwork_files + iSwork_file),
	   cSwork_files - iSwork_file,
	   sizeof (struct ssfilename), iswork_cmp);

  return TRUE;
}

/* Get the next work entry for a system.  This must parse the next
   line in the next work file.  The type of command is set into
   qcmd->bcmd If there are no more commands, qcmd->bcmd is set to 'H'.
   Each field in the structure is set to point to a spot in an
   malloced string.  The grade argument is never used; it has been
   used by fsysdep_get_work_init.  */

/*ARGSUSED*/
boolean
fsysdep_get_work (qsys, bgrade, qcmd)
     const struct uuconf_system *qsys;
     int bgrade;
     struct scmd *qcmd;
{
  char *zdir;

  if (qSwork_file != NULL && qSwork_file->cdid >= qSwork_file->clines)
    qSwork_file = NULL;

  if (asSwork_files == NULL)
    {
      qcmd->bcmd = 'H';
      return TRUE;
    }

  zdir = NULL;

  /* This loop continues until a line is returned.  */
  while (TRUE)
    {
      /* This loop continues until a file is opened and read in.  */
      while (qSwork_file == NULL)
	{
	  FILE *e;
	  struct ssfile *qfile;
	  int iline, callocated;
	  char *zline;
	  size_t cline;
	  char *zname;
	  char bfilegrade;

	  /* Read all the lines of a command file into memory.  */
	  do
	    {
	      if (iSwork_file >= cSwork_files)
		{
		  qcmd->bcmd = 'H';
		  ubuffree (zdir);
		  return TRUE;
		}

	      if (zdir == NULL)
		{
		  zdir = zswork_directory (qsys->uuconf_zname);
		  if (zdir == NULL)
		    return FALSE;
		}

	      zname = zsysdep_in_dir (zdir, asSwork_files[iSwork_file].zfile);
	      bfilegrade = asSwork_files[iSwork_file].bgrade;

	      ++iSwork_file;

	      e = fopen (zname, "r");
	      if (e == NULL)
		{
		  ulog (LOG_ERROR, "fopen (%s): %s", zname,
			strerror (errno));
		  ubuffree (zname);
		}
	    }
	  while (e == NULL);
	  
	  qfile = (struct ssfile *) xmalloc (sizeof (struct ssfile));
	  callocated = CFILELINES;
	  iline = 0;

	  zline = NULL;
	  cline = 0;
	  while (getline (&zline, &cline, e) > 0)
	    {
	      if (iline >= callocated)
		{
		  /* The sizeof (struct ssfile) includes CFILELINES
		     entries already, so using callocated * sizeof
		     (struct ssline) will give us callocated *
		     CFILELINES entries.  */
		  qfile =
		    ((struct ssfile *)
		     xrealloc ((pointer) qfile,
			       (sizeof (struct ssfile) +
				(callocated * sizeof (struct ssline)))));
		  callocated += CFILELINES;
		}
	      qfile->aslines[iline].zline = zbufcpy (zline);
	      qfile->aslines[iline].qfile = NULL;
	      qfile->aslines[iline].ztemp = NULL;
	      iline++;
	    }

	  xfree ((pointer) zline);

	  if (fclose (e) != 0)
	    ulog (LOG_ERROR, "fclose: %s", strerror (errno));

	  if (iline == 0)
	    {
	      /* There were no lines in the file; this is a poll file,
		 for which we return a 'P' command.  */
	      qfile->aslines[0].zline = zbufcpy ("P");
	      qfile->aslines[0].qfile = NULL;
	      qfile->aslines[0].ztemp = NULL;
	      iline = 1;
	    }

	  qfile->zfile = zname;
	  qfile->bgrade = bfilegrade;
	  qfile->clines = iline;
	  qfile->cdid = 0;
	  qSwork_file = qfile;
	}

      /* This loop continues until all the lines from the current file
	 are used up, or a line is returned.  */
      while (TRUE)
	{
	  int iline;
	  
	  if (qSwork_file->cdid >= qSwork_file->clines)
	    {
	      /* We don't want to free qSwork_file here, since it must
		 remain until all the lines have been completed.  It
		 is freed in fsysdep_did_work.  */
	      qSwork_file = NULL;
	      /* Go back to the main loop which finds another file.  */
	      break;
	    }

	  iline = qSwork_file->cdid;
	  ++qSwork_file->cdid;

	  /* Now parse the line into a command.  */
	  if (! fparse_cmd (qSwork_file->aslines[iline].zline, qcmd))
	    {
	      ulog (LOG_ERROR, "Bad line in command file %s",
		    qSwork_file->zfile);
	      ubuffree (qSwork_file->aslines[iline].zline);
	      qSwork_file->aslines[iline].zline = NULL;
	      continue;
	    }
	  qcmd->bgrade = qSwork_file->bgrade;

	  qSwork_file->aslines[iline].qfile = qSwork_file;
	  qcmd->pseq = (pointer) (&qSwork_file->aslines[iline]);

	  if (qcmd->bcmd == 'S' || qcmd->bcmd == 'E')
	    {
	      char *zreal;

	      zreal = zsysdep_spool_file_name (qsys, qcmd->ztemp,
					       qcmd->pseq);
	      if (zreal == NULL)
		{
		  ubuffree (qSwork_file->aslines[iline].zline);
		  qSwork_file->aslines[iline].zline = NULL;
		  ubuffree (zdir);
		  return FALSE;
		}
	      qSwork_file->aslines[iline].ztemp = zreal;
	    }

	  ubuffree (zdir);
	  return TRUE;
	}
    }
}

/* When a command has been complete, fsysdep_did_work is called.  The
   sequence entry was set above to be the address of an aslines
   structure whose pfile entry points to the ssfile corresponding to
   this file.  We can then check whether all the lines have been
   completed (they will have been if the pfile entry is NULL) and
   remove the file if they have been.  This means that we only remove
   a command file if we manage to complete every transfer it specifies
   in a single UUCP session.  I don't know if this is how regular UUCP
   works.  */

boolean
fsysdep_did_work (pseq)
     pointer pseq;
{
  struct ssfile *qfile;
  struct ssline *qline;
  int i;
  
  qline = (struct ssline *) pseq;

  ubuffree (qline->zline);
  qline->zline = NULL;

  qfile = qline->qfile;
  qline->qfile = NULL;

  /* Remove the temporary file, if there is one.  It really doesn't
     matter if this fails, and not checking the return value lets us
     attempt to remove D.0 or whatever an unused temporary file is
     called without complaining.  */
  if (qline->ztemp != NULL)
    {
      (void) remove (qline->ztemp);
      ubuffree (qline->ztemp);
      qline->ztemp = NULL;
    }

  /* If not all the lines have been returned from fsysdep_get_work,
     we can't remove the file yet.  */
  if (qfile->cdid < qfile->clines)
    return TRUE;

  /* See whether all the commands have been completed.  */
  for (i = 0; i < qfile->clines; i++)
    if (qfile->aslines[i].qfile != NULL)
      return TRUE;

  /* All commands have finished.  */
  if (remove (qfile->zfile) != 0)
    {
      ulog (LOG_ERROR, "remove (%s): %s", qfile->zfile,
	    strerror (errno));
      return FALSE;
    }

  ubuffree (qfile->zfile);
  xfree ((pointer) qfile);

  if (qfile == qSwork_file)
    qSwork_file = NULL;

  return TRUE;
}

/* Free up the results of a work scan, when we're done with this
   system.  */

/*ARGSUSED*/
void
usysdep_get_work_free (qsys)
     const struct uuconf_system *qsys;
{
  if (asSwork_files != NULL)
    {
      size_t i;

      for (i = 0; i < cSwork_files; i++)
	ubuffree ((pointer) asSwork_files[i].zfile);
      xfree ((pointer) asSwork_files);
      asSwork_files = NULL;
      cSwork_files = 0;
      iSwork_file = 0;
    }
  if (qSwork_file != NULL)
    {
      int i;

      ubuffree (qSwork_file->zfile);
      for (i = 0; i < qSwork_file->cdid; i++)
	{
	  ubuffree (qSwork_file->aslines[i].zline);
	  ubuffree (qSwork_file->aslines[i].ztemp);
	}
      for (i = qSwork_file->cdid; i < qSwork_file->clines; i++)
	ubuffree (qSwork_file->aslines[i].zline);
      xfree ((pointer) qSwork_file);
      qSwork_file = NULL;
    }
}

/* Save the temporary file used by a send command, and return an
   informative message to mail to the requestor.  This is called when
   a file transfer failed, to make sure that the potentially valuable
   file is not completely lost.  */

const char *
zsysdep_save_temp_file (pseq)
     pointer pseq;
{
  struct ssline *qline = (struct ssline *) pseq;
  char *zto, *zslash;
  size_t cwant;
  static char *zbuf;
  static int cbuf;

  if (! fsysdep_file_exists (qline->ztemp))
    return NULL;

  zslash = strrchr (qline->ztemp, '/');
  if (zslash == NULL)
    zslash = qline->ztemp;
  else
    ++zslash;

  zto = zbufalc (sizeof PRESERVEDIR + sizeof "/" + strlen (zslash));
  sprintf (zto, "%s/%s", PRESERVEDIR, zslash);

  if (! fsysdep_move_file (qline->ztemp, zto, TRUE, FALSE, FALSE,
			   (const char *) NULL))
    {
      /* Leave the file where it was, not that is much help.  */
      ubuffree (zto);
      return "Could not move file to preservation directory";
    }
    
  cwant = sizeof "File saved as\n\t/" + strlen (zSspooldir) + strlen (zto);
  if (cwant > cbuf)
    {
      ubuffree (zbuf);
      zbuf = zbufalc (cwant);
      cbuf = cwant;
    }

  sprintf (zbuf, "File saved as\n\t%s/%s", zSspooldir, zto);
  ubuffree (zto);
  return zbuf;
}

/* Get the jobid of a work file.  This is needed by uustat.  */

char *
zsysdep_jobid (qsys, pseq)
     const struct uuconf_system *qsys;
     pointer pseq;
{
  return zsfile_to_jobid (qsys, ((struct ssline *) pseq)->qfile->zfile,
			  bsgrade (pseq));
}

/* Get the grade of a work file.  The pseq argument can be NULL when
   this is called from zsysdep_spool_file_name, and simply means that
   this is a remote file; returning -1 will cause zsfind_file to do
   the right thing.  */

int
bsgrade (pseq)
     pointer pseq;
{
  const char *zfile;
  char bgrade;

  if (pseq == NULL)
    return -1;

  zfile = ((struct ssline *) pseq)->qfile->zfile;

#if SPOOLDIR_TAYLOR
  bgrade = *(strrchr (zfile, '/') + 3);
#else
#if ! SPOOLDIR_SVR4
  bgrade = zfile[strlen (zfile) - CSEQLEN - 1];
#else
  bgrade = *(strchr (zfile, '/') + 1);
#endif
#endif

  return bgrade;
}