/*
 * Copyright (C) 1996-2000 Michael R. Elkins.
 *
 *     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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif

#include "mutt.h"
#include "mutt_curses.h"
#ifdef USE_IMAP
# include "imap.h"
#endif

#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>

/* Invokes a command on a pipe and optionally connects its stdin and stdout
 * to the specified handles.
 */
pid_t
mutt_create_filter_fd(const char *cmd, FILE **in, FILE **out, FILE **err,
                      int fdin, int fdout, int fderr)
{
  int pin[2], pout[2], perr[2], thepid;
  char columns[11];

  if (in)
  {
    *in = 0;
    if (pipe(pin) == -1)
      return (-1);
  }

  if (out)
  {
    *out = 0;
    if (pipe(pout) == -1)
    {
      if (in)
      {
        close(pin[0]);
        close(pin[1]);
      }
      return (-1);
    }
  }

  if (err)
  {
    *err = 0;
    if (pipe(perr) == -1)
    {
      if (in)
      {
        close(pin[0]);
        close(pin[1]);
      }
      if (out)
      {
        close(pout[0]);
        close(pout[1]);
      }
      return (-1);
    }
  }

  mutt_block_signals_system();

  if ((thepid = fork()) == 0)
  {
    mutt_unblock_signals_system(0);
    mutt_reset_child_signals();

    if (in)
    {
      close(pin[1]);
      dup2(pin[0], 0);
      close(pin[0]);
    }
    else if (fdin != -1)
    {
      dup2(fdin, 0);
      close(fdin);
    }

    if (out)
    {
      close(pout[0]);
      dup2(pout[1], 1);
      close(pout[1]);
    }
    else if (fdout != -1)
    {
      dup2(fdout, 1);
      close(fdout);
    }

    if (err)
    {
      close(perr[0]);
      dup2(perr[1], 2);
      close(perr[1]);
    }
    else if (fderr != -1)
    {
      dup2(fderr, 2);
      close(fderr);
    }

    if (MuttIndexWindow && (MuttIndexWindow->cols > 0))
    {
      snprintf(columns, sizeof(columns), "%d", MuttIndexWindow->cols);
      mutt_envlist_set("COLUMNS", columns, 1);
    }

    execle(EXECSHELL, "sh", "-c", cmd, NULL, mutt_envlist());
    _exit(127);
  }
  else if (thepid == -1)
  {
    mutt_unblock_signals_system(1);

    if (in)
    {
      close(pin[0]);
      close(pin[1]);
    }

    if (out)
    {
      close(pout[0]);
      close(pout[1]);
    }

    if (err)
    {
      close(perr[0]);
      close(perr[1]);
    }

    return (-1);
  }

  if (out)
  {
    close(pout[1]);
    *out = fdopen(pout[0], "r");
  }

  if (in)
  {
    close(pin[0]);
    *in = fdopen(pin[1], "w");
  }

  if (err)
  {
    close(perr[1]);
    *err = fdopen(perr[0], "r");
  }

  return (thepid);
}

pid_t mutt_create_filter(const char *s, FILE **in, FILE **out, FILE **err)
{
  return (mutt_create_filter_fd(s, in, out, err, -1, -1, -1));
}

int mutt_wait_filter(pid_t pid)
{
  int rc;

  waitpid(pid, &rc, 0);
  mutt_unblock_signals_system(1);
  rc = WIFEXITED(rc) ? WEXITSTATUS(rc) : -1;

  return rc;
}

/*
 * This is used for filters that are actually interactive commands
 * with input piped in: e.g. in mutt_view_attachment(), a mailcap
 * entry without copiousoutput _and_ without a %s.
 *
 * For those cases, we treat it like a blocking system command, and
 * poll IMAP to keep connections open.
 */
int mutt_wait_interactive_filter(pid_t pid)
{
  int rc;

#ifndef USE_IMAP
  waitpid(pid, &rc, 0);
#else
  rc = imap_wait_keepalive(pid);
#endif
  mutt_unblock_signals_system(1);
  rc = WIFEXITED(rc) ? WEXITSTATUS(rc) : -1;

  return rc;
}
