/* -*-c-*- -------------- mixguile_cmd_dispatcher.c :
 * Implementation of the functions declared in mixguile_cmd_dispatcher.h
 * ------------------------------------------------------------------
 *  Last change: Time-stamp: "01/08/22 02:29:34 jao"
 * ------------------------------------------------------------------
 * Copyright (C) 2001 Free Software Foundation, Inc.
 *  
 * 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.
 *  
 */

#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#include <guile/gh.h>
#include "mixguile.h"
#include "xmixguile_cmd_dispatcher.h"

/* create/destroy cmd dispatcher */
mixguile_cmd_dispatcher_t *
mixguile_cmd_dispatcher_new (mix_vm_cmd_dispatcher_t *dis)
{
  static gboolean REGISTERED = FALSE;
  mixguile_cmd_dispatcher_t *result = NULL;
  int fildes[2], r;
  FILE *out;
  
  g_return_val_if_fail (dis != NULL, NULL);
  
  if (!REGISTERED)
    {
      register_scm_commands_ (DEFAULT_SCM_COMMANDS_);
      REGISTERED = TRUE;
    }
  
  r = pipe (fildes);
  g_return_val_if_fail (r == 0, NULL);
  out = fdopen (fildes[1], "w");
  g_return_val_if_fail (out != NULL, NULL);
  r = fcntl (fildes[0], F_GETFL, 0);
  g_return_val_if_fail (r != -1, NULL);
  r = fcntl (fildes[0], F_SETFL, r | O_NONBLOCK);
  g_return_val_if_fail (r != -1, NULL);

  result = g_new (mixguile_cmd_dispatcher_t, 1);
  result->dispatcher = dis;
  result->err = result->out = NULL;
  result->guile_out = out;
  result->fildes[0] = fildes[0];
  result->fildes[1] = fildes[1];
  result->result = NULL;
  
  register_cmd_dispatcher_ (result);
  
  return result;
}


void
mixguile_cmd_dispatcher_delete (mixguile_cmd_dispatcher_t *dis)
{
  g_return_if_fail (dis != NULL);
  fclose (dis->guile_out);
  close (dis->fildes[0]);
  close (dis->fildes[1]);
  mix_vm_cmd_dispatcher_delete (dis->dispatcher);
}

/* get the underlying vm dispatcher */
mix_vm_cmd_dispatcher_t *
mixguile_cmd_dispatcher_get_vm_dispatcher (const mixguile_cmd_dispatcher_t *dis)
{
  g_return_val_if_fail (dis != NULL, NULL);
  return dis->dispatcher;
}

/* get the result string of last executed command */
const gchar *
mixguile_cmd_dispatcher_last_result (mixguile_cmd_dispatcher_t *dis)
{
  enum {BLKSIZE = 256};
  static gchar BUFFER[BLKSIZE + 1];
  
  ssize_t k;
  gchar *tmp = NULL;
  
  g_return_val_if_fail (dis != NULL, NULL);
  if (dis->result) g_free (dis->result);
  dis->result = NULL;
  fflush (dis->guile_out);
  while ((k = read (dis->fildes[0], BUFFER, BLKSIZE)) != 0)
    {
      if (k == -1 && errno != EINTR) break;
      if (k != -1)
	{
	  tmp = dis->result;
	  BUFFER[k] = '\0';
	  dis->result = g_strconcat (tmp ? tmp : "", BUFFER, NULL);
	  g_free (tmp);
	}
    }

  if (dis->result && dis->result[strlen (dis->result) - 1] == '\n')
    dis->result[strlen (dis->result) - 1] = '\0';
  
  return dis->result;
}

/* prepare dispatcher for repl */
static void
prepare_dispatcher_ (mixguile_cmd_dispatcher_t *dis)
{
  dis->out = mix_vm_cmd_dispatcher_set_out_stream (dis->dispatcher,
						   dis->guile_out);
  dis->err = mix_vm_cmd_dispatcher_set_error_stream (dis->dispatcher,
						     dis->guile_out);
}

void
mixguile_cmd_dispatcher_prepare (mixguile_cmd_dispatcher_t *dis)
{
  g_return_if_fail (dis != NULL);
  prepare_dispatcher_ (dis);
}

/* interpret commands from file or string */
static void
reset_dispatcher_ (mixguile_cmd_dispatcher_t *dis)
{
  (void) mix_vm_cmd_dispatcher_set_out_stream (dis->dispatcher, dis->out);
  (void) mix_vm_cmd_dispatcher_set_error_stream (dis->dispatcher, dis->err);
}


void
mixguile_cmd_dispatcher_interpret_file (mixguile_cmd_dispatcher_t *dis,
					const gchar *path)
{
  g_return_if_fail (dis != NULL);
  g_return_if_fail (path != NULL);
  prepare_dispatcher_ (dis);
  (void) gh_eval_file ((char *)path);
  reset_dispatcher_ (dis);
}

void
mixguile_cmd_dispatcher_interpret_command (mixguile_cmd_dispatcher_t *dis,
					   const gchar *command)
{
  g_return_if_fail (dis != NULL);
  g_return_if_fail (command != NULL);
  prepare_dispatcher_ (dis);
  (void) gh_eval_str ((char *)command);
  reset_dispatcher_ (dis);
}