/* libguestfs
 * Copyright (C) 2009 Red Hat Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <guestfs.h>

#include <caml/config.h>
#include <caml/alloc.h>
#include <caml/callback.h>
#include <caml/custom.h>
#include <caml/fail.h>
#include <caml/memory.h>
#include <caml/mlvalues.h>

#include "guestfs_c.h"

/* Allocate handles and deal with finalization. */
static void
guestfs_finalize (value gv)
{
  guestfs_h *g = Guestfs_val (gv);
  if (g) guestfs_close (g);
}

static struct custom_operations guestfs_custom_operations = {
  "guestfs_custom_operations",
  guestfs_finalize,
  custom_compare_default,
  custom_hash_default,
  custom_serialize_default,
  custom_deserialize_default
};

static value
Val_guestfs (guestfs_h *g)
{
  CAMLparam0 ();
  CAMLlocal1 (rv);

  rv = caml_alloc_custom (&guestfs_custom_operations,
                          sizeof (guestfs_h *), 0, 1);
  Guestfs_val (rv) = g;

  CAMLreturn (rv);
}

/* Handle errors. */
/* XXX Like the current Perl bindings, this is unsafe in a multi-
 * threaded environment.
 */
static char *last_error = NULL;

static void
error_handler (guestfs_h *g,
	       void *data,
	       const char *msg)
{
  if (last_error != NULL) free (last_error);
  last_error = strdup (msg);
}

void
ocaml_guestfs_raise_error (guestfs_h *g, const char *func)
{
  CAMLparam0 ();
  CAMLlocal1 (v);

  v = caml_copy_string (last_error);
  caml_raise_with_arg (*caml_named_value ("ocaml_guestfs_error"), v);
  CAMLnoreturn;
}

/* Guestfs.create */
CAMLprim value
ocaml_guestfs_create (void)
{
  CAMLparam0 ();
  CAMLlocal1 (gv);
  guestfs_h *g;

  g = guestfs_create ();
  if (g == NULL)
    caml_failwith ("failed to create guestfs handle");

  guestfs_set_error_handler (g, error_handler, NULL);

  gv = Val_guestfs (g);
  CAMLreturn (gv);
}

/* Guestfs.close */
CAMLprim value
ocaml_guestfs_close (value gv)
{
  CAMLparam1 (gv);

  guestfs_finalize (gv);

  /* So we don't double-free in the finalizer. */
  Guestfs_val (gv) = NULL;

  CAMLreturn (Val_unit);
}