/* GNU mailutils - a suite of utilities for electronic mail
   Copyright (C) 1999, 2000, 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 Library Public License as published by
   the Free Software Foundation; either version 2, 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 Library General Public License for more details.

   You should have received a copy of the GNU Library General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif

#include <mailutils/error.h>
#include <mailutils/sys/attribute.h>

int
(attribute_add_ref) (attribute_t attribute)
{
  if (attribute == NULL || attribute->vtable == NULL
      || attribute->vtable->add_ref == NULL)
    return MU_ERROR_NOT_SUPPORTED;
  return attribute->vtable->add_ref (attribute);
}

int
(attribute_release) (attribute_t attribute)
{
  if (attribute == NULL || attribute->vtable == NULL
      || attribute->vtable->release == NULL)
    return MU_ERROR_NOT_SUPPORTED;
  return attribute->vtable->release (attribute);
}

int
(attribute_destroy) (attribute_t attribute)
{
  if (attribute == NULL || attribute->vtable == NULL
      || attribute->vtable->destroy == NULL)
    return MU_ERROR_NOT_SUPPORTED;
  return attribute->vtable->destroy (attribute);
}

int
(attribute_get_flags) (attribute_t attribute, int *pflags)
{
  if (attribute == NULL || attribute->vtable == NULL
      || attribute->vtable->get_flags == NULL)
    return MU_ERROR_NOT_SUPPORTED;
  return attribute->vtable->get_flags (attribute, pflags);
}

int
(attribute_set_flags) (attribute_t attribute, int flags)
{
  if (attribute == NULL || attribute->vtable == NULL
      || attribute->vtable->set_flags == NULL)
    return MU_ERROR_NOT_SUPPORTED;
  return attribute->vtable->set_flags (attribute, flags);
}

int
(attribute_unset_flags) (attribute_t attribute, int flags)
{
  if (attribute == NULL || attribute->vtable == NULL
      || attribute->vtable->unset_flags == NULL)
    return MU_ERROR_NOT_SUPPORTED;
  return attribute->vtable->unset_flags (attribute, flags);
}

int
(attribute_clear_flags) (attribute_t attribute)
{
  if (attribute == NULL || attribute->vtable == NULL
      || attribute->vtable->clear_flags == NULL)
    return MU_ERROR_NOT_SUPPORTED;
  return attribute->vtable->clear_flags (attribute);
}


/* Stub helpers for the wellknown flags.  */
int
attribute_set_seen (attribute_t attribute)
{
  if (attribute == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  return attribute_set_flags (attribute, MU_ATTRIBUTE_SEEN);
}

int
attribute_set_answered (attribute_t attribute)
{
  if (attribute == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  return attribute_set_flags (attribute, MU_ATTRIBUTE_ANSWERED);
}

int
attribute_set_flagged (attribute_t attribute)
{
  if (attribute == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  return attribute_set_flags (attribute, MU_ATTRIBUTE_FLAGGED);
}

int
attribute_set_read (attribute_t attribute)
{
  if (attribute == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  return attribute_set_flags (attribute, MU_ATTRIBUTE_READ);
}

int
attribute_set_deleted (attribute_t attribute)
{
  if (attribute == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  return attribute_set_flags (attribute, MU_ATTRIBUTE_DELETED);
}

int
attribute_set_draft (attribute_t attribute)
{
  if (attribute == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  return attribute_set_flags (attribute, MU_ATTRIBUTE_DRAFT);
}

int
attribute_set_recent (attribute_t attribute)
{
  if (attribute == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  attribute_unset_flags (attribute, MU_ATTRIBUTE_READ);
  return attribute_unset_flags (attribute, MU_ATTRIBUTE_SEEN);
}

int
attribute_set_modified (attribute_t attribute)
{
  if (attribute == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  return attribute_set_flags (attribute, MU_ATTRIBUTE_MODIFIED);
}

int
attribute_is_seen (attribute_t attribute)
{
  int flags = 0;
  if (attribute == NULL)
    return 0;
  attribute_get_flags (attribute, &flags);
  return flags & MU_ATTRIBUTE_SEEN;
}

int
attribute_is_answered (attribute_t attribute)
{
  int flags = 0;
  if (attribute == NULL)
    return 0;
  attribute_get_flags (attribute, &flags);
  return flags & MU_ATTRIBUTE_ANSWERED;
}

int
attribute_is_flagged (attribute_t attribute)
{
  int flags = 0;
  if (attribute == NULL)
    return 0;
  attribute_get_flags (attribute, &flags);
  return flags & MU_ATTRIBUTE_FLAGGED;
}

int
attribute_is_read (attribute_t attribute)
{
  int flags = 0;
  if (attribute == NULL)
    return 0;
  attribute_get_flags (attribute, &flags);
  return flags & MU_ATTRIBUTE_READ;
}

int
attribute_is_deleted (attribute_t attribute)
{
  int flags = 0;
  if (attribute == NULL)
    return 0;
  attribute_get_flags (attribute, &flags);
  return flags & MU_ATTRIBUTE_DELETED;
}

int
attribute_is_draft (attribute_t attribute)
{
  int flags = 0;
  if (attribute == NULL)
    return 0;
  attribute_get_flags (attribute, &flags);
  return flags & MU_ATTRIBUTE_DRAFT;
}

int
attribute_is_recent (attribute_t attribute)
{
  int flags = 0;
  if (attribute == NULL)
    return 0;
  attribute_get_flags (attribute, &flags);
  /* Something is recent when it is not read and not seen.  */
  return (flags == 0
	  || ! ((flags & MU_ATTRIBUTE_SEEN) || (flags & MU_ATTRIBUTE_READ)));
}

int
attribute_is_modified (attribute_t attribute)
{
  int flags = 0;
  if (attribute == NULL)
      return 0;
  attribute_get_flags (attribute, &flags);
  return flags & MU_ATTRIBUTE_MODIFIED;
}

int
attribute_unset_seen (attribute_t attribute)
{
  if (attribute == NULL)
    return 0;
  return attribute_unset_flags (attribute, MU_ATTRIBUTE_SEEN);
}

int
attribute_unset_answered (attribute_t attribute)
{
  if (attribute == NULL)
    return 0;
  return attribute_unset_flags (attribute, MU_ATTRIBUTE_ANSWERED);
}

int
attribute_unset_flagged (attribute_t attribute)
{
  if (attribute == NULL)
    return 0;
  return attribute_unset_flags (attribute, MU_ATTRIBUTE_FLAGGED);
}

int
attribute_unset_read (attribute_t attribute)
{
  if (attribute == NULL)
    return 0;
  return attribute_unset_flags (attribute, MU_ATTRIBUTE_READ);
}

int
attribute_unset_deleted (attribute_t attribute)
{
  if (attribute == NULL)
    return 0;
  return attribute_unset_flags (attribute, MU_ATTRIBUTE_DELETED);
}

int
attribute_unset_draft (attribute_t attribute)
{
  if (attribute == NULL)
    return 0;
  return attribute_unset_flags (attribute, MU_ATTRIBUTE_DRAFT);
}

int
attribute_unset_recent (attribute_t attribute)
{
  if (attribute == NULL)
    return 0;
  return attribute_unset_flags (attribute, MU_ATTRIBUTE_SEEN);
}

int
attribute_unset_modified (attribute_t attribute)
{
  if (attribute == NULL)
    return 0;
  return attribute_unset_flags (attribute, MU_ATTRIBUTE_MODIFIED);
}

/* Miscellaneous.  */
int
attribute_is_equal (attribute_t attribute1, attribute_t attribute2)
{
  int flags1 = 0;
  int flags2 = 0;
  if (attribute1)
    attribute_get_flags (attribute1, &flags1);
  if (attribute2)
    attribute_get_flags (attribute2, &flags2);
  return flags1 == flags2;
}

int
attribute_copy (attribute_t dest, attribute_t src)
{
  int sflags = 0;
  if (dest == NULL || src == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  attribute_get_flags (src, &sflags);
  attribute_clear_flags (dest);
  attribute_set_flags (dest, sflags);
  return 0;
}

static int
_da_add_ref (attribute_t attribute)
{
  struct _da *da = (struct _da *)attribute;
  int status;
  monitor_lock (da->lock);
  status = ++da->ref;
  monitor_unlock (da->lock);
  return status;
}

static int
_da_destroy (attribute_t attribute)
{
  struct _da *da = (struct _da *)attribute;
  monitor_destroy (da->lock);
  free (da);
  return 0;
}

static int
_da_release (attribute_t attribute)
{
  struct _da *da = (struct _da *)attribute;
  int status;
  monitor_lock (da->lock);
  status = --da->ref;
  if (status <= 0)
    {
      monitor_unlock (da->lock);
      _da_destroy (attribute);
      return 0;
    }
  monitor_unlock (da->lock);
  return status;
}

static int
_da_get_flags (attribute_t attribute, int *pflags)
{
  struct _da *da = (struct _da *)attribute;
  monitor_lock (da->lock);
  if (pflags)
    *pflags = da->flags;
  monitor_unlock (da->lock);
  return 0;
}

static int
_da_set_flags (attribute_t attribute, int flags)
{
  struct _da *da = (struct _da *)attribute;
  monitor_lock (da->lock);
  da->flags |= (flags | MU_ATTRIBUTE_MODIFIED);
  monitor_unlock (da->lock);
  return 0;
}

static int
_da_unset_flags (attribute_t attribute, int flags)
{
  struct _da *da = (struct _da *)attribute;
  monitor_lock (da->lock);
  da->flags &= ~flags;
  /* If Modified was being unset do not reset it.  */
  if (!(flags & MU_ATTRIBUTE_MODIFIED))
    da->flags |= MU_ATTRIBUTE_MODIFIED;
  monitor_unlock (da->lock);
  return 0;
}

static int
_da_clear_flags (attribute_t attribute)
{
  struct _da *da = (struct _da *)attribute;
  monitor_lock (da->lock);
  da->flags = 0;
  monitor_unlock (da->lock);
  return 0;
}

static struct _attribute_vtable _da_vtable =
{
  _da_add_ref,
  _da_release,
  _da_destroy,

  _da_get_flags,
  _da_set_flags,
  _da_unset_flags,
  _da_clear_flags
};

int
attribute_create (attribute_t *pattribute)
{
  struct _da *da;
  if (pattribute == NULL)
    return MU_ERROR_INVALID_PARAMETER;
  da = calloc (1, sizeof *da);
  if (da == NULL)
    return MU_ERROR_NO_MEMORY;

  da->base.vtable = &_da_vtable;
  da->ref = 1;
  da->flags = 0;
  monitor_create (&(da->lock));
  *pattribute = &da->base;
  return 0;
}