/*
   This file is part of GNUnet.
   Copyright (C) 2020--2025 GNUnet e.V.

   GNUnet is free software: you can redistribute it and/or modify it
   under the terms of the GNU Affero General Public License as published
   by the Free Software Foundation, either version 3 of the License,
   or (at your option) any later version.

   GNUnet 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
   Affero General Public License for more details.

   You should have received a copy of the GNU Affero General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.

   SPDX-License-Identifier: AGPL3.0-or-later
 */
/**
 * @author Tobias Frisch
 * @file src/messenger/gnunet-service-messenger_list_messages.c
 * @brief GNUnet MESSENGER service
 */

#include "gnunet-service-messenger_list_messages.h"

#include "gnunet_util_lib.h"

void
init_list_messages (struct GNUNET_MESSENGER_ListMessages *messages)
{
  GNUNET_assert (messages);

  messages->head = NULL;
  messages->tail = NULL;
}


void
clear_list_messages (struct GNUNET_MESSENGER_ListMessages *messages)
{
  GNUNET_assert (messages);

  while (messages->head)
  {
    struct GNUNET_MESSENGER_ListMessage *element = messages->head;

    GNUNET_CONTAINER_DLL_remove (messages->head, messages->tail, element);
    GNUNET_free (element);
  }

  messages->head = NULL;
  messages->tail = NULL;
}


void
add_to_list_messages (struct GNUNET_MESSENGER_ListMessages *messages,
                      const struct GNUNET_HashCode *hash)
{
  struct GNUNET_MESSENGER_ListMessage *element;

  GNUNET_assert ((messages) && (hash));

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Add new message to list: %s\n",
              GNUNET_h2s (hash));

  element = GNUNET_new (struct GNUNET_MESSENGER_ListMessage);

  GNUNET_memcpy (&(element->hash), hash, sizeof(struct GNUNET_HashCode));

  GNUNET_CONTAINER_DLL_insert_tail (messages->head, messages->tail, element);
}


void
copy_list_messages (struct GNUNET_MESSENGER_ListMessages *messages,
                    const struct GNUNET_MESSENGER_ListMessages *origin)
{
  struct GNUNET_MESSENGER_ListMessage *element;

  GNUNET_assert ((messages) && (origin));

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Copy messages from list!\n");

  for (element = origin->head; element; element = element->next)
    add_to_list_messages (messages, &(element->hash));
}


void
remove_from_list_messages (struct GNUNET_MESSENGER_ListMessages *messages,
                           const struct GNUNET_HashCode *hash)
{
  struct GNUNET_MESSENGER_ListMessage *element;

  GNUNET_assert ((messages) && (hash));

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Remove message from list: %s\n",
              GNUNET_h2s (hash));

  for (element = messages->head; element; element = element->next)
    if (0 == GNUNET_CRYPTO_hash_cmp (&(element->hash), hash))
    {
      GNUNET_CONTAINER_DLL_remove (messages->head, messages->tail, element);
      GNUNET_free (element);
      break;
    }
}


void
load_list_messages (struct GNUNET_MESSENGER_ListMessages *messages,
                    const char *path)
{
  struct GNUNET_DISK_FileHandle *handle;
  struct GNUNET_HashCode hash;
  ssize_t len;

  GNUNET_assert ((messages) && (path));

  if (GNUNET_YES != GNUNET_DISK_file_test (path))
    return;

  {
    enum GNUNET_DISK_AccessPermissions permission;

    permission = (GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE);

    handle = GNUNET_DISK_file_open (path, GNUNET_DISK_OPEN_READ, permission);
  }

  if (! handle)
    return;

  GNUNET_DISK_file_seek (handle, 0, GNUNET_DISK_SEEK_SET);

  do {
    len = GNUNET_DISK_file_read (handle, &hash, sizeof(hash));

    if (len != sizeof(hash))
      break;

    add_to_list_messages (messages, &hash);
  } while (len == sizeof(hash));

  GNUNET_DISK_file_close (handle);
}


void
save_list_messages (const struct GNUNET_MESSENGER_ListMessages *messages,
                    const char *path)
{
  struct GNUNET_DISK_FileHandle *handle;

  GNUNET_assert ((messages) && (path));

  {
    enum GNUNET_DISK_AccessPermissions permission;

    permission = (GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE);

    handle = GNUNET_DISK_file_open (
      path, GNUNET_DISK_OPEN_CREATE | GNUNET_DISK_OPEN_WRITE, permission);
  }

  if (! handle)
    return;

  GNUNET_DISK_file_seek (handle, 0, GNUNET_DISK_SEEK_SET);

  {
    struct GNUNET_MESSENGER_ListMessage *element;

    for (element = messages->head; element; element = element->next)
      GNUNET_DISK_file_write (handle, &(element->hash), sizeof(element->hash));
  }

  GNUNET_DISK_file_sync (handle);
  GNUNET_DISK_file_close (handle);
}
