/*
     This file is part of GNUnet.
     Copyright (C) 2011 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
 */
/**
 * @file ats/gnunet-service-ats.c
 * @brief ats service
 * @author Matthias Wachs
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet-service-ats.h"
#include "gnunet-service-ats_addresses.h"
#include "gnunet-service-ats_connectivity.h"
#include "gnunet-service-ats_normalization.h"
#include "gnunet-service-ats_performance.h"
#include "gnunet-service-ats_preferences.h"
#include "gnunet-service-ats_scheduling.h"
#include "gnunet-service-ats_reservations.h"
#include "gnunet-service-ats_plugins.h"
#include "ats.h"

/**
 * Handle for statistics.
 */
struct GNUNET_STATISTICS_Handle *GSA_stats;


/**
 * We have received a `struct ClientStartMessage` from a client.  Find
 * out which type of client it is and notify the respective subsystem.
 *
 * @param cls handle to the client
 * @param msg the start message
 */
static void
handle_ats_start(void *cls,
                 const struct ClientStartMessage *msg)
{
  struct GNUNET_SERVICE_Client *client = cls;
  enum StartFlag flag;

  flag = ntohl(msg->start_flag);
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "Received ATS_START (%d) message\n",
             (int)flag);
  switch (flag)
    {
    case START_FLAG_SCHEDULING:
      if (GNUNET_OK !=
          GAS_scheduling_add_client(client))
        {
          GNUNET_SERVICE_client_drop(client);
          return;
        }
      break;

    case START_FLAG_PERFORMANCE_WITH_PIC:
      GAS_performance_add_client(client,
                                 flag);
      break;

    case START_FLAG_PERFORMANCE_NO_PIC:
      GAS_performance_add_client(client,
                                 flag);
      break;

    case START_FLAG_CONNECTION_SUGGESTION:
      /* This client won't receive messages from us, no need to 'add' */
      break;

    default:
      GNUNET_break(0);
      GNUNET_SERVICE_client_drop(client);
      return;
    }
  GNUNET_SERVICE_client_continue(client);
}



/**
 * Handle 'reservation request' messages from clients.
 *
 * @param cls client that sent the request
 * @param message the request message
 */
static void
handle_reservation_request(void *cls,
                           const struct ReservationRequestMessage *message)
{
  struct GNUNET_SERVICE_Client *client = cls;

  GAS_handle_reservation_request(client,
                                 message);
  GNUNET_SERVICE_client_continue(client);
}


/**
 * Check 'preference feedback' message is well-formed
 *
 * @param cls client that sent the request
 * @param message the request message
 * @return #GNUNET_OK if @a message is well-formed
 */
static int
check_feedback(void *cls,
               const struct FeedbackPreferenceMessage *message)
{
  uint16_t msize;
  uint32_t nump;

  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "Received PREFERENCE_FEEDBACK message\n");
  msize = ntohs(message->header.size);
  nump = ntohl(message->num_feedback);
  if (msize !=
      sizeof(struct FeedbackPreferenceMessage) +
      nump * sizeof(struct PreferenceInformation))
    {
      GNUNET_break(0);
      return GNUNET_SYSERR;
    }
  return GNUNET_OK;
}


/**
 * Handle 'preference feedback' messages from clients.
 *
 * @param cls client that sent the request
 * @param msg the request message
 */
static void
handle_feedback(void *cls,
                const struct FeedbackPreferenceMessage *msg)
{
  struct GNUNET_SERVICE_Client *client = cls;
  const struct PreferenceInformation *pi;
  uint32_t nump;

  nump = ntohl(msg->num_feedback);
  if (GNUNET_NO ==
      GNUNET_CONTAINER_multipeermap_contains(GSA_addresses,
                                             &msg->peer))
    {
      GNUNET_log(GNUNET_ERROR_TYPE_WARNING,
                 "Received PREFERENCE FEEDBACK for unknown peer `%s'\n",
                 GNUNET_i2s(&msg->peer));
      GNUNET_SERVICE_client_continue(client);
      return;
    }

  GNUNET_STATISTICS_update(GSA_stats,
                           "# preference feedbacks requests processed",
                           1,
                           GNUNET_NO);
  pi = (const struct PreferenceInformation *)&msg[1];
  for (uint32_t i = 0; i < nump; i++)
    {
      GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
                 "Received PREFERENCE FEEDBACK for peer `%s'\n",
                 GNUNET_i2s(&msg->peer));
      GAS_plugin_notify_feedback(client,
                                 &msg->peer,
                                 GNUNET_TIME_relative_ntoh(msg->scope),
                                 (enum GNUNET_ATS_PreferenceKind)ntohl(pi[i].preference_kind),
                                 pi[i].preference_value);
    }
  GNUNET_SERVICE_client_continue(client);
}


/**
 * Handle 'request address list' messages from clients.
 *
 * @param cls client that sent the request
 * @param message the request message
 */
static void
handle_request_address_list(void *cls,
                            const struct AddressListRequestMessage *message)
{
  struct GNUNET_SERVICE_Client *client = cls;

  GAS_handle_request_address_list(client,
                                  message);
  GNUNET_SERVICE_client_continue(client);
}


/**
 * Handle 'request address' messages from clients.
 *
 * @param cls client that sent the request
 * @param message the request message
 */
static void
handle_request_address(void *cls,
                       const struct RequestAddressMessage * message)
{
  struct GNUNET_SERVICE_Client *client = cls;

  GAS_handle_request_address(client,
                             message);
  GNUNET_SERVICE_client_continue(client);
}


/**
 * Cancel 'request address' messages from clients.
 *
 * @param cls client that sent the request
 * @param message the request message
 */
static void
handle_request_address_cancel(void *cls,
                              const struct RequestAddressMessage *message)
{
  struct GNUNET_SERVICE_Client *client = cls;

  GAS_handle_request_address_cancel(client,
                                    message);
  GNUNET_SERVICE_client_continue(client);
}


/**
 * Handle 'address add' messages from clients.
 *
 * @param cls client that sent the request
 * @param m the request message
 */
static int
check_address_add(void *cls,
                  const struct AddressAddMessage *m)
{
  const char *address;
  const char *plugin_name;
  uint16_t address_length;
  uint16_t plugin_name_length;
  uint16_t size;

  size = ntohs(m->header.size);
  address_length = ntohs(m->address_length);
  plugin_name_length = ntohs(m->plugin_name_length);
  address = (const char *)&m[1];
  if (plugin_name_length != 0)
    plugin_name = &address[address_length];
  else
    plugin_name = "";

  if ((address_length + plugin_name_length +
       sizeof(struct AddressAddMessage) != size) ||
      ((plugin_name_length > 0) &&
       (plugin_name[plugin_name_length - 1] != '\0')))
    {
      GNUNET_break(0);
      return GNUNET_SYSERR;
    }
  return GNUNET_OK;
}


/**
 * Handle 'address add' messages from clients.
 *
 * @param cls client that sent the request
 * @param message the request message
 */
static void
handle_address_add(void *cls,
                   const struct AddressAddMessage *message)
{
  struct GNUNET_SERVICE_Client *client = cls;

  GAS_handle_address_add(message);
  GNUNET_SERVICE_client_continue(client);
}


/**
 * Handle 'address update' messages from clients.
 *
 * @param cls client that sent the request
 * @param message the request message
 */
static void
handle_address_update(void *cls,
                      const struct AddressUpdateMessage *message)
{
  struct GNUNET_SERVICE_Client *client = cls;

  GAS_handle_address_update(message);
  GNUNET_SERVICE_client_continue(client);
}


/**
 * Handle 'address destroyed' messages from clients.
 *
 * @param cls client that sent the request
 * @param message the request message
 */
static void
handle_address_destroyed(void *cls,
                         const struct AddressDestroyedMessage *message)
{
  struct GNUNET_SERVICE_Client *client = cls;

  GAS_handle_address_destroyed(message);
  GNUNET_SERVICE_client_continue(client);
}


/**
 * Check that 'change preference' message is well-formed.
 *
 * @param cls client that sent the request
 * @param message the request message
 * @return #GNUNET_OK if @a message is well-formed
 */
static int
check_preference_change(void *cls,
                        const struct ChangePreferenceMessage *message)
{
  uint16_t msize;
  uint32_t nump;

  msize = ntohs(message->header.size);
  nump = ntohl(message->num_preferences);
  if ((msize !=
       sizeof(struct ChangePreferenceMessage) +
       nump * sizeof(struct PreferenceInformation)) ||
      (UINT16_MAX / sizeof(struct PreferenceInformation) < nump))
    {
      GNUNET_break(0);
      return GNUNET_SYSERR;
    }
  return GNUNET_OK;
}


/**
 * Handle 'change preference' messages from clients.
 *
 * @param cls client that sent the request
 * @param message the request message
 */
static void
handle_preference_change(void *cls,
                         const struct ChangePreferenceMessage *message)
{
  struct GNUNET_SERVICE_Client *client = cls;

  GAS_handle_preference_change(client,
                               message);
  GNUNET_SERVICE_client_continue(client);
}


/**
 * A client connected to us. Setup the local client
 * record.
 *
 * @param cls unused
 * @param client handle of the client
 * @param mq message queue to talk to @a client
 * @return @a client
 */
static void *
client_connect_cb(void *cls,
                  struct GNUNET_SERVICE_Client *client,
                  struct GNUNET_MQ_Handle *mq)
{
  return client;
}


/**
 * A client disconnected from us.  Tear down the local client
 * record.
 *
 * @param cls unused
 * @param client handle of the client
 * @param app_ctx
 */
static void
client_disconnect_cb(void *cls,
                     struct GNUNET_SERVICE_Client *client,
                     void *app_ctx)
{
  if (NULL == client)
    return;
  GAS_scheduling_remove_client(client);
  GAS_connectivity_remove_client(client);
  GAS_preference_client_disconnect(client);
}


/**
 * Task run during shutdown.
 *
 * @param cls unused
 */
static void
cleanup_task(void *cls)
{
  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "ATS shutdown initiated\n");
  GAS_connectivity_done();
  GAS_addresses_done();
  GAS_plugin_done();
  GAS_normalization_stop();
  GAS_performance_done();
  GAS_preference_done();
  GAS_reservations_done();
  if (NULL != GSA_stats)
    {
      GNUNET_STATISTICS_destroy(GSA_stats, GNUNET_NO);
      GSA_stats = NULL;
    }
}


/**
 * Process template requests.
 *
 * @param cls closure
 * @param cfg configuration to use
 * @param service the initialized service
 */
static void
run(void *cls,
    const struct GNUNET_CONFIGURATION_Handle *cfg,
    struct GNUNET_SERVICE_Handle *service)
{
  GSA_stats = GNUNET_STATISTICS_create("ats",
                                       cfg);
  GAS_reservations_init();
  GAS_connectivity_init();
  GAS_preference_init();
  GAS_normalization_start();
  GAS_addresses_init();
  if (GNUNET_OK !=
      GAS_plugin_init(cfg))
    {
      GNUNET_break(0);
      GAS_addresses_done();
      GAS_normalization_stop();
      GAS_reservations_done();
      GAS_connectivity_done();
      GAS_preference_done();
      if (NULL != GSA_stats)
        {
          GNUNET_STATISTICS_destroy(GSA_stats,
                                    GNUNET_NO);
          GSA_stats = NULL;
        }
      return;
    }
  GAS_performance_init();
  GNUNET_SCHEDULER_add_shutdown(&cleanup_task,
                                NULL);
}


/**
 * Define "main" method using service macro.
 */
GNUNET_SERVICE_MAIN
  ("ats",
  GNUNET_SERVICE_OPTION_NONE,
  &run,
  &client_connect_cb,
  &client_disconnect_cb,
  NULL,
  GNUNET_MQ_hd_fixed_size(ats_start,
                          GNUNET_MESSAGE_TYPE_ATS_START,
                          struct ClientStartMessage,
                          NULL),
  GNUNET_MQ_hd_fixed_size(request_address,
                          GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS,
                          struct RequestAddressMessage,
                          NULL),
  GNUNET_MQ_hd_fixed_size(request_address_cancel,
                          GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS_CANCEL,
                          struct RequestAddressMessage,
                          NULL),
  GNUNET_MQ_hd_fixed_size(request_address_list,
                          GNUNET_MESSAGE_TYPE_ATS_ADDRESSLIST_REQUEST,
                          struct AddressListRequestMessage,
                          NULL),
  GNUNET_MQ_hd_var_size(address_add,
                        GNUNET_MESSAGE_TYPE_ATS_ADDRESS_ADD,
                        struct AddressAddMessage,
                        NULL),
  GNUNET_MQ_hd_fixed_size(address_update,
                          GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE,
                          struct AddressUpdateMessage,
                          NULL),
  GNUNET_MQ_hd_fixed_size(address_destroyed,
                          GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED,
                          struct AddressDestroyedMessage,
                          NULL),
  GNUNET_MQ_hd_fixed_size(reservation_request,
                          GNUNET_MESSAGE_TYPE_ATS_RESERVATION_REQUEST,
                          struct ReservationRequestMessage,
                          NULL),
  GNUNET_MQ_hd_var_size(preference_change,
                        GNUNET_MESSAGE_TYPE_ATS_PREFERENCE_CHANGE,
                        struct ChangePreferenceMessage,
                        NULL),
  GNUNET_MQ_hd_var_size(feedback,
                        GNUNET_MESSAGE_TYPE_ATS_PREFERENCE_FEEDBACK,
                        struct FeedbackPreferenceMessage,
                        NULL),
  GNUNET_MQ_handler_end());


/* end of gnunet-service-ats.c */