/*
     This file is part of GNUnet.
     Copyright (C) 2009, 2012 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 nse/test_nse_multipeer.c
 * @brief Testcase for the network size estimation service.  Starts
 *        a peergroup with a given number of peers, then waits to
 *        receive size estimates from each peer.  Expects to wait
 *        for one message from each peer.
 */
#include "platform.h"
#include "gnunet_testbed_service.h"
#include "gnunet_nse_service.h"


/**
 * How many peers do we start?
 */
#define NUM_PEERS 4

/**
 * How long do we run the test?
 */
#define TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 300)


/**
 * Information we track for each peer.
 */
struct NSEPeer
{
  /**
   * Handle for NSE connect operation.
   */
  struct GNUNET_TESTBED_Operation *op;

  /**
   * Handle to NSE service.
   */
  struct GNUNET_NSE_Handle *nse_handle;
};


/**
 * Information for all the peers.
 */
static struct NSEPeer nse_peers[NUM_PEERS];

/**
 * Return value from 'main'.
 */
static int ok;


/**
 * Task run on timeout to shut everything down.
 */
static void
shutdown_task (void *cls)
{
  unsigned int i;

  for (i = 0; i < NUM_PEERS; i++)
    GNUNET_TESTBED_operation_done (nse_peers[i].op);
  GNUNET_SCHEDULER_shutdown ();
}


/**
 * Callback to call when network size estimate is updated.
 *
 * @param cls closure
 * @param timestamp server timestamp
 * @param estimate the value of the current network size estimate
 * @param std_dev standard deviation (rounded down to nearest integer)
 *                of the size estimation values seen
 *
 */
static void
handle_estimate (void *cls, struct GNUNET_TIME_Absolute timestamp,
                 double estimate, double std_dev)
{
  struct NSEPeer *peer = cls;

  fprintf (stderr,
           "Received network size estimate from peer %u. logSize: %f std.dev. %f (%f/%u)\n",
           (unsigned int) (peer - nse_peers),
           estimate, std_dev,
           GNUNET_NSE_log_estimate_to_n (estimate),
           NUM_PEERS);
  ok = 0;
}


/**
 * Callback to be called when NSE service connect operation is completed
 *
 * @param cls the callback closure from functions generating an operation
 * @param op the operation that has been finished
 * @param ca_result the NSE service handle returned from nse_connect_adapter
 * @param emsg error message in case the operation has failed; will be NULL if
 *          operation has executed successfully.
 */
static void
nse_connect_complete_cb (void *cls,
                         struct GNUNET_TESTBED_Operation *op,
                         void *ca_result,
                         const char *emsg)
{
  struct NSEPeer *peer = cls;
  struct GNUNET_NSE_Handle *nse = ca_result;

  GNUNET_assert (op == peer->op);
  if (NULL != emsg)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Failed to connect to NSE service: %s\n",
                emsg);
    ok = 1;
    GNUNET_SCHEDULER_shutdown ();
    return;
  }
  peer->nse_handle = nse;
}


/**
 * Adapter function called to establish a connection to
 * the NSE service.
 *
 * @param cls closure
 * @param cfg configuration of the peer to connect to; will be available until
 *          GNUNET_TESTBED_operation_done() is called on the operation returned
 *          from GNUNET_TESTBED_service_connect()
 * @return service handle to return in 'op_result', NULL on error
 */
static void *
nse_connect_adapter (void *cls,
                     const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  return GNUNET_NSE_connect (cfg,
                             &handle_estimate,
                             cls);
}


/**
 * Adapter function called to destroy connection to
 * NSE service.
 *
 * @param cls closure
 * @param op_result service handle returned from the connect adapter
 */
static void
nse_disconnect_adapter (void *cls,
                        void *op_result)
{
  GNUNET_NSE_disconnect (op_result);
}


/**
 * Actual "main" function for the testcase.
 *
 * @param cls closure
 * @param h the run handle
 * @param num_peers number of peers in 'peers'
 * @param peers handle to peers run in the testbed
 * @param links_succeeded the number of overlay link connection attempts that
 *          succeeded
 * @param links_failed the number of overlay link connection attempts that
 *          failed
 */
static void
run (void *cls,
     struct GNUNET_TESTBED_RunHandle *h,
     unsigned int num_peers,
     struct GNUNET_TESTBED_Peer **peers,
     unsigned int links_succeeded,
     unsigned int links_failed)
{
  unsigned int i;

  GNUNET_assert (NUM_PEERS == num_peers);
  for (i = 0; i < num_peers; i++)
    nse_peers[i].op = GNUNET_TESTBED_service_connect (&nse_peers[i],
                                                      peers[i],
                                                      "nse",
                                                      &nse_connect_complete_cb,
                                                      &nse_peers[i],
                                                      &nse_connect_adapter,
                                                      &nse_disconnect_adapter,
                                                      &nse_peers[i]);
  GNUNET_SCHEDULER_add_delayed (TIMEOUT,
                                &shutdown_task, NULL);
}


/**
 * Entry point for the testcase, sets up the testbed.
 *
 * @param argc unused
 * @param argv unused
 * @return 0 on success
 */
int
main (int argc, char *argv[])
{
  ok = 1;
  (void) GNUNET_TESTBED_test_run ("test-nse-multipeer",
                                  "test_nse.conf",
                                  NUM_PEERS,
                                  0, NULL, NULL,
                                  &run, NULL);
  return ok;
}


/* end of test_nse_multipeer.c */