/*
     This file is part of GNUnet.
     Copyright (C) 2009, 2016 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 arm/test_exponential_backoff.c
 * @brief testcase for gnunet-service-arm.c
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_arm_service.h"
#include "gnunet_util_lib.h"
#include "gnunet_protocols.h"

#define LOG(...) GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, __VA_ARGS__)

#define LOG_BACKOFF GNUNET_NO

#define TIMEOUT GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 10)

#define SERVICE_TEST_TIMEOUT GNUNET_TIME_UNIT_FOREVER_REL

#define FIVE_MILLISECONDS GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 5)

#define SERVICE "do-nothing"

#define BINARY "mockup-service"

#define CFGFILENAME "test_arm_api_data2.conf"


static const struct GNUNET_CONFIGURATION_Handle *cfg;

static struct GNUNET_ARM_Handle *arm;

static struct GNUNET_ARM_MonitorHandle *mon;

static struct GNUNET_SCHEDULER_Task *kt;

static int ok = 1;

static int phase = 0;

static int trialCount;

static struct GNUNET_TIME_Absolute startedWaitingAt;

struct GNUNET_TIME_Relative waitedFor;

struct GNUNET_TIME_Relative waitedFor_prev;

#if LOG_BACKOFF
static FILE *killLogFilePtr;

static char *killLogFileName;
#endif


/**
 * Context for handling the shutdown of a service.
 */
struct ShutdownContext {
  /**
   * Connection to the service that is being shutdown.
   */
  struct GNUNET_MQ_Handle *mq;

  /**
   * Task set up to cancel the shutdown request on timeout.
   */
  struct GNUNET_SCHEDULER_Task *cancel_task;
};


static void
kill_task(void *cbData);


/**
 * Shutting down took too long, cancel receive and return error.
 *
 * @param cls closure
 */
static void
service_shutdown_timeout(void *cls)
{
  GNUNET_assert(0);
}


/**
 * Generic error handler, called with the appropriate error code and
 * the same closure specified at the creation of the message queue.
 * Not every message queue implementation supports an error handler.
 *
 * @param cls closure with the `struct ShutdownContext *`
 * @param error error code
 */
static void
mq_error_handler(void *cls,
                 enum GNUNET_MQ_Error error)
{
  struct ShutdownContext *shutdown_ctx = cls;

  GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
             "Service shutdown complete (MQ error).\n");
  GNUNET_SCHEDULER_cancel(shutdown_ctx->cancel_task);
  GNUNET_MQ_destroy(shutdown_ctx->mq);
  GNUNET_free(shutdown_ctx);
}


static void
kill_task(void *cbData)
{
  struct ShutdownContext *shutdown_ctx
    = GNUNET_new(struct ShutdownContext);
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_MessageHeader *msg;
  struct GNUNET_MQ_MessageHandler handlers[] = {
    GNUNET_MQ_handler_end()
  };

  kt = NULL;
  if (trialCount == 13)
    {
      LOG("Saw enough kills, asking ARM to stop mock service for good\n");
      GNUNET_ARM_request_service_stop(arm,
                                      SERVICE,
                                      NULL,
                                      NULL);
      ok = 0;
      trialCount++;
      GNUNET_free(shutdown_ctx);
      return;
    }
  shutdown_ctx->mq = GNUNET_CLIENT_connect(cfg,
                                           SERVICE,
                                           handlers,
                                           &mq_error_handler,
                                           shutdown_ctx);
  GNUNET_assert(NULL != shutdown_ctx->mq);
  trialCount++;
  LOG("Sending a shutdown request to the mock service\n");
  env = GNUNET_MQ_msg(msg,
                      GNUNET_MESSAGE_TYPE_ARM_STOP);  /* FIXME: abuse of message type */
  GNUNET_MQ_send(shutdown_ctx->mq,
                 env);
  shutdown_ctx->cancel_task
    = GNUNET_SCHEDULER_add_delayed(TIMEOUT,
                                   &service_shutdown_timeout,
                                   shutdown_ctx);
}


static void
trigger_disconnect(void *cls)
{
  GNUNET_ARM_disconnect(arm);
  GNUNET_ARM_monitor_stop(mon);
  if (NULL != kt)
    {
      GNUNET_SCHEDULER_cancel(kt);
      kt = NULL;
    }
}


static void
arm_stop_cb(void *cls,
            enum GNUNET_ARM_RequestStatus status,
            enum GNUNET_ARM_Result result)
{
  GNUNET_break(status == GNUNET_ARM_REQUEST_SENT_OK);
  GNUNET_break(result == GNUNET_ARM_RESULT_STOPPED);
  LOG("ARM service stopped\n");
  GNUNET_SCHEDULER_shutdown();
}


static void
srv_status(void *cls,
           const char *service,
           enum GNUNET_ARM_ServiceMonitorStatus status)
{
  if (status == GNUNET_ARM_SERVICE_MONITORING_STARTED)
    {
      LOG("ARM monitor started, starting mock service\n");
      phase++;
      GNUNET_ARM_request_service_start(arm,
                                       SERVICE,
                                       GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
                                       NULL,
                                       NULL);
      return;
    }
  if (0 != strcasecmp(service, SERVICE))
    return; /* not what we care about */
  if (phase == 1)
    {
      GNUNET_break(status == GNUNET_ARM_SERVICE_STARTING);
      GNUNET_break(phase == 1);
      LOG("do-nothing is starting\n");
      phase++;
      ok = 1;
      GNUNET_assert(NULL == kt);
      startedWaitingAt = GNUNET_TIME_absolute_get();
      kt = GNUNET_SCHEDULER_add_delayed(GNUNET_TIME_UNIT_SECONDS,
                                        &kill_task,
                                        NULL);
    }
  else if (phase == 2)
    {
      /* We passively monitor ARM for status updates. ARM should tell us
       * when do-nothing dies (no need to run a service upness test ourselves).
       */
      if (status == GNUNET_ARM_SERVICE_STARTING)
        {
          waitedFor = GNUNET_TIME_absolute_get_duration(startedWaitingAt);
          LOG("Waited for: %s\n",
              GNUNET_STRINGS_relative_time_to_string(waitedFor,
                                                     GNUNET_YES));

          LOG("do-nothing is starting, killing it...\n");
          GNUNET_assert(NULL == kt);
          kt = GNUNET_SCHEDULER_add_now(&kill_task, &ok);
        }
      else if ((status == GNUNET_ARM_SERVICE_STOPPED) && (trialCount == 14))
        {
          phase++;
          LOG("do-nothing stopped working %u times, we are done here\n",
              (unsigned int)trialCount);
          GNUNET_ARM_request_service_stop(arm,
                                          "arm",
                                          &arm_stop_cb,
                                          NULL);
        }
    }
}


static void
arm_start_cb(void *cls,
             enum GNUNET_ARM_RequestStatus status,
             enum GNUNET_ARM_Result result)
{
  GNUNET_break(status == GNUNET_ARM_REQUEST_SENT_OK);
  GNUNET_break(result == GNUNET_ARM_RESULT_STARTING);
  GNUNET_break(phase == 0);
  LOG("Sent 'START' request for arm to ARM %s\n",
      (status == GNUNET_ARM_REQUEST_SENT_OK) ? "successfully" : "unsuccessfully");
}


static void
task(void *cls,
     char *const *args,
     const char *cfgfile,
     const struct GNUNET_CONFIGURATION_Handle *c)
{
  cfg = c;
  arm = GNUNET_ARM_connect(cfg, NULL, NULL);
  if (NULL == arm)
    {
      GNUNET_break(0);
      return;
    }
  mon = GNUNET_ARM_monitor_start(cfg,
                                 &srv_status,
                                 NULL);
  if (NULL == mon)
    {
      GNUNET_break(0);
      GNUNET_ARM_disconnect(arm);
      arm = NULL;
      return;
    }
  GNUNET_ARM_request_service_start(arm,
                                   "arm",
                                   GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
                                   &arm_start_cb,
                                   NULL);
  GNUNET_SCHEDULER_add_shutdown(&trigger_disconnect,
                                NULL);
}


static int
check()
{
  char *const argv[] = {
    "test-exponential-backoff",
    "-c", CFGFILENAME,
    NULL
  };
  struct GNUNET_GETOPT_CommandLineOption options[] = {
    GNUNET_GETOPT_OPTION_END
  };

  /* Running ARM  and running the do_nothing task */
  GNUNET_assert(GNUNET_OK ==
                GNUNET_PROGRAM_run((sizeof(argv) / sizeof(char *)) - 1,
                                   argv,
                                   "test-exponential-backoff",
                                   "nohelp",
                                   options,
                                   &task,
                                   NULL));
  return ok;
}


#ifndef PATH_MAX
/**
 * Assumed maximum path length (for the log file name).
 */
#define PATH_MAX 4096
#endif


static int
init()
{
  struct GNUNET_CONFIGURATION_Handle *cfg;
  char pwd[PATH_MAX];
  char *binary;

  cfg = GNUNET_CONFIGURATION_create();
  if (GNUNET_OK != GNUNET_CONFIGURATION_parse(cfg,
                                              "test_arm_api_data.conf"))
    {
      GNUNET_CONFIGURATION_destroy(cfg);
      return GNUNET_SYSERR;
    }
  if (NULL == getcwd(pwd, PATH_MAX))
    return GNUNET_SYSERR;
  GNUNET_assert(0 < GNUNET_asprintf(&binary,
                                    "%s/%s",
                                    pwd,
                                    BINARY));
  GNUNET_CONFIGURATION_set_value_string(cfg,
                                        SERVICE,
                                        "BINARY",
                                        binary);
  GNUNET_free(binary);
  if (GNUNET_OK != GNUNET_CONFIGURATION_write(cfg,
                                              CFGFILENAME))
    {
      GNUNET_CONFIGURATION_destroy(cfg);
      return GNUNET_SYSERR;
    }
  GNUNET_CONFIGURATION_destroy(cfg);

#if LOG_BACKOFF
  killLogFileName = GNUNET_DISK_mktemp("exponential-backoff-waiting.log");
  if (NULL == (killLogFilePtr = fopen(killLogFileName,
                                      "w")))
    {
      GNUNET_log_strerror_file(GNUNET_ERROR_TYPE_WARNING,
                               "fopen",
                               killLogFileName);
      GNUNET_free(killLogFileName);
      return GNUNET_SYSERR;
    }
#endif
  return GNUNET_OK;
}


static void
houseKeep()
{
#if LOG_BACKOFF
  GNUNET_assert(0 == fclose(killLogFilePtr));
  GNUNET_free(killLogFileName);
#endif
  (void)unlink(CFGFILENAME);
}


int
main(int argc, char *argv[])
{
  int ret;

  GNUNET_log_setup("test-exponential-backoff",
                   "WARNING",
                   NULL);

  if (GNUNET_OK != init())
    return 1;
  ret = check();
  houseKeep();
  return ret;
}

/* end of test_exponential_backoff.c */