////////////////////////////////////////////////////////////////////////////////
/// @brief test suite for MaintenanceFeature
///
/// @file
///
/// DISCLAIMER
///
/// Copyright 2018 ArangoDB GmbH, Cologne, Germany
///
/// Licensed under the Apache License, Version 2.0 (the "License");
/// you may not use this file except in compliance with the License.
/// You may obtain a copy of the License at
///
///     http://www.apache.org/licenses/LICENSE-2.0
///
/// Unless required by applicable law or agreed to in writing, software
/// distributed under the License is distributed on an "AS IS" BASIS,
/// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
/// See the License for the specific language governing permissions and
/// limitations under the License.
///
/// Copyright holder is ArangoDB GmbH, Cologne, Germany
///
/// @author Kaveh Vahedipour
/// @author Matthew Von-Maszewski
/// @author Copyright 2018, ArangoDB GmbH, Cologne, Germany
////////////////////////////////////////////////////////////////////////////////

#include "gtest/gtest.h"

#include <iostream>

#include <velocypack/velocypack-aliases.h>
#include <velocypack/vpack.h>

#include "ApplicationFeatures/ApplicationServer.h"
#include "Basics/Result.h"
#include "Cluster/Action.h"
#include "Cluster/Maintenance.h"
#include "Cluster/MaintenanceFeature.h"

#include "MaintenanceFeatureMock.h"

//
// TestActionBasic simulates a multistep action by counting down
//  on each call to first() and next() until iteration counter is zero.
//  Returns false upon reaching zero
//
class TestActionBasic : public ActionBase {
 public:
  TestActionBasic(arangodb::MaintenanceFeature& feature, ActionDescription const& description)
      : ActionBase(feature, description), _iteration(1), _resultCode(0) {
    std::string value, iterate_count;
    auto gres = description.get("iterate_count", iterate_count);

    if (gres.ok()) {
      _iteration = std::atol(iterate_count.c_str());
      // safety check
      if (_iteration < 0) {
        _iteration = 1;
      }  // if
    }    // if

    if (description.get(FAST_TRACK, value).ok()) {
      _labels.emplace(FAST_TRACK);
    }

    if (description.get("result_code", value).ok()) {
      _resultCode = std::atol(value.c_str());
    }  // if

    if (description.get("preaction_result_code", value).ok()) {
      std::map<std::string, std::string> pred{{"name", "TestActionBasic"},
                                              {"result_code", value}};
      if (gres.ok()) {
        pred.insert({"iterate_count", iterate_count});
      }
      _preAction = std::make_shared<ActionDescription>(pred, arangodb::maintenance::NORMAL_PRIORITY);
    }  // if

    if (description.get("postaction_result_code", value).ok()) {
      std::map<std::string, std::string> postd{{"name", "TestActionBasic"},
                                               {"result_code", value}};
      if (gres.ok()) {
        postd.insert({"iterate_count", iterate_count});
      }
      _postAction =
          std::make_shared<ActionDescription>(postd, arangodb::maintenance::NORMAL_PRIORITY);
    }  // if
  };

  virtual ~TestActionBasic(){};

  bool first() override {
    // a pre action needs to push before setting _result
    if (_preDesc) {
      createPreAction(_preDesc);
    } else if (0 == _iteration) {
      // time to set result?
      _result.reset(_resultCode);
    }  // if

    // verify first() called once
    if (0 != getProgress()) {
      _result.reset(2);
    }  // if

    return (iteratorEndTest());
  };

  bool next() override {
    // time to set result?
    if (0 == _iteration) {
      _result.reset(_resultCode);
    }  // if

    // verify next() called properly
    if (0 == getProgress()) {
      _result.reset(2);
    }  // if

    return (iteratorEndTest());
  };

 protected:
  bool iteratorEndTest() {
    bool more;

    //
    if (_result.ok()) {
      more = 0 < _iteration--;

      // if going to stop, see if a postAction is needed
      if (!more && _postDesc) {
        createPostAction(_postDesc);
      }  // if
    } else {
      // !ok() ... always stop iteration
      more = false;
    }
    return more;
  }  // iteratorEndTest

 public:
  int _iteration;
  int _resultCode;
  std::shared_ptr<ActionDescription> _preDesc;
  std::shared_ptr<ActionDescription> _postDesc;

};  // TestActionBasic

//
//
// Unit Tests start here
//
//
class MaintenanceFeatureTestUnthreaded : public ::testing::Test {
 protected:
  std::chrono::system_clock::time_point baseTime;
  std::chrono::system_clock::time_point noTime;
  MaintenanceFeatureTestUnthreaded()
      : baseTime(std::chrono::system_clock::now()) {}
};

TEST_F(MaintenanceFeatureTestUnthreaded, iterate_action_0_times_ok) {
  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);

  TestMaintenanceFeature tf(as);
  tf.setSecondsActionsBlock(0);  // disable retry wait for now

  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      tf, ActionDescription(
              std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                 {"iterate_count", "0"}},
              arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf.addAction(std::make_shared<Action>(std::move(action_base_ptr)), true);

  ASSERT_TRUE(result.ok());
  ASSERT_TRUE(tf._recentAction->result().ok());
  ASSERT_TRUE(0 == tf._recentAction->getProgress());
  ASSERT_TRUE(tf._recentAction->getState() == COMPLETE);
  ASSERT_TRUE(tf._recentAction->done());
  ASSERT_TRUE(1 == tf._recentAction->id());

  ASSERT_TRUE(baseTime <= tf._recentAction->getCreateTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getStartTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(noTime == tf._recentAction->getLastStatTime());
  ASSERT_TRUE(tf._recentAction->getCreateTime() <= tf._recentAction->getStartTime());
  ASSERT_TRUE(tf._recentAction->getStartTime() <= tf._recentAction->getDoneTime());
}

TEST_F(MaintenanceFeatureTestUnthreaded, iterate_action_0_times_fail) {
  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature tf(as);
  tf.setSecondsActionsBlock(0);  // disable retry wait for now

  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      tf, ActionDescription(
              std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                 {"iterate_count", "0"},
                                                 {"result_code", "1"}},
              arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf.addAction(std::make_shared<Action>(std::move(action_base_ptr)), true);

  ASSERT_TRUE(!result.ok());
  ASSERT_TRUE(!tf._recentAction->result().ok());
  ASSERT_TRUE(0 == tf._recentAction->getProgress());
  ASSERT_TRUE(tf._recentAction->getState() == FAILED);
  ASSERT_TRUE(tf._recentAction->done());
  ASSERT_TRUE(1 == tf._recentAction->id());

  ASSERT_TRUE(baseTime <= tf._recentAction->getCreateTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getStartTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(noTime == tf._recentAction->getLastStatTime());
  ASSERT_TRUE(tf._recentAction->getCreateTime() <= tf._recentAction->getStartTime());
  ASSERT_TRUE(tf._recentAction->getStartTime() <= tf._recentAction->getDoneTime());
}

TEST_F(MaintenanceFeatureTestUnthreaded, iterate_action_1_time_ok) {
  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature tf(as);
  tf.setSecondsActionsBlock(0);  // disable retry wait for now

  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      tf, ActionDescription(
              std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                 {"iterate_count", "1"}},
              arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf.addAction(std::make_shared<Action>(std::move(action_base_ptr)), true);

  ASSERT_TRUE(result.ok());
  ASSERT_TRUE(tf._recentAction->result().ok());
  ASSERT_TRUE(1 == tf._recentAction->getProgress());
  ASSERT_TRUE(tf._recentAction->getState() == COMPLETE);
  ASSERT_TRUE(tf._recentAction->done());
  ASSERT_TRUE(1 == tf._recentAction->id());

  ASSERT_TRUE(baseTime <= tf._recentAction->getCreateTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getStartTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getLastStatTime());
  ASSERT_TRUE(tf._recentAction->getCreateTime() <= tf._recentAction->getStartTime());
  ASSERT_TRUE(tf._recentAction->getStartTime() <= tf._recentAction->getDoneTime());
}

TEST_F(MaintenanceFeatureTestUnthreaded, iterate_action_1_time_fail) {
  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature tf(as);
  tf.setSecondsActionsBlock(0);  // disable retry wait for now

  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      tf, ActionDescription(
              std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                 {"iterate_count", "1"},
                                                 {"result_code", "1"}},
              arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf.addAction(std::make_shared<Action>(std::move(action_base_ptr)), true);

  ASSERT_TRUE(!result.ok());
  ASSERT_TRUE(!tf._recentAction->result().ok());
  ASSERT_TRUE(1 == tf._recentAction->getProgress());
  ASSERT_TRUE(tf._recentAction->getState() == FAILED);
  ASSERT_TRUE(tf._recentAction->done());
  ASSERT_TRUE(1 == tf._recentAction->id());

  ASSERT_TRUE(baseTime <= tf._recentAction->getCreateTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getStartTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getLastStatTime());
  ASSERT_TRUE(tf._recentAction->getCreateTime() <= tf._recentAction->getStartTime());
  ASSERT_TRUE(tf._recentAction->getStartTime() <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(tf._recentAction->getLastStatTime() <= tf._recentAction->getDoneTime());
}

TEST_F(MaintenanceFeatureTestUnthreaded, iterate_action_2_times_ok) {
  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature tf(as);
  tf.setSecondsActionsBlock(0);  // disable retry wait for now

  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      tf, ActionDescription(
              std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                 {"iterate_count", "2"}},
              arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf.addAction(std::make_shared<Action>(std::move(action_base_ptr)), true);

  ASSERT_TRUE(result.ok());
  ASSERT_TRUE(tf._recentAction->result().ok());
  ASSERT_TRUE(2 == tf._recentAction->getProgress());
  ASSERT_TRUE(tf._recentAction->getState() == COMPLETE);
  ASSERT_TRUE(tf._recentAction->done());
  ASSERT_TRUE(1 == tf._recentAction->id());

  ASSERT_TRUE(baseTime <= tf._recentAction->getCreateTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getStartTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getLastStatTime());
  ASSERT_TRUE(tf._recentAction->getCreateTime() <= tf._recentAction->getStartTime());
  ASSERT_TRUE(tf._recentAction->getStartTime() <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(tf._recentAction->getLastStatTime() <= tf._recentAction->getDoneTime());
}

TEST_F(MaintenanceFeatureTestUnthreaded, iterate_action_100_times_ok) {
  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature tf(as);
  tf.setSecondsActionsBlock(0);  // disable retry wait for now

  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      tf, ActionDescription(
              std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                 {"iterate_count", "100"}},
              arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf.addAction(std::make_shared<Action>(std::move(action_base_ptr)), true);

  ASSERT_TRUE(result.ok());
  ASSERT_TRUE(tf._recentAction->result().ok());
  ASSERT_TRUE(100 == tf._recentAction->getProgress());
  ASSERT_TRUE(tf._recentAction->getState() == COMPLETE);
  ASSERT_TRUE(tf._recentAction->done());
  ASSERT_TRUE(1 == tf._recentAction->id());

  ASSERT_TRUE(baseTime <= tf._recentAction->getCreateTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getStartTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getLastStatTime());
  ASSERT_TRUE(tf._recentAction->getCreateTime() <= tf._recentAction->getStartTime());
  ASSERT_TRUE(tf._recentAction->getStartTime() <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(tf._recentAction->getLastStatTime() <= tf._recentAction->getDoneTime());
}

TEST_F(MaintenanceFeatureTestUnthreaded, iterate_action_100_times_fail) {
  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature tf(as);
  tf.setSecondsActionsBlock(0);  // disable retry wait for now

  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      tf, ActionDescription(
              std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                 {"iterate_count", "100"},
                                                 {"result_code", "1"}},
              arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf.addAction(std::make_shared<Action>(std::move(action_base_ptr)), true);

  ASSERT_TRUE(!result.ok());
  ASSERT_TRUE(!tf._recentAction->result().ok());
  ASSERT_TRUE(100 == tf._recentAction->getProgress());
  ASSERT_TRUE(tf._recentAction->getState() == FAILED);
  ASSERT_TRUE(tf._recentAction->done());
  ASSERT_TRUE(1 == tf._recentAction->id());

  ASSERT_TRUE(baseTime <= tf._recentAction->getCreateTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getStartTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(baseTime <= tf._recentAction->getLastStatTime());
  ASSERT_TRUE(tf._recentAction->getCreateTime() <= tf._recentAction->getStartTime());
  ASSERT_TRUE(tf._recentAction->getStartTime() <= tf._recentAction->getDoneTime());
  ASSERT_TRUE(tf._recentAction->getLastStatTime() <= tf._recentAction->getDoneTime());
}

TEST(MaintenanceFeatureTestThreaded, populate_action_queue_and_validate) {
  std::vector<Expected> pre_thread, post_thread;

  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature* tf = new TestMaintenanceFeature(as);
  as.addFeature(tf);
  std::thread th(&arangodb::application_features::ApplicationServer::run, &as, 0, nullptr);

  //
  // 1. load up the queue without threads running
  //   a. 100 iterations then fail

  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      *tf, ActionDescription(
               std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                  {"iterate_count", "100"},
                                                  {"result_code", "1"}},
               arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf->addAction(std::make_shared<Action>(std::move(action_base_ptr)), false);

  ASSERT_TRUE(result.ok());  // has not executed, ok() is about parse and list add
  ASSERT_TRUE(tf->_recentAction->result().ok());
  pre_thread.push_back({1, 0, READY, 0});
  post_thread.push_back({1, 1, FAILED, 100});

  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      *tf, ActionDescription(
               std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                  {"iterate_count", "2"}},
               arangodb::maintenance::NORMAL_PRIORITY)));
  result = tf->addAction(std::make_shared<Action>(std::move(action_base_ptr)), false);

  ASSERT_TRUE(result.ok());  // has not executed, ok() is about parse and list add
  ASSERT_TRUE(tf->_recentAction->result().ok());
  pre_thread.push_back({2, 0, READY, 0});
  post_thread.push_back({2, 0, COMPLETE, 2});

  //   c. duplicate of 'a', should fail to add
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      *tf, ActionDescription(
               std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                                  {"iterate_count", "100"},
                                                  {"result_code", "1"}},
               arangodb::maintenance::NORMAL_PRIORITY)));
  result = tf->addAction(std::make_shared<Action>(std::move(action_base_ptr)), false);

  ASSERT_TRUE(!result.ok());  // has not executed, ok() is about parse and list add
  // _recentAction will NOT contain the aborted object ... don't test it

  //
  // 2. see if happy about queue prior to threads running
  ASSERT_TRUE(tf->verifyRegistryState(pre_thread));

  //
  // 3. start threads AFTER ApplicationServer known to be running
  tf->setMaintenanceThreadsMax(arangodb::MaintenanceFeature::minThreadLimit);

  //
  // 4. loop while waiting for threads to complete all actions
  tf->waitRegistryComplete();

  //
  // 5. verify completed actions
  ASSERT_TRUE(tf->verifyRegistryState(post_thread));

#if 0  // for debugging
    std::cout << tf->toVelocyPack().toJson() << std::endl;
#endif

  //
  // 6. bring down the ApplicationServer, i.e. clean up
  as.beginShutdown();

  th.join();
}

TEST(MaintenanceFeatureTestThreaded, action_that_generates_a_preaction) {
  std::vector<Expected> pre_thread, post_thread;

  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature* tf = new TestMaintenanceFeature(as);
  as.addFeature(tf);
  std::thread th(&arangodb::application_features::ApplicationServer::run, &as, 0, nullptr);

  //
  // 1. load up the queue without threads running
  //   a. 100 iterations then fail
  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      *tf,
      ActionDescription(
          std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                             {"iterate_count", "100"},
                                             {"preaction_result_code", "0"}},
          arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf->addAction(std::make_shared<Action>(std::move(action_base_ptr)), false);

  ASSERT_TRUE(result.ok());  // has not executed, ok() is about parse and list add
  ASSERT_TRUE(tf->_recentAction->result().ok());
  pre_thread.push_back({1, 0, READY, 0});
  post_thread.push_back({1, 0, COMPLETE, 100});
  post_thread.push_back({2, 0, COMPLETE, 100});  // preaction results

  //
  // 2. see if happy about queue prior to threads running
  ASSERT_TRUE(tf->verifyRegistryState(pre_thread));

  //
  // 3. start threads AFTER ApplicationServer known to be running
  tf->setMaintenanceThreadsMax(arangodb::MaintenanceFeature::minThreadLimit);

  //
  // 4. loop while waiting for threads to complete all actions
  tf->waitRegistryComplete();

  //
  // 5. verify completed actions
  ASSERT_TRUE(tf->verifyRegistryState(post_thread));

#if 0  // for debugging
    std::cout << tf->toVelocyPack().toJson() << std::endl;
#endif

  //
  // 6. bring down the ApplicationServer, i.e. clean up
  as.beginShutdown();
  th.join();
}

TEST(MaintenanceFeatureTestThreaded, action_that_generates_a_postaction) {
  std::vector<Expected> pre_thread, post_thread;

  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature* tf = new TestMaintenanceFeature(as);
  as.addFeature(tf);
  std::thread th(&arangodb::application_features::ApplicationServer::run, &as, 0, nullptr);

  //
  // 1. load up the queue without threads running
  //   a. 100 iterations then fail
  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      *tf,
      ActionDescription(
          std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                             {"iterate_count", "100"},
                                             {"postaction_result_code", "0"}},
          arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf->addAction(std::make_shared<Action>(std::move(action_base_ptr)), false);

  ASSERT_TRUE(result.ok());  // has not executed, ok() is about parse and list add
  ASSERT_TRUE(tf->_recentAction->result().ok());
  pre_thread.push_back({1, 0, READY, 0});
  post_thread.push_back({1, 0, COMPLETE, 100});
  post_thread.push_back({2, 0, COMPLETE, 100});  // postaction results

  //
  // 2. see if happy about queue prior to threads running
  ASSERT_TRUE(tf->verifyRegistryState(pre_thread));

  //
  // 3. start threads AFTER ApplicationServer known to be running
  tf->setMaintenanceThreadsMax(arangodb::MaintenanceFeature::minThreadLimit);

  //
  // 4. loop while waiting for threads to complete all actions
  tf->waitRegistryComplete();

  //
  // 5. verify completed actions
  ASSERT_TRUE(tf->verifyRegistryState(post_thread));

#if 0  // for debugging
    std::cout << tf->toVelocyPack().toJson() << std::endl;
#endif

  //
  // 6. bring down the ApplicationServer, i.e. clean up
  as.beginShutdown();
  th.join();
}

TEST(MaintenanceFeatureTestThreaded, priority_queue_should_be_able_to_process_fast_tracked_action) {
  std::vector<Expected> pre_thread, post_thread;

  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");

  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature* tf = new TestMaintenanceFeature(as);
  as.addFeature(tf);
  std::thread th(&arangodb::application_features::ApplicationServer::run, &as, 0, nullptr);

  //
  // 1. load up the queue without threads running
  //   a. 100 iterations then fail
  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      *tf,
      ActionDescription(
          std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                             {"iterate_count", "100"},
                                             {TestActionBasic::FAST_TRACK, ""}},
          arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf->addAction(std::make_shared<Action>(std::move(action_base_ptr)), false);

  ASSERT_TRUE(result.ok());  // has not executed, ok() is about parse and list add
  ASSERT_TRUE(tf->_recentAction->result().ok());

  //
  // 2. start threads AFTER ApplicationServer known to be running
  tf->setMaintenanceThreadsMax(arangodb::MaintenanceFeature::minThreadLimit - 1);

  //
  // 3. loop while waiting for threads to complete all actions
  tf->waitRegistryComplete();

#if 0  // for debugging
    std::cout << tf->toVelocyPack().toJson() << std::endl;
#endif

  //
  // 4. bring down the ApplicationServer, i.e. clean up
  as.beginShutdown();
  th.join();
}

TEST(MaintenanceFeatureTestThreaded, action_delete) {
  std::vector<Expected> pre_thread, post_thread;

  std::shared_ptr<arangodb::options::ProgramOptions> po =
      std::make_shared<arangodb::options::ProgramOptions>("test", std::string(),
                                                          std::string(), "path");
  arangodb::application_features::ApplicationServer as(po, nullptr);
  TestMaintenanceFeature* tf = new TestMaintenanceFeature(as);
  as.addFeature(tf);
  std::thread th(&arangodb::application_features::ApplicationServer::run, &as, 0, nullptr);

  //
  // 1. load up the queue without threads running
  //   a. 100 iterations then fail
  std::unique_ptr<ActionBase> action_base_ptr;
  action_base_ptr.reset((ActionBase*)new TestActionBasic(
      *tf,
      ActionDescription(
          std::map<std::string, std::string>{{"name", "TestActionBasic"},
                                             {"iterate_count", "100"},
                                             {"postaction_result_code", "0"}},
          arangodb::maintenance::NORMAL_PRIORITY)));
  arangodb::Result result =
      tf->addAction(std::make_shared<Action>(std::move(action_base_ptr)), false);

  ASSERT_TRUE(result.ok());  // has not executed, ok() is about parse and list add
  ASSERT_TRUE(tf->_recentAction->result().ok());
  pre_thread.push_back({1, 0, READY, 0});
  post_thread.push_back({1, 0, FAILED, 0});

  //
  // 2. see if happy about queue prior to threads running
  ASSERT_TRUE(tf->verifyRegistryState(pre_thread));
  tf->deleteAction(1);

  //
  // 3. start threads AFTER ApplicationServer known to be running
  tf->setMaintenanceThreadsMax(arangodb::MaintenanceFeature::minThreadLimit);

  //
  // 4. loop while waiting for threads to complete all actions
  tf->waitRegistryComplete();

  //
  // 5. verify completed actions
  ASSERT_TRUE(tf->verifyRegistryState(post_thread));

#if 0  // for debugging
    std::cout << tf->toVelocyPack().toJson() << std::endl;
#endif

  //
  // 6. bring down the ApplicationServer, i.e. clean up
  as.beginShutdown();
  th.join();
}