/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.
 */

#include <config.h>
#include <concurrency/Thread.h>
#include <concurrency/PosixThreadFactory.h>
#include <concurrency/Monitor.h>
#include <concurrency/Util.h>

#include <assert.h>
#include <iostream>
#include <set>

namespace apache { namespace thrift { namespace concurrency { namespace test {

using boost::shared_ptr;
using namespace apache::thrift::concurrency;

/**
 * ThreadManagerTests class
 *
 * @version $Id:$
 */
class ThreadFactoryTests {

public:

  static const double ERROR;

  class Task: public Runnable {

  public:

    Task() {}

    void run() {
      std::cout << "\t\t\tHello World" << std::endl;
    }
  };

  /**
   * Hello world test
   */
  bool helloWorldTest() {

    PosixThreadFactory threadFactory = PosixThreadFactory();

    shared_ptr<Task> task = shared_ptr<Task>(new ThreadFactoryTests::Task());

    shared_ptr<Thread> thread = threadFactory.newThread(task);

    thread->start();

    thread->join();

    std::cout << "\t\t\tSuccess!" << std::endl;

    return true;
  }

  /**
   * Reap N threads
   */
  class ReapNTask: public Runnable {

   public:

    ReapNTask(Monitor& monitor, int& activeCount) :
      _monitor(monitor),
      _count(activeCount) {}

    void run() {
      Synchronized s(_monitor);

      _count--;

      //std::cout << "\t\t\tthread count: " << _count << std::endl;

      if (_count == 0) {
        _monitor.notify();
      }
    }

    Monitor& _monitor;

    int& _count;
  };

  bool reapNThreads(int loop=1, int count=10) {

    PosixThreadFactory threadFactory =  PosixThreadFactory();

    Monitor* monitor = new Monitor();

    for(int lix = 0; lix < loop; lix++) {

      int* activeCount  = new int(count);

      std::set<shared_ptr<Thread> > threads;

      int tix;

      for (tix = 0; tix < count; tix++) {
        try {
          threads.insert(threadFactory.newThread(shared_ptr<Runnable>(new ReapNTask(*monitor, *activeCount))));
        } catch(SystemResourceException& e) {
          std::cout << "\t\t\tfailed to create " << lix * count + tix << " thread " << e.what() << std::endl;
          throw e;
        }
      }

      tix = 0;
      for (std::set<shared_ptr<Thread> >::const_iterator thread = threads.begin(); thread != threads.end(); tix++, ++thread) {

        try {
          (*thread)->start();
        } catch(SystemResourceException& e) {
          std::cout << "\t\t\tfailed to start  " << lix * count + tix << " thread " << e.what() << std::endl;
          throw e;
        }
      }

      {
        Synchronized s(*monitor);
        while (*activeCount > 0) {
          monitor->wait(1000);
        }
      }

      for (std::set<shared_ptr<Thread> >::const_iterator thread = threads.begin(); thread != threads.end(); thread++) {
        threads.erase(*thread);
      }

      std::cout << "\t\t\treaped " << lix * count << " threads" << std::endl;
    }

    std::cout << "\t\t\tSuccess!" << std::endl;

    return true;
  }

  class SynchStartTask: public Runnable {

   public:

    enum STATE {
      UNINITIALIZED,
      STARTING,
      STARTED,
      STOPPING,
      STOPPED
    };

    SynchStartTask(Monitor& monitor, volatile  STATE& state) :
      _monitor(monitor),
      _state(state) {}

    void run() {
      {
        Synchronized s(_monitor);
        if (_state == SynchStartTask::STARTING) {
          _state = SynchStartTask::STARTED;
          _monitor.notify();
        }
      }

      {
        Synchronized s(_monitor);
        while (_state == SynchStartTask::STARTED) {
          _monitor.wait();
        }

        if (_state == SynchStartTask::STOPPING) {
          _state = SynchStartTask::STOPPED;
          _monitor.notifyAll();
        }
      }
    }

   private:
    Monitor& _monitor;
    volatile  STATE& _state;
  };

  bool synchStartTest() {

    Monitor monitor;

    SynchStartTask::STATE state = SynchStartTask::UNINITIALIZED;

    shared_ptr<SynchStartTask> task = shared_ptr<SynchStartTask>(new SynchStartTask(monitor, state));

    PosixThreadFactory threadFactory =  PosixThreadFactory();

    shared_ptr<Thread> thread = threadFactory.newThread(task);

    if (state == SynchStartTask::UNINITIALIZED) {

      state = SynchStartTask::STARTING;

      thread->start();
    }

    {
      Synchronized s(monitor);
      while (state == SynchStartTask::STARTING) {
        monitor.wait();
      }
    }

    assert(state != SynchStartTask::STARTING);

    {
      Synchronized s(monitor);

      try {
          monitor.wait(100);
      } catch(TimedOutException& e) {
      }

      if (state == SynchStartTask::STARTED) {

        state = SynchStartTask::STOPPING;

        monitor.notify();
      }

      while (state == SynchStartTask::STOPPING) {
        monitor.wait();
      }
    }

    assert(state == SynchStartTask::STOPPED);

    bool success = true;

    std::cout << "\t\t\t" << (success ? "Success" : "Failure") << "!" << std::endl;

    return true;
  }

  /** See how accurate monitor timeout is. */

  bool monitorTimeoutTest(size_t count=1000, int64_t timeout=10) {

    Monitor monitor;

    int64_t startTime = Util::currentTime();

    for (size_t ix = 0; ix < count; ix++) {
      {
        Synchronized s(monitor);
        try {
            monitor.wait(timeout);
        } catch(TimedOutException& e) {
        }
      }
    }

    int64_t endTime = Util::currentTime();

    double error = ((endTime - startTime) - (count * timeout)) / (double)(count * timeout);

    if (error < 0.0)  {

      error *= 1.0;
    }

    bool success = error < ThreadFactoryTests::ERROR;

    std::cout << "\t\t\t" << (success ? "Success" : "Failure") << "! expected time: " << count * timeout << "ms elapsed time: "<< endTime - startTime << "ms error%: " << error * 100.0 << std::endl;

    return success;
  }


  class FloodTask : public Runnable {
  public:

    FloodTask(const size_t id) :_id(id) {}
    ~FloodTask(){
      if(_id % 1000 == 0) {
        std::cout << "\t\tthread " << _id << " done" << std::endl;
      }
    }

    void run(){
      if(_id % 1000 == 0) {
        std::cout << "\t\tthread " << _id << " started" << std::endl;
      }

      usleep(1);
    }
    const size_t _id;
  };

  void foo(PosixThreadFactory *tf) {
  }

  bool floodNTest(size_t loop=1, size_t count=100000) {

    bool success = false;

    for(size_t lix = 0; lix < loop; lix++) {

      PosixThreadFactory threadFactory = PosixThreadFactory();
      threadFactory.setDetached(true);

        for(size_t tix = 0; tix < count; tix++) {

          try {

            shared_ptr<FloodTask> task(new FloodTask(lix * count + tix ));

            shared_ptr<Thread> thread = threadFactory.newThread(task);

            thread->start();

            usleep(1);

          } catch (TException& e) {

            std::cout << "\t\t\tfailed to start  " << lix * count + tix << " thread " << e.what() << std::endl;

            return success;
          }
        }

        std::cout << "\t\t\tflooded " << (lix + 1) * count << " threads" << std::endl;

        success = true;
    }

    return success;
  }
};

const double ThreadFactoryTests::ERROR = .20;

}}}} // apache::thrift::concurrency::test