/************************************************************************
* file name         : thread_pool_task.h
* ----------------- :
* creation time     : 2018/01/28
* author            : Victor Zarubkin
* email             : v.s.zarubkin@gmail.com
* ----------------- :
* description       : The file contains declaration of ThreadPoolTask.
* ----------------- :
* license           : Lightweight profiler library for c++
*                   : Copyright(C) 2016-2019  Sergey Yagovtsev, Victor Zarubkin
*                   :
*                   : Licensed under either of
*                   :     * MIT license (LICENSE.MIT or http://opensource.org/licenses/MIT)
*                   :     * Apache License, Version 2.0, (LICENSE.APACHE or http://www.apache.org/licenses/LICENSE-2.0)
*                   : at your option.
*                   :
*                   : The MIT License
*                   :
*                   : Permission is hereby granted, free of charge, to any person obtaining a copy
*                   : of this software and associated documentation files (the "Software"), to deal
*                   : in the Software without restriction, including without limitation the rights
*                   : to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
*                   : of the Software, and to permit persons to whom the Software is furnished
*                   : to do so, subject to the following conditions:
*                   :
*                   : The above copyright notice and this permission notice shall be included in all
*                   : copies or substantial portions of the Software.
*                   :
*                   : THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
*                   : INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
*                   : PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
*                   : LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
*                   : TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
*                   : USE OR OTHER DEALINGS IN THE SOFTWARE.
*                   :
*                   : 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.
************************************************************************/

#ifndef EASY_PROFILER_THREAD_POOL_TASK_H
#define EASY_PROFILER_THREAD_POOL_TASK_H

#include <easy/details/easy_compiler_support.h>
#include <functional>
#include <atomic>
#include <mutex>

#include <QObject>

enum class TaskStatus : int8_t
{
    Enqueued,
    Processing,
    Finished,
};

class ThreadPoolTaskSignals : public QObject
{
    Q_OBJECT;

public:

    ThreadPoolTaskSignals() : QObject() {}

signals:

    void finished();
};

class ThreadPoolTask EASY_FINAL
{
public:

    using Func = std::function<void()>;

private:

    friend class ThreadPool;

    ThreadPoolTaskSignals m_signals;
    Func                     m_func;
    std::atomic_bool*   m_interrupt;
    std::mutex              m_mutex;
    std::atomic<int8_t>    m_status;
    const bool  m_creatingQtObjects;

public:

    ThreadPoolTask(const ThreadPoolTask&) = delete;
    ThreadPoolTask(ThreadPoolTask&&) = delete;

    explicit ThreadPoolTask(bool creatingQtObjects = false);
    ~ThreadPoolTask();

    void enqueue(Func&& func, std::atomic_bool& interruptFlag);
    void dequeue();

    ThreadPoolTaskSignals& events();

private:

    bool creatingQtObjects() const;

    void operator() ();

    TaskStatus status() const;
    void setStatus(TaskStatus status);
};

#endif //EASY_PROFILER_THREAD_POOL_TASK_H