#include <iostream>
#include <mutex>
#include <thread>
#include <memory>
#include <vector>
#include <string>

class context
{

public:
  virtual int run() = 0;
};

class TaskManager
{
private:
  std::mutex mtx;
  std::condition_variable cond;

  std::thread m_handle;

  std::thread::id thread_id;
  bool stopped;
  std::string thread_name;

private:
  virtual void entry();
  std::vector<std::shared_ptr<context>> task;

  void _process(std::vector<std::shared_ptr<context>> &);

public:
  void create(const std::string &name)
  {
    thread_name = name;
    m_handle = std::thread(&TaskManager::entry, this);
    thread_id = m_handle.get_id();
  }

  void join()
  {
    if (m_handle.joinable())
      m_handle.join();
  }
  void detach()
  {
    m_handle.detach();
  }
  int add_task(std::shared_ptr<context>);
  void stop()
  {
    std::lock_guard<std::mutex> lock{mtx};
    stopped = true;
    cond.notify_all();
  }
};

void TaskManager::entry()
{
  while (!stopped || !task.empty())
  {
    std::unique_lock<std::mutex> lock{mtx};
    cond.wait(lock, [this]() { return (!task.empty() || stopped); });
    std::vector<std::shared_ptr<context>> tmp;
    tmp.swap(task);
    lock.unlock();
    _process(tmp);
  }
}

void TaskManager::_process(std::vector<std::shared_ptr<context>> &tsk)
{
  for (const auto &tk : tsk)
  {
    tk->run();
  }
}

int TaskManager::add_task(std::shared_ptr<context> ts)
{
  if (stopped)
    return -1;
  {
    std::lock_guard<std::mutex> lock{mtx};
    task.push_back(ts);
    cond.notify_all();
  }
  return 0;
}

class test : public context
{
private:
  std::string name;

public:
  test(const std::string &name) : name(name) {}
  int run() override
  {
    std::cout << "Task Run: " << name << std::endl;
    return 0;
  }
};

int main(int argc, char *argv[])
{
  std::shared_ptr<TaskManager> tm = std::make_shared<TaskManager>();
  tm->create("TaskManager");
  tm->add_task(std::make_shared<test>("TaskA"));
  tm->add_task(std::make_shared<test>("TaskB"));
  tm->add_task(std::make_shared<test>(std::string("TaskC")));
  tm->stop();
  tm->join();
}