#include "stdafx.h"
#include "EventSystem.h"

using namespace Sia::Api;

CEventSystem CEventSystem::EventSystem;

CEventSystem::CEventSystem() :
	_stopEvent(INVALID_HANDLE_VALUE)
{
}

CEventSystem::~CEventSystem()
{
	Stop();
	::CloseHandle(_stopEvent);
}

void CEventSystem::ProcessEvents()
{
	while (::WaitForSingleObject(_stopEvent, 10) == WAIT_TIMEOUT)
	{
		CEventPtr eventData;
		do
		{
			{
				std::lock_guard<std::mutex> l(_eventMutex);
				if (_eventQueue.size())
				{
					eventData = _eventQueue.front();
					_eventQueue.pop_front();
				}
				else
				{
					eventData.reset();
				}
			}

			if (eventData)
			{
				for (auto& v : _eventConsumers)
				{
					v(*eventData);
				}
			}
		} while (eventData);
	}
}

void CEventSystem::NotifyEvent(CEventPtr eventData)
{
	std::lock_guard<std::mutex> l(_eventMutex);
	if (_eventConsumers.size())
	{
		_eventQueue.push_back(eventData);
	}
}

void CEventSystem::AddEventConsumer(std::function<void(const CEvent&)> consumer)
{
	if (!_processThread)
	{
		_eventConsumers.push_back(consumer);
	}
}

void CEventSystem::Start()
{
	if (!_processThread)
	{
		_stopEvent = ::CreateEvent(nullptr, FALSE, FALSE, nullptr);
		_processThread.reset(new std::thread([this]() {ProcessEvents(); }));
	}
}

void CEventSystem::Stop()
{
	if (_processThread)
	{
		::SetEvent(_stopEvent);
		_processThread->join();
		_processThread.reset();
	}
}