//
// SocketReactor.cpp
//
// Library: Net
// Package: Reactor
// Module:  SocketReactor
//
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#include "Poco/Net/SocketReactor.h"
#include "Poco/Net/SocketNotification.h"
#include "Poco/Net/SocketNotifier.h"
#include "Poco/ErrorHandler.h"
#include "Poco/Thread.h"
#include "Poco/Exception.h"


using Poco::Exception;
using Poco::ErrorHandler;


namespace Poco {
namespace Net {


SocketReactor::SocketReactor():
	_stop(false),
	_timeout(DEFAULT_TIMEOUT),
	_pReadableNotification(new ReadableNotification(this)),
	_pWritableNotification(new WritableNotification(this)),
	_pErrorNotification(new ErrorNotification(this)),
	_pTimeoutNotification(new TimeoutNotification(this)),
	_pIdleNotification(new IdleNotification(this)),
	_pShutdownNotification(new ShutdownNotification(this)),
	_pThread(0)
{
}


SocketReactor::SocketReactor(const Poco::Timespan& timeout):
	_stop(false),
	_timeout(timeout),
	_pReadableNotification(new ReadableNotification(this)),
	_pWritableNotification(new WritableNotification(this)),
	_pErrorNotification(new ErrorNotification(this)),
	_pTimeoutNotification(new TimeoutNotification(this)),
	_pIdleNotification(new IdleNotification(this)),
	_pShutdownNotification(new ShutdownNotification(this)),
	_pThread(0)
{
}


SocketReactor::~SocketReactor()
{
}


void SocketReactor::run()
{
	_pThread = Thread::current();
	while (!_stop)
	{
		try
		{
			if (!hasSocketHandlers())
			{
				onIdle();
				Thread::trySleep(static_cast<long>(_timeout.totalMilliseconds()));
			}
			else
			{
				bool readable = false;
				PollSet::SocketModeMap sm = _pollSet.poll(_timeout);
				if (sm.size() > 0)
				{
					onBusy();
					PollSet::SocketModeMap::iterator it = sm.begin();
					PollSet::SocketModeMap::iterator end = sm.end();
					for (; it != end; ++it)
					{
						if (it->second & PollSet::POLL_READ)
						{
							dispatch(it->first, _pReadableNotification);
							readable = true;
						}
						if (it->second & PollSet::POLL_WRITE) dispatch(it->first, _pWritableNotification);
						if (it->second & PollSet::POLL_ERROR) dispatch(it->first, _pErrorNotification);
					}
				}
				if (!readable) onTimeout();
			}
		}
		catch (Exception& exc)
		{
			ErrorHandler::handle(exc);
		}
		catch (std::exception& exc)
		{
			ErrorHandler::handle(exc);
		}
		catch (...)
		{
			ErrorHandler::handle();
		}
	}
	onShutdown();
}


bool SocketReactor::hasSocketHandlers()
{
	if (!_pollSet.empty())
	{
		ScopedLock lock(_mutex);
		for (auto& p: _handlers)
		{
			if (p.second->accepts(_pReadableNotification) ||
				p.second->accepts(_pWritableNotification) ||
				p.second->accepts(_pErrorNotification)) return true;
		}
	}

	return false;
}


void SocketReactor::stop()
{
	_stop = true;
}


void SocketReactor::wakeUp()
{
	if (_pThread) _pThread->wakeUp();
}


void SocketReactor::setTimeout(const Poco::Timespan& timeout)
{
	_timeout = timeout;
}


const Poco::Timespan& SocketReactor::getTimeout() const
{
	return _timeout;
}


void SocketReactor::addEventHandler(const Socket& socket, const Poco::AbstractObserver& observer)
{
	NotifierPtr pNotifier = getNotifier(socket, true);

	if (!pNotifier->hasObserver(observer)) pNotifier->addObserver(this, observer);

	int mode = 0;
	if (pNotifier->accepts(_pReadableNotification)) mode |= PollSet::POLL_READ;
	if (pNotifier->accepts(_pWritableNotification)) mode |= PollSet::POLL_WRITE;
	if (pNotifier->accepts(_pErrorNotification))    mode |= PollSet::POLL_ERROR;
	if (mode) _pollSet.add(socket, mode);
}


bool SocketReactor::hasEventHandler(const Socket& socket, const Poco::AbstractObserver& observer)
{
	NotifierPtr pNotifier = getNotifier(socket);
	if (!pNotifier) return false;
	if (pNotifier->hasObserver(observer)) return true;
	return false;
}


SocketReactor::NotifierPtr SocketReactor::getNotifier(const Socket& socket, bool makeNew)
{
	ScopedLock lock(_mutex);

	EventHandlerMap::iterator it = _handlers.find(socket);
	if (it != _handlers.end()) return it->second;
	else if (makeNew) return (_handlers[socket] = new SocketNotifier(socket));

	return 0;
}


void SocketReactor::removeEventHandler(const Socket& socket, const Poco::AbstractObserver& observer)
{
	NotifierPtr pNotifier = getNotifier(socket);
	if (pNotifier && pNotifier->hasObserver(observer))
	{
		if(pNotifier->countObservers() == 1)
		{
			{
				ScopedLock lock(_mutex);
				_handlers.erase(socket);
			}
			_pollSet.remove(socket);
		}
		pNotifier->removeObserver(this, observer);
	}
}


bool SocketReactor::has(const Socket& socket) const
{
	return _pollSet.has(socket);
}


void SocketReactor::onTimeout()
{
	dispatch(_pTimeoutNotification);
}


void SocketReactor::onIdle()
{
	dispatch(_pIdleNotification);
}


void SocketReactor::onShutdown()
{
	dispatch(_pShutdownNotification);
}


void SocketReactor::onBusy()
{
}


void SocketReactor::dispatch(const Socket& socket, SocketNotification* pNotification)
{
	NotifierPtr pNotifier = getNotifier(socket);
	if (!pNotifier) return;
	dispatch(pNotifier, pNotification);
}


void SocketReactor::dispatch(SocketNotification* pNotification)
{
	std::vector<NotifierPtr> delegates;
	{
		ScopedLock lock(_mutex);
		delegates.reserve(_handlers.size());
		for (EventHandlerMap::iterator it = _handlers.begin(); it != _handlers.end(); ++it)
			delegates.push_back(it->second);
	}
	for (std::vector<NotifierPtr>::iterator it = delegates.begin(); it != delegates.end(); ++it)
	{
		dispatch(*it, pNotification);
	}
}


void SocketReactor::dispatch(NotifierPtr& pNotifier, SocketNotification* pNotification)
{
	try
	{
		pNotifier->dispatch(pNotification);
	}
	catch (Exception& exc)
	{
		ErrorHandler::handle(exc);
	}
	catch (std::exception& exc)
	{
		ErrorHandler::handle(exc);
	}
	catch (...)
	{
		ErrorHandler::handle();
	}
}


} } // namespace Poco::Net