// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010  Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "stdmisc.h"

#ifdef NL_OS_WINDOWS
#include "nel/misc/inter_window_msg_queue.h"
//
#include "nel/misc/mem_stream.h"
#include "nel/misc/shared_memory.h"

namespace NLMISC
{


	CSynchronized<CInterWindowMsgQueue::TMessageQueueMap> CInterWindowMsgQueue::_MessageQueueMap("CInterWindowMsgQueue::_MessageQueueMap");
	const uint CInterWindowMsgQueue::_CurrentVersion = 0;
	CInterWindowMsgQueue::TOldWinProcMap CInterWindowMsgQueue::_OldWinProcMap;




	// **************************************************************************************************

	////////////////////////////////////////
	// CInterWindowMsgQueue::CProtagonist //
	////////////////////////////////////////

	// **************************************************************************************************
	CInterWindowMsgQueue::CProtagonist::CProtagonist() : _Id(0),
														 _Wnd(0),
														 _SharedMemMutex(0),
														 _SharedWndHandle(NULL)
	{
	}


	// **************************************************************************************************
	CInterWindowMsgQueue::CProtagonist::~CProtagonist()
	{
		release();
	}

	// **************************************************************************************************
	void CInterWindowMsgQueue::CProtagonist::release()
	{
		CloseHandle(_SharedMemMutex);
		_SharedMemMutex = 0;
		if (_SharedWndHandle)
		{
			CSharedMemory::closeSharedMemory(_SharedWndHandle);
			_SharedWndHandle = NULL;
		}
		_Wnd = 0;
		_Id = 0;
		// unhook window
	}

	// **************************************************************************************************
	void CInterWindowMsgQueue::CProtagonist::acquireSMMutex()
	{
		nlassert(_SharedMemMutex);
		DWORD result = WaitForSingleObject(_SharedMemMutex, INFINITE);
		nlassert(result != WAIT_FAILED);
	}

	// **************************************************************************************************
	void CInterWindowMsgQueue::CProtagonist::releaseSMMutex()
	{
		nlassert(_SharedMemMutex);
		ReleaseMutex(_SharedMemMutex);
	}

	// **************************************************************************************************
	bool CInterWindowMsgQueue::CProtagonist::init(uint32 id)
	{
		nlassert(id != 0);
		nlassert(id != 0x3a732235); // cf doc of NLMISC::CSharedMemory : this id is reserved
		nlassert(_Id == 0); // init done twice
		release();
		// create a system wide mutex
		_SharedMemMutex = CreateMutex(NULL, FALSE, toString("NL_MUTEX_%d", (int) id).c_str());
		if (!_SharedMemMutex) return false;
		_Id = id;
		return true;
	}

	// **************************************************************************************************
	void CInterWindowMsgQueue::CProtagonist::setWnd(HWND wnd)
	{
		nlassert(wnd != 0);
		nlassert(_SharedWndHandle == NULL); // setWnd was called before ?
											// setWnd should be called once for the 'local' window at beginning
		acquireSMMutex();
		_SharedWndHandle = CSharedMemory::createSharedMemory(toSharedMemId((int) _Id), sizeof(HWND));
		if (_SharedWndHandle)
		{
			*(HWND *) _SharedWndHandle = wnd;
		}
		releaseSMMutex();
		_Wnd = wnd;
	}

	// **************************************************************************************************
	HWND CInterWindowMsgQueue::CProtagonist::getWnd()
	{
		if (!_SharedMemMutex)
		{
			nlassert(_Wnd == 0);
			nlassert(!_SharedWndHandle);
			return 0;
		}
		if (_Wnd != 0)
		{
			// local window case
			return _Wnd;
		}
		// this is the foreign window
		// access shared memory just for the time of the query 	(this allow to see if foreign window is still alive)
		nlassert(!_SharedWndHandle);
		HWND result = 0;
		acquireSMMutex();
		void *sharedMem = CSharedMemory::accessSharedMemory(toSharedMemId((int) _Id));
		if (sharedMem)
		{
			result = *(HWND *) sharedMem;
			CSharedMemory::closeSharedMemory(sharedMem);
		}
		releaseSMMutex();
		return result;

	}


	// **************************************************************************************************

	/////////////////////////////////////
	// CInterWindowMsgQueue::CSendTask //
	/////////////////////////////////////

	// **************************************************************************************************
	CInterWindowMsgQueue::CSendTask::CSendTask(CInterWindowMsgQueue *parent) : _StopAsked(false)
	{
		nlassert(parent);
		_Parent = parent;
	}

	// **************************************************************************************************
	void CInterWindowMsgQueue::CSendTask::run()
	{
		while(!_StopAsked)
		{
			nlassert(_Parent);
			HWND targetWindow = _Parent->_ForeignWindow.getWnd();
			if (targetWindow == 0)
			{
				// there is no receiver, so message queue has become irrelevant, so just clear it
				_Parent->clearOutQueue();
			}
			else
			{
				TMsgList nestedMsgs;
				CMemStream outMsg;
				{
					CSynchronized<TMsgList>::CAccessor outMessageQueue(&_Parent->_OutMessageQueue);
					nestedMsgs.swap(outMessageQueue.value());
				}
				if (!nestedMsgs.empty())
				{
					CMemStream msgOut(false);
					msgOut.serialVersion(CInterWindowMsgQueue::_CurrentVersion);
					uint32 fromId(_Parent->_LocalWindow.getId());
					uint32 toId(_Parent->_ForeignWindow.getId());
					msgOut.serial(fromId);
					msgOut.serial(toId);
					msgOut.serialCont(nestedMsgs);
					COPYDATASTRUCT cds;
					cds.dwData = 0;
					cds.cbData = msgOut.length();
					cds.lpData = (PVOID) msgOut.buffer();
					for(;;)
					{
						LRESULT result = ::SendMessage(targetWindow, WM_COPYDATA, (WPARAM) _Parent->_LocalWindow.getWnd(), (LPARAM) &cds);
						if (result) break;
						// retry ...
						Sleep(30);
						if (!_Parent->_ForeignWindow.getWnd())
						{
							nlwarning("CInterWindowMsgQueue : tried to send message, but destination window has been closed");
							break;
						}
					}
				}
			}
			Sleep(30);
		}
	}

	// **************************************************************************************************
	void CInterWindowMsgQueue::CSendTask::stop()
	{
		_StopAsked = true;
	}


	// **************************************************************************************************

	//////////////////////////
	// CInterWindowMsgQueue //
	//////////////////////////

	// **************************************************************************************************
	CInterWindowMsgQueue::CInterWindowMsgQueue() : _SendTask(NULL),
												   _SendThread(NULL),
												   _OutMessageQueue("CInterWindowMsgQueue::_OutMessageQueue")
	{
	}

	// **************************************************************************************************
	bool CInterWindowMsgQueue::init(HWND ownerWindow, uint32 localId, uint32 foreignId)
	{
		return initInternal(NULL, ownerWindow, localId, foreignId);
	}

	// **************************************************************************************************
	bool CInterWindowMsgQueue::init(HINSTANCE hInstance, uint32 localId, uint32 foreignId)
	{
		return initInternal(hInstance, NULL, localId, foreignId);
	}

	// **************************************************************************************************
	bool CInterWindowMsgQueue::initInternal(HINSTANCE hInstance, HWND ownerWindow, uint32 localId, uint32 foreignId)
	{
		if (!ownerWindow)
		{
			// see if
			nlassert(hInstance);
			bool ok = _DummyWindow.init(hInstance, invisibleWindowListenerProc);
			if (!ok) return false;
			ownerWindow = _DummyWindow.getWnd();
		}
		else
		{
			nlassert(ownerWindow);
			nlassert(!hInstance);
		}
		nlassert(localId != 0);
		nlassert(foreignId != 0);
		nlassert(localId != foreignId);
		{
			typedef CSynchronized<TMessageQueueMap>::CAccessor TAccessor;
			// NB : use a 'new' instead of an automatic object here, because I got an 'INTERNAL COMPILER ERROR' compiler file 'msc1.cpp', line 1794
			// else, this is one of the way recommended by microsoft to solve the problem.
			std::auto_ptr<TAccessor> messageQueueMap(new TAccessor(&_MessageQueueMap));
			CMsgQueueIdent msgQueueIdent(ownerWindow, localId, foreignId);
			if (messageQueueMap->value().count(msgQueueIdent))
			{
				nlassert(!_DummyWindow.getWnd()); // invisible window has just been created, it can't be in the map now!
				// message queue already exists
				return false;
			}
			if (ownerWindow != _DummyWindow.getWnd())
			{
				// subclass window
				WNDPROC oldWinProc = (WNDPROC) GetWindowLongPtr(ownerWindow, GWLP_WNDPROC);
				uint &refCount = _OldWinProcMap[ownerWindow].RefCount;
				++ refCount;
				if (refCount == 1)
				{
					nlassert(oldWinProc != listenerProc); // first registration so the winproc must be different
					SetWindowLongPtr(ownerWindow, GWLP_WNDPROC, (LONG_PTR) listenerProc);
					_OldWinProcMap[ownerWindow].OldWinProc = oldWinProc;
				}
				else
				{
					nlassert(oldWinProc == listenerProc);
				}
			}
			//
			messageQueueMap->value()[msgQueueIdent] = this;
			_SendTask = new CSendTask(this);
			_SendThread = IThread::create(_SendTask);
			_SendThread->start();
			// init the window handle in shared memory last,
			// this way we are sure that the new win proc has been installed, and can start received messages
			bool ok = _LocalWindow.init(localId) && _ForeignWindow.init(foreignId);
			if (!ok)
			{
				release();
				return false;
			}
			_LocalWindow.setWnd(ownerWindow);
		}
		return true;
	}

	// **************************************************************************************************
	void CInterWindowMsgQueue::release()
	{
		if (_LocalWindow.getWnd() != 0)
		{
			if (IsWindow(_LocalWindow.getWnd())) // handle gracefully case where the window has been destroyed before
												 // this manager
			{

				if (_LocalWindow.getWnd() != _DummyWindow.getWnd())
				{
					WNDPROC currWinProc = (WNDPROC) GetWindowLongPtr(_LocalWindow.getWnd(), GWLP_WNDPROC);
					if (currWinProc != listenerProc)
					{
						nlassert(0); // IF THIS ASSERT FIRES :
									 // either :
									 // - The window handle has been removed, and recreated
									 // - The window has been hooked by someone else
									 // in the application, but not unhooked properly.
									 // Hook (performed at init) and unhook (performed here at release) should be
									 // done in reverse order ! We got no way to unhook correclty, else.
					}
				}
			}
			if (_LocalWindow.getWnd() != _DummyWindow.getWnd())
			{
				TOldWinProcMap::iterator it = _OldWinProcMap.find(_LocalWindow.getWnd());
				nlassert(it != _OldWinProcMap.end());
				nlassert(it->second.RefCount > 0);
				-- it->second.RefCount;
				if (it->second.RefCount == 0)
				{
					if (IsWindow(_LocalWindow.getWnd()))
					{
						SetWindowLongPtr(_LocalWindow.getWnd(), GWLP_WNDPROC, (LONG_PTR) it->second.OldWinProc);
					}
					_OldWinProcMap.erase(it);
				}
			}
		}
		if (_SendThread)
		{
			if (_SendTask)
			{
				_SendTask->stop();
				_SendThread->wait();
			}
			delete _SendTask;
			delete _SendThread;
			_SendTask = NULL;
			_SendThread = NULL;
		}
		if (_LocalWindow.getId() != 0)
		{
			typedef CSynchronized<TMessageQueueMap>::CAccessor TAccessor;
			// NB : use a 'new' instead of an automatic object here, because I got an 'INTERNAL COMPILER ERROR' compiler file 'msc1.cpp', line 1794
			// else, this is one of the way recommended by microsoft to solve the problem.
			std::auto_ptr<TAccessor> messageQueueMap(new TAccessor(&_MessageQueueMap));
			TMessageQueueMap::iterator it = messageQueueMap->value().find(CMsgQueueIdent(_LocalWindow.getWnd(), _LocalWindow.getId(), _ForeignWindow.getId()));
			nlassert(it != messageQueueMap->value().end());
			messageQueueMap->value().erase(it);
		}
		clearOutQueue();
		_LocalWindow.release();
		_ForeignWindow.release();
		_DummyWindow.release();
	}


	//=====================================================
	LRESULT CInterWindowMsgQueue::handleWMCopyData(HWND hwnd, COPYDATASTRUCT *cds)
	{
		// ctruct a write stream
		CMemStream msgIn;
		if (cds->lpData)
		{
			uint32 fromId;
			uint32 toId;
			TMsgList nestedMsgs;
			try
			{

				msgIn.serialBuffer((uint8 *) cds->lpData, cds->cbData);
				// make it a read stream
				msgIn.resetPtrTable();
				msgIn.invert();
				nlassert(msgIn.isReading());
				msgIn.serialVersion(_CurrentVersion);
				msgIn.serial(fromId);
				msgIn.serial(toId);
				msgIn.serialCont(nestedMsgs);

				CInterWindowMsgQueue messageQueue;
				{
					typedef CSynchronized<TMessageQueueMap>::CAccessor TAccessor;
					// NB : use a 'new' instead of an automatic object here, because I got an 'INTERNAL COMPILER ERROR' compiler file 'msc1.cpp', line 1794
					// else, this is one of the way recommended by microsoft to solve the problem.
					std::auto_ptr<TAccessor> messageQueueMap(new TAccessor(&_MessageQueueMap));
					TMessageQueueMap::iterator it = messageQueueMap->value().find(CMsgQueueIdent(hwnd, toId, fromId));
					if (it != messageQueueMap->value().end())
					{
						// no mutex stuff here, we're in the main thread
						TMsgList &targetList = it->second->_InMessageQueue;
						targetList.splice(targetList.end(), nestedMsgs); // append
						return TRUE;
					}
					else
					{
						nlwarning("CInterWindowMsgQueue : Received inter window message from '%x' to '%x', but there's no associated message queue", (int) fromId, (int) toId);
					}
				}
			}
			catch(EStream &)
			{
				nlwarning("CInterWindowMsgQueue : Bad message format in inter window communication");
			}

		}
		else
		{
			// msg received with NULL content
			nlwarning("CInterWindowMsgQueue : NULL message received");
		}
		return FALSE;
	}

	//=====================================================
	LRESULT CALLBACK CInterWindowMsgQueue::listenerProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
	{
		if (uMsg == WM_COPYDATA) // WM_COPYDATA messages are sent by the other window to communicate with the client
		{
			return handleWMCopyData(hwnd, (COPYDATASTRUCT *) lParam);
		}
		else
		{
			TOldWinProcMap::iterator it = _OldWinProcMap.find(hwnd);
			nlassert(it != _OldWinProcMap.end());
			return CallWindowProc(it->second.OldWinProc, hwnd, uMsg, wParam, lParam);
		}
	}

	//=====================================================
	LRESULT CALLBACK CInterWindowMsgQueue::invisibleWindowListenerProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
	{
		if (uMsg == WM_COPYDATA) // WM_COPYDATA messages are sent by the other window to communicate with the client
		{
			return handleWMCopyData(hwnd, (COPYDATASTRUCT *) lParam);
		}
		return DefWindowProc(hwnd, uMsg, wParam, lParam);
	}

	// **************************************************************************************************
	CInterWindowMsgQueue::~CInterWindowMsgQueue()
	{
		release();
	}

	// **************************************************************************************************
	void CInterWindowMsgQueue::clearOutQueue()
	{
		CSynchronized<TMsgList>::CAccessor  outMessageQueue(&_OutMessageQueue);
		if (!outMessageQueue.value().empty())
		{
			outMessageQueue.value().clear();
		}
	}

	// **************************************************************************************************
	void CInterWindowMsgQueue::sendMessage(CMemStream &msg)
	{
		if (!msg.isReading())
		{
			msg.invert();
		}
		msg.resetPtrTable();
		{
			CSynchronized<TMsgList>::CAccessor outMessageQueue(&_OutMessageQueue);
			std::vector<uint8> sentMsg(msg.buffer(), msg.buffer() + msg.length());
			outMessageQueue.value().push_back(CMsg());
			outMessageQueue.value().back().Msg.swap(sentMsg);
		}
	}


	// **************************************************************************************************
	bool CInterWindowMsgQueue::pumpMessage(CMemStream &dest)
	{
		if (_InMessageQueue.empty()) return false;
		if (dest.isReading())
		{
			dest.invert();
			dest.clear();
		}
		std::vector<uint8> &msgIn = _InMessageQueue.front().Msg;
		dest.serialBuffer(&(msgIn[0]), (uint)msgIn.size());
		_InMessageQueue.pop_front();
		// make dest a read stream
		dest.invert();
		dest.resetPtrTable();
		return true;
	}

	// **************************************************************************************************
	bool CInterWindowMsgQueue::connected() const
	{
		return const_cast<CProtagonist &>(_ForeignWindow).getWnd() != NULL;
	}

	// **************************************************************************************************
	uint CInterWindowMsgQueue::getSendQueueSize() const
	{
		CSynchronized<TMsgList>::CAccessor outMessageQueue(&const_cast<CSynchronized<TMsgList> &>(_OutMessageQueue));
		return (uint)outMessageQueue.value().size();
	}

	// **************************************************************************************************
	uint CInterWindowMsgQueue::getReceiveQueueSize() const
	{
		return (uint)_InMessageQueue.size();
	}

} // NLMISC

#endif // NL_OS_WINDOWS