// Ryzom - MMORPG Framework <http://dev.ryzom.com/projects/ryzom/>
// 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 "stdpch.h"
#include "interface_link.h"
#include "interface_expr.h"
#include "interface_element.h"
#include "interface_manager.h"
#include "interface_expr_node.h"
#include "reflect.h"
#include "nel/misc/cdb_branch.h"

using namespace std;
using namespace NLMISC;

/////////////
// GLOBALS //
/////////////

CInterfaceLink::TLinkList CInterfaceLink::_LinkList;
CInterfaceLink::TLinkVect CInterfaceLink::_LinksWithNoTarget;
//
CInterfaceLink *CInterfaceLink::_FirstTriggeredLink[2] = { NULL, NULL };
CInterfaceLink *CInterfaceLink::_LastTriggeredLink[2] = { NULL, NULL };
CInterfaceLink *CInterfaceLink::_CurrUpdatedLink = NULL;
CInterfaceLink *CInterfaceLink::_NextUpdatedLink = NULL;
uint CInterfaceLink::_CurrentTriggeredLinkList = 0;

bool CInterfaceLink::_UpdateAllLinks = false;


///////////////
// FUNCTIONS //
///////////////

/** Tool fct : affect a value to a reflected property of an interface element.
  */
static bool affect(const CInterfaceExprValue &value, CInterfaceElement &destElem, const CReflectedProperty &property)
{

	CInterfaceExprValue valueToAffect = value;
	switch(property.Type)
	{
		case CReflectedProperty::Boolean:
			if (valueToAffect.toBool())
			{
				(destElem.*(property.SetMethod.SetBool))(valueToAffect.getBool());
			}
			else
			{

				return false;
			}
		break;
		case CReflectedProperty::SInt32:
			if (valueToAffect.toInteger())
			{
				(destElem.*(property.SetMethod.SetSInt32))((sint32) valueToAffect.getInteger());
			}
			else
			{

				return false;
			}
		break;
		case CReflectedProperty::Float:
			if (valueToAffect.toDouble())
			{
				(destElem.*(property.SetMethod.SetFloat))((float) valueToAffect.getDouble());
			}
			else
			{

				return false;
			}
		break;
		case CReflectedProperty::String:
			if (valueToAffect.toString())
			{
				(destElem.*(property.SetMethod.SetString))(valueToAffect.getString());
			}
			else
			{

				return false;
			}
		break;
		case CReflectedProperty::UCString:
			if (valueToAffect.toString())
			{
				(destElem.*(property.SetMethod.SetUCString))(valueToAffect.getUCString());
			}
			else
			{

				return false;
			}
		break;
		case CReflectedProperty::RGBA:
			if (valueToAffect.toRGBA())
			{
				(destElem.*(property.SetMethod.SetRGBA))(valueToAffect.getRGBA());
			}
			else
			{

				return false;
			}
		break;
		default:
		break;
	}

	return true;
}

CInterfaceLink::CInterfaceLinkUpdater::CInterfaceLinkUpdater()
{
	CCDBNodeBranch::addFlushObserver( this );
}

CInterfaceLink::CInterfaceLinkUpdater::~CInterfaceLinkUpdater()
{
	CCDBNodeBranch::removeFlushObserver( this );
}

void CInterfaceLink::CInterfaceLinkUpdater::onObserverCallFlush()
{
	CInterfaceLink::updateTrigeredLinks();
}

/////////////
// MEMBERS //
/////////////

//===========================================================
CInterfaceLink::CInterfaceLink() : _On(true)
{
	// add an entry in the links list
	_LinkList.push_front(this);
	_ListEntry = _LinkList.begin();
	_PrevTriggeredLink[0] = _PrevTriggeredLink[1] = NULL;
	_NextTriggeredLink[0] = _NextTriggeredLink[1] = NULL;
	_Triggered[0] = _Triggered[1] = false;
	_ParseTree = NULL;
}

//===========================================================
CInterfaceLink::~CInterfaceLink()
{
	if (this == _CurrUpdatedLink)
	{
		_CurrUpdatedLink = NULL;
	}
	if (this == _NextUpdatedLink)
	{
		_NextUpdatedLink = _NextUpdatedLink->_NextTriggeredLink[1 - _CurrentTriggeredLinkList];
	}
	// unlink observer from both update lists
	unlinkFromTriggerList(0);
	unlinkFromTriggerList(1);

	removeObservers(_ObservedNodes);
	// removes from the link list
	_LinkList.erase(_ListEntry);

	delete _ParseTree;
}

//===========================================================
bool CInterfaceLink::init(const std::vector<CTargetInfo> &targets, const std::string &expr, const std::string &actionHandler, const std::string &ahParams, const std::string &ahCond, CInterfaceGroup *parentGroup)
{
	CInterfaceExprValue result;
	// Build the parse tree
	nlassert(!_ParseTree);
	_ParseTree = CInterfaceExpr::buildExprTree(expr);
	if (!_ParseTree)
	{
		// wrong expression : release the link
		nlwarning("CInterfaceLink::init : can't parse expression %s", expr.c_str());
		_LinksWithNoTarget.push_back(TLinkSmartPtr(this));
		return false;
	}
	// Examine the expression, to see which database nodes it depends on
	_ParseTree->getDepends(_ObservedNodes);
	// must keep observerd node sorted (for std::set_xx ops)
	std::sort(_ObservedNodes.begin(), _ObservedNodes.end());
	if (!targets.empty())
	{
		// retrieve properties from the element
		_Targets.resize(targets.size());
		for (uint k = 0; k < targets.size(); ++k)
		{
			CInterfaceElement *elem = targets[k].Elem;
			if (!elem)
			{
				nlwarning("<CInterfaceLink::init> : Element %d is NULL", k);
				_Targets[k]._InterfaceElement = NULL;
				continue;
			}
			_Targets[k]._Property = elem->getReflectedProperty(targets[k].PropertyName);
			if (!_Targets[k]._Property)
			{
				nlwarning("<CInterfaceLink::init> : Can't retrieve property %s for element %d.", targets[k].PropertyName.c_str(), k);
				_Targets[k]._InterfaceElement = NULL;
				continue;
			}
			_Targets[k]._InterfaceElement = elem;
			elem->addLink(this);
		}
	}
	else
	{
		// There are no target for this link, so, put in a dedicated list to ensure that the link will be destroyed at exit
		_LinksWithNoTarget.push_back(TLinkSmartPtr(this));
	}

	// create observers
	createObservers(_ObservedNodes);
	_Expr = expr;
	//
	_ActionHandler = actionHandler;
	_AHParams = ahParams;
	_AHCond = ahCond;
	_AHParent = parentGroup;
	return true;
}

//===========================================================
void CInterfaceLink::uninit()
{
	for (uint32 i = 0; i < _LinksWithNoTarget.size(); i++)
	{
		CInterfaceLink *pLink = _LinksWithNoTarget[i];
		if (pLink == this)
		{
			_LinksWithNoTarget.erase(_LinksWithNoTarget.begin()+i);
			return;
		}
	}
}

//===========================================================
void CInterfaceLink::update(ICDBNode * /* node */)
{
	// mark link as triggered
	linkInTriggerList(_CurrentTriggeredLinkList);
}

//===========================================================
void CInterfaceLink::createObservers(const TNodeVect &nodes)
{
	for(std::vector<ICDBNode *>::const_iterator it = nodes.begin(); it != nodes.end(); ++it)
	{
		if ((*it)->isLeaf())
		{
			ICDBNode::CTextId textId;
			(*it)->addObserver(this, textId);
		}
		else
		{
			CCDBNodeBranch *br = static_cast<CCDBNodeBranch *>(*it);
			br->addBranchObserver(this);
		}
	}
}

//===========================================================
void CInterfaceLink::removeObservers(const TNodeVect &nodes)
{
	for(std::vector<ICDBNode *>::const_iterator it = nodes.begin(); it != nodes.end(); ++it)
	{
		if ((*it)->isLeaf())
		{
			ICDBNode::CTextId textId;
			(*it)->removeObserver(this, textId);
		}
		else
		{
			CCDBNodeBranch *br = static_cast<CCDBNodeBranch *>(*it);
			br->removeBranchObserver(this);
		}
	}
}

//===========================================================
void CInterfaceLink::updateAllLinks()
{
	nlassert(!_UpdateAllLinks);
	_UpdateAllLinks = true;
	for(TLinkList::iterator it = _LinkList.begin(); it != _LinkList.end(); ++it)
	{
		CInterfaceLink *pLink = *it;
		pLink->update();
	}
	_UpdateAllLinks = false;
}

//===========================================================
void CInterfaceLink::update()
{
	//_On = false; // prvent recursive calls
	if (!_ParseTree) return;
	static TNodeVect observedNodes; // should not be too big, so ok to keep it static.
	static TNodeVect tmpNodes;
	observedNodes.clear();
	CInterfaceExprValue result;
	_ParseTree->evalWithDepends(result, observedNodes);
	// std::set_xxx require ordered container
	std::sort(observedNodes.begin(), observedNodes.end());
	// we assume that _ObservedNode are also sorted
	// compute new observers
	tmpNodes.clear();
	std::set_difference(observedNodes.begin(), observedNodes.end(), _ObservedNodes.begin(), _ObservedNodes.end(), std::back_inserter(tmpNodes));
	// add these observers
	createObservers(tmpNodes);
	// compute lost observers
	tmpNodes.clear();
	std::set_difference(_ObservedNodes.begin(), _ObservedNodes.end(), observedNodes.begin(), observedNodes.end(), std::back_inserter(tmpNodes));
	// remove these observers
	removeObservers(tmpNodes);
	// subsitute new (sorted) list to current
	_ObservedNodes.swap(observedNodes);
	//
	for (uint k = 0; k < _Targets.size(); ++k)
	{
		CInterfaceElement *elem = _Targets[k]._InterfaceElement;
		const CReflectedProperty    *prop = _Targets[k]._Property;
		if (elem && prop)
		{
			if (!affect(result, *elem, *prop))
			{
				nlwarning("CInterfaceLink::update: Result conversion failed");
			}
		}
	}
	// if there's an action handler, execute it
	if (!_ActionHandler.empty())
	{
		// If there is a condition, test it.
		bool	launch= true;
		if(!_AHCond.empty())
		{
			launch= false;
			CInterfaceExprValue		result;
			if(CInterfaceExpr::eval(_AHCond, result))
				launch= result.getBool();
		}
		if(launch)
		{
			CInterfaceManager *im = CInterfaceManager::getInstance();
			im->runActionHandler(_ActionHandler, _AHParent, _AHParams);
			// do not add any code after this line because this can be deleted !!!!
		}
	}

	//_On = true; // prevent recursive calls
}

// predicate to remove an element from a list
struct CRemoveTargetPred
{
	CInterfaceElement *Target;
	bool operator()(const CInterfaceLink::CTarget &target) const { return target._InterfaceElement == Target; }
};

//===========================================================
void CInterfaceLink::removeTarget(CInterfaceElement *elem)
{
	CRemoveTargetPred pred;
	pred.Target = elem;
	_Targets.erase(std::remove_if(_Targets.begin(), _Targets.end(), pred), _Targets.end());
}

//===========================================================
bool CInterfaceLink::CTargetInfo::affect(const CInterfaceExprValue &value)
{

	if (!Elem)
	{
		nlwarning("<CInterfaceLink::CTargetInfo::affect> : Target element is NULL");

		return false;
	}
	const CReflectedProperty    *property = Elem->getReflectedProperty(PropertyName);
	if (!property)
	{
		nlwarning("<CInterfaceLink::CTargetInfo::affect> : Can't retrieve property %s for element %s.", PropertyName.c_str(), Elem->getId().c_str());

		return false;
	}
	// try to affect the property
	if (!::affect(value, *Elem, *property))
	{
		nlwarning("<CInterfaceLink::CTargetInfo::affect> Couldn't convert the value to affect to %s", Elem->getId().c_str());

		return false;
	}

	return true;
}

//===========================================================
void CInterfaceLink::removeAllLinks()
{
	_LinksWithNoTarget.clear();
	TLinkList::iterator curr = _LinkList.begin();
	TLinkList::iterator nextIt;
	uint k;
	while(curr != _LinkList.end())
	{
		nextIt = curr;
		++ nextIt;
		CInterfaceLink &link = **curr;
		link.checkNbRefs();
		NLMISC::CSmartPtr<CInterfaceLink> linkPtr = *curr; // must keep a smart ptr because of the test in the loop
		for (k = 0; k < link._Targets.size(); ++k)
		{
			if (link._Targets[k]._InterfaceElement)
			{
				nlinfo("InterfaceElement %s was not remove.", link._Targets[k]._InterfaceElement->getId().c_str());
				link._Targets[k]._InterfaceElement->removeLink(&link);
			}
		}
		linkPtr = NULL; // effectively destroy link
		curr = nextIt;
	}
	nlassert(_LinkList.empty());
}

//===========================================================
void    CInterfaceLink::checkNbRefs()
{
	uint numValidPtr = 0;
	for(uint k = 0; k < _Targets.size(); ++k)
	{
		if (_Targets[k]._InterfaceElement != NULL) ++numValidPtr;
	}
	nlassert(numValidPtr == (uint) crefs);
}


//===========================================================
void    CInterfaceLink::setTargetProperty (const std::string &Target, const CInterfaceExprValue &val)
{
	// Eval target !
	string elt = Target.substr(0,Target.rfind(':'));
	CInterfaceManager *pIM = CInterfaceManager::getInstance();
	CInterfaceElement *pIE = pIM->getElementFromId(elt);
	CInterfaceGroup *pIG = dynamic_cast<CInterfaceGroup*>(pIE);
	if (pIG == NULL)
		pIG = pIE->getParent();

	if (pIG != NULL)
	{
		std::vector<CTargetInfo> vTargets;
		CInterfaceParser::splitLinkTargets(Target, pIG, vTargets);
		if ((vTargets.size() > 0) && (vTargets[0].Elem))
		{
			vTargets[0].affect(val);
		}
	}
}

//-----------------------------------------------
void CInterfaceLink::linkInTriggerList(uint list)
{
	nlassert(list < 2);
	if (_Triggered[list]) return; // already inserted in list
	_Triggered[list] = true;
	nlassert(!_PrevTriggeredLink[list]);
	nlassert(!_NextTriggeredLink[list]);
	if (!_FirstTriggeredLink[list])
	{
		_FirstTriggeredLink[list] = _LastTriggeredLink[list] = this;
	}
	else
	{
		nlassert(!_LastTriggeredLink[list]->_NextTriggeredLink[list]);
		_LastTriggeredLink[list]->_NextTriggeredLink[list] = this;
		_PrevTriggeredLink[list] = _LastTriggeredLink[list];
		_LastTriggeredLink[list] = this;
	}
}

//-----------------------------------------------
void CInterfaceLink::unlinkFromTriggerList(uint list)
{
	nlassert(list < 2);
	if (!_Triggered[list])
	{
		// not linked in this list
		nlassert(_PrevTriggeredLink[list] == NULL);
		nlassert(_NextTriggeredLink[list] == NULL);
		return;
	}
	if (_PrevTriggeredLink[list])
	{
		_PrevTriggeredLink[list]->_NextTriggeredLink[list] = _NextTriggeredLink[list];
	}
	else
	{
		// this was the first node
		_FirstTriggeredLink[list] = _NextTriggeredLink[list];
	}
	if (_NextTriggeredLink[list])
	{
		_NextTriggeredLink[list]->_PrevTriggeredLink[list] = _PrevTriggeredLink[list];
	}
	else
	{
		// this was the last node
		_LastTriggeredLink[list] = _PrevTriggeredLink[list];
	}
	_PrevTriggeredLink[list] = NULL;
	_NextTriggeredLink[list] = NULL;
	_Triggered[list] = false;
}





//-----------------------------------------------
void CInterfaceLink::updateTrigeredLinks()
{
	static bool called = false;
	nlassert(!called);
	called = true;
	_CurrUpdatedLink = _FirstTriggeredLink[_CurrentTriggeredLinkList];
	while (_CurrUpdatedLink)
	{
		// modified node should now store them in other list when they're modified
		_CurrentTriggeredLinkList = 1 - _CurrentTriggeredLinkList;
		// switch list so that modified node are stored in the other list
		while (_CurrUpdatedLink)
		{
			_NextUpdatedLink = _CurrUpdatedLink->_NextTriggeredLink[1 - _CurrentTriggeredLinkList];
			_CurrUpdatedLink->update();
			if (_CurrUpdatedLink) // this may be modified by the call (if current observer is removed)
			{
				_CurrUpdatedLink->unlinkFromTriggerList(1 - _CurrentTriggeredLinkList);
			}
			_CurrUpdatedLink = _NextUpdatedLink;
		}
		nlassert(_FirstTriggeredLink[1 - _CurrentTriggeredLinkList] == NULL);
		nlassert(_LastTriggeredLink[1 - _CurrentTriggeredLinkList] == NULL);
		// examine other list to see if nodes have been registered
		_CurrUpdatedLink = _FirstTriggeredLink[_CurrentTriggeredLinkList];
	}
	called = false;
}