/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/*
 * Copyright (C) 2006-2010 - Frictional Games
 *
 * This file is part of HPL1 Engine.
 */

#include "hpl1/engine/ai/AINodeGenerator.h"

#include "hpl1/engine/scene/World3D.h"

#include "hpl1/engine/system/String.h"
#include "hpl1/engine/system/System.h"
#include "hpl1/engine/system/low_level_system.h"

#include "hpl1/engine/resources/FileSearcher.h"
#include "hpl1/engine/resources/Resources.h"

#include "hpl1/engine/physics/PhysicsBody.h"
#include "hpl1/engine/physics/PhysicsWorld.h"

#include "hpl1/engine/impl/tinyXML/tinyxml.h"

namespace hpl {

//////////////////////////////////////////////////////////////////////////
// PARAMS
//////////////////////////////////////////////////////////////////////////

//-----------------------------------------------------------------------

cAINodeGeneratorParams::cAINodeGeneratorParams() {
	msNodeType = "node";

	mfHeightFromGround = 0.1f;
	mfMinWallDist = 0.4f;

	mvMinPos = cVector3f(-10000, -10000, -10000);
	mvMaxPos = cVector3f(10000, 10000, 10000);

	mfGridSize = 0.4f;
}

//-----------------------------------------------------------------------

//-----------------------------------------------------------------------

bool cCollideRayCallback::OnIntersect(iPhysicsBody *pBody, cPhysicsRayParams *apParams) {
	if (pBody->GetMass() != 0)
		return true;

	mbIntersected = true;
	mvPos = apParams->mvPoint;
	mfDist = apParams->mfDist;

	return false;
}

//-----------------------------------------------------------------------

//////////////////////////////////////////////////////////////////////////
// CONSTRUCTORS
//////////////////////////////////////////////////////////////////////////

//-----------------------------------------------------------------------

unsigned generatorInstances = 0;

cAINodeGenerator::cAINodeGenerator() {
	++generatorInstances;
	assert(generatorInstances == 1);
}

cAINodeGenerator::~cAINodeGenerator() {
	--generatorInstances;
}

//-----------------------------------------------------------------------

//////////////////////////////////////////////////////////////////////////
// PUBLIC METHODS
//////////////////////////////////////////////////////////////////////////

//-----------------------------------------------------------------------

// static cCollideRayCallback gCollideRayCallback;

//-----------------------------------------------------------------------

void cAINodeGenerator::Generate(cWorld3D *apWorld, cAINodeGeneratorParams *apParams) {
	mpWorld = apWorld;
	mpParams = apParams;

	iPhysicsWorld *pPhysicsWorld = apWorld->GetPhysicsWorld();

	// bool mbLoadFromFile = false;

	/*cSystem *pSystem = */ apWorld->GetSystem();
	cResources *pResources = apWorld->GetResources();
	cFileSearcher *pFileSearcher = pResources->GetFileSearcher();

	mpNodeList = apWorld->GetAINodeList(mpParams->msNodeType);

	if (mpWorld->GetFileName() != "") {
		tString sPath = pFileSearcher->GetFilePath(mpWorld->GetFileName());
		tWString sSaveFile = cString::To16Char(cString::SetFileExt(sPath, "ainodes"));

		if (sPath != "" && FileExists(sSaveFile)) {
			cDate mapDate = FileModifiedDate(cString::To16Char(sPath));
			cDate saveDate = FileModifiedDate(sSaveFile);

			// If the save file is newer than the map load from it.
			if (saveDate > mapDate) {
				LoadFromFile();
				return;
			}
		}
	}

	/////////////////////////////////
	// Get the size of the world
	cPhysicsBodyIterator it = pPhysicsWorld->GetBodyIterator();
	cVector3f vWorldMax(-100000, -100000, -100000);
	cVector3f vWorldMin(100000, 100000, 100000);

	while (it.HasNext()) {
		iPhysicsBody *pBody = it.Next();

		cVector3f vMin = pBody->GetBV()->GetMin();
		cVector3f vMax = pBody->GetBV()->GetMax();

		// X
		if (vWorldMin.x > vMin.x)
			vWorldMin.x = vMin.x;
		if (vWorldMax.x < vMax.x)
			vWorldMax.x = vMax.x;

		// Y
		if (vWorldMin.y > vMin.y)
			vWorldMin.y = vMin.y;
		if (vWorldMax.y < vMax.y)
			vWorldMax.y = vMax.y;

		// Z
		if (vWorldMin.z > vMin.z)
			vWorldMin.z = vMin.z;
		if (vWorldMax.z < vMax.z)
			vWorldMax.z = vMax.z;
	}

	// Make the world small according to grid size.
	vWorldMin.x += mpParams->mfGridSize;
	vWorldMin.z += mpParams->mfGridSize;
	vWorldMax.x -= mpParams->mfGridSize;
	vWorldMax.z -= mpParams->mfGridSize;

	/////////////////////////////////////////
	// Check against the user set min and max
	if (vWorldMin.x < mpParams->mvMinPos.x)
		vWorldMin.x = mpParams->mvMinPos.x;
	if (vWorldMax.x > mpParams->mvMaxPos.x)
		vWorldMax.x = mpParams->mvMaxPos.x;

	if (vWorldMin.y < mpParams->mvMinPos.y)
		vWorldMin.y = mpParams->mvMinPos.y;
	if (vWorldMax.y > mpParams->mvMaxPos.y)
		vWorldMax.y = mpParams->mvMaxPos.y;

	if (vWorldMin.z < mpParams->mvMinPos.z)
		vWorldMin.z = mpParams->mvMinPos.z;
	if (vWorldMax.z > mpParams->mvMaxPos.z)
		vWorldMax.z = mpParams->mvMaxPos.z;

	/////////////////////////////////////////
	// Place the nodes in the world
	cVector3f vPos(vWorldMin.x, 0, vWorldMin.z);

	while (vPos.z <= vWorldMax.z) {
		cVector3f vStart(vPos.x, vWorldMax.y, vPos.z);
		cVector3f vEnd(vPos.x, vWorldMin.y, vPos.z);

		pPhysicsWorld->CastRay(this, vStart, vEnd, false, false, true);

		// Log("Pos: %s Min: %s Max: %s\n",vPos.ToString().c_str(),
		//								vWorldMin.ToString().c_str(),
		//								vWorldMax.ToString().c_str());

		vPos.x += apParams->mfGridSize;
		if (vPos.x > vWorldMax.x) {
			vPos.x = vWorldMin.x;
			vPos.z += apParams->mfGridSize;
		}
	}

	/////////////////////////////////////////
	// Check so that the nodes are not too close to walls
	cVector3f vEnds[4] = {cVector3f(mpParams->mfMinWallDist, 0, 0),
						  cVector3f(-mpParams->mfMinWallDist, 0, 0),
						  cVector3f(0, 0, mpParams->mfMinWallDist),
						  cVector3f(0, 0, -mpParams->mfMinWallDist)};

	cVector3f vPushBackDirs[4] = {cVector3f(-1, 0, 0),
								  cVector3f(1, 0, 0),
								  cVector3f(0, 0, -1),
								  cVector3f(0, 0, 1)};

	tTempAiNodeListIt nodeIt = mpNodeList->begin();
	for (; nodeIt != mpNodeList->end(); ++nodeIt) {
		cTempAiNode &Node = *nodeIt;

		// Check if there are any walls close by.
		for (int i = 0; i < 4; ++i) {
			_rayCallback.mbIntersected = false;
			pPhysicsWorld->CastRay(&_rayCallback, Node.mvPos, Node.mvPos + vEnds[i], true, false, true);

			if (_rayCallback.mbIntersected) {
				// Log("Walldistance %f : Add: (%s) Push (%s) Min: %f\n",gCollideRayCallback.mfDist,
				//											vEnds[i].ToString().c_str(),
				//											vPushBackDirs[i].ToString().c_str(),
				//											mpParams->mfMinWallDist);
				if (_rayCallback.mfDist < mpParams->mfMinWallDist) {
					Node.mvPos += vPushBackDirs[i] * (mpParams->mfMinWallDist - _rayCallback.mfDist);
				}
			}
		}
	}

	///////////////////////////////////////////
	// Save to file

	SaveToFile();
}

//////////////////////////////////////////////////////////////////////////
// PRIVATE
//////////////////////////////////////////////////////////////////////////

//-----------------------------------------------------------------------

bool cAINodeGenerator::OnIntersect(iPhysicsBody *pBody, cPhysicsRayParams *apParams) {
	if (pBody->GetMass() != 0)
		return true;

	/*iPhysicsWorld *pPhysicsWorld = */ mpWorld->GetPhysicsWorld();

	cVector3f vPosition = apParams->mvPoint + cVector3f(0, mpParams->mfHeightFromGround, 0);

	mpNodeList->push_back(cTempAiNode(vPosition, ""));

	return true;
}

//-----------------------------------------------------------------------

void cAINodeGenerator::SaveToFile() {
	if (mpWorld->GetFileName() == "")
		return;

	/*cSystem *pSystem = */ mpWorld->GetSystem();
	cResources *pResources = mpWorld->GetResources();
	cFileSearcher *pFileSearcher = pResources->GetFileSearcher();

	tString sMapPath = pFileSearcher->GetFilePath(mpWorld->GetFileName());
	tString sSaveFile = cString::SetFileExt(sMapPath, "ainodes");

	TiXmlDocument *pXmlDoc = hplNew(TiXmlDocument, (sSaveFile.c_str()));

	TiXmlElement *pRootElem = static_cast<TiXmlElement *>(pXmlDoc->InsertEndChild(TiXmlElement("AiNodes")));

	tTempAiNodeListIt nodeIt = mpNodeList->begin();
	for (; nodeIt != mpNodeList->end(); ++nodeIt) {
		cTempAiNode &Node = *nodeIt;
		TiXmlElement *pNodeElem = static_cast<TiXmlElement *>(pRootElem->InsertEndChild(TiXmlElement("Node")));

		tString sPos = cString::ToString(Node.mvPos.x) + " " +
					   cString::ToString(Node.mvPos.y) + " " +
					   cString::ToString(Node.mvPos.z);
		pNodeElem->SetAttribute("Pos", sPos.c_str());
		pNodeElem->SetAttribute("Name", Node.msName.c_str());
	}

	if (pXmlDoc->SaveFile() == false) {
		Error("Couldn't save XML file %s\n", sSaveFile.c_str());
	}
	hplDelete(pXmlDoc);
}

//-----------------------------------------------------------------------

void cAINodeGenerator::LoadFromFile() {
	if (mpWorld->GetFileName() == "")
		return;

	/*cSystem *pSystem = */ mpWorld->GetSystem();
	cResources *pResources = mpWorld->GetResources();
	cFileSearcher *pFileSearcher = pResources->GetFileSearcher();

	tString sMapPath = pFileSearcher->GetFilePath(mpWorld->GetFileName());
	tString sSaveFile = cString::SetFileExt(sMapPath, "ainodes");

	TiXmlDocument *pXmlDoc = hplNew(TiXmlDocument, (sSaveFile.c_str()));
	if (pXmlDoc->LoadFile() == false) {
		Warning("Couldn't open XML file %s\n", sSaveFile.c_str());
		hplDelete(pXmlDoc);
		return;
	}

	TiXmlElement *pRootElem = pXmlDoc->RootElement();

	TiXmlElement *pNodeElem = pRootElem->FirstChildElement("Node");
	for (; pNodeElem != NULL; pNodeElem = pNodeElem->NextSiblingElement("Node")) {
		cVector3f vPos = cString::ToVector3f(pNodeElem->Attribute("Pos"), 0);
		tString sName = cString::ToString(pNodeElem->Attribute("Name"), "");

		mpNodeList->push_back(cTempAiNode(vPos, sName));
	}

	hplDelete(pXmlDoc);
}

//-----------------------------------------------------------------------
} // namespace hpl