/* 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.
 */

#ifndef HPL_AI_NODE_CONTAINER_H
#define HPL_AI_NODE_CONTAINER_H

#include "hpl1/engine/math/MathTypes.h"
#include "hpl1/engine/system/SystemTypes.h"

#include "common/array.h"
#include "common/list.h"
#include "hpl1/engine/physics/PhysicsWorld.h"

namespace hpl {

class cWorld3D;

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

typedef tFlag tAIFreePathFlag;

#define eAIFreePathFlag_SkipStatic (0x00000001)
#define eAIFreePathFlag_SkipDynamic (0x00000002)
#define eAIFreePathFlag_SkipVolatile (0x00000004)

//--------------------------------
class cAINode;

class cAINodeEdge {
public:
	float mfDistance;
	float mfSqrDistance;
	cAINode *mpNode;
};

typedef Common::Array<cAINodeEdge> tAINodeEdgeVec;
typedef tAINodeEdgeVec::iterator tAINodeEdgeVecIt;

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

class cAINode {
	friend class cAINodeContainer;

public:
	cAINode();
	~cAINode();

	void AddEdge(cAINode *pNode);

	int GetEdgeNum() const { return (int)mvEdges.size(); }
	inline cAINodeEdge *GetEdge(int alIdx) { return &mvEdges[alIdx]; }

	const cVector3f &GetPosition() { return mvPosition; }

	const tString &GetName() { return msName; }

private:
	tString msName;
	cVector3f mvPosition;
	void *mpUserData;

	tAINodeEdgeVec mvEdges;
};

typedef Common::Array<cAINode *> tAINodeVec;
typedef tAINodeVec::iterator tAINodeVecIt;

typedef Common::List<cAINode *> tAINodeList;
typedef tAINodeList::iterator tAINodeListIt;

typedef Common::StableMap<tString, cAINode *> tAINodeMap;
typedef tAINodeMap::iterator tAINodeMapIt;

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

class iAIFreePathCallback {
public:
	virtual ~iAIFreePathCallback() = default;
	virtual bool Intersects(iPhysicsBody *pBody, cPhysicsRayParams *apParams) = 0;
};

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

class cAINodeRayCallback : public iPhysicsRayCallback {
public:
	void Reset();
	void SetFlags(tAIFreePathFlag aFlags) { mFlags = aFlags; }

	bool BeforeIntersect(iPhysicsBody *pBody);
	bool OnIntersect(iPhysicsBody *pBody, cPhysicsRayParams *apParams);

	bool Intersected();

	iAIFreePathCallback *mpCallback;

private:
	bool mbIntersected;
	tAIFreePathFlag mFlags;
};

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

class cAIGridNode {
public:
	tAINodeList mlstNodes;
};

//--------------------------------
class cAINodeContainer;

class cAINodeIterator {
public:
	cAINodeIterator(cAINodeContainer *apContainer, const cVector3f &avPos, float afRadius);

	bool HasNext();
	cAINode *Next();

private:
	bool IncGridPos();

	cAINodeContainer *mpContainer;
	cVector3f mvPosition;
	float mfRadius;
	cVector2l mvStartGridPos;
	cVector2l mvEndGridPos;
	cVector2l mvGridPos;

	tAINodeList *mpNodeList;
	tAINodeListIt mNodeIt;
};

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

class cAINodeContainer {
	friend class cAINodeIterator;

public:
	cAINodeContainer(const tString &asName, const tString &asNodeName,
					 cWorld3D *apWorld, const cVector3f &avCollideSize);
	~cAINodeContainer();

	const tString &GetNodeName() { return msNodeName; }
	const tString &GetName() { return msName; }

	const cVector3f &GetCollideSize() { return mvSize; }

	/**
	 * Reserves spaces for nodes.
	 * \param alReserveSpace Number of nodes to reserve space for.
	 */
	void ReserveSpace(size_t alReserveSpace);

	/**
	 * Adds a new node to the container.
	 * \param &asName Name of the node
	 * \param &avPosition Position of the node.
	 * \param *apUserData Data supplied by user.
	 */
	void AddNode(const tString &asName, const cVector3f &avPosition, void *apUserData = NULL);

	/**
	 * Get the number of nodes.
	 */
	int GetNodeNum() const;

	/**
	 * Get a node.
	 * \param alIdx index of node.
	 */
	inline cAINode *GetNode(int alIdx) { return mvNodes[alIdx]; }

	/**
	 * Gets a node based on the name.
	 * \param &asName Name of the node.
	 */
	cAINode *GetNodeFromName(const tString &asName);

	/**
	 * Compile the added nodes.
	 */
	void Compile();

	/**
	 * Build a grid map for nodes. (Used internally mostly)
	 */
	void BuildNodeGridMap();

	/**
	 * Returns a node iterator. Note that the radius is not checked, some nodes may lie outside.
	 * \param &avPosition
	 * \param afRadius
	 * \return
	 */
	cAINodeIterator GetNodeIterator(const cVector3f &avPosition, float afRadius);

	/**
	 * Checks for a free path using the containers collide size.
	 * \param &avStart
	 * \param &avEnd
	 * \param alRayNum The max number of rays cast, -1 = maximum
	 * \param alFlags Set Flags for the ray casting.
	 * \param apCallback Check for every body and overrides alFlags.
	 * \return
	 */
	bool FreePath(const cVector3f &avStart, const cVector3f &avEnd, int alRayNum = -1,
				  tAIFreePathFlag aFlags = 0, iAIFreePathCallback *apCallback = NULL);

	/**
	 * Sets the max number of end node added to a node.
	 * \param alX The max number, -1 = unlimited
	 */
	void SetMaxEdges(int alX) { mlMaxNodeEnds = alX; }

	/**
	 * Sets the min number of end node added to a node. This overrides max distance when needed.
	 */
	void SetMinEdges(int alX) { mlMinNodeEnds = alX; }

	/**
	 * Sets the max distance for an end node.
	 * \param afX
	 */
	void SetMaxEdgeDistance(float afX) { mfMaxEndDistance = afX; }

	float GetMaxEdgeDistance() const { return mfMaxEndDistance; }

	void SetMaxHeight(float afX) { mfMaxHeight = afX; }
	float GetMaxHeight() const { return mfMaxHeight; }

	/**
	 * When calculating if there is a free path between two nodes. Is the node position the center of the collider.
	 * If not the position is the feet position.
	 */
	void SetNodeIsAtCenter(bool abX) { mbNodeIsAtCenter = abX; }
	bool GetNodeIsAtCenter() { return mbNodeIsAtCenter; }

	/**
	 * Saves all the node connections to file.
	 */
	void SaveToFile(const tString &asFile);
	/**
	 * Loads all node connections from file. Only to be done after all nodes are loaded.
	 */
	void LoadFromFile(const tString &asFile);

private:
	cVector2l GetGridPosFromLocal(const cVector2f &avLocalPos);
	cAIGridNode *GetGrid(const cVector2l &avPos);

	tString msName;
	tString msNodeName;

	cWorld3D *mpWorld;
	cVector3f mvSize;

	cAINodeRayCallback *mpRayCallback;
	tAINodeVec mvNodes;
	tAINodeMap m_mapNodes;

	bool mbNodeIsAtCenter;

	cVector2l mvGridMapSize;
	cVector2f mvGridSize;
	cVector2f mvMinGridPos;
	cVector2f mvMaxGridPos;
	int mlNodesPerGrid;

	Common::Array<cAIGridNode> mvGrids;

	// properties
	int mlMaxNodeEnds;
	int mlMinNodeEnds;
	float mfMaxEndDistance;
	float mfMaxHeight;
};

} // namespace hpl

#endif // HPL_AI_NODE_CONTAINER_H