/*!
 * @file p_node.h
 * @brief  Definition of a parenting node
 *
 *  parenting is how coordinates are handled in orxonox, meaning, that all coordinates
 *  are representet relative to another parent node. this nodes build a parenting
 *  tree of one-sided references (from up to down referenced).
 *  Every node manages itself a list of childrens (of whos it is parent - easy...).
 *
 *  absCoordinate, absDirection have to be recalculated as soon as there was a change in
 *  place or ortientation. this is only the case if
 *  o bDirChanged is true (so changed) AND timeStamp != now
 *  o bCoorChanged is true (so moved) AND timeStamp != now
 *  this conditions make it cheaper to recalculate the tree (reduces redundant work).
 */


#ifndef _P_NODE_H
#define _P_NODE_H

#include "base_object.h"
#include "vector.h"

// FORWARD DECLARATION
class TiXmlElement;
template<class T> class tList;

#define PNODE_ITERATION_DELTA    .001
//! Parental linkage modes
typedef enum
{
  PNODE_LOCAL_ROTATE          =   1,    //!< Rotates all the children around their centers.
  PNODE_ROTATE_MOVEMENT       =   2,    //!< Moves all the children around the center of their parent, without the rotation around their own centers.

  PNODE_MOVEMENT              =   4,    //!< Moves all children along with the parent.
// special linkage modes
  PNODE_ALL                   =   3,    //!< Moves all children around the center of their parent, and also rotates their centers
  PNODE_ROTATE_AND_MOVE       =   5     //!< Rotates all children around their axis, and moves them as the Parent Moves, but does not rotate around the center of their parent.

} PARENT_MODE;

//! The default mode of the translation-binding.
#define PNODE_PARENT_MODE_DEFAULT PNODE_ALL


//! Patent Node is a Engine to calculate the position of an Object in respect to the position of its parent.
class PNode : virtual public BaseObject {

 public:
  PNode ();
  PNode(const TiXmlElement* root);
  PNode (const Vector& absCoor, PNode* pNode);
  virtual ~PNode ();

  void loadParams(const TiXmlElement* root);

  void setRelCoor (const Vector& relCoord);
  void setRelCoor (float x, float y, float z);
  void setRelCoorSoft(const Vector& relCoordSoft, float bias = 1.0);
  void setRelCoorSoft(float x, float y, float z, float bias = 1.0);
  /** @returns the relative position */
  inline const Vector& getRelCoor () const { return this->prevRelCoordinate; };
  /** @returns the Relative Coordinate Destination */
  inline const Vector& getRelCoorSoft2D() const { return (this->toCoordinate)?*this->toCoordinate:this->relCoordinate; };
  void setAbsCoor (const Vector& absCoord);
  void setAbsCoor (float x, float y, float z);
  void setAbsCoorSoft(const Vector& absCoordSoft, float bias = 1.0);
  void setAbsCoorSoft(float x, float y, float z, float bias = 1.0);
  /** @returns the absolute position */
  inline const Vector& getAbsCoor () const { return this->absCoordinate; };
  void shiftCoor (const Vector& shift);
  void shiftCoor (float x, float y, float z) { this->shiftCoor(Vector(x, y, z)); };

  void setRelDir (const Quaternion& relDir);
  void setRelDir (float x, float y, float z);
  void setRelDirSoft(const Quaternion& relDirSoft, float bias = 1.0);
  void setRelDirSoft(float x, float y, float z, float bias = 1.0);
  /** @returns the relative Direction */
  inline const Quaternion& getRelDir () const { return this->prevRelDirection; };
  /** @returns the Relative Directional Destination */
  inline const Quaternion& getRelDirSoft2D() const { return (this->toDirection)?*this->toDirection:this->relDirection; };
  /** @returns a Vector pointing into the relative Direction */
  inline Vector getRelDirV() const { return this->prevRelDirection.apply(Vector(0,1,0)); };
  void setAbsDir (const Quaternion& absDir);
  void setAbsDir (float x, float y, float z);
  void setAbsDirSoft(const Quaternion& absDirSoft, float bias = 1.0);
  void setAbsDirSoft(float x, float y, float z, float bias = 1.0);
  /** @returns the absolute Direction */
  inline const Quaternion& getAbsDir () const { return this->absDirection; };
  /** @returns a Vector pointing into the absolute Direction */
  inline Vector getAbsDirV() const { return this->absDirection.apply(Vector(0,1,0)); };
  void shiftDir (const Quaternion& shift);

  /** @returns the Speed of the Node */
  inline float getSpeed() const { return this->velocity.len(); };
  /** @returns the Velocity of the Node */
  inline const Vector& getVelocity() const { return this->velocity; };


  void addChild (PNode* child);
  void addChild (const char* childName);
  void removeChild (PNode* child);
  void remove();

  void setParent (PNode* parent);
  void setParent (const char* parentName);
  /** @returns the parent of this PNode */
  inline PNode* getParent () const { return this->parent; };
  /** @returns the List of Children of this PNode */
  inline const tList<PNode>* getChildren() const { return this->children; };

  void setParentSoft(PNode* parentNode, float bias = 1.0);
  void setParentSoft(const char* parentName, float bias = 1.0);

  /** @param parentMode sets the parentingMode of this Node */
  void setParentMode (PARENT_MODE parentMode) { this->parentMode = parentMode; };
  void setParentMode (const char* parentingMode);
  /** @returns the Parenting mode of this node */
  int getParentMode() const { return this->parentMode; };

  void update (float dt);

  void debug (unsigned int depth = 1, unsigned int level = 0) const;
  void debugDraw(unsigned int depth = 1, float size = 1.0, const Vector& color = Vector(1, 0, 0), unsigned int level = 0) const;


  // helper functions //
  static const char* parentingModeToChar(int parentingMode);
  static PARENT_MODE charToParentingMode(const char* parentingMode);


 private:
  void init(PNode* parent);
  /** tells the child that the parent's Coordinate has changed */
  inline void parentCoorChanged () { this->bRelCoorChanged = true; }
  /** tells the child that the parent's Direction has changed */
  inline void parentDirChanged () { this->bRelDirChanged = true; }
  /** @returns the last calculated coordinate */
  inline Vector getLastAbsCoor() { return this->lastAbsCoordinate; }


 private:
  bool            bRelCoorChanged;    //!< If Relative Coordinate has changed since last time we checked
  bool            bRelDirChanged;     //!< If Relative Direction has changed since last time we checked

  Vector          relCoordinate;      //!< coordinates relative to the parent
  Vector          absCoordinate;      //!< absolute coordinates in the world ( from (0,0,0) )
  Quaternion      relDirection;       //!< direction relative to the parent
  Quaternion      absDirection;       //!< absolute direvtion in the world ( from (0,0,1) )

  Vector          prevRelCoordinate;  //!< The last Relative Coordinate from the last update-Cycle.
  Vector          lastAbsCoordinate;  //!< this is used for speedcalculation, it stores the last coordinate
  Quaternion      prevRelDirection;   //!< The last Relative Direciton from the last update-Cycle.
//  Quaternion      lastAbsDirection;

  Vector          velocity;           //!< Saves the velocity.

  Vector*         toCoordinate;       //!< a position to which to iterate. (This is used in conjunction with setParentSoft.and set*CoorSoft)
  Quaternion*     toDirection;        //!< a direction to which to iterate. (This is used in conjunction with setParentSoft and set*DirSoft)
  float           bias;               //!< how fast to iterate to the given position (default is 1)

  PNode*          parent;             //!< a pointer to the parent node
  tList<PNode>*   children;           //!< list of the children of this PNode

  unsigned int    parentMode;         //!< the mode of the binding
};

#endif /* _P_NODE_H */