/*!
 * @file p_node.h
 * @brief Definition of THE 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 bRelCoorChanged is true (so moved)
 *  o bRelDirChanged is true (so changed)
 *  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"
#include <list>

// FORWARD DECLARATION
class TiXmlElement;

#define PNODE_ITERATION_DELTA    .001

//! Parental linkage modes
typedef enum
{
  // PARENTAL FOLLOWING
  PNODE_LOCAL_ROTATE                   = 0x0001,    //!< Rotates all the children around their centers.
  PNODE_ROTATE_MOVEMENT                = 0x0002,    //!< Moves all the children around the center of their parent, without the rotation around their own centers.

  PNODE_MOVEMENT                       = 0x0004,    //!< Moves all children along with the parent.
  // special linkage modes
  PNODE_ALL                            = 0x0003,    //!< Moves all children around the center of their parent, and also rotates their centers
  PNODE_ROTATE_AND_MOVE                = 0x0005,    //!< Rotates all children around their axis, and moves them as the Parent Moves, but does not rotate around the center of their parent.


  // REPARENTING
  PNODE_REPARENT_TO_NULL               = 0x0010,    //!< Reparents to the Null, if the Parent is Removed. Meaning the Node wont have a parent anymore.
  PNODE_REPARENT_TO_PARENTS_PARENT     = 0x0020,    //!< Reparents the Node to the parents (old) parent it the parent gets removed.
  /////////////////////////////////////////////     //  ELSE: Reparents to the NullParent.
  PNODE_REPARENT_DELETE_CHILDREN       = 0x0040,    //!< Deletes the Children of the node when This Node is Removed. (Use with care).
  /// FIXME
   PNODE_REPARENT_KEEP_POSITION         = 0x0080,    //!< Tries to keep the Position if the Node is reparented.


  // DELETION
  PNODE_PROHIBIT_CHILD_DELETE          = 0x0100,    //!< Prohibits the Children from being deleted if this Node gets deleted.
  PNODE_PROHIBIT_DELETE_WITH_PARENT    = 0x0200,    //!< Prohibits the Node to be deleted if the Parent is. Child will be reparented according to the Repaenting-Rules
  PNODE_REPARENT_CHILDREN_ON_REMOVE    = 0x0400,    //!< Reparents the Children of the Node if the Node gets Removed.
  PNODE_REPARENT_ON_PARENTS_REMOVE     = 0x0800,    //!< The Node gets Reparented if its Parent gets removed. Child will be reparented according to the Reparenting-Rules.

  // VISIBILITY/ACTIVITY
  PNODE_HIDE_CHILDREN_IF_HIDDEN        = 0x1000,    //!< Prohibits the Children from being drawn if this node isn't visible. (used for Draw))
  PNODE_HIDE_IF_PARENT_HIDDEN          = 0x2000,    //!< Prohibits the node from being drawn if the Parent is invisible.
  PNODE_UPDATE_CHILDREN_IF_INACTIVE    = 0x4000,    //!< Updates the Children of this Node even if the Parent is Inactive (note if this's parent is inactive children won't be updated.)
  PNODE_STATIC_NODE                    = 0x8000,    //!< Used for nodes that do not have any moving children, and that do not move.

} PARENT_MODE;

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


//! 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* parent = PNode::getNullParent(), long nodeFlags = PNODE_PARENT_MODE_DEFAULT);
  virtual ~PNode ();

  void loadParams(const TiXmlElement* root);

  // ACTIVATION //
  inline void activateNode() { this->bActive = this->bRelCoorChanged = this->bRelDirChanged = true; };
  inline void deactivateNode() { this->bActive = false; };
  inline bool getNodeActiveState() { return this->bActive; };

  // POSITION //
  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)); };

  // SPEED //
  /** @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; };


  // ROTATION //
  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);
  void shiftDir (const Quaternion& shift);
  /** @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)); };
  /** @returns A Vector pointing into the forward direction (X) of the Node */
  inline Vector getAbsDirX() const { return this->absDirection.apply(Vector(1,0,0)); };
  /** @returns A Vector pointing into the upward direction (Y) of the Node */
  inline Vector getAbsDirY() const { return this->absDirection.apply(Vector(0,1,0)); };
  /** @returns A Vector pointing into the right direction (Z) of the Node */
  inline Vector getAbsDirZ() const { return this->absDirection.apply(Vector(0,0,1)); };


  // PARENTING //
  void addChild (PNode* child);
  void addChild (const char* childName);
  void removeChild (PNode* child);
  void removeNode();

  /** @param parent the new parent of this node */
  inline void setParent (PNode* parent) { parent->addChild(this); };
  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 */
  const std::list<PNode*>& getNodesChildren() const { return this->children; };

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

  // PARENTING_MODE AND OTHER FLAGS //
  void setParentMode (PARENT_MODE parentMode);
  void setParentMode (const char* parentingMode);
  /** @returns the Parenting mode of this node */
  int getParentMode() const { return 0x000f & this->parentMode; };

  void addNodeFlags(unsigned short nodeFlags);
  void removeNodeFlags(unsigned short nodeFlags);

  // NULL_PARENT //
  /** @returns the NullParent, the (main) ROOT of the PNode Tree. If it does not yet exist, it will be created. */
  static PNode* getNullParent()  { return (PNode::nullParent != NULL)? PNode::nullParent : PNode::createNullParent(); };

  // UPDATING //
  void updateNode (float dt);

  // DEBUG //
  void countChildNodes(int& nodes) const;
  void debugNode (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:
  /** 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; }

  static PNode* createNullParent();
  void reparent();
  bool checkIntegrity(const PNode* checkParent) const;
  void eraseChild(PNode* child);

 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.
  std::list<PNode*>  children;           //!< list of the children of this PNode.

  bool               bActive;            //!< If the Node is Active (for cutting off the rest of the tree in update).
  unsigned short     parentMode;         //!< the mode of the binding


  static PNode*      nullParent;         //!< The ROOT of the main PNode Tree.
};

#endif /* _P_NODE_H */