/*
 * QtObservedAtom.hpp
 *
 *  Created on: Oct 28, 2015
 *      Author: heber
 */


#ifndef QTOBSERVEDATOM_HPP_
#define QTOBSERVEDATOM_HPP_

// include config.h
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <QtGui/QWidget>

#include <boost/function.hpp>
#include <boost/shared_ptr.hpp>

#include "CodePatterns/Observer/Observable.hpp"
#include "CodePatterns/Observer/Observer.hpp"

#include "LinearAlgebra/Vector.hpp"

#include "UIElements/Qt4/InstanceBoard/ObservedValue_types.hpp"
#include "UIElements/Qt4/InstanceBoard/ObservedValuesContainer.hpp"
#include "types.hpp"

class atom;
class QtObservedInstanceBoard;
class QtObservedMolecule;

/** This instance is the ObservedValue representation of a World's atom.
 *
 * Due to the signal/slot mechanism and its delays, lifetime of objects in the
 * World and their QtGui representation cannot directly be related (without
 * slowing down Actions just for having the representation up to speed).
 * Hence, the required information for displaying and representing these
 * objects must be contained in an extra instance.
 *
 * This is the instance for information about a particular atom.
 *
 * Essentially, this is the interface between molecuilder's World (and a
 * particular atom) and the QtGui part of the code.
 */
class QtObservedAtom : public QWidget, public Observer
{
  Q_OBJECT

public:

  //!> typedef for instance wrapped in shared ptr
  typedef boost::shared_ptr<QtObservedAtom> ptr;

  //!> typedef for instance wrapped in weak shared ptr
  typedef boost::weak_ptr<QtObservedAtom> weak_ptr;

private:
  //!> ObservedValuesContainer needs to access private cstor and dstor
  friend class ObservedValuesContainer<QtObservedAtom, ObservedValue_Index_t>;
  //!> QtObservedInstanceBoard needs to access private cstor and dstor
  friend class QtObservedInstanceBoard;

  /** Cstor of QtObservedAtom.
   *
   * \param _id id of observed atom
   * \param _atom ref to observed atom
   * \param _board ref to InstanceBoard for callbacks on occasion of subjectKilled()
   * \param _parent Qt parent to automatically destroy when parent is destroyed
   */
  QtObservedAtom(
      const atomId_t _id,
      const atom * const _atom,
      QtObservedInstanceBoard &_board,
      QWidget * _parent=0);

public:

  /** Dstor of QtObservedAtom.
   *
   */
  ~QtObservedAtom();

  // Observer functions
  void update(Observable *publisher);
  void subjectKilled(Observable *publisher);
  void recieveNotification(Observable *publisher, Notification_ptr notification);

  /** Getter for a permanent and unique index of this instance.
   *
   * \note ALWAYS use this index if you need to store and identifier to this
   * instance which you might need to retrieve at some later date.
   *
   * \warning DO NOT STORE the QtObserved...:ptr directly. This will possibly
   * prevent their eventual destruction. Only store the ObservedValue_Index_t
   * as means to obtain the ptr from the QtObservedInstanceBoard.
   *
   * \return returns a unique and permanent index that can be used to retrieve this
   * instance from the QtObservedInstanceBoard as it must not be stored.
   */
  ObservedValue_Index_t getIndex() const;

  /** Getter to atom index contained in \a ObservedValues.
   *
   * \return atom's index
   */
  const atomId_t& getAtomIndex() const;

  //!> typedef for list of bonds, defined by pairs of atom ids
  typedef std::vector< std::pair<atomId_t, atomId_t> > ListOfBonds_t;

  /** Getter to atom bonds contained in \a ObservedValues.
   *
   * \return atom's bonds
   */
  const ListOfBonds_t& getAtomBonds() const;

  /** Getter to atom element contained in \a ObservedValues.
   *
   * \return atom's element
   */
  const atomicNumber_t& getAtomElement() const;

  /** Getter to atom name contained in \a ObservedValues.
   *
   * \return atom's name
   */
  const std::string& getAtomName() const;

  /** Getter to atom position contained in \a ObservedValues.
   *
   * \return atom's position
   */
  const Vector& getAtomPosition() const;

  /** Getter to the observed state of the associated molecule.
   *
   * \return const ref to observed state of molecule
   */
  const QtObservedMolecule* const getMoleculeRef() const;

  /** Getter to atom's selected status.
   *
   * \return true - atom selected, false - else
   */
  const bool getAtomSelected() const;

signals:
  void indexChanged(const atomId_t, const atomId_t);
  void bondsChanged();
  void elementChanged();
  void moleculeChanged();
  void nameChanged();
  void positionChanged();
  void atomRemoved();
  void selectedChanged();

//private slots:

private:
  void activateObserver();
  void deactivateObserver();

  static const atom * const getAtomConst(const atomId_t _id);
  static atom * const getAtom(const atomId_t _id);

private:
  static atomId_t updateIndex(const atom &_atomref);
  static ListOfBonds_t updateBonds(const atom &_atom);
  static atomicNumber_t updateElement(const atom &_atom);
  QtObservedMolecule* updateMoleculeRef(const atom &_atom);
  static std::string updateName(const atom &_atom);
  static Vector updatePosition(const atom &_atom);
  static bool updateSelected(const atom &_atom);

  //!> enumeration of observed values to match with entries in ObservedValues
  enum ObservedTypes {
    //!> contains the current atom index
    AtomIndex,
    //!> contains the current set of bonds atoms for the atom
    AtomBonds,
    //!> contains the current atom element
    AtomElement,
    //!> contains the current atom position
    AtomName,
    //!> contains the current atom position
    AtomPosition,
    //!> contains the current atom's selection status
    AtomSelected,
    //!> contains the current atom's molecule index
    MoleculeRef,
    //!> gives the size of the enumeration
    MAX_ObservedTypes
  };

  /** Initializes all \a ObservedValues entries.
   *
   * \param _ObservedValues vector of ObservedValue to be filled
   * \param _id atom id
   * \param _atomref reference to atom
   * \param _subjectKilled ref to function to call on subjectKilled()
   */
  void initObservedValues(
      ObservedValues_t &_ObservedValues,
      const atomId_t _id,
      const atom * const _atomref,
      const boost::function<void()> &_subjectKilled);

  /** Destroys all \a ObservedValues entries.
   *
   * \param _ObservedValues vector of ObservedValue to be destroyed
   */
  void destroyObservedValues(
      std::vector<boost::any> &_ObservedValues);

  /** Function is called by InstanceBoard to inform about its destruction.
   *
   * \note callbacks must not be used after this
   */
  void noteBoardIsGone()
  { BoardIsGone = true; }

  /** Counts the number of subject killed received from the observed values.
   *
   * \param _id id to check against ours
   */
  void countValuesSubjectKilled(ObservedValue_Index_t _id);

  //!> counts how many ObservedValues have already been subjectKilled()
  mutable size_t subjectKilledCount;

  /** Helper function to check that all subjectKilled have been received for both
   * this instance and all its internal observed values.
   *
   * \param _id id to check against ours
   */
  void checkForRemoval(ObservedValue_Index_t _id);

private:

  //!> list of channels when index needs to update
  static const Observable::channels_t AtomIndexChannels;
  //!> list of channels when bonds needs to update
  static const Observable::channels_t AtomBondsChannels;
  //!> list of channels when element needs to update
  static const Observable::channels_t AtomElementChannels;
  //!> list of channels when molecule index needs to update
  static const Observable::channels_t MoleculeChangedChannels;
  //!> list of channels when name needs to update
  static const Observable::channels_t AtomNameChannels;
  //!> list of channels when position needs to update
  static const Observable::channels_t AtomPositionChannels;
  //!> list of channels when selection needs to update
  static const Observable::channels_t AtomSelectedChannels;

  //!> we get multiple subjectKilled(), count and call callback() only on last
  const unsigned int AllsignedOnChannels;
  unsigned int signedOffChannels;

  //!> the Observable we are signed on, also indicates whether we are sign on (not NULL)
  const Observable *owner;

private:

  /** Internal setter for the weak shared_ptr instance that we sometimes
   * need to convert the ref to this instance into an shared ptr instance that
   * is safe to hand around.
   *
   * \param _selfref ref to shared ptr instance that is internally stored
   */
  void setSelfRef(const weak_ptr &_selfref)
  { const_cast<weak_ptr &>(selfref) = _selfref; }

  //!> reference to this instance wrapped in a shared ptr for handing around
  const weak_ptr selfref;

public:

  /** Getter for this instance safely wrapped in a shared ptr instance for
   * handing arount.
   *
   * \return shared ptr of this instance
   */
  ptr getRef() const
  { return ptr(selfref); }

private:
  //!> contains still the old id after the index of the atom changed
  atomId_t oldId;

  //!> unique index among all observed instances
  const ObservedValue_Index_t index;

  //!> reference to InstanceBoard for callbacks on subjectKilled()
  QtObservedInstanceBoard & board;

  //!> is board still alive or not, impacts callbacks
  bool BoardIsGone;

  //!> internal reference to ObservedValues held by QtObservedInstanceBoard
  ObservedValues_t ObservedValues;
};


#endif /* QTOBSERVEDATOM_HPP_ */