#ifndef __VolumeBlockMinAndMax_h_
#define __VolumeBlockMinAndMax_h_

/* TVolumeBlockMinAndMax converts volume bars into a series of upward and
 * downward lines.  Sometimes it can be slow to show a change in direction
 * because it needs at least one whole volume bar going in the opposite
 * direction of the current trend before it makes an announcement.
 *
 * This class wakes the listener every time the underlying volume bars
 * data node wakes it.  The turning points may or may not have changed.
 * One update may contain zero, one, or more additions to the list of
 * turning points.
 *
 * If the volume blocks data node resets, this data node will also reset,
 * presenting a list of 0 turning points.  Except for that case, the list
 * of turning points can only grow.  The existing points won't change or
 * go away.
 */

#include "NormalVolumeBreakBars.h"

class VolumeBlockMinAndMax : public DataNode
{
public:
  enum Orientation { vboHigh, vboLow };
  struct TurningPoint
  {
    double price;
    int index;
    Orientation orientation;
  };
  typedef std::vector< TurningPoint > TurningPoints;
private:
  enum Direction 
    { vbdUnknown, vbdUp, vbdDown, vbdPossibleUp, vbdPossibleDown };
  class MinAndMaxAccumulator
  {
  private:
    int _blockCount;
    Direction _initialDirection;  // This will never be vbdPossibleUp or vbdPossibleDown.
    Direction _currentDirection;
    struct RecentBlock
    {
      VolumeBlock block;
      int index;
    };
    std::vector< RecentBlock > _recentBlocks; 
    TurningPoints _turningPoints;
    void addRecentBlock(VolumeBlock const &block);
    void setRecentBlock(VolumeBlock const &block);
    void addTurningPoint(VolumeBlock const &block, int recentBlockIndex,
			 Orientation orientation);
  public:
    void reset();
    MinAndMaxAccumulator();
    int getBlockCount() const { return _blockCount; }
    Direction getInitialDirection() const { return _initialDirection; }
    Direction getCurrentDirection() const;  // This will never be vbdPossibleUp or vbdPossibleDown.
    TurningPoints const &getTurningPoints() const { return _turningPoints; }
    void addBlock(VolumeBlock const &block);
  };
  NormalVolumeBreakBars *_barData;
  MinAndMaxAccumulator _highsAndLows;
  void onWakeup(int msgId);
  void checkInvariants(std::string const &symbol);
  
  VolumeBlockMinAndMax(DataNodeArgument const &args);
  friend class DataNode;

public:
  VolumeBlocks const &getAllBlocks() const { return _barData->getBlocks(); }
  TurningPoints const &getTurningPoints() const 
  { return _highsAndLows.getTurningPoints(); }

  static DataNodeLink *find(DataNodeListener *listener, int msgId,
			    VolumeBlockMinAndMax *&node,
			    std::string const &symbol);
};

#endif