#ifndef popinfo_h
#define popinfo_h

#include "gadget.h"
#include "mathfunc.h"

/**
 * \class PopInfo
 * \brief This is the class used to store information about the number, and mean weight, of a population cell of a stock
 */
class PopInfo {
public:
  /**
   * \brief This is the PopInfo constructor
   */
  PopInfo(double Ni = 0.0, double Wi = 0.0)
  : N(Ni), W(Wi)
  {};
  /**
   * \brief This is the PopInfo destructor
   */
  ~PopInfo() {};
  /**
   * \brief This is the number of fish in the population cell
   */
  double N;
  /**
   * \brief This is the mean weight of the fish in the population cell
   */
  double W;
  /**
   * \brief This operator will subtract a number from the PopInfo
   * \param a is the number to subtract
   */
  void operator -= (double a) { N -= a; };
  /**
   * \brief This operator will increase the PopInfo by a multiplicative constant
   * \param a is the multiplicative constant
   */
  void operator *= (double a) { N *= a; };
  /**
   * \brief This function will set the PopInfo to zero
   */
  void setToZero() { N = 0.0; W = 0.0; };
  /**
   * \brief This operator will set the PopInfo equal to an existing PopInfo
   * \param a is the PopInfo to copy
   */
  PopInfo& operator = (const PopInfo& a) {
    N = a.N;
    W = a.W;
    return *this;
  }

  /**
   * \brief This operator will add an existing PopInfo to the current PopInfo
   * \param a is the PopInfo to add
   */
  PopInfo& operator += (const PopInfo& a) {
	  if (isZero(N + a.N)) {
	    W = 0.0;
	    N = 0.0;
	  } else if (isZero(a.N)) {
	    //adding a zero popinfo, so don't do anything
	  } else if (isZero(N)) {
	    W = a.W;
	    N = a.N;
	  } else {
	    W = (N * W + a.N * a.W) / (N + a.N);
	    N = N + a.N;
	  }
	  return *this;
	}


						  ;
  /**
   * \brief This operator will multiply the PopInfo by a constant
   * \param a is the constant
   */
  PopInfo operator * (double a) const {
    return PopInfo(N * a, W);
  }
};

#endif