#ifndef MATERIAL_HPP
#define MATERIAL_HPP
//
// $Id: Material.hpp,v 1.4 1999/10/01 17:22:04 hobbs Exp $
//
// File: Material.hpp
// Purpose: Represent a material
// Created: 03-SEP-1998   Harry L. Melanson
//
// $Revision: 1.4 $
//
// This code was orginally based on the beta 01 release of Geant4
// G4Element.  It is a greatly simplified version which currently only
// supports radiation lengths.
//
// Code commented using doc++ format.
//

// Include files

#include <iostream>
#include <string>

namespace D0Material {

  /** The D0 Material Class.
      
      This class is used to represent material as needed by the D0
      reconstruction program.
      
  */
  
  class Material
  {
    
    //------------------  Public Methods -------------------//
    
  public:
    
    /**  Constructor -- calculates radiation length from (A,Z).
	 
	 This constructor creates a {\bf Material} with the user
	 specified name, symbold, effective atomic number (Z), number of
	 nucleons (A) and density (rho) in gm/cm$^3$.  It calculates the
	 radiation length of the material, using Tsai's expression (Phys
	 Rev. D50 3-1 (1994) page 1254).
	 
	 @param  name    Name of material
	 @param  symbol  Symbol to represent material
	 @param  zeff    Effective atomic number
	 @param  aeff    Effective number of nucleons
	 @param  rho     Density (gm/cm$^3$)
	 
    */
    
    Material(const std::string& name, 
	     const std::string& symbol, 
	     double zeff,
	     double aeff,
	     double rho);
    
    /**  Constructor -- user specified radiation length.
	 
	 This constructor creates a {\bf Material} with the user
	 specified name, symbold, effective atomic number (Z), number of
	 nucleons (A), density (rho) in gm/cm$^3$ and radiation length
	 (X0) in gm/cm$^2$.
	 
	 @param  name    Name of material
	 @param  symbol  Symbol to represent material
	 @param  zeff    Effective atomic number
	 @param  aeff    Effective number of nucleons
	 @param  rho     Density (gm/cm$^3$)
	 @param  x0      Radiation length  (gm/cm$^2$)
	 
    */
    
    Material(const std::string& name,
	     const std::string& symbol,
	     double zeff,
	     double aeff,
	     double rho,
	     double x0);

    /// Default constructor.   Needed for use in STL.
    Material(): 
      d_name("DUMMY MATERIAL"), d_symbol("XXX"), 
      d_zeff(1.0), d_aeff(1.0), d_rho(1.0), d_x0(1.0) {}
    
    ///  Returns name of Material.
    std::string getName() const {return d_name;};
    
    ///  Returns symbol representing Material.
    std::string getSymbol() const {return d_symbol;};
    
    ///  Returns effective atomic number of Material.
    double getZ() const {return d_zeff;};
    
    ///  Returns effective number of nucleons of Material.
    double getA() const {return d_aeff;};
    
    ///  Returns density of Material (gm/cm$^3$).
    double getDensity() const {return d_rho;};
    
    ///  Returns radiation length of Material, in cm.
    double getX0_cm() const {return d_x0 / d_rho;};
    
    ///  Returns radiation length of Material, in gm/cm$^2$.
    double getX0_gm() const {return d_x0;};
    
    ///  Stream insertion operator.
    friend std::ostream& operator<<(std::ostream&, const Material*);
    
    ///  Stream insertion operator.
    friend std::ostream& operator<<(std::ostream&, const Material&);
    
    /**  Equality operator.

	 Two {\bf Materials} are {\em equal} if their properties are
	 equal (ignoring their {\bf names} and {\bf symbols}).

      */

    bool operator==(const Material&) const;
    
    /**  Inequality operator.

	 Two {\bf Materials} are {\em unequal} if their properties are
	 are not the same (ignoring their {\bf names} and {\bf
	 symbols}).

      */

    bool operator!=(const Material&) const;
    
    ///  Assignment operator.
    const Material& operator=(const Material &right);
    
    ///  Copy constructor.
    Material(const Material &right);
    
    //------------------  Private Methods -------------------//
    
  private:
    
    ///  Method used to compute radiation length.
    void ComputeLradTsaiFactor();
    
    //------------------  Public Data Members -------------------//
    
  protected:
    
    ///  Material name.
    std::string d_name;
    
    ///  Material symbol.
    std::string d_symbol;
    
    ///  Effective atomic number of Material.
    double d_zeff;
    
    ///  Effective number of nucleons of Material.
    double d_aeff;       
    
    ///  Density of Material (gm/cm$^3$).
    double d_rho;
    
    ///  Radiation length of material (gm/cm$^2$).
    double d_x0;            

  };    // class Material

}       // namespace D0Material

#endif  // MATERIAL_HPP