/*
 * Copyright 2007-2008, Christof Lutteroth, lutteroth@cs.auckland.ac.nz
 * Copyright 2007-2008, James Kim, jkim202@ec.auckland.ac.nz
 * Distributed under the terms of the MIT License.
 */
#ifndef VARIABLE_H
#define VARIABLE_H


#include <ObjectList.h>
#include <String.h>

namespace LinearProgramming {

class Constraint;
class LinearSpec;
class Summand;

/**
 * Contains minimum and maximum values.
 */
class Variable {
public:
                        int32                           Index() const;
                        int32                           GlobalIndex() const;
                        LinearSpec*                     LS() const;
                        double                          Value() const;
                        void                            SetValue(double value);
                        double                          Min() const;
                        void                            SetMin(double min);
                        double                          Max() const;
                        void                            SetMax(double max);
                        void                            SetRange(double min, double max);

                        const char*                     Label();
                        void                            SetLabel(const char* label);

                        BString                         ToString() const;

                        Constraint*                     IsEqual(Variable* var);
                        Constraint*                     IsSmallerOrEqual(Variable* var);
                        Constraint*                     IsGreaterOrEqual(Variable* var);

                        Constraint*                     IsEqual(Variable* var,
                                                                        double penaltyNeg, double penaltyPos);
                        Constraint*                     IsSmallerOrEqual(Variable* var,
                                                                        double penaltyNeg, double penaltyPos);
                        Constraint*                     IsGreaterOrEqual(Variable* var,
                                                                        double penaltyNeg, double penaltyPos);

                        bool                            IsValid();
                        //! Dangerous the variable don't belong to the LinearSpec anymore,
                        //! delete it yourself!
                        void                            Invalidate();

        virtual                                         ~Variable();

protected:
                                                                Variable(LinearSpec* ls);

                        //! returns the ref count
                        int32                           AddReference();
                        int32                           RemoveReference();
private:
                        LinearSpec*                     fLS;

                        double                          fValue;
                        double                          fMin;
                        double                          fMax;
                        BString                         fLabel;

                        bool                            fIsValid;

                        int32                           fReferenceCount;
public:
        friend class            LinearSpec;
};


typedef BObjectList<Variable> VariableList;


}       // namespace LinearProgramming

using LinearProgramming::Variable;
using LinearProgramming::VariableList;

#endif  // VARIABLE_H