#ifndef STORM_STORAGE_PRISM_ASSIGNMENT_H_
#define STORM_STORAGE_PRISM_ASSIGNMENT_H_

#include <map>

#include "storm/storage/prism/LocatedInformation.h"
#include "storm/storage/expressions/Expression.h"
#include "storm/storage/expressions/Variable.h"
#include "storm/utility/OsDetection.h"

namespace storm {
    namespace prism {
        class Assignment : public LocatedInformation {
        public:
            /*!
             * Constructs an assignment using the given variable name and expression.
             *
             * @param variable The variable that this assignment targets.
             * @param expression The expression to assign to the variable.
             * @param filename The filename in which the assignment is defined.
             * @param lineNumber The line number in which the assignment is defined.
             */
            Assignment(storm::expressions::Variable const& variable, storm::expressions::Expression const& expression, std::string const& filename = "", uint_fast64_t lineNumber = 0);
                        
            // Create default implementations of constructors/assignment.
            Assignment() = default;
            Assignment(Assignment const& other) = default;
            Assignment& operator=(Assignment const& other)= default;
            Assignment(Assignment&& other) = default;
            Assignment& operator=(Assignment&& other) = default;

            /*!
             * Retrieves the name of the variable that this assignment targets.
             *
             * @return The name of the variable that this assignment targets.
             */
            std::string const& getVariableName() const;
            
            /*!
             * Retrieves the variable that is written to by this assignment.
             *
             * @return The variable that is written to by this assignment.
             */
            storm::expressions::Variable const& getVariable() const;
            
            /*!
             * Retrieves the expression that is assigned to the variable.
             *
             * @return The expression that is assigned to the variable.
             */
            storm::expressions::Expression const& getExpression() const;
            
            /*!
             * Substitutes all variables in the assignment according to the given map.
             *
             * @param substitution The substitution to perform.
             * @return The resulting assignment.
             */
            Assignment substitute(std::map<storm::expressions::Variable, storm::expressions::Expression> const& substitution) const;
            
            /*!
             * Checks whether the assignment is an identity (lhs equals rhs)
             * 
             * @return true iff the assignment is of the form a' = a.
             */
            bool isIdentity() const;
            
            friend std::ostream& operator<<(std::ostream& stream, Assignment const& assignment);
            
        private:
            // The variable written in this assignment.
            storm::expressions::Variable variable;
            
            // The expression that is assigned to the variable.
            storm::expressions::Expression expression;
        };
    } // namespace ir
} // namespace storm

#endif /* STORM_STORAGE_PRISM_ASSIGNMENT_H_ */