#include "storm/storage/expressions/ToRationalNumberVisitor.h"


#include "storm/utility/constants.h"
#include "storm/exceptions/InvalidArgumentException.h"
#include "storm/exceptions/NotSupportedException.h"

namespace storm {
    namespace expressions {
    template<typename RationalNumberType>
        ToRationalNumberVisitor<RationalNumberType>::ToRationalNumberVisitor() : ExpressionVisitor() {
            // Intentionally left empty.
        }

        template<typename RationalNumberType>
        ToRationalNumberVisitor<RationalNumberType>::ToRationalNumberVisitor(ExpressionEvaluatorBase<RationalNumberType> const& evaluator) : ExpressionVisitor(), evaluator(evaluator) {
            // Intentionally left empty.
        }
        
        template<typename RationalNumberType>
        RationalNumberType ToRationalNumberVisitor<RationalNumberType>::toRationalNumber(Expression const& expression) {
            return boost::any_cast<RationalNumberType>(expression.accept(*this, boost::none));
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(IfThenElseExpression const& expression, boost::any const& data) {
            bool conditionValue;
            if (evaluator) {
            	conditionValue = evaluator->asBool(expression.getCondition());
            } else {
            	// no evaluator, fall back to evaluateBool
            	conditionValue = expression.getCondition()->evaluateAsBool();
            }
            if (conditionValue) {
                return expression.getThenExpression()->accept(*this, data);
            } else {
                return expression.getElseExpression()->accept(*this, data);
            }
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(BinaryBooleanFunctionExpression const&, boost::any const&) {
            STORM_LOG_THROW(false, storm::exceptions::InvalidArgumentException, "Expression cannot be translated into a rational number.");
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(BinaryNumericalFunctionExpression const& expression, boost::any const& data) {
            RationalNumberType firstOperandAsRationalNumber = boost::any_cast<RationalNumberType>(expression.getFirstOperand()->accept(*this, data));
            RationalNumberType secondOperandAsRationalNumber = boost::any_cast<RationalNumberType>(expression.getSecondOperand()->accept(*this, data));
            RationalNumberType result;
            uint_fast64_t exponentAsInteger;
            switch(expression.getOperatorType()) {
                case BinaryNumericalFunctionExpression::OperatorType::Plus:
                    result = firstOperandAsRationalNumber + secondOperandAsRationalNumber;
                    return result;
                    break;
                case BinaryNumericalFunctionExpression::OperatorType::Minus:
                    result = firstOperandAsRationalNumber - secondOperandAsRationalNumber;
                    return result;
                    break;
                case BinaryNumericalFunctionExpression::OperatorType::Times:
                    result = firstOperandAsRationalNumber * secondOperandAsRationalNumber;
                    return result;
                    break;
                case BinaryNumericalFunctionExpression::OperatorType::Divide:
                    result = firstOperandAsRationalNumber / secondOperandAsRationalNumber;
                    return result;
                    break;
                case BinaryNumericalFunctionExpression::OperatorType::Min:
                    result = std::min(firstOperandAsRationalNumber, secondOperandAsRationalNumber);
                    return result;
                    break;
                case BinaryNumericalFunctionExpression::OperatorType::Max:
                    result = std::max(firstOperandAsRationalNumber, secondOperandAsRationalNumber);
                    return result;
                    break;
                case BinaryNumericalFunctionExpression::OperatorType::Power:
                    STORM_LOG_THROW(storm::utility::isInteger(secondOperandAsRationalNumber), storm::exceptions::InvalidArgumentException, "Exponent of power operator must be a positive integer.");
                    exponentAsInteger = storm::utility::convertNumber<carl::uint>(secondOperandAsRationalNumber);
                    result = storm::utility::pow(firstOperandAsRationalNumber, exponentAsInteger);
                    return result;
                    break;
                default:
                    STORM_LOG_ASSERT(false, "Illegal operator type.");
            }
            
            // Return a dummy. This point must, however, never be reached.
            STORM_LOG_ASSERT(false, "Illegal operator type.");
            return boost::any();
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(BinaryRelationExpression const&, boost::any const&) {
            STORM_LOG_THROW(false, storm::exceptions::InvalidArgumentException, "Expression cannot be translated into a rational number.");
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(VariableExpression const& expression, boost::any const&) {
            return valueMapping.at(expression.getVariable());
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(UnaryBooleanFunctionExpression const&, boost::any const&) {
            STORM_LOG_THROW(false, storm::exceptions::InvalidArgumentException, "Expression cannot be translated into a rational number.");
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(UnaryNumericalFunctionExpression const& expression, boost::any const& data) {
            RationalNumberType operandAsRationalNumber = boost::any_cast<RationalNumberType>(expression.getOperand()->accept(*this, data));
            RationalNumberType result;
            switch (expression.getOperatorType()) {
                case UnaryNumericalFunctionExpression::OperatorType::Minus:
                    result = -operandAsRationalNumber;
                    return result;
                    break;
                case UnaryNumericalFunctionExpression::OperatorType::Floor:
                    result = storm::utility::floor(operandAsRationalNumber);
                    return result;
                    break;
                case UnaryNumericalFunctionExpression::OperatorType::Ceil:
                    result = storm::utility::ceil(operandAsRationalNumber);
                    return result;
                    break;
            }
            // Dummy return.
            return result;
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(BooleanLiteralExpression const&, boost::any const&) {
            STORM_LOG_THROW(false, storm::exceptions::InvalidArgumentException, "Expression cannot be translated into a rational number.");
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(IntegerLiteralExpression const& expression, boost::any const&) {
            return RationalNumberType(carl::rationalize<storm::RationalNumber>(static_cast<carl::sint>(expression.getValue())));
        }
        
        template<typename RationalNumberType>
        boost::any ToRationalNumberVisitor<RationalNumberType>::visit(RationalLiteralExpression const& expression, boost::any const&) {
            return expression.getValue();
        }
        
        template<typename RationalNumberType>
        void ToRationalNumberVisitor<RationalNumberType>::setMapping(storm::expressions::Variable const& variable, RationalNumberType const& value) {
            valueMapping[variable] = value;
        }
        

        template class ToRationalNumberVisitor<storm::RationalNumber>;

    }
}