#include "storm/adapters/Z3ExpressionAdapter.h"

#include "storm/storage/expressions/Expressions.h"
#include "storm/storage/expressions/ExpressionManager.h"
#include "storm/utility/macros.h"
#include "storm/utility/constants.h"
#include "storm/exceptions/ExpressionEvaluationException.h"
#include "storm/exceptions/InvalidTypeException.h"
#include "storm/exceptions/NotImplementedException.h"

namespace storm {
    namespace adapters {

#ifdef STORM_HAVE_Z3
            Z3ExpressionAdapter::Z3ExpressionAdapter(storm::expressions::ExpressionManager& manager, z3::context& context) : manager(manager), context(context), additionalAssertions(), variableToExpressionMapping() {
                // Intentionally left empty.
            }
            
            z3::expr Z3ExpressionAdapter::translateExpression(storm::expressions::Expression const& expression) {
                STORM_LOG_ASSERT(expression.getManager() == this->manager, "Invalid expression for solver.");
                z3::expr result = boost::any_cast<z3::expr>(expression.getBaseExpression().accept(*this, boost::none));
                
                for (z3::expr const& assertion : additionalAssertions) {
                    result = result && assertion;
                }
                additionalAssertions.clear();

                return result;
            }
            
            z3::expr Z3ExpressionAdapter::translateExpression(storm::expressions::Variable const& variable) {
                STORM_LOG_ASSERT(variable.getManager() == this->manager, "Invalid expression for solver.");
                
                auto const& variableExpressionPair = variableToExpressionMapping.find(variable);
                if (variableExpressionPair == variableToExpressionMapping.end()) {
                    return createVariable(variable);
                }

                return variableExpressionPair->second;
            }
            
            storm::expressions::Variable const& Z3ExpressionAdapter::getVariable(z3::func_decl z3Declaration) {
                auto const& declarationVariablePair = declarationToVariableMapping.find(z3Declaration);
                STORM_LOG_ASSERT(declarationVariablePair != declarationToVariableMapping.end(), "Unable to find declaration.");
                return declarationVariablePair->second;
            }
            
            storm::expressions::Expression Z3ExpressionAdapter::translateExpression(z3::expr const& expr) {
                if (expr.is_app()) {
                        switch (expr.decl().decl_kind()) {
                            case Z3_OP_TRUE:
                                    return manager.boolean(true);
                            case Z3_OP_FALSE:
                                    return manager.boolean(false);
                            case Z3_OP_EQ:
                                    return this->translateExpression(expr.arg(0)) == this->translateExpression(expr.arg(1));
                            case Z3_OP_ITE:
                                    return storm::expressions::ite(this->translateExpression(expr.arg(0)), this->translateExpression(expr.arg(1)), this->translateExpression(expr.arg(2)));
                            case Z3_OP_AND: {
                                    unsigned args = expr.num_args();
                                    STORM_LOG_THROW(args != 0, storm::exceptions::ExpressionEvaluationException, "Failed to convert Z3 expression. 0-ary AND is assumed to be an error.");
                                    if (args == 1) {
                                            return this->translateExpression(expr.arg(0));
                                    } else {
                                            storm::expressions::Expression retVal = this->translateExpression(expr.arg(0));
                                            for (unsigned i = 1; i < args; i++) {
                                                    retVal = retVal && this->translateExpression(expr.arg(i));
                                            }
                                            return retVal;
                                    }
                            }
                            case Z3_OP_OR: {
                                    unsigned args = expr.num_args();
                                    STORM_LOG_THROW(args != 0, storm::exceptions::ExpressionEvaluationException, "Failed to convert Z3 expression. 0-ary OR is assumed to be an error.");
                                    if (args == 1) {
                                            return this->translateExpression(expr.arg(0));
                                    } else {
                                            storm::expressions::Expression retVal = this->translateExpression(expr.arg(0));
                                            for (unsigned i = 1; i < args; i++) {
                                                    retVal = retVal || this->translateExpression(expr.arg(i));
                                            }
                                            return retVal;
                                    }
                            }
                            case Z3_OP_IFF:
                                    return storm::expressions::iff(this->translateExpression(expr.arg(0)), this->translateExpression(expr.arg(1)));
                            case Z3_OP_XOR:
                                    return this->translateExpression(expr.arg(0)) ^ this->translateExpression(expr.arg(1));
                            case Z3_OP_NOT:
                                    return !this->translateExpression(expr.arg(0));
                            case Z3_OP_IMPLIES:
                                    return storm::expressions::implies(this->translateExpression(expr.arg(0)), this->translateExpression(expr.arg(1)));
                            case Z3_OP_LE:
                                    return this->translateExpression(expr.arg(0)) <= this->translateExpression(expr.arg(1));
                            case Z3_OP_GE:
                                    return this->translateExpression(expr.arg(0)) >= this->translateExpression(expr.arg(1));
                            case Z3_OP_LT:
                                    return this->translateExpression(expr.arg(0)) < this->translateExpression(expr.arg(1));
                            case Z3_OP_GT:
                                    return this->translateExpression(expr.arg(0)) > this->translateExpression(expr.arg(1));
                            case Z3_OP_ADD:
                                    return this->translateExpression(expr.arg(0)) + this->translateExpression(expr.arg(1));
                            case Z3_OP_SUB:
                                    return this->translateExpression(expr.arg(0)) - this->translateExpression(expr.arg(1));
                            case Z3_OP_UMINUS:
                                    return -this->translateExpression(expr.arg(0));
                            case Z3_OP_MUL:
                                    return this->translateExpression(expr.arg(0)) * this->translateExpression(expr.arg(1));
                            case Z3_OP_DIV:
                                    return this->translateExpression(expr.arg(0)) / this->translateExpression(expr.arg(1));
                            case Z3_OP_IDIV:
                                    return this->translateExpression(expr.arg(0)) / this->translateExpression(expr.arg(1));
                            case Z3_OP_ANUM:
                                // Arithmetic numeral.
                                if (expr.is_int() && expr.is_const()) {
                                    long long value;
                                    if (Z3_get_numeral_int64(expr.ctx(), expr, &value)) {
                                        return manager.integer(value);
                                    } else {
                                        STORM_LOG_THROW(false, storm::exceptions::ExpressionEvaluationException, "Failed to convert Z3 expression. Expression is constant integer and value does not fit into 64-bit integer.");
                                    }
                                } else if (expr.is_real() && expr.is_const()) {
                                    long long num;
                                    long long den;
                                    if (Z3_get_numeral_rational_int64(expr.ctx(), expr, &num, &den)) {
                                        return manager.rational(storm::utility::convertNumber<storm::RationalNumber>(num) / storm::utility::convertNumber<storm::RationalNumber>(den));
                                    } else {
                                        return manager.rational(storm::utility::convertNumber<storm::RationalNumber>(std::string(Z3_get_numeral_string(expr.ctx(), expr))));
                                    }
                                }
                            case Z3_OP_UNINTERPRETED:
                                // Currently, we only support uninterpreted constant functions.
                                STORM_LOG_THROW(expr.is_const(), storm::exceptions::ExpressionEvaluationException, "Failed to convert Z3 expression. Encountered non-constant uninterpreted function.");
                                return manager.getVariable(expr.decl().name().str()).getExpression();
                            default:
                                STORM_LOG_THROW(false, storm::exceptions::ExpressionEvaluationException, "Failed to convert Z3 expression. Encountered unhandled Z3_decl_kind " << expr.decl().kind() <<".");
                                break;
                        }
                    } else {
                        STORM_LOG_THROW(false, storm::exceptions::ExpressionEvaluationException, "Failed to convert Z3 expression. Encountered unknown expression type.");
                    }
            }

            boost::any Z3ExpressionAdapter::visit(storm::expressions::BinaryBooleanFunctionExpression const& expression, boost::any const& data)  {
                z3::expr leftResult = boost::any_cast<z3::expr>(expression.getFirstOperand()->accept(*this, data));
                z3::expr rightResult = boost::any_cast<z3::expr>(expression.getSecondOperand()->accept(*this, data));
                
                switch(expression.getOperatorType()) {
					case storm::expressions::BinaryBooleanFunctionExpression::OperatorType::And:
                        return leftResult && rightResult;
					case storm::expressions::BinaryBooleanFunctionExpression::OperatorType::Or:
                        return leftResult || rightResult;
					case storm::expressions::BinaryBooleanFunctionExpression::OperatorType::Xor:
						return z3::expr(context, Z3_mk_xor(context, leftResult, rightResult));
					case storm::expressions::BinaryBooleanFunctionExpression::OperatorType::Implies:
						return z3::expr(context, Z3_mk_implies(context, leftResult, rightResult));
					case storm::expressions::BinaryBooleanFunctionExpression::OperatorType::Iff:
						return z3::expr(context, Z3_mk_iff(context, leftResult, rightResult));
                    default:
                        STORM_LOG_THROW(false, storm::exceptions::ExpressionEvaluationException, "Cannot evaluate expression: unknown boolean binary operator '" << static_cast<int>(expression.getOperatorType()) << "' in expression " << expression << ".");
                }
                
            }
            
            boost::any Z3ExpressionAdapter::visit(storm::expressions::BinaryNumericalFunctionExpression const& expression, boost::any const& data)  {
                z3::expr leftResult = boost::any_cast<z3::expr>(expression.getFirstOperand()->accept(*this, data));
                z3::expr rightResult = boost::any_cast<z3::expr>(expression.getSecondOperand()->accept(*this, data));
        
                switch(expression.getOperatorType()) {
					case storm::expressions::BinaryNumericalFunctionExpression::OperatorType::Plus:
                        return leftResult + rightResult;
					case storm::expressions::BinaryNumericalFunctionExpression::OperatorType::Minus:
                        return leftResult - rightResult;
					case storm::expressions::BinaryNumericalFunctionExpression::OperatorType::Times:
                        return leftResult * rightResult;
					case storm::expressions::BinaryNumericalFunctionExpression::OperatorType::Divide:
                        return leftResult / rightResult;
					case storm::expressions::BinaryNumericalFunctionExpression::OperatorType::Min:
                        return ite(leftResult <= rightResult, leftResult, rightResult);
					case storm::expressions::BinaryNumericalFunctionExpression::OperatorType::Max:
                        return ite(leftResult >= rightResult, leftResult, rightResult);
					case storm::expressions::BinaryNumericalFunctionExpression::OperatorType::Power:
                        return pw(leftResult,rightResult);
                    default:
                        STORM_LOG_THROW(false, storm::exceptions::ExpressionEvaluationException, "Cannot evaluate expression: unknown numerical binary operator '" << static_cast<int>(expression.getOperatorType()) << "' in expression " << expression << ".");
                }
            }
            
            boost::any Z3ExpressionAdapter::visit(storm::expressions::BinaryRelationExpression const& expression, boost::any const& data)  {
                z3::expr leftResult = boost::any_cast<z3::expr>(expression.getFirstOperand()->accept(*this, data));
                z3::expr rightResult = boost::any_cast<z3::expr>(expression.getSecondOperand()->accept(*this, data));
    
                switch(expression.getRelationType()) {
					case storm::expressions::BinaryRelationExpression::RelationType::Equal:
                        return leftResult == rightResult;
					case storm::expressions::BinaryRelationExpression::RelationType::NotEqual:
                        return leftResult != rightResult;
					case storm::expressions::BinaryRelationExpression::RelationType::Less:
                        return leftResult < rightResult;
					case storm::expressions::BinaryRelationExpression::RelationType::LessOrEqual:
                        return leftResult <= rightResult;
					case storm::expressions::BinaryRelationExpression::RelationType::Greater:
                        return leftResult > rightResult;
					case storm::expressions::BinaryRelationExpression::RelationType::GreaterOrEqual:
                        return leftResult >= rightResult;
                    default:
                        STORM_LOG_THROW(false, storm::exceptions::ExpressionEvaluationException, "Cannot evaluate expression: unknown boolean binary operator '" << static_cast<int>(expression.getRelationType()) << "' in expression " << expression << ".");
                }    
            }
            
            boost::any Z3ExpressionAdapter::visit(storm::expressions::BooleanLiteralExpression const& expression, boost::any const&)  {
                return context.bool_val(expression.getValue());
            }
            
            boost::any Z3ExpressionAdapter::visit(storm::expressions::RationalLiteralExpression const& expression, boost::any const&)  {
                std::stringstream fractionStream;
                fractionStream << expression.getValue();
                return context.real_val(fractionStream.str().c_str());
            }
            
            boost::any Z3ExpressionAdapter::visit(storm::expressions::IntegerLiteralExpression const& expression, boost::any const&)  {
                return context.int_val(static_cast<int>(expression.getValue()));
            }
            
            boost::any Z3ExpressionAdapter::visit(storm::expressions::UnaryBooleanFunctionExpression const& expression, boost::any const& data)  {
                z3::expr childResult = boost::any_cast<z3::expr>(expression.getOperand()->accept(*this, data));
                
                switch (expression.getOperatorType()) {
					case storm::expressions::UnaryBooleanFunctionExpression::OperatorType::Not:
                        return !childResult;
                    default:
                        STORM_LOG_THROW(false, storm::exceptions::ExpressionEvaluationException, "Cannot evaluate expression: unknown boolean binary operator '" << static_cast<int>(expression.getOperatorType()) << "' in expression " << expression << ".");
                }    
            }
            
            boost::any Z3ExpressionAdapter::visit(storm::expressions::UnaryNumericalFunctionExpression const& expression, boost::any const& data)  {
                z3::expr childResult = boost::any_cast<z3::expr>(expression.getOperand()->accept(*this, data));
                
                switch(expression.getOperatorType()) {
					case storm::expressions::UnaryNumericalFunctionExpression::OperatorType::Minus:
                        return 0 - childResult;
					case storm::expressions::UnaryNumericalFunctionExpression::OperatorType::Floor: {
                        storm::expressions::Variable freshAuxiliaryVariable = manager.declareFreshVariable(manager.getIntegerType(), true);
                        z3::expr floorVariable = context.int_const(freshAuxiliaryVariable.getName().c_str());
						additionalAssertions.push_back(z3::expr(context, Z3_mk_int2real(context, floorVariable)) <= childResult && childResult < (z3::expr(context, Z3_mk_int2real(context, floorVariable)) + 1));
						return floorVariable;
					}
					case storm::expressions::UnaryNumericalFunctionExpression::OperatorType::Ceil:{
                        storm::expressions::Variable freshAuxiliaryVariable = manager.declareFreshVariable(manager.getIntegerType(), true);
                        z3::expr ceilVariable = context.int_const(freshAuxiliaryVariable.getName().c_str());
						additionalAssertions.push_back(z3::expr(context, Z3_mk_int2real(context, ceilVariable)) - 1 <= childResult && childResult < z3::expr(context, Z3_mk_int2real(context, ceilVariable)));
						return ceilVariable;
					}
                    default: STORM_LOG_THROW(false, storm::exceptions::ExpressionEvaluationException, "Cannot evaluate expression: unknown numerical unary operator '" << static_cast<int>(expression.getOperatorType()) << "'.");
                }
            }

            boost::any Z3ExpressionAdapter::visit(storm::expressions::IfThenElseExpression const& expression, boost::any const& data)  {
                z3::expr conditionResult = boost::any_cast<z3::expr>(expression.getCondition()->accept(*this, data));
                z3::expr thenResult = boost::any_cast<z3::expr>(expression.getThenExpression()->accept(*this, data));
                z3::expr elseResult = boost::any_cast<z3::expr>(expression.getElseExpression()->accept(*this, data));
                return z3::expr(context, Z3_mk_ite(context, conditionResult, thenResult, elseResult));
            }
            
            boost::any Z3ExpressionAdapter::visit(storm::expressions::VariableExpression const& expression, boost::any const&)  {
                return this->translateExpression(expression.getVariable());
            }

            z3::expr Z3ExpressionAdapter::createVariable(storm::expressions::Variable const& variable) {
                z3::expr z3Variable(context);
                if (variable.getType().isBooleanType()) {
                    z3Variable = context.bool_const(variable.getName().c_str());
                } else if (variable.getType().isIntegerType()) {
                    z3Variable = context.int_const(variable.getName().c_str());
                } else if (variable.getType().isBitVectorType()) {
                    z3Variable = context.bv_const(variable.getName().c_str(), variable.getType().getWidth());
                } else if (variable.getType().isRationalType()) {
                    z3Variable = context.real_const(variable.getName().c_str());
                } else {
                    STORM_LOG_THROW(false, storm::exceptions::InvalidTypeException, "Encountered variable '" << variable.getName() << "' with unknown type while trying to create solver variables.");
                }
                variableToExpressionMapping.insert(std::make_pair(variable, z3Variable));
                declarationToVariableMapping.insert(std::make_pair(z3Variable.decl(), variable));
                return z3Variable;
            }


#endif
    } // namespace adapters
} // namespace storm