#include "src/solver/Z3Smtsolver.h"

#include "src/exceptions/NotSupportedException.h"
#include "src/exceptions/InvalidStateException.h"

namespace storm {
	namespace solver {
#ifdef STORM_HAVE_Z3
		Z3SmtSolver::Z3ModelReference::Z3ModelReference(storm::expressions::ExpressionManager const& manager, z3::model model, storm::adapters::Z3ExpressionAdapter& expressionAdapter) : ModelReference(manager), model(model), expressionAdapter(expressionAdapter) {
            // Intentionally left empty.
		}
#endif

        bool Z3SmtSolver::Z3ModelReference::getBooleanValue(storm::expressions::Variable const& variable) const {
#ifdef STORM_HAVE_Z3
            STORM_LOG_ASSERT(variable.getManager() == this->getManager(), "Requested variable is managed by a different manager.");
			z3::expr z3Expr = this->expressionAdapter.translateExpression(variable);
			z3::expr z3ExprValuation = model.eval(z3Expr, true);
			return this->expressionAdapter.translateExpression(z3ExprValuation).isTrue();
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

        int_fast64_t Z3SmtSolver::Z3ModelReference::getIntegerValue(storm::expressions::Variable const& variable) const {
#ifdef STORM_HAVE_Z3
            STORM_LOG_ASSERT(variable.getManager() == this->getManager(), "Requested variable is managed by a different manager.");
			z3::expr z3Expr = this->expressionAdapter.translateExpression(variable);
			z3::expr z3ExprValuation = model.eval(z3Expr, true);
			return this->expressionAdapter.translateExpression(z3ExprValuation).evaluateAsInt();
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

        double Z3SmtSolver::Z3ModelReference::getRationalValue(storm::expressions::Variable const& variable) const {
#ifdef STORM_HAVE_Z3
            STORM_LOG_ASSERT(variable.getManager() == this->getManager(), "Requested variable is managed by a different manager.");
			z3::expr z3Expr = this->expressionAdapter.translateExpression(variable);
			z3::expr z3ExprValuation = model.eval(z3Expr, true);
			return this->expressionAdapter.translateExpression(z3ExprValuation).evaluateAsDouble();
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}
        
		Z3SmtSolver::Z3SmtSolver(storm::expressions::ExpressionManager& manager)
#ifdef STORM_HAVE_Z3
        : SmtSolver(manager), context(nullptr), solver(nullptr), expressionAdapter(nullptr), lastCheckAssumptions(false), lastResult(CheckResult::Unknown)
#endif
		{
            z3::config config;
            config.set("model", true);
            context = std::unique_ptr<z3::context>(new z3::context(config));
            solver = std::unique_ptr<z3::solver>(new z3::solver(*context));
            expressionAdapter = std::unique_ptr<storm::adapters::Z3ExpressionAdapter>(new storm::adapters::Z3ExpressionAdapter(this->getManager(), *context));
        }
        
		Z3SmtSolver::~Z3SmtSolver() {
            // Intentionally left empty.
        }

		void Z3SmtSolver::push()
		{
#ifdef STORM_HAVE_Z3
			this->solver->push();
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		void Z3SmtSolver::pop()
		{
#ifdef STORM_HAVE_Z3
			this->solver->pop();
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		void Z3SmtSolver::pop(uint_fast64_t n)
		{
#ifdef STORM_HAVE_Z3
			this->solver->pop(static_cast<unsigned int>(n));
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		void Z3SmtSolver::reset()
		{
#ifdef STORM_HAVE_Z3
			this->solver->reset();
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		void Z3SmtSolver::add(storm::expressions::Expression const& assertion)
		{
#ifdef STORM_HAVE_Z3
			this->solver->add(expressionAdapter->translateExpression(assertion));
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		SmtSolver::CheckResult Z3SmtSolver::check()
		{
#ifdef STORM_HAVE_Z3
			lastCheckAssumptions = false;
			switch (this->solver->check()) {
				case z3::sat:
					this->lastResult = SmtSolver::CheckResult::Sat;
					break;
				case z3::unsat:
					this->lastResult = SmtSolver::CheckResult::Unsat;
					break;
				default:
					this->lastResult = SmtSolver::CheckResult::Unknown;
					break;
			}
			return this->lastResult;
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		SmtSolver::CheckResult Z3SmtSolver::checkWithAssumptions(std::set<storm::expressions::Expression> const& assumptions)
		{
#ifdef STORM_HAVE_Z3
			lastCheckAssumptions = true;
			z3::expr_vector z3Assumptions(*this->context);

			for (storm::expressions::Expression assumption : assumptions) {
				z3Assumptions.push_back(this->expressionAdapter->translateExpression(assumption));
			}

			switch (this->solver->check(z3Assumptions)) {
				case z3::sat:
					this->lastResult = SmtSolver::CheckResult::Sat;
					break;
				case z3::unsat:
					this->lastResult = SmtSolver::CheckResult::Unsat;
					break;
				default:
					this->lastResult = SmtSolver::CheckResult::Unknown;
					break;
			}
			return this->lastResult;
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		SmtSolver::CheckResult Z3SmtSolver::checkWithAssumptions(std::initializer_list<storm::expressions::Expression> const& assumptions)
		{
#ifdef STORM_HAVE_Z3
			lastCheckAssumptions = true;
			z3::expr_vector z3Assumptions(*this->context);

			for (storm::expressions::Expression assumption : assumptions) {
				z3Assumptions.push_back(this->expressionAdapter->translateExpression(assumption));
			}

			switch (this->solver->check(z3Assumptions)) {
				case z3::sat:
					this->lastResult = SmtSolver::CheckResult::Sat;
					break;
				case z3::unsat:
					this->lastResult = SmtSolver::CheckResult::Unsat;
					break;
				default:
					this->lastResult = SmtSolver::CheckResult::Unknown;
					break;
			}
			return this->lastResult;
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		storm::expressions::SimpleValuation Z3SmtSolver::getModelAsValuation()
		{
#ifdef STORM_HAVE_Z3
			STORM_LOG_THROW(this->lastResult == SmtSolver::CheckResult::Sat, storm::exceptions::InvalidStateException, "Unable to create model for formula that was not determined to be satisfiable.");
			return this->convertZ3ModelToValuation(this->solver->get_model());
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}
        
        std::shared_ptr<SmtSolver::ModelReference> Z3SmtSolver::getModel() {
#ifdef STORM_HAVE_Z3
			STORM_LOG_THROW(this->lastResult == SmtSolver::CheckResult::Sat, storm::exceptions::InvalidStateException, "Unable to create model for formula that was not determined to be satisfiable.");
            return std::shared_ptr<SmtSolver::ModelReference>(new Z3ModelReference(this->getManager(), this->solver->get_model(), *this->expressionAdapter));
#else
            STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
        }

#ifdef STORM_HAVE_Z3
		storm::expressions::SimpleValuation Z3SmtSolver::convertZ3ModelToValuation(z3::model const& model) {
			storm::expressions::SimpleValuation stormModel(this->getManager());

			for (unsigned i = 0; i < model.num_consts(); ++i) {
				z3::func_decl variableI = model.get_const_decl(i);
                storm::expressions::Variable stormVariable = this->expressionAdapter->getVariable(variableI);
				storm::expressions::Expression variableInterpretation = this->expressionAdapter->translateExpression(model.get_const_interp(variableI));

                if (variableInterpretation.getType().isBooleanType()) {
                    stormModel.setBooleanValue(this->getManager().getVariable(variableI.name().str()), variableInterpretation.isTrue());
                } else if (variableInterpretation.getType().isIntegralType()) {
                    stormModel.setIntegerValue(this->getManager().getVariable(variableI.name().str()), variableInterpretation.evaluateAsInt());
                } else if (variableInterpretation.getType().isRationalType()) {
                    stormModel.setRationalValue(this->getManager().getVariable(variableI.name().str()), variableInterpretation.evaluateAsDouble());
                } else {
                    STORM_LOG_ASSERT(false, "Variable interpretation in model is not of type bool, int or rational.");
                }
			}

			return stormModel;
		}
#endif

		std::vector<storm::expressions::SimpleValuation> Z3SmtSolver::allSat(std::vector<storm::expressions::Variable> const& important)
		{
#ifdef STORM_HAVE_Z3
			std::vector<storm::expressions::SimpleValuation> valuations;
			this->allSat(important, [&valuations](storm::expressions::SimpleValuation const& valuation) -> bool { valuations.push_back(valuation); return true; });
			return valuations;
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		uint_fast64_t Z3SmtSolver::allSat(std::vector<storm::expressions::Variable> const& important, std::function<bool(storm::expressions::SimpleValuation&)> const& callback) {
#ifdef STORM_HAVE_Z3
			for (storm::expressions::Variable const& variable : important) {
                STORM_LOG_THROW(variable.hasBooleanType(), storm::exceptions::InvalidArgumentException, "The important atoms for AllSat must be boolean variables.");
			}

			uint_fast64_t numberOfModels = 0;
			bool proceed = true;

            // Save the current assertion stack, to be able to backtrack after the procedure.
			this->push();

            // Enumerate models as long as the conjunction is satisfiable and the callback has not aborted the enumeration.
			while (proceed && this->check() == CheckResult::Sat) {
				++numberOfModels;
				z3::model model = this->solver->get_model();

				z3::expr modelExpr = this->context->bool_val(true);
				storm::expressions::SimpleValuation valuation(this->getManager());

				for (storm::expressions::Variable const& importantAtom : important) {
					z3::expr z3ImportantAtom = this->expressionAdapter->translateExpression(importantAtom.getExpression());
					z3::expr z3ImportantAtomValuation = model.eval(z3ImportantAtom, true);
					modelExpr = modelExpr && (z3ImportantAtom == z3ImportantAtomValuation);
                    valuation.setBooleanValue(importantAtom, this->expressionAdapter->translateExpression(z3ImportantAtomValuation).isTrue());
				}

                // Check if we are required to proceed, and if so rule out the current model.
				proceed = callback(valuation);
                if (proceed) {
                    this->solver->add(!modelExpr);
                }
			}

            // Restore the old assertion stack and return.
			this->pop();
			return numberOfModels;
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		uint_fast64_t Z3SmtSolver::allSat(std::vector<storm::expressions::Variable> const& important, std::function<bool(SmtSolver::ModelReference&)> const& callback) {
#ifdef STORM_HAVE_Z3
            for (storm::expressions::Variable const& variable : important) {
                STORM_LOG_THROW(variable.hasBooleanType(), storm::exceptions::InvalidArgumentException, "The important atoms for AllSat must be boolean variables.");
            }

			uint_fast64_t numberOfModels = 0;
			bool proceed = true;

            // Save the current assertion stack, to be able to backtrack after the procedure.
			this->push();

            // Enumerate models as long as the conjunction is satisfiable and the callback has not aborted the enumeration.
			while (proceed && this->check() == CheckResult::Sat) {
				++numberOfModels;
				z3::model model = this->solver->get_model();

				z3::expr modelExpr = this->context->bool_val(true);
				storm::expressions::SimpleValuation valuation(this->getManager());

				for (storm::expressions::Variable const& importantAtom : important) {
					z3::expr z3ImportantAtom = this->expressionAdapter->translateExpression(importantAtom.getExpression());
					z3::expr z3ImportantAtomValuation = model.eval(z3ImportantAtom, true);
					modelExpr = modelExpr && (z3ImportantAtom == z3ImportantAtomValuation);
				}
				Z3ModelReference modelRef(this->getManager(), model, *expressionAdapter);

                // Check if we are required to proceed, and if so rule out the current model.
				proceed = callback(modelRef);
                if (proceed) {
                    this->solver->add(!modelExpr);
                }
			}

			this->pop();
			return numberOfModels;
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}

		std::vector<storm::expressions::Expression> Z3SmtSolver::getUnsatAssumptions() {
#ifdef STORM_HAVE_Z3
            STORM_LOG_THROW(lastResult == SmtSolver::CheckResult::Unsat, storm::exceptions::InvalidStateException, "Unable to generate unsatisfiable core of assumptions, because the last check did not determine the formulas to be unsatisfiable.")
            STORM_LOG_THROW(lastCheckAssumptions, storm::exceptions::InvalidStateException, "Unable to generate unsatisfiable core of assumptions, because the last check did not involve assumptions.");

			z3::expr_vector z3UnsatAssumptions = this->solver->unsat_core();
			std::vector<storm::expressions::Expression> unsatAssumptions;
			
			for (unsigned int i = 0; i < z3UnsatAssumptions.size(); ++i) {
				unsatAssumptions.push_back(this->expressionAdapter->translateExpression(z3UnsatAssumptions[i]));
			}

			return unsatAssumptions;
#else
			STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "StoRM is compiled without Z3 support.");
#endif
		}
	}
}