tempest/src/storm-pgcl/builder/JaniProgramGraphBuilder.cpp

#include "JaniProgramGraphBuilder.h"

#include "storm/storage/jani/EdgeDestination.h"
#include "storm/exceptions/NotSupportedException.h"

namespace storm {
    namespace builder {
        unsigned JaniProgramGraphBuilder::janiVersion = 1;
        
        void JaniProgramGraphBuilder::addProcedureVariables(storm::jani::Model& model, storm::jani::Automaton& automaton) {
            for (auto const& v : programGraph.getVariables()) {
                if (isConstant(v.first)) {
                    storm::jani::Constant constant(v.second.getName(), v.second, programGraph.getInitialValue(v.first));
                    model.addConstant(constant);
                } else if (v.second.hasBooleanType()) {
                    storm::jani::BooleanVariable* janiVar = new storm::jani::BooleanVariable(v.second.getName(), v.second, programGraph.getInitialValue(v.first), false);
                    automaton.addVariable(*janiVar);
                    variables.emplace(v.first, janiVar);
                } else if (isRestrictedVariable(v.first) && !isRewardVariable(v.first)) {
                    storm::storage::IntegerInterval const& bounds = variableBounds(v.first);
                    if (bounds.hasLeftBound()) {
                        if (bounds.hasRightBound()) {
                            storm::jani::BoundedIntegerVariable* janiVar = new storm::jani::BoundedIntegerVariable (v.second.getName(), v.second, programGraph.getInitialValue(v.first), false, expManager->integer(bounds.getLeftBound().get()), expManager->integer(bounds.getRightBound().get()));
                            variables.emplace(v.first, janiVar);
                            automaton.addVariable(*janiVar);
                        } else {
                            STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "Unbounded right bound is not supported yet");
                        }
                    } else {
                        STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "Unbounded left bound is not supported yet");
                    }
                } else {
                    storm::jani::UnboundedIntegerVariable* janiVar = new storm::jani::UnboundedIntegerVariable(v.second.getName(), v.second, programGraph.getInitialValue(v.first), isRewardVariable(v.first));
                    if(isRewardVariable(v.first)) {
                        model.addVariable(*janiVar);
                    } else {
                        automaton.addVariable(*janiVar);
                    }
                    variables.emplace(v.first, janiVar);
                    
                }
            }
        }
        
        
        
        storm::jani::OrderedAssignments JaniProgramGraphBuilder::buildOrderedAssignments(storm::jani::Automaton& automaton, storm::ppg::DeterministicProgramAction const& act) {
            std::vector<storm::jani::Assignment> vec;
            uint64_t level = 0;
            for(auto const& group : act) {
                for(auto const& assignment : group) {
                    if(isRewardVariable(assignment.first)) {
                        std::unordered_map<storm::expressions::Variable, storm::expressions::Expression> eval;
                        eval.emplace((variables.at(assignment.first))->getExpressionVariable(), expManager->integer(0));
                        vec.emplace_back(storm::jani::LValue(*(variables.at(assignment.first))), assignment.second.substitute(eval).simplify(), level);
                    } else {
                        vec.emplace_back(storm::jani::LValue(*(variables.at(assignment.first))), assignment.second, level);
                    }
                }
                ++level;
            }
            return storm::jani::OrderedAssignments(vec);
        }
        
        std::vector<std::pair<uint64_t, storm::expressions::Expression>> JaniProgramGraphBuilder::buildProbabilisticDestinations(storm::jani::Automaton& automaton, storm::ppg::ProgramEdge const& edge, storm::jani::TemplateEdge& templateEdge) {
            storm::ppg::ProbabilisticProgramAction const& act = static_cast<storm::ppg::ProbabilisticProgramAction const&>(edge.getAction());
            std::vector<std::pair<uint64_t, storm::expressions::Expression>> vec;
            for(auto const& assign : act) {
                storm::jani::Assignment assignment(storm::jani::LValue(automaton.getVariables().getVariable(act.getVariableName())), expManager->integer(assign.value), 0);
                templateEdge.addDestination(storm::jani::TemplateEdgeDestination(storm::jani::OrderedAssignments(assignment)));
                vec.emplace_back(janiLocId.at(edge.getTargetId()), assign.probability);
            }
            return vec;
        }
    
        std::vector<std::pair<uint64_t, storm::expressions::Expression>> JaniProgramGraphBuilder::buildDestinations(storm::jani::Automaton& automaton, storm::ppg::ProgramEdge const& edge, storm::jani::TemplateEdge& templateEdge) {
            if (edge.getAction().isProbabilistic()) {
                return buildProbabilisticDestinations(automaton, edge, templateEdge);
            } else {
                storm::jani::OrderedAssignments oa = buildOrderedAssignments(automaton, static_cast<storm::ppg::DeterministicProgramAction const&>(edge.getAction()));
                templateEdge.addDestination(storm::jani::TemplateEdgeDestination(oa));
                return {std::make_pair(janiLocId.at(edge.getTargetId()), expManager->rational(1.0))};
            }
        }
        
        storm::expressions::Expression simplifyExpression(storm::expressions::Expression const& in) {
            // TODO use bound restrictions etc.
            return in.simplify();
        }
        
        std::pair<std::vector<storm::jani::Edge>, storm::expressions::Expression> JaniProgramGraphBuilder::addVariableChecks(storm::jani::Automaton& automaton, storm::ppg::ProgramEdge const& edge) {
            std::vector<storm::jani::Edge> edges;
            storm::expressions::Expression newGuard;
            newGuard = expManager->boolean(true);
            if (edge.getAction().isProbabilistic()) {
                // No check necessary currently, but at least we should statically check that the bounds are okay.
                storm::ppg::ProbabilisticProgramAction const& act = static_cast<storm::ppg::ProbabilisticProgramAction const&>(edge.getAction());
                if (isUserRestrictedVariable(act.getVariableIdentifier())) {
                    storm::storage::IntegerInterval const& bound = userVariableRestrictions.at(act.getVariableIdentifier());
                    storm::storage::IntegerInterval supportInterval = act.getSupportInterval();
                    STORM_LOG_THROW(bound.contains(supportInterval), storm::exceptions::NotSupportedException, "User provided bounds must contain all constant expressions");
                }
            } else {
                storm::ppg::DeterministicProgramAction const& act = static_cast<storm::ppg::DeterministicProgramAction const&>(edge.getAction());
                STORM_LOG_THROW(act.nrLevels() <= 1, storm::exceptions::NotSupportedException, "Multi-level assignments with user variable bounds not supported");
                for(auto const& group : act) {
                    for(auto const& assignment : group) {
                        if (isUserRestrictedVariable(assignment.first)) {
                            assert(userVariableRestrictions.count(assignment.first) == 1);
                            storm::storage::IntegerInterval const& bound = userVariableRestrictions.at(assignment.first);
                            if (!assignment.second.containsVariables()) {
                                // Constant assignments can be checked statically.
                                // TODO we might still want to allow assignments which go out of bounds.
                                STORM_LOG_THROW(bound.contains(assignment.second.evaluateAsInt()), storm::exceptions::NotSupportedException, "User provided bounds must contain all constant expressions");
                            } else {
                                // TODO currently only fully bounded restrictions are supported;
                                assert(userVariableRestrictions.at(assignment.first).hasLeftBound() && userVariableRestrictions.at(assignment.first).hasRightBound());
                                storm::expressions::Expression newCondition = simplifyExpression(edge.getCondition() && (assignment.second > bound.getRightBound().get() || assignment.second < bound.getLeftBound().get()));
                                
                                std::shared_ptr<storm::jani::TemplateEdge> templateEdge = std::make_shared<storm::jani::TemplateEdge>(newCondition);
                                automaton.registerTemplateEdge(templateEdge);
                                templateEdge->addDestination(storm::jani::TemplateEdgeDestination());
                                storm::jani::Edge e(janiLocId.at(edge.getSourceId()), storm::jani::Model::SILENT_ACTION_INDEX, boost::none, templateEdge, {varOutOfBoundsLocations.at(assignment.first)}, {expManager->rational(1.0)});
                                edges.push_back(e);
                                newGuard = newGuard && assignment.second <= bound.getRightBound().get() && assignment.second >= bound.getLeftBound().get();
                            }
                        }
                    }
                }
            }
            return {edges, newGuard};
        }
        
        
        void JaniProgramGraphBuilder::addEdges(storm::jani::Automaton& automaton) {
            for(auto it = programGraph.locationBegin(); it != programGraph.locationEnd(); ++it) {
                ppg::ProgramLocation const& loc = it->second;
                if (loc.nrOutgoingEdgeGroups() == 0) {
                    std::shared_ptr<storm::jani::TemplateEdge> templateEdge = std::make_shared<storm::jani::TemplateEdge>(expManager->boolean(true));
                    automaton.registerTemplateEdge(templateEdge);
                    templateEdge->addDestination(storm::jani::TemplateEdgeDestination());
                    storm::jani::Edge e(janiLocId.at(loc.id()), storm::jani::Model::SILENT_ACTION_INDEX, boost::none, templateEdge, {janiLocId.at(loc.id())}, {expManager->rational(1.0)});
                    automaton.addEdge(e);
                } else if (loc.nrOutgoingEdgeGroups() == 1) {
                    for(auto const& edge :  **(loc.begin())) {
                        std::pair<std::vector<storm::jani::Edge>, storm::expressions::Expression> checks = addVariableChecks(automaton, *edge);
                        for(auto const& check : checks.first) {
                            automaton.addEdge(check);
                        }
                        std::shared_ptr<storm::jani::TemplateEdge> templateEdge = std::make_shared<storm::jani::TemplateEdge>(simplifyExpression(edge->getCondition() && checks.second));
                        automaton.registerTemplateEdge(templateEdge);

                        std::vector<std::pair<uint64_t, storm::expressions::Expression>> destinationLocationsAndProbabilities = buildDestinations(automaton, *edge, *templateEdge);

                        storm::jani::Edge e(janiLocId.at(loc.id()), storm::jani::Model::SILENT_ACTION_INDEX, boost::none, templateEdge, destinationLocationsAndProbabilities);
                        automaton.addEdge(e);
                    }
                } else {
                    // We have probabilistic branching
                    if(loc.hasNonDeterminism())
                    {
                        STORM_LOG_THROW(false, storm::exceptions::NotSupportedException, "Combi of nondeterminism and probabilistic choices within a loc not supported yet");
                    } else {
                        std::shared_ptr<storm::jani::TemplateEdge> templateEdge = std::make_shared<storm::jani::TemplateEdge>(expManager->boolean(true));
                        automaton.registerTemplateEdge(templateEdge);


                        std::vector<storm::expressions::Expression> destinationProbabilities;
                        std::vector<uint64_t> destinationLocations;
                        for(auto const& eg : loc) {
                            // TODO add assignments
                            assert(eg->nrEdges() < 2); // Otherwise, non-determinism occurs.
                            assert(eg->nrEdges() > 0); // Empty edge groups should not occur in input.
                            destinationLocations.push_back(janiLocId.at((*eg->begin())->getTargetId()));
                            destinationProbabilities.push_back(eg->getProbability());
                            templateEdge->addDestination(storm::jani::TemplateEdgeDestination());
                        }
                        
                        storm::jani::Edge e(janiLocId.at(it->second.id()), storm::jani::Model::SILENT_ACTION_INDEX, boost::none, templateEdge, destinationLocations, destinationProbabilities);
                        automaton.addEdge(e);
                    }
                }
            }
        }

    }
}