tempest/src/storm/transformer/ProductBuilder.h

#pragma once

#include "storm/models/sparse/StateLabeling.h"
#include "storm/storage/SparseMatrix.h"
#include "storm/storage/BitVector.h"

#include <vector>
#include <deque>
#include <map>

namespace storm {
    namespace transformer {

        template <typename Model>
        class ProductBuilder {
        public:
            typedef storm::storage::SparseMatrix<typename Model::ValueType> matrix_type;

            template <typename ProductOperator>
            static typename Product<Model>::ptr buildProduct(const Model& originalModel, ProductOperator& prodOp, const storm::storage::BitVector& statesOfInterest) {
                const matrix_type& originalMatrix = originalModel.getTransitionMatrix();
                bool deterministic = originalMatrix.hasTrivialRowGrouping();

                typedef storm::storage::sparse::state_type state_type;
                typedef std::pair<state_type, state_type> product_state_type;

                state_type nextState = 0;
                std::map<product_state_type, state_type> productStateToProductIndex;
                std::vector<product_state_type> productIndexToProductState;
                std::vector<state_type> prodInitial;

                // use deque for todo so that the states are handled in the order
                // of their index in the product model, which is required due to the
                // use of the SparseMatrixBuilder that can only handle linear addNextValue
                // calls
                std::deque<state_type> todo;

                for (state_type s_0 : statesOfInterest) {
                    state_type q_0 = prodOp.getInitialState(s_0);

                    // std::cout << "Initial: " << s_0 << ", " << q_0 << " = " << nextState << "\n";

                    product_state_type s_q(s_0, q_0);
                    state_type index = nextState++;
                    productStateToProductIndex[s_q] = index;
                    productIndexToProductState.push_back(s_q);
                    prodInitial.push_back(index);
                    todo.push_back(index);
                }

                storm::storage::SparseMatrixBuilder<typename Model::ValueType> builder(0, 0, 0, false, deterministic ? false : true, 0);
                std::size_t curRow = 0;
                while (!todo.empty()) {
                    state_type prodIndexFrom = todo.front();
                    todo.pop_front();

                    product_state_type from = productIndexToProductState.at(prodIndexFrom);
                    // std::cout << "Handle " << from.first << "," << from.second << " (prodIndexFrom = " << prodIndexFrom << "):\n";
                    if (deterministic) {
                        typename matrix_type::const_rows row = originalMatrix.getRow(from.first);
                        for (auto const& entry : row) {
                            state_type t = entry.getColumn();
                            state_type p = prodOp.getSuccessor(from.first, from.second, t);
                            // std::cout << " p = " << p << "\n";
                            product_state_type t_p(t, p);
                            state_type prodIndexTo;
                            auto it = productStateToProductIndex.find(t_p);
                            if (it == productStateToProductIndex.end()) {
                                prodIndexTo = nextState++;
                                todo.push_back(prodIndexTo);
                                productIndexToProductState.push_back(t_p);
                                productStateToProductIndex[t_p] = prodIndexTo;
                                // std::cout << " Adding " << t_p.first << "," << t_p.second << " as " << prodIndexTo << "\n";
                            } else {
                                prodIndexTo = it->second;
                            }
                            // std::cout << " " << t_p.first << "," << t_p.second << ": to = " << prodIndexTo << "\n";

                            // std::cout << " addNextValue(" << prodIndexFrom << "," << prodIndexTo << "," << entry.getValue() << ")\n";
                            builder.addNextValue(prodIndexFrom, prodIndexTo, entry.getValue());
                        }
                    } else {
                        std::size_t numRows = originalMatrix.getRowGroupSize(from.first);
                        builder.newRowGroup(curRow);
                        for (std::size_t i = 0; i < numRows; i++) {
                            auto const& row = originalMatrix.getRow(from.first, i);
                            for (auto const& entry : row) {
                                state_type t = entry.getColumn();
                                state_type p = prodOp.getSuccessor(from.first, from.second, t);
                                // std::cout << " p = " << p << "\n";
                                product_state_type t_p(t, p);
                                state_type prodIndexTo;
                                auto it = productStateToProductIndex.find(t_p);
                                if (it == productStateToProductIndex.end()) {
                                    prodIndexTo = nextState++;
                                    todo.push_back(prodIndexTo);
                                    productIndexToProductState.push_back(t_p);
                                    productStateToProductIndex[t_p] = prodIndexTo;
                                    // std::cout << " Adding " << t_p.first << "," << t_p.second << " as " << prodIndexTo << "\n";
                                } else {
                                    prodIndexTo = it->second;
                                }
                                // std::cout << " " << t_p.first << "," << t_p.second << ": to = " << prodIndexTo << "\n";

                                // std::cout << " addNextValue(" << prodIndexFrom << "," << prodIndexTo << "," << entry.getValue() << ")\n";
                                builder.addNextValue(curRow, prodIndexTo, entry.getValue());
                            }
                            curRow++;
                        }
                    }
                }

                state_type numberOfProductStates = nextState;

                Model product(builder.build(), storm::models::sparse::StateLabeling(numberOfProductStates));
                storm::storage::BitVector productStatesOfInterest(product.getNumberOfStates());
                for (auto& s : prodInitial) {
                    productStatesOfInterest.set(s);
                }
                std::string prodSoiLabel = product.getStateLabeling().addUniqueLabel("soi", productStatesOfInterest);

                // const storm::models::sparse::StateLabeling& orignalLabels = dtmc->getStateLabeling();
                // for (originalLabels.)

                return typename Product<Model>::ptr(new Product<Model>(std::move(product),
                                                                       std::move(prodSoiLabel),
                                                                       std::move(productStateToProductIndex),
                                                                       std::move(productIndexToProductState)));
            }
        };
    }
}