#ifndef STORM_PARSER_NONDETERMINISTICSPARSETRANSITIONPARSER_H_
#define STORM_PARSER_NONDETERMINISTICSPARSETRANSITIONPARSER_H_

#include "src/storage/SparseMatrix.h"

#include <vector>

namespace storm {
	namespace parser {

		/*!
		 * A class providing the functionality to parse the transitions of a nondeterministic model.
		 *
		 * The file is parsed in two passes.
		 * The first pass tests the file format and collects statistical data needed for the second pass.
		 * The second pass then collects the actual file data and compiles it into a Result.
		 */
		class NondeterministicSparseTransitionParser {

		public:

			/*!
			 * A structure representing the result of the first pass of this parser.
			 * It contains the number of non-zero entries in the model, the highest state index and the total number if nondeterministic choices.
			 */
			struct FirstPassResult {

				/*!
				 * The default constructor.
				 * Constructs an empty FirstPassResult.
				 */
				FirstPassResult() : numberOfNonzeroEntries(0), highestStateIndex(0), choices(0) {
					// Intentionally left empty.
				}

				//! The total number of non-zero entries of the model.
				uint_fast64_t numberOfNonzeroEntries;

				//! The highest state index that appears in the model.
				uint_fast64_t highestStateIndex;

				//! The total number of nondeterministic choices within the transition system.
				uint_fast64_t choices;
			};

			/*!
			 * A structure representing the result of the parser.
			 * It contains the resulting matrix as well as the row mapping.
			 */
			struct Result {

				/*!
				 *  The default constructor.
				 *  Constructs an empty Result.
				 */
				Result() : transitionMatrix(), rowMapping() {
					// Intentionally left empty.
				}

				/*!
				 * Constructs a Result, initializing its members with the given values.
				 *
				 * @param transitionMatrix The matrix containing the parsed transition system.
				 * @param rowMapping A mapping from rows of the matrix to states of the model.
				 */
				Result(storm::storage::SparseMatrix<double> transitionMatrix, std::vector<uint_fast64_t> rowMapping) : transitionMatrix(transitionMatrix), rowMapping(rowMapping) {
					// Intentionally left empty.
				}

				/*!
				 * The matrix containing the parsed transition system.
				 */
				storm::storage::SparseMatrix<double> transitionMatrix;

				/*!
				 * A mapping from rows of the matrix to states of the model.
				 * This resolves the nondeterministic choices inside the transition system.
				 */
				std::vector<uint_fast64_t> rowMapping;
			};

			/*!
			 * Load a nondeterministic transition system from file and create a sparse adjacency matrix whose entries represent the weights of the edges
			 *
			 * @param filename The path and name of file to be parsed.
			 */
			static Result parseNondeterministicTransitions(std::string const & filename);

			/*!
			 * Load a nondeterministic transition system from file and create a sparse adjacency matrix whose entries represent the weights of the edges
			 *
			 * @param filename The path and name of file to be parsed.
			 * @param modelInformation The information about the transition structure of nondeterministic model in which the transition rewards shall be used.
			 * @return A struct containing the parsed file contents, i.e. the transition reward matrix and the mapping between its rows and the states of the model.
			 */
			static Result parseNondeterministicTransitionRewards(std::string const & filename, Result const & modelInformation);

		private:

			/*!
			 * This method does the first pass through the buffer containing the content of some transition file.
			 *
			 * It computes the overall number of nondeterministic choices, i.e. the
			 * number of rows in the matrix that should be created.
			 * It also calculates the overall number of non-zero cells, i.e. the number
			 * of elements the matrix has to hold, and the maximum node id, i.e. the
			 * number of columns of the matrix.
			 *
			 * @param buffer Buffer containing the data to scan. This is expected to be some char array.
			 * @param insertDiagonalEntriesIfMissing A flag set iff entries on the primary diagonal of the matrix should be added in case they are missing in the parsed file.
			 * @return A structure representing the result of the first pass.
			 */
			static FirstPassResult firstPass(char* buffer, bool isRewardFile, Result const & modelInformation);

			/*!
			 * The main parsing routine.
			 * Opens the given file, calls the first pass and performs the second pass, parsing the content of the file into a SparseMatrix.
			 *
			 * @param filename The path and name of file to be parsed.
			 * @param rewardFile A flag set iff the file to be parsed contains transition rewards.
			 * @param insertDiagonalEntriesIfMissing A flag set iff entries on the primary diagonal of the matrix should be added in case they are missing in the parsed file.
			 * @param modelInformation A struct containing information that is used to check if the transition reward matrix fits to the rest of the model.
			 * @return A SparseMatrix containing the parsed file contents.
			 */
			static Result parse(std::string const& filename, bool isRewardFile, Result const & modelInformation);

		};
	
	} // namespace parser
} // namespace storm

#endif /* STORM_PARSER_NONDETERMINISTICSPARSETRANSITIONPARSER_H__H_ */