/*
 * RandomAutomatonFactory.h
 *
 * This file is part of Algorithms library toolkit.
 * Copyright (C) 2017 Jan Travnicek (jan.travnicek@fit.cvut.cz)

 * Algorithms library toolkit is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.

 * Algorithms library toolkit is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License
 * along with Algorithms library toolkit.  If not, see <http://www.gnu.org/licenses/>.
 *
 *  Created on: 27. 3. 2014
 *	  Author: Tomas Pecka
 */

#ifndef RANDOM_AUTOMATON_FACTORY_H_
#define RANDOM_AUTOMATON_FACTORY_H_

#include <alib/deque>
#include <alib/set>

#include <automaton/FSM/NFA.h>

namespace automaton {

namespace generate {

/**
 * Generator of random automata.
 *
 * @details
 * The underlying generation algorithm is from Leslie, T: Efficient Approaches to Subset Construction, 1995.
 */
class RandomAutomatonFactory {
public:
	/**
	 * Generates a random finite automaton.
	 * @param statesCount number of states in the generated automaton
	 * @param alphabet Input alphabet of the automaton
	 * @param density density of the transition function
	 * @return random nondeterministic finite automaton
	 */
	static automaton::NFA < > generateNFA( size_t statesCount, const ext::set<DefaultSymbolType> & alphabet, double density );

	/**
	 * \overload
	 *
	 * Generates a random finite automaton.
	 * @param statesCount number of states in the generated automaton
	 * @param alphabetSize size of the alphabet (1-26)
	 * @param randomizedAlphabet selects random symbols from a-z range if true
	 * @param density density of the transition function (0-1). 1 means every possible transition is created
	 * @return random nondeterministic finite automaton
	 */
	static automaton::NFA < > generateNFA( size_t statesCount, size_t alphabetSize, bool randomizedAlphabet, double density );

private:
	/**
	 * Leslie's connected NFA algorithm
	 * @param n number of states
	 * @param alphabet input alphabet
	 * @param density density of the transition function (0-1). 1 means every possible transition is created
	 */
	static automaton::NFA < > LeslieConnectedNFA( size_t n, const ext::deque<DefaultSymbolType> & alphabet, double density );
};

} /* namespace generate */

} /* namespace automaton */

#endif /* RANDOM_AUTOMATON_FACTORY_H_ */