/*
 * Copyright (C) 2015 Alexander Nutz (nutz@informatik.uni-freiburg.de)
 * Copyright (C) 2015 Carl Kuesters
 * Copyright (C) 2015 University of Freiburg
 *
 * This file is part of the ULTIMATE Automata Library.
 *
 * The ULTIMATE Automata Library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published
 * by the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * The ULTIMATE Automata Library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with the ULTIMATE Automata Library. If not, see <http://www.gnu.org/licenses/>.
 *
 * Additional permission under GNU GPL version 3 section 7:
 * If you modify the ULTIMATE Automata Library, or any covered work, by linking
 * or combining it with Eclipse RCP (or a modified version of Eclipse RCP),
 * containing parts covered by the terms of the Eclipse Public License, the
 * licensors of the ULTIMATE Automata Library grant you additional permission
 * to convey the resulting work.
 */
package de.uni_freiburg.informatik.ultimate.automata.alternating;

import java.util.HashMap;
import java.util.Map.Entry;

import de.uni_freiburg.informatik.ultimate.automata.AutomataLibraryServices;
import de.uni_freiburg.informatik.ultimate.automata.GeneralOperation;
import de.uni_freiburg.informatik.ultimate.automata.IAutomaton;
import de.uni_freiburg.informatik.ultimate.automata.statefactory.IStateFactory;

public class AA_MergedUnion<LETTER, STATE> extends GeneralOperation<LETTER, STATE, IStateFactory<STATE>> {
	private final AlternatingAutomaton<LETTER, STATE> mResultAutomaton;

	public AA_MergedUnion(final AutomataLibraryServices services, final AlternatingAutomaton<LETTER, STATE> automaton1,
			final AlternatingAutomaton<LETTER, STATE> automaton2) {
		super(services);
		assert IAutomaton.sameAlphabet(automaton1, automaton2);
		assert automaton1.isReversed() == automaton2.isReversed();
		mResultAutomaton = new AlternatingAutomaton<>(automaton1.getAlphabet());
		final HashMap<Integer, Integer> shiftMap1 = new HashMap<>();
		final HashMap<Integer, Integer> shiftMap2 = new HashMap<>();
		for (final STATE state : automaton1.getStates()) {
			mResultAutomaton.addState(state);
			shiftMap1.put(automaton1.getStateIndex(state), mResultAutomaton.getStateIndex(state));
			if (automaton1.isStateFinal(state)) {
				mResultAutomaton.setStateFinal(state);
			}
		}
		for (final STATE state : automaton2.getStates()) {
			mResultAutomaton.addState(state);
			shiftMap2.put(automaton2.getStateIndex(state), mResultAutomaton.getStateIndex(state));
			if (automaton2.isStateFinal(state)) {
				mResultAutomaton.setStateFinal(state);
			}
		}
		final int newSize = mResultAutomaton.getStates().size();
		for (final Entry<LETTER, BooleanExpression[]> entry : automaton1.getTransitionFunction().entrySet()) {
			for (int i = 0; i < automaton1.getStates().size(); i++) {
				if (entry.getValue()[i] != null) {
					mResultAutomaton.addTransition(entry.getKey(), automaton1.getStates().get(i),
							entry.getValue()[i].cloneShifted(shiftMap1, newSize));
				}
			}
		}
		for (final Entry<LETTER, BooleanExpression[]> entry : automaton2.getTransitionFunction().entrySet()) {
			for (int i = 0; i < automaton2.getStates().size(); i++) {
				if (entry.getValue()[i] != null) {
					mResultAutomaton.addTransition(entry.getKey(), automaton2.getStates().get(i),
							entry.getValue()[i].cloneShifted(shiftMap2, newSize));
				}
			}
		}
		mResultAutomaton.addAcceptingConjunction(automaton1.getAcceptingFunction().cloneShifted(shiftMap1, newSize));
		mResultAutomaton.addAcceptingConjunction(automaton2.getAcceptingFunction().cloneShifted(shiftMap2, newSize));
		mResultAutomaton.setReversed(automaton1.isReversed());
	}

	@Override
	public AlternatingAutomaton<LETTER, STATE> getResult() {
		return mResultAutomaton;
	}
}