/* Copyright (C) 2013-2020 TU Dortmund
 * This file is part of LearnLib, http://www.learnlib.de/.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package de.learnlib.oracle.membership;

import de.learnlib.api.StateLocalInputSUL;
import de.learnlib.api.oracle.SymbolQueryOracle;

import java.util.Collection;

/**
 * Not thread safe.
 *
 * @param <I>
 * @param <O>
 */
public class StateLocalInputSULSymbolQueryOracle<I, O> implements SymbolQueryOracle<I, O> {

    private final StateLocalInputSUL<I, O> sul;
    private final O undefinedOutput;

    public StateLocalInputSULSymbolQueryOracle(StateLocalInputSUL<I, O> sul, O undefinedOutput) {
        this.sul = sul;
        this.undefinedOutput = undefinedOutput;
    }

    @Override
    public O query(I i) {
        final Collection<I> enabledInputs = sul.currentlyEnabledInputs();
        if (enabledInputs.contains(i)) {
            return sul.step(i);
        } else {
            return undefinedOutput;
        }
    }

    @Override
    public void reset() {
        this.sul.post();
        this.sul.pre();
    }
}

add state local sul oracle for symbol-based learners