/* 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.mapper;

import java.util.Optional;

import de.learnlib.api.exception.SULException;
import de.learnlib.mapper.api.SULMapper;

final class SULMapperComposition<AI, AO, ACI, CAO, CI, CO>
        extends MapperComposition<AI, AO, ACI, CAO, CI, CO, SULMapper<? super AI, ? extends AO, ACI, CAO>, SULMapper<? super ACI, ? extends CAO, ? extends CI, ? super CO>>
        implements SULMapper<AI, AO, CI, CO> {

    SULMapperComposition(SULMapper<? super AI, ? extends AO, ACI, CAO> outerMapper,
                         SULMapper<? super ACI, ? extends CAO, ? extends CI, ? super CO> innerMapper) {
        super(outerMapper, innerMapper);
    }

    @SuppressWarnings("PMD.AvoidCatchingGenericException") //  we want to allow mapping generic RuntimeExceptions
    @Override
    public MappedException<? extends AO> mapWrappedException(SULException exception) {
        MappedException<? extends CAO> mappedEx;
        try {
            mappedEx = mapper2.mapWrappedException(exception);
        } catch (SULException ex) {
            return mapper1.mapWrappedException(ex);
        } catch (RuntimeException ex) {
            return mapper1.mapUnwrappedException(ex);
        }

        return mapMappedException(mappedEx);
    }

    @SuppressWarnings("PMD.AvoidCatchingGenericException") //  we want to allow mapping generic RuntimeExceptions
    @Override
    public MappedException<? extends AO> mapUnwrappedException(RuntimeException exception) {
        MappedException<? extends CAO> mappedEx;
        try {
            mappedEx = mapper2.mapUnwrappedException(exception);
        } catch (SULException ex) {
            return mapper1.mapWrappedException(ex);
        } catch (RuntimeException ex) {
            return mapper1.mapUnwrappedException(ex);
        }

        return mapMappedException(mappedEx);
    }

    @Override
    public boolean canFork() {
        return mapper1.canFork() && mapper2.canFork();
    }

    @Override
    public SULMapper<AI, AO, CI, CO> fork() {
        return new SULMapperComposition<>(mapper1.fork(), mapper2.fork());
    }

    private MappedException<? extends AO> mapMappedException(MappedException<? extends CAO> mappedEx) {
        AO thisStepOutput = mapper1.mapOutput(mappedEx.getThisStepOutput());
        Optional<? extends CAO> repeatOutput = mappedEx.getSubsequentStepsOutput();
        if (repeatOutput.isPresent()) {
            AO repeatOutputMapped = mapper1.mapOutput(repeatOutput.get());
            return MappedException.repeatOutput(thisStepOutput, repeatOutputMapped);
        }
        return MappedException.ignoreAndContinue(thisStepOutput);
    }

}
