/*
 * Copyright 2020 Red Hat, Inc. and/or its affiliates.
 *
 * 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 org.optaplanner.core.impl.score.stream.bi;

import java.util.function.Function;

import org.optaplanner.core.impl.score.stream.common.JoinerType;

public final class SingleBiJoiner<A, B> extends AbstractBiJoiner<A, B> {

    private final Function<A, ?> leftMapping;
    private final JoinerType joinerType;
    private final Function<B, ?> rightMapping;

    public SingleBiJoiner(Function<A, ?> leftMapping, JoinerType joinerType, Function<B, ?> rightMapping) {
        this.leftMapping = leftMapping;
        this.joinerType = joinerType;
        this.rightMapping = rightMapping;
    }

    public Function<A, ?> getLeftMapping() {
        return leftMapping;
    }

    public JoinerType getJoinerType() {
        return joinerType;
    }

    public Function<B, ?> getRightMapping() {
        return rightMapping;
    }

    // ************************************************************************
    // Builders
    // ************************************************************************

    @Override
    public Function<A, Object> getLeftMapping(int index) {
        return (Function<A, Object>) getLeftMapping();
    }

    @Override
    public Function<A, Object[]> getLeftCombinedMapping() {
        return (A a) -> new Object[] { getLeftMapping(0).apply(a) };
    }

    @Override
    public JoinerType[] getJoinerTypes() {
        return new JoinerType[] { joinerType };
    }

    @Override
    public Function<B, Object> getRightMapping(int index) {
        return (Function<B, Object>) getRightMapping();
    }

    @Override
    public Function<B, Object[]> getRightCombinedMapping() {
        return (B b) -> new Object[] { getRightMapping(0).apply(b) };
    }
}
