/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2017-2020 Yegor Bugayenko
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package org.cactoos.scalar;

import org.cactoos.Func;
import org.cactoos.Scalar;

/**
 * Ternary operation.
 *
 * <p>There is no thread-safety guarantee.
 *
 * <p>This class implements {@link Scalar}, which throws a checked
 * {@link Exception}. This may not be convenient in many cases. To make
 * it more convenient and get rid of the checked exception you can
 * use the {@link Unchecked} decorator. Or you may use
 * {@link IoChecked} to wrap it in an IOException.</p>
 *
 * <pre>{@code
 * new Ternary<>(
 *     5,
 *     input -> input > 3,
 *     input -> input = 8,
 *     input -> input = 2
 * ).value() // will be equal to 8
 * }</pre>
 *
 * @param <T> Type of item.
 * @since 0.8
 */
public final class Ternary<T> implements Scalar<T> {

    /**
     * The condition.
     */
    private final Scalar<Boolean> condition;

    /**
     * The consequent.
     */
    private final Scalar<T> consequent;

    /**
     * The alternative.
     */
    private final Scalar<T> alternative;

    /**
     * Ctor.
     * @param input The input to pass to all of them
     * @param cnd The condition
     * @param cons The consequent
     * @param alter The alternative
     * @param <X> Type of input
     * @since 0.9
     * @checkstyle ParameterNumberCheck (5 lines)
     */
    public <X> Ternary(final X input, final Func<X, Boolean> cnd,
        final Func<X, T> cons, final Func<X, T> alter) {
        this(
            () -> cnd.apply(input),
            () -> cons.apply(input),
            () -> alter.apply(input)
        );
    }

    /**
     * Ctor.
     * @param cnd The condition
     * @param cons The consequent
     * @param alter The alternative
     * @since 0.9
     */
    public Ternary(final boolean cnd, final T cons, final T alter) {
        this(() -> cnd, cons, alter);
    }

    /**
     * Ctor.
     * @param cnd The condition
     * @param cons The consequent
     * @param alter The alternative
     */
    public Ternary(final Scalar<Boolean> cnd, final T cons, final T alter) {
        this(cnd, () -> cons, () -> alter);
    }

    /**
     * Ctor.
     * @param cnd The condition
     * @param cons The consequent
     * @param alter The alternative
     * @since 0.9
     */
    public Ternary(final Scalar<Boolean> cnd, final Scalar<T> cons,
        final Scalar<T> alter) {
        this.condition = cnd;
        this.consequent = cons;
        this.alternative = alter;
    }

    @Override
    public T value() throws Exception {
        final Scalar<T> result;
        if (this.condition.value()) {
            result = this.consequent;
        } else {
            result = this.alternative;
        }
        return result.value();
    }
}