/*
 * Java Genetic Algorithm Library (jenetics-8.2.0).
 * Copyright (c) 2007-2025 Franz Wilhelmstötter
 *
 * 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.
 *
 * Author:
 *    Franz Wilhelmstötter (franz.wilhelmstoetter@gmail.com)
 */
package io.jenetics.util;

import static java.lang.String.format;
import static io.jenetics.internal.util.Hashes.hash;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.Serial;
import java.io.Serializable;
import java.util.Optional;

/**
 * Double range class.
 *
 * @implNote
 * This class is immutable and thread-safe.
 *
 * @author <a href="mailto:franz.wilhelmstoetter@gmail.com">Franz Wilhelmstötter</a>
 * @version 6.0
 * @since 3.2
 */
public final /*record*/ class DoubleRange implements Serializable {

        @Serial
        private static final long serialVersionUID = 2L;

        private final double _min;
        private final double _max;

        private DoubleRange(final double min, final double max) {
                if (!Double.isFinite(min) || !Double.isFinite(max) || min > max) {
                        throw new IllegalArgumentException(format(
                                "Min greater than max: %s > %s", min, max
                        ));
                }

                _min = min;
                _max = max;
        }

        /**
         * Return the minimum value of the double range.
         *
         * @return the minimum value of the double range
         */
        public double min() {
                return _min;
        }

        /**
         * Return the maximum value of the double range.
         *
         * @return the maximum value of the double range
         */
        public double max() {
                return _max;
        }

        /**
         * Checks whether the given {@code value} is within the range
         * {@code [min, max)}.
         *
         * @since 8.0
         *
         * @param value the value to check
         * @return {@code true} if the {@code value} is with the range
         *         {@code [min, max)}, {@code false} otherwise
         */
        public boolean contains(final double value) {
                return Double.isFinite(value) &&
                        Double.compare(value, _min) >= 0 &&
                        Double.compare(value, _max) < 0;
        }

        /**
         * Return the intersection of {@code this} range with the {@code other}.
         *
         * @since 8.0
         *
         * @param other the intersection range or {@link Optional#empty()} if there
         *        is none
         * @return the range intersection
         */
        public Optional<DoubleRange> intersect(final DoubleRange other) {
                if (Double.compare(_max, other._min) <= 0 ||
                        Double.compare(_min, other._max) >= 0)
                {
                        return Optional.empty();
                } else {
                        return Optional.of(
                                DoubleRange.of(
                                        Math.max(_min, other._min),
                                        Math.min(_max, other._max)
                                )
                        );
                }
        }

        /**
         * Create a new {@code DoubleRange} object with the given {@code min} and
         * {@code max} values.
         *
         * @param min the lower bound of the double range
         * @param max the upper bound of the double range
         * @return a new {@code DoubleRange} object
         * @throws IllegalArgumentException if {@code min > max}
         */
        public static DoubleRange of(final double min, final double max) {
                return new DoubleRange(min, max);
        }

        @Override
        public int hashCode() {
                return hash(_min, hash(_max));
        }

        @Override
        public boolean equals(final Object obj) {
                return obj instanceof DoubleRange other &&
                        Double.compare(_min, other._min) == 0 &&
                        Double.compare(_max, other._max) == 0;
        }

        @Override
        public String toString() {
                return "[" + _min + ", " + _max + "]";
        }


        /* *************************************************************************
         *  Java object serialization
         * ************************************************************************/

        @Serial
        private Object writeReplace() {
                return new SerialProxy(SerialProxy.DOUBLE_RANGE, this);
        }

        @Serial
        private void readObject(final ObjectInputStream stream)
                throws InvalidObjectException
        {
                throw new InvalidObjectException("Serialization proxy required.");
        }

        void write(final DataOutput out) throws IOException {
                out.writeDouble(_min);
                out.writeDouble(_max);
        }

        static DoubleRange read(final DataInput in) throws IOException {
                return of(in.readDouble(), in.readDouble());
        }

}