/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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
 *
 *      https://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.apache.tsfile.external.commons.lang3.tuple;

import java.io.Serializable;
import java.util.Objects;

/////////////////////////////////////////////////////////////////////////////////////////////////
// IoTDB
/////////////////////////////////////////////////////////////////////////////////////////////////

/**
 * A triple consisting of three elements.
 *
 * <p>This class is an abstract implementation defining the basic API. It refers to the elements as
 * 'left', 'middle' and 'right'.
 *
 * <p>Subclass implementations may be mutable or immutable. However, there is no restriction on the
 * type of the stored objects that may be stored. If mutable objects are stored in the triple, then
 * the triple itself effectively becomes mutable.
 *
 * @param <L> the left element type.
 * @param <M> the middle element type.
 * @param <R> the right element type.
 * @since 3.2
 */
public abstract class Triple<L, M, R> implements Comparable<Triple<L, M, R>>, Serializable {

  /** Serialization version */
  private static final long serialVersionUID = 1L;

  /**
   * An empty array.
   *
   * <p>Consider using {@link #emptyArray()} to avoid generics warnings.
   *
   * @since 3.10
   */
  public static final Triple<?, ?, ?>[] EMPTY_ARRAY = {};

  /**
   * Returns the empty array singleton that can be assigned without compiler warning.
   *
   * @param <L> the left element type.
   * @param <M> the middle element type.
   * @param <R> the right element type.
   * @return the empty array singleton that can be assigned without compiler warning.
   * @since 3.10
   */
  @SuppressWarnings("unchecked")
  public static <L, M, R> Triple<L, M, R>[] emptyArray() {
    return (Triple<L, M, R>[]) EMPTY_ARRAY;
  }

  /**
   * Obtains an immutable triple of three objects inferring the generic types.
   *
   * <p>This factory allows the triple to be created using inference to obtain the generic types.
   *
   * @param <L> the left element type.
   * @param <M> the middle element type.
   * @param <R> the right element type.
   * @param left the left element, may be null.
   * @param middle the middle element, may be null.
   * @param right the right element, may be null.
   * @return a triple formed from the three parameters, not null.
   */
  public static <L, M, R> Triple<L, M, R> of(final L left, final M middle, final R right) {
    return ImmutableTriple.of(left, middle, right);
  }

  /**
   * Obtains an immutable triple of three non-null objects inferring the generic types.
   *
   * <p>This factory allows the triple to be created using inference to obtain the generic types.
   *
   * @param <L> the left element type.
   * @param <M> the middle element type.
   * @param <R> the right element type.
   * @param left the left element, may not be null.
   * @param middle the middle element, may not be null.
   * @param right the right element, may not be null.
   * @return a triple formed from the three parameters, not null.
   * @throws NullPointerException if any input is null.
   * @since 3.13.0
   */
  public static <L, M, R> Triple<L, M, R> ofNonNull(final L left, final M middle, final R right) {
    return ImmutableTriple.ofNonNull(left, middle, right);
  }

  /** Constructs a new instance. */
  public Triple() {
    // empty
  }

  /**
   * Compares the triple based on the left element, followed by the middle element, finally the
   * right element. The types must be {@link Comparable}.
   *
   * @param other the other triple, not null.
   * @return negative if this is less, zero if equal, positive if greater.
   */
  @Override
  public int compareTo(final Triple<L, M, R> other) {
    // Currently not used
    return 0;
  }

  /**
   * Compares this triple to another based on the three elements.
   *
   * @param obj the object to compare to, null returns false.
   * @return true if the elements of the triple are equal.
   */
  @Override
  public boolean equals(final Object obj) {
    if (obj == this) {
      return true;
    }
    if (obj instanceof Triple<?, ?, ?>) {
      final Triple<?, ?, ?> other = (Triple<?, ?, ?>) obj;
      return Objects.equals(getLeft(), other.getLeft())
          && Objects.equals(getMiddle(), other.getMiddle())
          && Objects.equals(getRight(), other.getRight());
    }
    return false;
  }

  /**
   * Gets the left element from this triple.
   *
   * @return the left element, may be null.
   */
  public abstract L getLeft();

  /**
   * Gets the middle element from this triple.
   *
   * @return the middle element, may be null.
   */
  public abstract M getMiddle();

  /**
   * Gets the right element from this triple.
   *
   * @return the right element, may be null.
   */
  public abstract R getRight();

  /**
   * Returns a suitable hash code.
   *
   * <p>The hash code is adapted from the definition in {@code Map.Entry}.
   *
   * @return the hash code.
   */
  @Override
  public int hashCode() {
    // See Map.Entry API specification
    return Objects.hashCode(getLeft())
        ^ Objects.hashCode(getMiddle())
        ^ Objects.hashCode(getRight());
  }

  /**
   * Returns a String representation of this triple using the format {@code (left,middle,right)}.
   *
   * @return a string describing this object, not null.
   */
  @Override
  public String toString() {
    return "(" + getLeft() + "," + getMiddle() + "," + getRight() + ")";
  }

  /**
   * Formats the receiver using the given format.
   *
   * <p>This uses {@link java.util.Formattable} to perform the formatting. Three variables may be
   * used to embed the left and right elements. Use {@code %1$s} for the left element, {@code %2$s}
   * for the middle and {@code %3$s} for the right element. The default format used by {@code
   * toString()} is {@code (%1$s,%2$s,%3$s)}.
   *
   * @param format the format string, optionally containing {@code %1$s}, {@code %2$s} and {@code
   *     %3$s}, not null.
   * @return the formatted string, not null.
   */
  public String toString(final String format) {
    return String.format(format, getLeft(), getMiddle(), getRight());
  }
}
