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Java Simplified. Extensions and Useful Constructs for the Java Platform. Codeprimate Elements (a.k.a. cp-elements) is a Java library and micro-framework used to simplify the development of software applications written in Java. Elements packages several APIs into one library in order to address various application concerns and aspects of software design and development collectively and conveniently. Elements is a highly simple, yet robust and proven library built on solid OO principles, software design patterns and best practices to effectively solve common and reoccurring problems in software development.

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/*
 * Copyright 2016 Author or Authors.
 *
 * 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.cp.elements.util;

import static org.cp.elements.util.ComparatorUtils.compareIgnoreNull;

import java.util.Comparator;

import org.cp.elements.lang.Builder;
import org.cp.elements.lang.annotation.NullSafe;

/**
 * The {@link ComparatorResultBuilder} class is a {@link Comparator} implementation that builds a comparison expression
 * accumulating the result.
 *
 * @author John J. Blum
 * @see java.lang.Comparable
 * @see java.util.Comparator
 * @see org.cp.elements.lang.Builder
 * @since 1.0.0
 */
@SuppressWarnings("unused")
public class ComparatorResultBuilder> implements Builder, Comparator {

  private int result = 0;

  /**
   * Factory method to construct a new instance of {@link ComparatorResultBuilder}.
   *
   * @param  {@link Class} type of the {@link Comparable} objects evaluated in the comparison operation.
   * @return a new instance of {@link ComparatorResultBuilder}.
   * @see org.cp.elements.util.ComparatorResultBuilder
   */
  public static > ComparatorResultBuilder create() {
    return new ComparatorResultBuilder<>();
  }

  /**
   * Builds the result of the collective {@link Comparator} operations.
   *
   * @return an {@link Integer} value containing the result of this {@link Comparator} calculations.
   * @see #getResult()
   */
  @Override
  public Integer build() {
    return getResult();
  }

  /**
   * Compares two {@link Comparable} objects.
   *
   * @param obj1 left hand side {@link Comparable} operand in the comparison expression.
   * @param obj2 right hand side {@link Comparable} operand in the comparison expression.
   * @return the result of comparing the {@link Comparable} objects.
   * @see org.cp.elements.util.ComparatorUtils#compareIgnoreNull(Comparable, Comparable)
   */
  @NullSafe
  @Override
  public int compare(T obj1, T obj2) {
    return compareIgnoreNull(obj1, obj2);
  }

  /**
   * Performs the comparison between 2 {@link Comparable} objects.
   *
   * @param obj1 {@link Comparable} object in the comparison operation.
   * @param obj2 {@link Comparable} object in the comparison operation.
   * @return this {@link ComparatorResultBuilder}.
   * @see org.cp.elements.util.ComparatorResultBuilder
   * @see #compare(Comparable, Comparable)
   */
  @NullSafe
  public ComparatorResultBuilder doCompare(T obj1, T obj2) {
    this.result = (this.result != 0 ? this.result : compare(obj1, obj2));
    return this;
  }

  /**
   * Returns the result of the comparison.
   *
   * @return an {@link Integer} value containing the result of the comparison.
   */
  public int getResult() {
    return this.result;
  }
}