/**
 * 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.
 *
 * Copyright 2012-2017 the original author or authors.
 */
package org.assertj.core.internal;

import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;

import org.assertj.core.api.Assertions;
import org.assertj.core.util.introspection.IntrospectionError;

/**
 * Compares objects field/property by field/property including private fields unless
 * {@link Assertions#setAllowComparingPrivateFields(boolean)} has been called with false.
 */
public class FieldByFieldComparator implements Comparator<Object> {

  private static final int NOT_EQUAL = -1;

  protected final Map<String, Comparator<?>> comparatorByPropertyOrField;
  protected final TypeComparators comparatorByType;

  public FieldByFieldComparator(Map<String, Comparator<?>> comparatorByPropertyOrField,
                                TypeComparators comparatorByType) {
    this.comparatorByPropertyOrField = comparatorByPropertyOrField;
    this.comparatorByType = comparatorByType;
  }

  public FieldByFieldComparator() {
    this.comparatorByPropertyOrField = new HashMap<>();
    this.comparatorByType = new TypeComparators();
  }

  @Override
  public int compare(Object actual, Object other) {
	if (actual == null && other == null) return 0;
	if (actual == null || other == null) return NOT_EQUAL;
	// value returned is not relevant for ordering if objects are not equal.
	return areEqual(actual, other) ? 0 : NOT_EQUAL;
  }

  protected boolean areEqual(Object actual, Object other) {
    try {
      return Objects.instance().areEqualToIgnoringGivenFields(actual, other, comparatorByPropertyOrField,
                                                              comparatorByType);
    } catch (IntrospectionError e) {
      return false;
    }
  }

  @Override
  public String toString() {
    return "field/property by field/property comparator on all fields/properties";
  }

}
