/*
 * 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 2012-2024 the original author or authors.
 */
package org.assertj.core.api.recursive.comparison;

import static org.assertj.core.util.introspection.PropertyOrFieldSupport.COMPARISON;

import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import org.assertj.core.internal.Objects;
import org.assertj.core.util.introspection.PropertyOrFieldSupport;

/**
 * Introspects all fields (including inherited ones) and get their value according to {@link PropertyOrFieldSupport#getSimpleValue(String, Object)}.
 * <p>
 * There is a bit of discrepancy in this strategy as it looks for fields to compare but gets the value in this order: property
 * first, then field and finally tries as map value if the instance is a map.
 */
public class DefaultRecursiveComparisonIntrospectionStrategy implements RecursiveComparisonIntrospectionStrategy {

  // use ConcurrentHashMap in case this strategy instance is used in a multi-thread context
  private final Map<Class<?>, Set<String>> fieldNamesPerClass = new ConcurrentHashMap<>();

  @Override
  public Set<String> getChildrenNodeNamesOf(Object node) {
    if (node == null) return new HashSet<>();
    // Caches the names after getting them for efficiency, a node can be introspected multiple times for example if
    // it belongs to an unordered collection as all actual elements are compared to all expected elements.
    return fieldNamesPerClass.computeIfAbsent(node.getClass(), Objects::getFieldsNames);
  }

  @Override
  public Object getChildNodeValue(String childNodeName, Object instance) {
    return COMPARISON.getSimpleValue(childNodeName, instance);
  }
}
