/*
    * 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.commons.collections4.properties;
  
  import java.util.AbstractMap;
  import java.util.Collections;
  import java.util.Enumeration;
  import java.util.LinkedHashSet;
  import java.util.Map;
  import java.util.Properties;
  import java.util.Set;
  import java.util.TreeSet;
  import java.util.function.BiConsumer;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  /**
   * A drop-in replacement for {@link Properties} for sorting keys.
   * <p>
   * Overrides {@link Properties#keys()} to sort keys. Allows other methods on the superclass to work with sorted keys.
   * </p>
   *
   * @see SortedPropertiesFactory#INSTANCE
   * @since 4.2
   */
  public class SortedProperties extends Properties {
  
      private static final long serialVersionUID = 1L;
  
      /**
       * Constructs a new instance.
       */
      public SortedProperties() {
          // empty
      }
  
      @Override
      public Set<Map.Entry<Object, Object>> entrySet() {
          return keyStream().map(k -> new AbstractMap.SimpleEntry<>(k, get(k))).collect(Collectors.toCollection(LinkedHashSet::new));
      }
  
      /**
       * Enumerates all key/value pairs in the specified TreeSet and omits the property if the key or value is not a string.
       *
       * @param result The result set to populate.
       * @return The given set.
       */
      private synchronized TreeSet<String> enumerateStringProperties(final TreeSet<String> result) {
          if (defaults != null) {
              result.addAll(defaults.stringPropertyNames());
          }
          for (final Enumeration<?> e = keys(); e.hasMoreElements();) {
              final Object k = e.nextElement();
              final Object v = get(k);
              if (k instanceof String && v instanceof String) {
                  result.add((String) k);
              }
          }
          return result;
      }
  
      @Override
      public synchronized void forEach(final BiConsumer<? super Object, ? super Object> action) {
          keyStream().forEach(k -> action.accept(k, get(k)));
      }
  
      @Override
      public synchronized Enumeration<Object> keys() {
          return Collections.enumeration(keySet());
      }
  
      @Override
      public Set<Object> keySet() {
          return new TreeSet<>(super.keySet());
      }
  
      private Stream<Object> keyStream() {
          return keySet().stream();
      }
  
      @Override
      public Enumeration<?> propertyNames() {
          return Collections.enumeration(stringPropertyNames());
      }
 
     @Override
     public Set<String> stringPropertyNames() {
         return enumerateStringProperties(new TreeSet<>());
     }
 }