/*
    * 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
    *
    *     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.apache.commons.configuration2;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.Reader;
  import java.io.Writer;
  import java.util.Map;
  
  import org.apache.commons.configuration2.ex.ConfigurationException;
  import org.apache.commons.configuration2.io.InputStreamSupport;
  import org.apache.commons.configuration2.tree.ImmutableNode;
  import org.yaml.snakeyaml.DumperOptions;
  import org.yaml.snakeyaml.LoaderOptions;
  import org.yaml.snakeyaml.Yaml;
  import org.yaml.snakeyaml.constructor.SafeConstructor;
  import org.yaml.snakeyaml.representer.Representer;
  
  /**
   * <p>
   * A specialized hierarchical configuration class that is able to parse YAML documents.
   * </p>
   *
   * @since 2.2
   */
  public class YAMLConfiguration extends AbstractYAMLBasedConfiguration implements FileBasedConfiguration, InputStreamSupport {
      /**
       * Creates a {@code Yaml} object for reading a Yaml file. The object is configured with some default settings.
       *
       * @param options options for loading the file
       * @return the {@code Yaml} instance for loading a file
       */
      private static Yaml createYamlForReading(final LoaderOptions options) {
          return new Yaml(new SafeConstructor(options), new Representer(new DumperOptions()), new DumperOptions(), options);
      }
  
      /**
       * Creates a new instance of {@code YAMLConfiguration}.
       */
      public YAMLConfiguration() {
      }
  
      /**
       * Creates a new instance of {@code YAMLConfiguration} as a copy of the specified configuration.
       *
       * @param c the configuration to be copied
       */
      public YAMLConfiguration(final HierarchicalConfiguration<ImmutableNode> c) {
          super(c);
      }
  
      public void dump(final Writer out, final DumperOptions options)
              throws ConfigurationException, IOException {
          final Yaml yaml = new Yaml(options);
          yaml.dump(constructMap(getNodeModel().getNodeHandler().getRootNode()), out);
      }
  
      /**
       * Loads the configuration from the given input stream.
       *
       * @param in the input stream
       * @throws ConfigurationException if an error occurs
       */
      @Override
      public void read(final InputStream in) throws ConfigurationException {
          try {
              final Yaml yaml = createYamlForReading(new LoaderOptions());
              final Map<String, Object> map = yaml.load(in);
              load(map);
          } catch (final Exception e) {
              rethrowException(e);
          }
      }
  
      public void read(final InputStream in, final LoaderOptions options) throws ConfigurationException {
          try {
              final Yaml yaml = createYamlForReading(options);
              final Map<String, Object> map = yaml.load(in);
              load(map);
          } catch (final Exception e) {
              rethrowException(e);
          }
      }
 
     @Override
     public void read(final Reader in) throws ConfigurationException {
         try {
             final Yaml yaml = createYamlForReading(new LoaderOptions());
             final Map<String, Object> map = yaml.load(in);
             load(map);
         } catch (final Exception e) {
             rethrowException(e);
         }
     }
 
     public void read(final Reader in, final LoaderOptions options) throws ConfigurationException {
         try {
             final Yaml yaml = createYamlForReading(options);
             final Map<String, Object> map = yaml.load(in);
             load(map);
         } catch (final Exception e) {
             rethrowException(e);
         }
     }
 
     @Override
     public void write(final Writer out) throws ConfigurationException, IOException {
         final DumperOptions options = new DumperOptions();
         options.setDefaultFlowStyle(DumperOptions.FlowStyle.BLOCK);
         dump(out, options);
     }
 
 }