content: /*
   *  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.causeway.viewer.restfulobjects.applib.util;
  
  import java.io.ByteArrayInputStream;
  import java.io.InputStream;
  import java.nio.charset.StandardCharsets;
  import java.util.List;
  
  import com.fasterxml.jackson.databind.JsonNode;
  import com.fasterxml.jackson.databind.node.JsonNodeFactory;
  import com.fasterxml.jackson.databind.node.ObjectNode;
  
  import org.apache.causeway.viewer.restfulobjects.applib.JsonRepresentation;
  
  /**
   * @since 1.x {@index}
   */
  public class JsonNodeUtils {
  
      private JsonNodeUtils() {
      }
  
      public static InputStream asInputStream(final JsonNode jsonNode) {
          final String jsonStr = jsonNode.toString();
          final byte[] bytes = jsonStr.getBytes(StandardCharsets.UTF_8);
          return new ByteArrayInputStream(bytes);
      }
  
      public static InputStream asInputStream(final JsonRepresentation jsonRepresentation) {
          final String jsonStr = jsonRepresentation.toString();
          final byte[] bytes = jsonStr.getBytes(StandardCharsets.UTF_8);
          return new ByteArrayInputStream(bytes);
      }
  
      /**
       * Walks the path, ensuring keys exist and are maps, or creating required
       * maps as it goes.
       *
       * <p>
       * For example, if given a list ("a", "b", "c") and starting with an empty
       * map, then will create:
       *
       * <pre>
       * {
       *   "a": {
       *     "b: {
       *       "c": {
       *       }
       *     }
       *   }
       * }
       */
      public static ObjectNode walkNodeUpTo(ObjectNode node, final List<String> keys) {
          for (final String key : keys) {
              JsonNode jsonNode = node.get(key);
              if (jsonNode == null) {
                  jsonNode = new ObjectNode(JsonNodeFactory.instance);
                  node.set(key, jsonNode);
              } else {
                  if (!jsonNode.isObject()) {
                      throw new IllegalArgumentException(String.format("walking path: '%s', existing key '%s' is not a map", keys, key));
                  }
              }
              node = (ObjectNode) jsonNode;
          }
          return node;
      }
  
  }
  