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.kafka.server.util.json;
  
  import com.fasterxml.jackson.databind.JsonMappingException;
  import com.fasterxml.jackson.databind.JsonNode;
  import com.fasterxml.jackson.databind.node.ArrayNode;
  import com.fasterxml.jackson.databind.node.ObjectNode;
  
  import java.util.Optional;
  
  /**
   * A simple wrapper over Jackson's JsonNode that enables type safe parsing via the `DecodeJson` type
   * class.
   * <br>
   * Typical usage would be something like:
   * <pre><code>
   * // Given a jsonNode containing a parsed JSON:
   * JsonObject jsonObject = JsonValue.apply(jsonNode).asJsonObject();
   * Integer intField = jsonObject.apply("int_field").to(new DecodeJson.DecodeInteger());
   * Optional<Integer> optionLongField = jsonObject.apply("option_long_field").to(DecodeJson.decodeOptional(new DecodeJson.DecodeInteger()));
   * Map<String, Integer> mapStringIntField = jsonObject.apply("map_string_int_field").to(DecodeJson.decodeMap(new DecodeJson.DecodeInteger()));
   * List<String> seqStringField = jsonObject.apply("seq_string_field").to(DecodeJson.decodeList(new DecodeJson.DecodeString()));
   * </code></pre>
   * The `to` method throws an exception if the value cannot be converted to the requested type.
   */
  
  public interface JsonValue {
      JsonNode node();
  
      default <T> T to(DecodeJson<T> decodeJson) throws JsonMappingException {
          return decodeJson.decode(node());
      }
  
      /**
       * If this is a JSON object, return an instance of JsonObject. Otherwise, throw a JsonMappingException.
       */
      default JsonObject asJsonObject() throws JsonMappingException {
          return asJsonObjectOptional()
                  .orElseThrow(() -> new JsonMappingException(null, String.format("Expected JSON object, received %s", node())));
      }
  
      /**
       * If this is a JSON object, return a JsonObject wrapped by an `Optional`. Otherwise, return Empty.
       */
      default Optional<JsonObject> asJsonObjectOptional() {
          if (this instanceof JsonObject) {
              return Optional.of((JsonObject) this);
          } else if (node() instanceof ObjectNode) {
              return Optional.of(new JsonObject((ObjectNode) node()));
          } else {
              return Optional.empty();
          }
      }
  
      /**
       * If this is a JSON array, return an instance of JsonArray. Otherwise, throw a JsonMappingException.
       */
      default JsonArray asJsonArray() throws JsonMappingException {
          return asJsonArrayOptional()
                  .orElseThrow(() -> new JsonMappingException(null, String.format("Expected JSON array, received %s", node())));
  
      }
  
      /**
       * If this is a JSON array, return a JsonArray wrapped by an `Optional`. Otherwise, return Empty.
       */
      default Optional<JsonArray> asJsonArrayOptional() {
          if (this instanceof JsonArray) {
              return Optional.of((JsonArray) this);
          } else if (node() instanceof ArrayNode) {
              return Optional.of(new JsonArray((ArrayNode) node()));
          } else {
              return Optional.empty();
          }
      }
  
      static JsonValue apply(JsonNode node) {
          if (node instanceof ObjectNode) {
              return new JsonObject((ObjectNode) node);
          } else if (node instanceof ArrayNode) {
              return new JsonArray((ArrayNode) node);
          } else {
              return new BasicJsonValue(node);
          }
      }
  
      class BasicJsonValue implements JsonValue {
          protected JsonNode node;
          BasicJsonValue(JsonNode node) {
              this.node = node;
          }
  
          @Override
          public JsonNode node() {
              return node;
          }
          @Override
          public int hashCode() {
              return node().hashCode();
          }
          @Override
          public boolean equals(Object a) {
              if (a instanceof BasicJsonValue) {
                  return node().equals(((BasicJsonValue) a).node());
              }
              return false;
          }
          @Override
          public String toString() {
              return node().toString();
          }
      }
  }
  