content: /*
   * Copyright 2024-2025 the original author or authors.
   *
   * 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
   *
   *      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 com.alibaba.cloud.ai.graph.serializer.plain_text.jackson;
  
  import java.io.IOException;
  import java.util.Map;
  
  import com.fasterxml.jackson.core.JsonGenerator;
  import com.fasterxml.jackson.core.JsonProcessingException;
  import com.fasterxml.jackson.core.type.TypeReference;
  import com.fasterxml.jackson.databind.JsonNode;
  import com.fasterxml.jackson.databind.ObjectMapper;
  
  class SerializationHelper {
  
  	static final String METADATA_FIELD = "metadata";
  
  	static Map<String, Object> deserializeMetadata(ObjectMapper mapper, JsonNode parentNode)
  			throws JsonProcessingException {
  		var node = parentNode.findValue(METADATA_FIELD);
  
  		if (node.isNull() || node.isEmpty()) {
  			return Map.of();
  		}
  		if (!node.isObject()) {
  			throw new IllegalStateException("Metadata must be an object");
  		}
  		return mapper.treeToValue(node, new TypeReference<>() {
  		});
  	}
  
  	static void serializeMetadata(JsonGenerator gen, Map<String, Object> metadata) throws IOException {
  		gen.writeObjectField(METADATA_FIELD, metadata);
  	}
  
  }
  