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.connect.header;
  
  import org.apache.kafka.connect.data.Schema;
  import org.apache.kafka.connect.data.SchemaAndValue;
  import org.apache.kafka.connect.data.Struct;
  
  import java.util.Objects;
  
  /**
   * A {@link Header} implementation.
   */
  class ConnectHeader implements Header {
  
      private static final SchemaAndValue NULL_SCHEMA_AND_VALUE = new SchemaAndValue(null, null);
  
      private final String key;
      private final SchemaAndValue schemaAndValue;
  
      protected ConnectHeader(String key, SchemaAndValue schemaAndValue) {
          Objects.requireNonNull(key, "Null header keys are not permitted");
          this.key = key;
          this.schemaAndValue = schemaAndValue != null ? schemaAndValue : NULL_SCHEMA_AND_VALUE;
      }
  
      @Override
      public String key() {
          return key;
      }
  
      @Override
      public Object value() {
          return schemaAndValue.value();
      }
  
      @Override
      public Schema schema() {
          Schema schema = schemaAndValue.schema();
          if (schema == null && value() instanceof Struct) {
              schema = ((Struct) value()).schema();
          }
          return schema;
      }
  
      @Override
      public Header rename(String key) {
          Objects.requireNonNull(key, "Null header keys are not permitted");
          if (this.key.equals(key)) {
              return this;
          }
          return new ConnectHeader(key, schemaAndValue);
      }
  
      @Override
      public Header with(Schema schema, Object value) {
          return new ConnectHeader(key, new SchemaAndValue(schema, value));
      }
  
      @Override
      public int hashCode() {
          return Objects.hash(key, schemaAndValue);
      }
  
      @Override
      public boolean equals(Object obj) {
          if (obj == this) {
              return true;
          }
          if (obj instanceof Header that) {
              return Objects.equals(this.key, that.key()) && Objects.equals(this.schema(), that.schema()) && Objects.equals(this.value(),
                                                                                                                            that.value());
          }
          return false;
      }
  
      @Override
      public String toString() {
          return "ConnectHeader(key=" + key + ", value=" + value() + ", schema=" + schema() + ")";
      }
  }
  