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.camel.kafkaconnector.transforms;
  
  import java.util.Map;
  
  import org.apache.camel.TypeConverter;
  import org.apache.camel.kafkaconnector.utils.SchemaHelper;
  import org.apache.kafka.common.config.ConfigDef;
  import org.apache.kafka.common.config.ConfigException;
  import org.apache.kafka.connect.connector.ConnectRecord;
  import org.apache.kafka.connect.data.Schema;
  import org.apache.kafka.connect.data.SchemaBuilder;
  import org.apache.kafka.connect.errors.DataException;
  import org.apache.kafka.connect.transforms.util.SchemaUtil;
  import org.apache.kafka.connect.transforms.util.SimpleConfig;
  
  public abstract class CamelTypeConverterTransform<R extends ConnectRecord<R>> extends CamelTransformSupport<R> {
  
      public static final String FIELD_TARGET_TYPE_CONFIG = "target.type";
      public static final ConfigDef CONFIG_DEF = new ConfigDef()
              .define(FIELD_TARGET_TYPE_CONFIG, ConfigDef.Type.CLASS, null, ConfigDef.Importance.HIGH,
                      "The target field type to convert the value from, this is full qualified Java class, e.g: java.util.Map");
  
      private static TypeConverter typeConverter;
      private Class<?> fieldTargetType;
  
      @Override
      public R apply(R record) {
          final Schema schema = operatingSchema(record);
          final Object value = operatingValue(record);
  
          final Object convertedValue = convertValueWithCamelTypeConverter(value);
          final Schema updatedSchema = getOrBuildRecordSchema(schema, convertedValue);
  
          return newRecord(record, updatedSchema, convertedValue);
      }
  
      private Object convertValueWithCamelTypeConverter(final Object originalValue) {
          final Object convertedValue = typeConverter.tryConvertTo(fieldTargetType, originalValue);
  
          if (convertedValue == null) {
              throw new DataException(String.format("CamelTypeConverter was not able to convert value `%s` to target type of `%s`", originalValue, fieldTargetType.getSimpleName()));
          }
  
          return convertedValue;
      }
  
      private Schema getOrBuildRecordSchema(final Schema originalSchema, final Object value) {
          final SchemaBuilder builder = SchemaUtil.copySchemaBasics(originalSchema, SchemaHelper.buildSchemaBuilderForType(value));
  
          if (originalSchema.isOptional()) {
              builder.optional();
          }
          if (originalSchema.defaultValue() != null) {
              builder.defaultValue(convertValueWithCamelTypeConverter(originalSchema.defaultValue()));
          }
  
          return builder.build();
      }
  
      @Override
      public ConfigDef config() {
          return CONFIG_DEF;
      }
  
      @Override
      public void close() {
      }
  
      @Override
      public void configure(Map<String, ?> props) {
          final SimpleConfig config = new SimpleConfig(CONFIG_DEF, props);
          fieldTargetType = config.getClass(FIELD_TARGET_TYPE_CONFIG);
  
          if (fieldTargetType == null) {
              throw new ConfigException("Configuration 'target.type' can not be empty!");
          }
  
          // initialize type converter from camel context
          typeConverter = getCamelContext().getTypeConverter();
      }
  
      protected abstract Schema operatingSchema(R record);
  
      protected abstract Object operatingValue(R record);
  
      protected abstract R newRecord(R record, Schema updatedSchema, Object updatedValue);
  
      public static final class Key<R extends ConnectRecord<R>> extends CamelTypeConverterTransform<R> {
          @Override
          protected Schema operatingSchema(R record) {
              return record.keySchema();
          }
  
          @Override
          protected Object operatingValue(R record) {
              return record.key();
          }
  
          @Override
          protected R newRecord(R record, Schema updatedSchema, Object updatedValue) {
              return record.newRecord(record.topic(), record.kafkaPartition(), updatedSchema, updatedValue, record.valueSchema(), record.value(), record.timestamp());
          }
      }
  
      public static final class Value<R extends ConnectRecord<R>> extends CamelTypeConverterTransform<R> {
          @Override
          protected Schema operatingSchema(R record) {
              return record.valueSchema();
          }
  
          @Override
          protected Object operatingValue(R record) {
              return record.value();
          }
  
          @Override
          protected R newRecord(R record, Schema updatedSchema, Object updatedValue) {
              return record.newRecord(record.topic(), record.kafkaPartition(), record.keySchema(), record.key(), updatedSchema, updatedValue, record.timestamp());
          }
      }
  }
  