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.io.IOException;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  import java.util.function.Function;
  
  import com.fasterxml.jackson.databind.ObjectMapper;
  import com.fasterxml.jackson.databind.ObjectWriter;
  import com.fasterxml.jackson.dataformat.avro.AvroFactory;
  import com.fasterxml.jackson.dataformat.avro.AvroSchema;
  import com.fasterxml.jackson.dataformat.avro.schema.AvroSchemaGenerator;
  import io.apicurio.registry.utils.converter.avro.AvroData;
  import io.apicurio.registry.utils.converter.avro.AvroDataConfig;
  import org.apache.avro.generic.GenericDatumReader;
  import org.apache.avro.generic.GenericRecord;
  import org.apache.avro.io.DatumReader;
  import org.apache.avro.io.Decoder;
  import org.apache.avro.io.DecoderFactory;
  import org.apache.kafka.common.config.ConfigDef;
  import org.apache.kafka.connect.connector.ConnectRecord;
  import org.apache.kafka.connect.data.SchemaAndValue;
  import org.apache.kafka.connect.errors.ConnectException;
  import org.apache.kafka.connect.transforms.Transformation;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class SourcePojoToSchemaAndStructTransform<R extends ConnectRecord<R>> implements Transformation<R> {
      private static final Logger LOG = LoggerFactory.getLogger(SourcePojoToSchemaAndStructTransform.class);
      private static final ObjectMapper MAPPER = new ObjectMapper(new AvroFactory());
  
      private AvroData avroData;
      private ConcurrentMap<String, CacheEntry> avroSchemaWrapperCache;
  
      @Override
      public R apply(R r) {
          LOG.debug("Incoming record: {}", r);
  
          if (r.value() != null) {
              String recordClassCanonicalName = r.value().getClass().getName();
              CacheEntry cacheEntry = avroSchemaWrapperCache.computeIfAbsent(recordClassCanonicalName, new Function<String, CacheEntry>() {
                  @Override
                  public CacheEntry apply(String s) {
                      //cache miss
                      AvroSchemaGenerator gen = new AvroSchemaGenerator();
  
                      try {
                          MAPPER.acceptJsonFormatVisitor(r.value().getClass(), gen);
                          AvroSchema schemaWrapper = gen.getGeneratedSchema();
                          LOG.debug("Generated and cached avro schema: {}", schemaWrapper.getAvroSchema().toString(true));
  
                          return new CacheEntry(schemaWrapper, MAPPER.writer(schemaWrapper));
                      } catch (Exception e) {
                          throw new ConnectException("Error in generating POJO schema.", e);
                      }
                  }
              });
  
              SchemaAndValue connectSchemaAndData = null;
              try {
                  byte[] avroDataByte = cacheEntry.getObjectWriter().writeValueAsBytes(r.value());
                  Decoder decoder = DecoderFactory.get().binaryDecoder(avroDataByte, null);
                  org.apache.avro.Schema avroSchema = cacheEntry.getAvroSchemaWrapper().getAvroSchema();
                  DatumReader<GenericRecord> datumReader = new GenericDatumReader<>(avroSchema);
                  GenericRecord genericAvroData = datumReader.read(null, decoder);
  
                  connectSchemaAndData = this.avroData.toConnectData(avroSchema, genericAvroData);
              } catch (IOException e) {
                  throw new ConnectException("Error in generating POJO Struct.", e);
              }
  
              LOG.debug("Generate kafka connect schema: {}", connectSchemaAndData.schema());
              LOG.debug("Generate kafka connect value (as Struct): {}", connectSchemaAndData.value());
              return r.newRecord(r.topic(), r.kafkaPartition(), r.keySchema(), r.key(),
                      connectSchemaAndData.schema(), connectSchemaAndData.value(), r.timestamp());
          } else {
              LOG.debug("Incoming record with a null value, nothing to be done.");
              return r;
          }
      }
  
      @Override
      public ConfigDef config() {
          return AvroDataConfig.baseConfigDef();
      }
  
      @Override
      public void close() {
          //NOOP
      }
  
      @Override
      public void configure(Map<String, ?> configs) {
          this.avroSchemaWrapperCache = new ConcurrentHashMap<>();
          this.avroData = new AvroData(new AvroDataConfig(configs));
      }
  
      public Map<String, CacheEntry> getCache() {
          return this.avroSchemaWrapperCache;
      }
  
      public class CacheEntry {
          private AvroSchema avroSchemaWrapper;
          private ObjectWriter objectWriter;
  
          public CacheEntry(AvroSchema avroSchemaWrapper, ObjectWriter objectWriter) {
              this.avroSchemaWrapper = avroSchemaWrapper;
              this.objectWriter = objectWriter;
          }
  
          public AvroSchema getAvroSchemaWrapper() {
              return avroSchemaWrapper;
          }
  
          public ObjectWriter getObjectWriter() {
              return objectWriter;
          }
      }
  }