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.component.flink.annotations;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  
  import org.apache.camel.CamelContext;
  import org.apache.camel.RuntimeCamelException;
  import org.apache.flink.api.java.DataSet;
  
  import static org.apache.camel.support.ObjectHelper.invokeMethodSafe;
  import static org.apache.camel.util.ObjectHelper.findMethodsWithAnnotation;
  
  /**
   * Provides facade for working with annotated DataSet callbacks i.e. POJO classes with an appropriate annotations on
   * selected methods.
   */
  public class AnnotatedDataSetCallback implements org.apache.camel.component.flink.DataSetCallback {
  
      private final Object objectWithCallback;
  
      private final List<Method> dataSetCallbacks;
  
      private final CamelContext camelContext;
  
      public AnnotatedDataSetCallback(Object objectWithCallback, CamelContext camelContext) {
          this.objectWithCallback = objectWithCallback;
          this.camelContext = camelContext;
          this.dataSetCallbacks = findMethodsWithAnnotation(objectWithCallback.getClass(), DataSetCallback.class);
          if (dataSetCallbacks.isEmpty()) {
              throw new UnsupportedOperationException("Can't find methods annotated with @DataSetCallback");
          }
      }
  
      public AnnotatedDataSetCallback(Object objectWithCallback) {
          this(objectWithCallback, null);
      }
  
      @Override
      public Object onDataSet(DataSet ds, Object... payloads) {
          try {
              List<Object> arguments = new ArrayList<>(payloads.length + 1);
              arguments.add(ds);
              arguments.addAll(Arrays.asList(payloads));
              if (arguments.get(1) == null) {
                  arguments.remove(1);
              }
  
              Method callbackMethod = dataSetCallbacks.get(0);
  
              if (camelContext != null) {
                  for (int i = 1; i < arguments.size(); i++) {
                      arguments.set(i,
                              camelContext.getTypeConverter().convertTo(callbackMethod.getParameterTypes()[i], arguments.get(i)));
                  }
              }
  
              Object[] args = arguments.toArray(new Object[0]);
              return invokeMethodSafe(callbackMethod, objectWithCallback, args);
          } catch (IllegalAccessException | InvocationTargetException e) {
              throw new RuntimeCamelException(e);
          }
      }
  }
  