/*
 * 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.beam.runners.samza.runtime;

import org.apache.beam.runners.core.KeyedWorkItem;
import org.apache.beam.sdk.values.KV;
import org.apache.beam.sdk.values.WindowedValue;

/** Samza operator to map input stream of {@link KV} to {@link KeyedWorkItem}. */
public class KvToKeyedWorkItemOp<K, V> implements Op<KV<K, V>, KeyedWorkItem<K, V>, K> {

  @Override
  public void processElement(
      WindowedValue<KV<K, V>> inputElement, OpEmitter<KeyedWorkItem<K, V>> emitter) {
    final KV<K, V> kv = inputElement.getValue();
    for (WindowedValue<KV<K, V>> windowedValue : inputElement.explodeWindows()) {
      final KeyedWorkItem<K, V> workItem =
          new SingletonKeyedWorkItem<>(kv.getKey(), windowedValue.withValue(kv.getValue()));
      emitter.emitElement(windowedValue.withValue(workItem));
    }
  }
}
