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.streams.state.internals;
  
  import org.apache.kafka.common.utils.Bytes;
  import org.apache.kafka.streams.KeyValue;
  import org.apache.kafka.streams.kstream.Windowed;
  import org.apache.kafka.streams.state.KeyValueIterator;
  import org.apache.kafka.streams.state.WindowStoreIterator;
  
  import java.util.function.BiFunction;
  import java.util.function.Function;
  
  class WindowStoreIteratorWrapper {
  
      private final KeyValueIterator<Bytes, byte[]> bytesIterator;
      private final long windowSize;
      private final Function<byte[], Long> timestampExtractor;
      private final BiFunction<byte[], Long, Windowed<Bytes>> windowConstructor;
  
      WindowStoreIteratorWrapper(final KeyValueIterator<Bytes, byte[]> bytesIterator,
                                 final long windowSize) {
          this(bytesIterator, windowSize, WindowKeySchema::extractStoreTimestamp, WindowKeySchema::fromStoreBytesKey);
      }
  
      WindowStoreIteratorWrapper(final KeyValueIterator<Bytes, byte[]> bytesIterator,
                                 final long windowSize,
                                 final Function<byte[], Long> timestampExtractor,
                                 final BiFunction<byte[], Long, Windowed<Bytes>> windowConstructor) {
          this.bytesIterator = bytesIterator;
          this.windowSize = windowSize;
          this.timestampExtractor = timestampExtractor;
          this.windowConstructor = windowConstructor;
      }
  
      public WindowStoreIterator<byte[]> valuesIterator() {
          return new WrappedWindowStoreIterator(bytesIterator, timestampExtractor);
      }
  
      public KeyValueIterator<Windowed<Bytes>, byte[]> keyValueIterator() {
          return new WrappedKeyValueIterator(bytesIterator, windowSize, windowConstructor);
      }
  
      private static class WrappedWindowStoreIterator implements WindowStoreIterator<byte[]> {
          final KeyValueIterator<Bytes, byte[]> bytesIterator;
          final Function<byte[], Long> timestampExtractor;
  
          WrappedWindowStoreIterator(
              final KeyValueIterator<Bytes, byte[]> bytesIterator,
              final Function<byte[], Long> timestampExtractor) {
              this.bytesIterator = bytesIterator;
              this.timestampExtractor = timestampExtractor;
          }
  
          @Override
          public Long peekNextKey() {
              return timestampExtractor.apply(bytesIterator.peekNextKey().get());
          }
  
          @Override
          public boolean hasNext() {
              return bytesIterator.hasNext();
          }
  
          @Override
          public KeyValue<Long, byte[]> next() {
              final KeyValue<Bytes, byte[]> next = bytesIterator.next();
              final long timestamp = timestampExtractor.apply(next.key.get());
              return KeyValue.pair(timestamp, next.value);
          }
  
          @Override
          public void close() {
              bytesIterator.close();
          }
      }
  
      private static class WrappedKeyValueIterator implements KeyValueIterator<Windowed<Bytes>, byte[]> {
          final KeyValueIterator<Bytes, byte[]> bytesIterator;
          final long windowSize;
          final BiFunction<byte[], Long, Windowed<Bytes>> windowConstructor;
  
          WrappedKeyValueIterator(final KeyValueIterator<Bytes, byte[]> bytesIterator,
                                  final long windowSize,
                                  final BiFunction<byte[], Long, Windowed<Bytes>> windowConstructor) {
              this.bytesIterator = bytesIterator;
              this.windowSize = windowSize;
              this.windowConstructor = windowConstructor;
          }
  
          @Override
          public Windowed<Bytes> peekNextKey() {
              final byte[] nextKey = bytesIterator.peekNextKey().get();
              return windowConstructor.apply(nextKey, windowSize);
          }
  
          @Override
          public boolean hasNext() {
              return bytesIterator.hasNext();
          }
  
          @Override
          public KeyValue<Windowed<Bytes>, byte[]> next() {
              final KeyValue<Bytes, byte[]> next = bytesIterator.next();
              return KeyValue.pair(windowConstructor.apply(next.key.get(), windowSize), next.value);
          }
  
          @Override
          public void close() {
              bytesIterator.close();
          }
      }
  }
  