/*
    * 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.giraph.block_app.reducers.array;
  
  import java.util.ArrayList;
  
  import org.apache.giraph.block_app.framework.api.BlockMasterApi;
  import org.apache.giraph.block_app.framework.piece.global_comm.BroadcastHandle;
  import org.apache.giraph.block_app.framework.piece.global_comm.ReducerHandle;
  import org.apache.giraph.block_app.framework.piece.global_comm.array.ArrayHandle;
  import org.apache.giraph.block_app.framework.piece.global_comm.array.BroadcastArrayHandle;
  import org.apache.giraph.block_app.framework.piece.global_comm.array.ReducerArrayHandle;
  import org.apache.giraph.function.Supplier;
  import org.apache.giraph.function.primitive.Int2ObjFunction;
  import org.apache.giraph.worker.WorkerBroadcastUsage;
  
  /**
   * ArrayHandle implemented as an array of individual handles.
   *
   * @param <H> Handle type
   */
  public class ArrayOfHandles<H> implements ArrayHandle<H> {
    protected final ArrayList<H> handles;
  
    public ArrayOfHandles(int count, Supplier<H> reduceHandleFactory) {
      handles = new ArrayList<>();
      for (int i = 0; i < count; i++) {
        handles.add(reduceHandleFactory.get());
      }
    }
  
    public ArrayOfHandles(int count, Int2ObjFunction<H> reduceHandleFactory) {
      handles = new ArrayList<>();
      for (int i = 0; i < count; i++) {
        handles.add(reduceHandleFactory.apply(i));
      }
    }
  
    @Override
    public H get(int index) {
      return handles.get(index);
    }
  
    @Override
    public int getStaticSize() {
      return handles.size();
    }
  
    /**
     * ReducerArrayHandle implemented as an array of separate reducer handles.
     *
     * @param <S> Handle type
     * @param <R> Reduce value type
     */
    public static class ArrayOfReducers<S, R>
        extends ArrayOfHandles<ReducerHandle<S, R>>
        implements ReducerArrayHandle<S, R> {
  
      public ArrayOfReducers(
          int count, Supplier<ReducerHandle<S, R>> reduceHandleFactory) {
        super(count, reduceHandleFactory);
      }
  
      public ArrayOfReducers(
          int count, Int2ObjFunction<ReducerHandle<S, R>> reduceHandleFactory) {
        super(count, reduceHandleFactory);
      }
  
      @Override
      public int getReducedSize(BlockMasterApi master) {
        return getStaticSize();
      }
  
      @Override
      public BroadcastArrayHandle<R> broadcastValue(final BlockMasterApi master) {
        return new ArrayOfBroadcasts<>(
            getStaticSize(),
            new Int2ObjFunction<BroadcastHandle<R>>() {
              @Override
              public BroadcastHandle<R> apply(int index) {
                return get(index).broadcastValue(master);
              }
            });
      }
   }
 
   /**
    * BroadcastArrayHandle implemented as an array of separate broadcast handles.
    *
    * @param <T> Handle type
    */
   public static class ArrayOfBroadcasts<T>
       extends ArrayOfHandles<BroadcastHandle<T>>
       implements BroadcastArrayHandle<T> {
 
     public ArrayOfBroadcasts(
         int count,
         Int2ObjFunction<BroadcastHandle<T>> broadcastHandleFactory) {
       super(count, broadcastHandleFactory);
     }
 
     public ArrayOfBroadcasts(
         int count,
         Supplier<BroadcastHandle<T>> broadcastHandleFactory) {
       super(count, broadcastHandleFactory);
     }
 
     @Override
     public int getBroadcastedSize(WorkerBroadcastUsage worker) {
       return getStaticSize();
     }
   }
 }