/*
    * 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.collect;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.giraph.block_app.framework.api.BlockMasterApi;
  import org.apache.giraph.block_app.framework.api.CreateReducersApi;
  import org.apache.giraph.block_app.framework.piece.global_comm.BroadcastHandle;
  import org.apache.giraph.block_app.framework.piece.global_comm.array.BroadcastArrayHandle;
  import org.apache.giraph.master.MasterGlobalCommUsage;
  import org.apache.giraph.reducers.ReduceOperation;
  import org.apache.giraph.types.ops.PrimitiveTypeOps;
  import org.apache.giraph.types.ops.TypeOpsUtils;
  import org.apache.giraph.types.ops.collections.array.WArrayList;
  import org.apache.giraph.worker.WorkerBroadcastUsage;
  import org.apache.giraph.writable.kryo.KryoWritableWrapper;
  
  /**
   * ShardedReducerHandle where we keep a list of reduced values,
   * and values consist of multiple primitives, so we keep one primitive
   * list for each
   */
  @SuppressWarnings("unchecked")
  public class CollectShardedTuplesOfPrimitivesReducerHandle
  extends ShardedReducerHandle<List<Object>, List<WArrayList>> {
    /**
     * Type ops if available, or null
     */
    private final List<PrimitiveTypeOps> typeOpsList;
  
    public CollectShardedTuplesOfPrimitivesReducerHandle(
        final CreateReducersApi reduceApi, Class<?>... valueClasses) {
      typeOpsList = new ArrayList<>();
      for (Class<?> valueClass : valueClasses) {
        typeOpsList.add(TypeOpsUtils.getPrimitiveTypeOps(valueClass));
      }
      register(reduceApi);
    }
  
    public List<Object> createSingleValue() {
      List<Object> ret = new ArrayList<>();
      for (PrimitiveTypeOps typeOps : typeOpsList) {
        ret.add(typeOps.create());
      }
      return ret;
    }
  
    @Override
    public ReduceOperation<List<Object>,
        KryoWritableWrapper<List<WArrayList>>> createReduceOperation() {
      return new CollectTuplesOfPrimitivesReduceOperation(typeOpsList);
    }
  
    @Override
    public List<WArrayList> createReduceResult(
        MasterGlobalCommUsage master) {
      int size = 0;
      for (int i = 0; i < REDUCER_COUNT; i++) {
        size += reducers.get(i).getReducedValue(master).get().get(0).size();
      }
      return createLists(size);
    }
  
    public List<WArrayList> createLists(int size) {
      List<WArrayList> ret = new ArrayList<>();
      for (PrimitiveTypeOps typeOps : typeOpsList) {
        ret.add(typeOps.createArrayList(size));
      }
      return ret;
    }
  
    @Override
    public BroadcastHandle<List<WArrayList>> createBroadcastHandle(
        BroadcastArrayHandle<KryoWritableWrapper<List<WArrayList>>>
            broadcasts) {
      return new CollectShardedTuplesOfPrimitivesBroadcastHandle(broadcasts);
    }
  
    /**
     * BroadcastHandle for CollectShardedTuplesOfPrimitivesReducerHandle
     */
    public class CollectShardedTuplesOfPrimitivesBroadcastHandle
       extends ShardedBroadcastHandle {
     public CollectShardedTuplesOfPrimitivesBroadcastHandle(
         BroadcastArrayHandle<KryoWritableWrapper<List<WArrayList>>>
             broadcasts) {
       super(broadcasts);
     }
 
     @Override
     public List<WArrayList> createBroadcastResult(
         WorkerBroadcastUsage worker) {
       int size = 0;
       for (int i = 0; i < REDUCER_COUNT; i++) {
         size += broadcasts.get(i).getBroadcast(worker).get().size();
       }
       return createLists(size);
     }
   }
 
   /**
    * Reduce broadcast wrapper
    */
   public static class CollectShardedTuplesOfPrimitivesReduceBroadcast {
     private CollectShardedTuplesOfPrimitivesReducerHandle reducerHandle;
     private BroadcastHandle<List<WArrayList>> broadcastHandle;
 
     /** Set reducer handle to just registered handle */
     public void registeredReducer(CreateReducersApi reduceApi,
         Class<?>... valueClasses) {
       this.reducerHandle = new CollectShardedTuplesOfPrimitivesReducerHandle(
           reduceApi, valueClasses);
     }
 
     public List<Object> createSingleValue() {
       return reducerHandle.createSingleValue();
     }
 
     /** Reduce single value */
     public void reduce(List<Object> valueToReduce) {
       reducerHandle.reduce(valueToReduce);
     }
 
     /** Get reduced value */
     public List<WArrayList> getReducedValue(MasterGlobalCommUsage master) {
       return reducerHandle.getReducedValue(master);
     }
 
     /**
      * Broadcast reduced value from master
      */
     public void broadcastValue(BlockMasterApi master) {
       broadcastHandle = reducerHandle.broadcastValue(master);
     }
 
     /** Get broadcasted value */
     public List<WArrayList> getBroadcast(WorkerBroadcastUsage worker) {
       return broadcastHandle.getBroadcast(worker);
     }
   }
 }