/*

  * 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.framework.block;

 import java.util.Iterator;

 import org.apache.giraph.block_app.framework.piece.AbstractPiece;

 import org.apache.giraph.function.Consumer;

 import org.apache.giraph.function.Supplier;

 /**

  * Block that executes one of two branches based on a condition

  */

 @SuppressWarnings("rawtypes")

 public final class IfBlock implements Block {

   private final Block thenBlock;

   private final Block elseBlock;

   private final Supplier<Boolean> condition;

   public IfBlock(

       Supplier<Boolean> condition, Block thenBlock, Block elseBlock) {

     this.condition = condition;

     this.thenBlock = thenBlock;

     this.elseBlock = elseBlock;

   }

   public IfBlock(Supplier<Boolean> condition, Block thenBlock) {

     this.condition = condition;

     this.thenBlock = thenBlock;

     this.elseBlock = new EmptyBlock();

   }

   @Override

   public Iterator<AbstractPiece> iterator() {

     if (Boolean.TRUE.equals(condition.get())) {

       return thenBlock.iterator();

     } else {

       return elseBlock.iterator();

     }

   }

   @Override

   public void forAllPossiblePieces(Consumer<AbstractPiece> consumer) {

     thenBlock.forAllPossiblePieces(consumer);

     elseBlock.forAllPossiblePieces(consumer);

   }

   @Override

   public PieceCount getPieceCount() {

     PieceCount thenCount = thenBlock.getPieceCount();

     PieceCount elseCount = elseBlock.getPieceCount();

     return thenCount.equals(elseCount) ?

         thenCount : PieceCount.createUnknownCount();

   }

   @Override

   public String toString() {

     if (elseBlock instanceof EmptyBlock) {

       return "IfBlock(" + thenBlock + ")";

     }

     return "IfBlock(" + thenBlock + " , " + elseBlock + ")";

   }

 }