/*
 * 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.flink.optimizer;

import static org.junit.Assert.*;

import org.apache.flink.api.common.Plan;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.io.DiscardingOutputFormat;
import org.apache.flink.api.java.operators.DeltaIteration;
import org.apache.flink.api.java.tuple.Tuple2;
import org.apache.flink.optimizer.plan.OptimizedPlan;
import org.apache.flink.optimizer.plan.WorksetIterationPlanNode;
import org.apache.flink.optimizer.plantranslate.JobGraphGenerator;
import org.apache.flink.optimizer.util.CompilerTestBase;
import org.junit.Test;

@SuppressWarnings("serial")
public class WorksetIterationCornerCasesTest extends CompilerTestBase {

	@Test
	public void testWorksetIterationNotDependingOnSolutionSet() {
		try {
			ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
			
			DataSet<Tuple2<Long, Long>> input = env.generateSequence(1, 100).map(new Duplicator<Long>());
			
			DeltaIteration<Tuple2<Long, Long>, Tuple2<Long, Long>> iteration = input.iterateDelta(input, 100, 1);
			
			DataSet<Tuple2<Long, Long>> iterEnd = iteration.getWorkset().map(new TestMapper<Tuple2<Long,Long>>());
			iteration.closeWith(iterEnd, iterEnd)
				.output(new DiscardingOutputFormat<Tuple2<Long, Long>>());
			
			Plan p = env.createProgramPlan();
			OptimizedPlan op = compileNoStats(p);
			
			WorksetIterationPlanNode wipn = (WorksetIterationPlanNode) op.getDataSinks().iterator().next().getInput().getSource();
			assertTrue(wipn.getSolutionSetPlanNode().getOutgoingChannels().isEmpty());
			
			JobGraphGenerator jgg = new JobGraphGenerator();
			jgg.compileJobGraph(op);
		}
		catch (Exception e) {
			e.printStackTrace();
			fail(e.getMessage());
		}
	}
	
	private static final class Duplicator<T> implements MapFunction<T, Tuple2<T, T>> {
		@Override
		public Tuple2<T, T> map(T value) {
			return new Tuple2<T, T>(value, value);
		}
	}
	
	private static final class TestMapper<T> implements MapFunction<T, T> {
		@Override
		public T map(T value) {
			return value;
		}
	}
}