/*
 * 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.test.misc;

import org.apache.flink.api.common.functions.Partitioner;
import org.apache.flink.api.common.functions.RichMapFunction;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.functions.KeySelector;
import org.apache.flink.api.java.io.DiscardingOutputFormat;
import org.apache.flink.test.util.JavaProgramTestBase;
import org.junit.Assert;

@SuppressWarnings("serial")
public class CustomPartitioningITCase extends JavaProgramTestBase {

	@Override
	protected void testProgram() throws Exception {
		ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		if (!isCollectionExecution()) {
			Assert.assertTrue(env.getParallelism() > 1);
		}
		
		env.generateSequence(1, 1000)
			.partitionCustom(new AllZeroPartitioner(), new IdKeySelector<Long>())
			.map(new FailExceptInPartitionZeroMapper())
			.output(new DiscardingOutputFormat<Long>());
		
		env.execute();
	}
	
	public static class FailExceptInPartitionZeroMapper extends RichMapFunction<Long, Long> {
		
		@Override
		public Long map(Long value) throws Exception {
			if (getRuntimeContext().getIndexOfThisSubtask() == 0) {
				return value;
			} else {
				throw new Exception("Received data in a partition other than partition 0");
			}
		}
	}
	
	public static class AllZeroPartitioner implements Partitioner<Long> {
		@Override
		public int partition(Long key, int numPartitions) {
			return 0;
		}
	}
	
	public static class IdKeySelector<T> implements KeySelector<T, T> {
		@Override
		public T getKey(T value) {
			return value;
		}
	}
}