/*
 * 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.api.common.operators;

import static org.junit.Assert.*;

import org.apache.flink.api.common.JobExecutionResult;
import org.apache.flink.api.common.accumulators.IntCounter;
import org.apache.flink.api.common.functions.RichMapFunction;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.io.DiscardingOutputFormat;
import org.apache.flink.configuration.Configuration;
import org.junit.Test;

public class CollectionExecutionAccumulatorsTest {

	private static final String ACCUMULATOR_NAME = "TEST ACC";
	
	@Test
	public void testAccumulator() {
		try {
			final int NUM_ELEMENTS = 100;
			
			ExecutionEnvironment env = ExecutionEnvironment.createCollectionsEnvironment();
			
			env.generateSequence(1, NUM_ELEMENTS)
				.map(new CountingMapper())
				.output(new DiscardingOutputFormat<Long>());
			
			JobExecutionResult result = env.execute();
			
			assertTrue(result.getNetRuntime() >= 0);

			assertEquals(NUM_ELEMENTS, (int) result.getAccumulatorResult(ACCUMULATOR_NAME));
		}
		catch (Exception e) {
			e.printStackTrace();
			fail(e.getMessage());
		}
	}
	
	@SuppressWarnings("serial")
	public static class CountingMapper extends RichMapFunction<Long, Long> {
		
		private IntCounter accumulator;
		
		@Override
		public void open(Configuration parameters) {
			accumulator = getRuntimeContext().getIntCounter(ACCUMULATOR_NAME);
		}
		
		@Override
		public Long map(Long value) {
			accumulator.add(1);
			return value;
		}
	}
}