/***********************************************************************************************************************
 *
 * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
 *
 * Licensed 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 eu.stratosphere.test.javaApiOperators;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.Collection;
import java.util.LinkedList;

import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

import eu.stratosphere.api.java.DataSet;
import eu.stratosphere.api.java.ExecutionEnvironment;
import eu.stratosphere.api.java.aggregation.Aggregations;
import eu.stratosphere.api.java.tuple.Tuple1;
import eu.stratosphere.api.java.tuple.Tuple2;
import eu.stratosphere.api.java.tuple.Tuple3;
import eu.stratosphere.configuration.Configuration;
import eu.stratosphere.test.javaApiOperators.util.CollectionDataSets;
import eu.stratosphere.test.util.JavaProgramTestBase;

@RunWith(Parameterized.class)
public class AggregateITCase extends JavaProgramTestBase {
	
	private static int NUM_PROGRAMS = 3;
	
	private int curProgId = config.getInteger("ProgramId", -1);
	private String resultPath;
	private String expectedResult;
	
	public AggregateITCase(Configuration config) {
		super(config);
	}
	
	@Override
	protected void preSubmit() throws Exception {
		resultPath = getTempDirPath("result");
	}

	@Override
	protected void testProgram() throws Exception {
		expectedResult = AggregateProgs.runProgram(curProgId, resultPath);
	}
	
	@Override
	protected void postSubmit() throws Exception {
		compareResultsByLinesInMemory(expectedResult, resultPath);
	}
	
	@Parameters
	public static Collection<Object[]> getConfigurations() throws FileNotFoundException, IOException {

		LinkedList<Configuration> tConfigs = new LinkedList<Configuration>();

		for(int i=1; i <= NUM_PROGRAMS; i++) {
			Configuration config = new Configuration();
			config.setInteger("ProgramId", i);
			tConfigs.add(config);
		}
		
		return toParameterList(tConfigs);
	}
	
	private static class AggregateProgs {
		
		public static String runProgram(int progId, String resultPath) throws Exception {
			
			switch(progId) {
			case 1: {
				/*
				 * Full Aggregate
				 */
				
				final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
				
				DataSet<Tuple3<Integer, Long, String>> ds = CollectionDataSets.get3TupleDataSet(env);
				DataSet<Tuple2<Integer, Long>> aggregateDs = ds
						.aggregate(Aggregations.SUM, 0)
						.and(Aggregations.MAX, 1)
						.project(0, 1).types(Integer.class, Long.class);
				
				aggregateDs.writeAsCsv(resultPath);
				env.execute();
				
				// return expected result
				return "231,6\n";
			}
			case 2: {
				/*
				 * Grouped Aggregate
				 */
				
				final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
				
				DataSet<Tuple3<Integer, Long, String>> ds = CollectionDataSets.get3TupleDataSet(env);
				DataSet<Tuple2<Long, Integer>> aggregateDs = ds.groupBy(1)
						.aggregate(Aggregations.SUM, 0)
						.project(1, 0).types(Long.class, Integer.class);
				
				aggregateDs.writeAsCsv(resultPath);
				env.execute();
				
				// return expected result
				return "1,1\n" +
				"2,5\n" +
				"3,15\n" +
				"4,34\n" +
				"5,65\n" +
				"6,111\n";
			} 
			case 3: {
				/*
				 * Nested Aggregate
				 */
				
				final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
				
				DataSet<Tuple3<Integer, Long, String>> ds = CollectionDataSets.get3TupleDataSet(env);
				DataSet<Tuple1<Integer>> aggregateDs = ds.groupBy(1)
						.aggregate(Aggregations.MIN, 0)
						.aggregate(Aggregations.MIN, 0)
						.project(0).types(Integer.class);
				
				aggregateDs.writeAsCsv(resultPath);
				env.execute();
				
				// return expected result
				return "1\n";
			}
			default: 
				throw new IllegalArgumentException("Invalid program id");
			}
		}
	}
}