/*
 * 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.graph.test.operations;

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.tuple.Tuple2;
import org.apache.flink.api.java.tuple.Tuple3;
import org.apache.flink.graph.Edge;
import org.apache.flink.graph.EdgeJoinFunction;
import org.apache.flink.graph.Graph;
import org.apache.flink.graph.test.TestGraphUtils;
import org.apache.flink.graph.test.TestGraphUtils.DummyCustomParameterizedType;
import org.apache.flink.graph.utils.EdgeToTuple3Map;
import org.apache.flink.test.util.MultipleProgramsTestBase;

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

import java.util.List;

/**
 * Tests for {@link Graph#joinWithEdges}, {@link Graph#joinWithEdgesOnSource},
 * and {@link Graph#joinWithEdgesOnTarget}.
 */
@RunWith(Parameterized.class)
public class JoinWithEdgesITCase extends MultipleProgramsTestBase {

	public JoinWithEdgesITCase(TestExecutionMode mode) {
		super(mode);
	}

	private String expectedResult;

	@Test
	public void testWithEdgesInputDataset() throws Exception {
		/*
		 * Test joinWithEdges with the input DataSet parameter identical
		 * to the edge DataSet
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdges(graph.getEdges()
			.map(new EdgeToTuple3Map<>()), new AddValuesMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,26\n" +
			"2,3,46\n" +
			"3,4,68\n" +
			"3,5,70\n" +
			"4,5,90\n" +
			"5,1,102\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testWithLessElements() throws Exception {
		/*
		 * Test joinWithEdges with the input DataSet passed as a parameter containing
		 * less elements than the edge DataSet, but of the same type
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdges(graph.getEdges().first(3)
			.map(new EdgeToTuple3Map<>()), new AddValuesMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,26\n" +
			"2,3,46\n" +
			"3,4,34\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testWithLessElementsDifferentType() throws Exception {
		/*
		 * Test joinWithEdges with the input DataSet passed as a parameter containing
		 * less elements than the edge DataSet and of a different type(Boolean)
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdges(graph.getEdges().first(3)
			.map(new BooleanEdgeValueMapper()), new DoubleIfTrueMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,26\n" +
			"2,3,46\n" +
			"3,4,34\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testWithNoCommonKeys() throws Exception {
		/*
		 * Test joinWithEdges with the input DataSet containing different keys than the edge DataSet
		 * - the iterator becomes empty.
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdges(TestGraphUtils.getLongLongLongTuple3Data(env),
			new DoubleValueMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,26\n" +
			"2,3,46\n" +
			"3,4,68\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testWithCustomType() throws Exception {
		/*
	     * Test joinWithEdges with a DataSet containing custom parametrised type input values
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdges(TestGraphUtils.getLongLongCustomTuple3Data(env),
			new CustomValueMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,10\n" +
			"1,3,20\n" +
			"2,3,30\n" +
			"3,4,40\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testWithEdgesOnSource() throws Exception {
		/*
		 * Test joinWithEdgesOnSource with the input DataSet parameter identical
		 * to the edge DataSet
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnSource(graph.getEdges()
			.map(new ProjectSourceAndValueMapper()), new AddValuesMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,25\n" +
			"2,3,46\n" +
			"3,4,68\n" +
			"3,5,69\n" +
			"4,5,90\n" +
			"5,1,102\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testOnSourceWithLessElements() throws Exception {
		/*
		 * Test joinWithEdgesOnSource with the input DataSet passed as a parameter containing
		 * less elements than the edge DataSet, but of the same type
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnSource(graph.getEdges().first(3)
			.map(new ProjectSourceAndValueMapper()), new AddValuesMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,25\n" +
			"2,3,46\n" +
			"3,4,34\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testOnSourceWithDifferentType() throws Exception {
		/*
		 * Test joinWithEdgesOnSource with the input DataSet passed as a parameter containing
		 * less elements than the edge DataSet and of a different type(Boolean)
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnSource(graph.getEdges().first(3)
			.map(new ProjectSourceWithTrueMapper()), new DoubleIfTrueMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,26\n" +
			"2,3,46\n" +
			"3,4,34\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testOnSourceWithNoCommonKeys() throws Exception {
		/*
		 * Test joinWithEdgesOnSource with the input DataSet containing different keys than the edge DataSet
		 * - the iterator becomes empty.
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnSource(TestGraphUtils.getLongLongTuple2SourceData(env),
			new DoubleValueMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,20\n" +
			"1,3,20\n" +
			"2,3,60\n" +
			"3,4,80\n" +
			"3,5,80\n" +
			"4,5,120\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testOnSourceWithCustom() throws Exception {
		/*
	     * Test joinWithEdgesOnSource with a DataSet containing custom parametrised type input values
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnSource(TestGraphUtils.getLongCustomTuple2SourceData(env),
			new CustomValueMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,10\n" +
			"1,3,10\n" +
			"2,3,30\n" +
			"3,4,40\n" +
			"3,5,40\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testWithEdgesOnTarget() throws Exception {
		/*
		 * Test joinWithEdgesOnTarget with the input DataSet parameter identical
		 * to the edge DataSet
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnTarget(graph.getEdges()
			.map(new ProjectTargetAndValueMapper()), new AddValuesMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,26\n" +
			"2,3,36\n" +
			"3,4,68\n" +
			"3,5,70\n" +
			"4,5,80\n" +
			"5,1,102\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testWithOnTargetWithLessElements() throws Exception {
		/*
		 * Test joinWithEdgesOnTarget with the input DataSet passed as a parameter containing
		 * less elements than the edge DataSet, but of the same type
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnTarget(graph.getEdges().first(3)
			.map(new ProjectTargetAndValueMapper()), new AddValuesMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,26\n" +
			"2,3,36\n" +
			"3,4,34\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testOnTargetWithDifferentType() throws Exception {
		/*
		 * Test joinWithEdgesOnTarget with the input DataSet passed as a parameter containing
		 * less elements than the edge DataSet and of a different type(Boolean)
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnTarget(graph.getEdges().first(3)
			.map(new ProjectTargetWithTrueMapper()), new DoubleIfTrueMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,24\n" +
			"1,3,26\n" +
			"2,3,46\n" +
			"3,4,34\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testOnTargetWithNoCommonKeys() throws Exception {
		/*
		 * Test joinWithEdgesOnTarget with the input DataSet containing different keys than the edge DataSet
		 * - the iterator becomes empty.
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnTarget(TestGraphUtils.getLongLongTuple2TargetData(env),
			new DoubleValueMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,20\n" +
			"1,3,40\n" +
			"2,3,40\n" +
			"3,4,80\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,140\n";

		compareResultAsTuples(result, expectedResult);
	}

	@Test
	public void testOnTargetWithCustom() throws Exception {
		/*
	     * Test joinWithEdgesOnTarget with a DataSet containing custom parametrised type input values
		 */
		final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

		Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

		Graph<Long, Long, Long> res = graph.joinWithEdgesOnTarget(TestGraphUtils.getLongCustomTuple2TargetData(env),
			new CustomValueMapper());

		DataSet<Edge<Long, Long>> data = res.getEdges();
		List<Edge<Long, Long>> result = data.collect();

		expectedResult = "1,2,10\n" +
			"1,3,20\n" +
			"2,3,20\n" +
			"3,4,40\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

		compareResultAsTuples(result, expectedResult);
	}

	@SuppressWarnings("serial")
	private static final class AddValuesMapper implements EdgeJoinFunction<Long, Long> {

		public Long edgeJoin(Long edgeValue, Long inputValue) throws Exception {
			return edgeValue + inputValue;
		}
	}

	@SuppressWarnings("serial")
	private static final class BooleanEdgeValueMapper implements MapFunction<Edge<Long, Long>, Tuple3<Long, Long, Boolean>> {
		public Tuple3<Long, Long, Boolean> map(Edge<Long, Long> edge) throws Exception {
			return new Tuple3<>(edge.getSource(), edge.getTarget(), true);
		}
	}

	@SuppressWarnings("serial")
	private static final class DoubleIfTrueMapper implements EdgeJoinFunction<Long, Boolean> {

		public Long edgeJoin(Long edgeValue, Boolean inputValue) {
			if (inputValue) {
				return edgeValue * 2;
			} else {
				return edgeValue;
			}
		}
	}

	@SuppressWarnings("serial")
	private static final class DoubleValueMapper implements EdgeJoinFunction<Long, Long> {

		public Long edgeJoin(Long edgeValue, Long inputValue) {
			return inputValue * 2;
		}
	}

	@SuppressWarnings("serial")
	private static final class CustomValueMapper implements EdgeJoinFunction<Long, DummyCustomParameterizedType<Float>> {

		public Long edgeJoin(Long edgeValue, DummyCustomParameterizedType<Float> inputValue) {
			return (long) inputValue.getIntField();
		}
	}

	@SuppressWarnings("serial")
	private static final class ProjectSourceAndValueMapper implements MapFunction<Edge<Long, Long>, Tuple2<Long, Long>> {
		public Tuple2<Long, Long> map(Edge<Long, Long> edge) throws Exception {
			return new Tuple2<>(edge.getSource(), edge.getValue());
		}
	}

	@SuppressWarnings("serial")
	private static final class ProjectSourceWithTrueMapper implements MapFunction<Edge<Long, Long>, Tuple2<Long, Boolean>> {
		public Tuple2<Long, Boolean> map(Edge<Long, Long> edge) throws Exception {
			return new Tuple2<>(edge.getSource(), true);
		}
	}

	@SuppressWarnings("serial")
	private static final class ProjectTargetAndValueMapper implements MapFunction<Edge<Long, Long>, Tuple2<Long, Long>> {
		public Tuple2<Long, Long> map(Edge<Long, Long> edge) throws Exception {
			return new Tuple2<>(edge.getTarget(), edge.getValue());
		}
	}

	@SuppressWarnings("serial")
	private static final class ProjectTargetWithTrueMapper implements MapFunction<Edge<Long, Long>, Tuple2<Long, Boolean>> {
		public Tuple2<Long, Boolean> map(Edge<Long, Long> edge) throws Exception {
			return new Tuple2<>(edge.getTarget(), true);
		}
	}
}