/*
 * 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.asm.simple.undirected;

import org.apache.flink.api.java.io.DiscardingOutputFormat;
import org.apache.flink.graph.Edge;
import org.apache.flink.graph.Graph;
import org.apache.flink.graph.asm.AsmTestBase;
import org.apache.flink.graph.generator.TestUtils;
import org.apache.flink.test.util.TestBaseUtils;
import org.apache.flink.types.IntValue;
import org.apache.flink.types.NullValue;

import org.junit.Before;
import org.junit.Test;

import java.util.LinkedList;
import java.util.List;

/**
 * Tests for {@link Simplify}.
 */
public class SimplifyTest extends AsmTestBase {

	protected Graph<IntValue, NullValue, NullValue> graph;

	@Before
	@Override
	public void setup() throws Exception {
		super.setup();

		Object[][] edges = new Object[][]{
			new Object[]{0, 0},
			new Object[]{0, 1},
			new Object[]{0, 1},
			new Object[]{0, 2},
			new Object[]{0, 2},
			new Object[]{1, 0},
			new Object[]{2, 2},
		};

		List<Edge<IntValue, NullValue>> edgeList = new LinkedList<>();

		for (Object[] edge : edges) {
			edgeList.add(new Edge<>(new IntValue((int) edge[0]), new IntValue((int) edge[1]), NullValue.getInstance()));
		}

		graph = Graph.fromCollection(edgeList, env);
	}

	@Test
	public void testWithFullFlip() throws Exception {
		String expectedResult =
			"(0,1,(null))\n" +
			"(0,2,(null))\n" +
			"(1,0,(null))\n" +
			"(2,0,(null))";

		Graph<IntValue, NullValue, NullValue> simpleGraph = graph
			.run(new Simplify<>(false));

		TestBaseUtils.compareResultAsText(simpleGraph.getEdges().collect(), expectedResult);
	}

	@Test
	public void testWithClipAndFlip() throws Exception {
		String expectedResult =
			"(0,1,(null))\n" +
			"(1,0,(null))";

		Graph<IntValue, NullValue, NullValue> simpleGraph = graph
			.run(new Simplify<>(true));

		TestBaseUtils.compareResultAsText(simpleGraph.getEdges().collect(), expectedResult);
	}

	@Test
	public void testParallelism() throws Exception {
		int parallelism = 2;

		Graph<IntValue, NullValue, NullValue> simpleGraph = graph
			.run(new Simplify<>(true));

		simpleGraph.getVertices().output(new DiscardingOutputFormat<>());
		simpleGraph.getEdges().output(new DiscardingOutputFormat<>());

		TestUtils.verifyParallelism(env, parallelism);
	}
}