/*
 * 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.maven.surefire.its.jiras;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import org.apache.maven.it.VerificationException;
import org.apache.maven.surefire.its.fixture.OutputValidator;
import org.apache.maven.surefire.its.fixture.SurefireJUnit4IntegrationTestCase;
import org.apache.maven.surefire.its.fixture.SurefireLauncher;
import org.junit.Test;

import static org.hamcrest.core.AnyOf.anyOf;
import static org.hamcrest.core.Is.is;
import static org.junit.Assert.assertThat;

/**
 * The purpose of this IT is to assert that the run order of test classes is according to the settings:<br>
 * <p>
 * runOrder=balanced<br> parallel=classes<br> threadCount=2<br> perCoreThreadCount=false<br>
 * <br>
 * The list of tests should be reordered to (DTest, CTest, BTest, ATest) in the second run.
 *
 * @author <a href="mailto:tibordigana@apache.org">Tibor Digana (tibor17)</a>
 * @see <a href="https://issues.apache.org/jira/browse/SUREFIRE-1098">SUREFIRE-1098</a>
 * @since 2.18
 */
public class Surefire1098BalancedRunOrderIT extends SurefireJUnit4IntegrationTestCase {

    @Test
    public void reorderedParallelClasses() throws VerificationException {
        // first execution
        unpack().setLogFileName("log1.txt")
                // .runOrder( "balanced" ) call it in 3.x and remove it in surefire-1098-balanced-runorder/pom.xml
                // as soon as there is prefix available "failsafe" and "surefire" in system property for this parameter.
                .parallelClasses()
                .threadCount(2)
                .disablePerCoreThreadCount()
                .executeTest()
                .verifyErrorFree(4);

        // and second from new instance - if we use the same instance - hasExecutedBefore return true
        OutputValidator validator = unpack().setLogFileName("log2.txt")
                // .runOrder( "balanced" ) call it in 3.x and remove it in surefire-1098-balanced-runorder/pom.xml
                // as soon as there is prefix available "failsafe" and "surefire" in system property for this parameter.
                .parallelClasses()
                .threadCount(2)
                .disablePerCoreThreadCount()
                .executeTest()
                .verifyErrorFree(4);

        List<String> log = printOnlyTestLines(validator);
        assertThat(log.size(), is(4));
        Collections.sort(log);
        final int[] threadPoolIdsOfLongestTest = extractThreadPoolIds(log.get(3));
        final int pool = threadPoolIdsOfLongestTest[0];
        int thread = threadPoolIdsOfLongestTest[1];
        assertThat(thread, anyOf(is(1), is(2)));
        thread = thread == 1 ? 2 : 1;
        // If the longest test class DTest is running in pool-2-thread-1, the others should run in pool-2-thread-2
        // and vice versa.
        assertThat(log.get(0), is(testLine("A", pool, thread)));
        assertThat(log.get(1), is(testLine("B", pool, thread)));
        assertThat(log.get(2), is(testLine("C", pool, thread)));
    }

    private SurefireLauncher unpack() {
        return unpack("surefire-1098-balanced-runorder");
    }

    private static List<String> printOnlyTestLines(OutputValidator validator) throws VerificationException {
        List<String> log = new ArrayList<>(validator.loadLogLines());
        for (Iterator<String> it = log.iterator(); it.hasNext(); ) {
            String line = it.next();
            if (!line.startsWith("class jiras.surefire1098.")) {
                it.remove();
            }
        }
        return log;
    }

    private static int[] extractThreadPoolIds(String logLine) {
        // Example to parse "class jiras.surefire1098.DTest pool-2-thread-1" into {2, 1}.
        String t = logLine.split(" ")[2];
        String[] ids = t.split("-");
        return new int[] {Integer.parseInt(ids[1]), Integer.parseInt(ids[3])};
    }

    private String testLine(String test, int pool, int thread) {
        return String.format("class jiras.surefire1098.%sTest pool-%d-thread-%d", test, pool, thread);
    }
}
