/*
 * Copyright OpenSearch Contributors
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * OpenSearch Plugin build tools don't work with the Gradle Jacoco Plugin to report coverage out of the box.
 * https://github.com/elastic/elasticsearch/issues/28867.
 *
 * This code sets up coverage reporting manually for OpenSearch plugin tests. This is complicated because:
 *  1. The OpenSearch integTest Task doesn't implement Gradle's JavaForkOptions so we have to manually start the jacoco agent with the test JVM
 *  2. The cluster nodes are stopped using 'kill -9' which means jacoco can't dump it's execution output to a file on VM shutdown
 *  3. The Java Security Manager prevents JMX from writing execution output to the file.
 *
 *  To workaround these we start the cluster with jmx enabled and then use Jacoco's JMX MBean to get the execution data before the
 *  cluster is stopped and dump it to a file. Luckily our current security policy seems to allow this. This will also probably
 *  break if there are multiple nodes in the integTestCluster. But for now... it sorta works.
 */

// Get gradle to generate the required jvm agent arg for us using a dummy tasks of type Test. Unfortunately Elastic's
// testing tasks don't derive from Test so the jacoco plugin can't do this automatically.
def jacocoDir = "${buildDir}/jacoco"

task dummyTest(type: Test) {
    enabled = false
    workingDir = file("/") // Force absolute path to jacoco agent jar
    jacoco {
        destinationFile = file("${jacocoDir}/test.exec")
        destinationFile.parentFile.mkdirs()
        jmx = true
    }
}

task dummyIntegTest(type: Test) {
    enabled = false
    workingDir = file("/") // Force absolute path to jacoco agent jar
    jacoco {
        destinationFile = file("${jacocoDir}/integTest.exec")
        destinationFile.parentFile.mkdirs()
        jmx = true
    }
}

integTest {
    systemProperty 'jacoco.dir', "${jacocoDir}"
}

jacocoTestReport {
    dependsOn integTest, test
    executionData dummyTest.jacoco.destinationFile, dummyIntegTest.jacoco.destinationFile
    sourceDirectories.from = "src/main/kotlin"
    classDirectories.from = sourceSets.main.output
    reports {
        html.enabled = true // human readable
        xml.enabled = true // for coverlay
    }
}

allprojects{
    afterEvaluate {
        jacocoTestReport.dependsOn integTest

        testClusters.integTest {
            jvmArgs " ${dummyIntegTest.jacoco.getAsJvmArg()}".replace('javaagent:','javaagent:/')
            systemProperty 'com.sun.management.jmxremote', "true"
            systemProperty 'com.sun.management.jmxremote.authenticate', "false"
            systemProperty 'com.sun.management.jmxremote.port', "7777"
            systemProperty 'com.sun.management.jmxremote.ssl', "false"
            systemProperty 'java.rmi.server.hostname', "127.0.0.1"
        }
    }
}