/*
 * Copyright (C) 2021. Uber Technologies
 *
 * 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.
 */
plugins {
    id 'java-library'
    id 'nullaway.jacoco-conventions'
    id 'me.champeau.jmh'
}

configurations {
    // create a configuration for the sources and dependencies of each benchmark
    caffeineSources
    caffeineDeps

    autodisposeSources
    autodisposeDeps
}
dependencies {

    // Add NullAway and Error Prone Core as dependencies.  This ensures that the classes get included
    // in the jmh-generated jar, and hence get JIT-compiled during benchmarking.  Without this dependence, NullAway
    // can still be loaded via the processor path, but it gets reloaded on each run of compilation, skewing
    // performance measurements
    implementation project(':nullaway')
    // use the same version of Error Prone Core that we are compiling NullAway against, so we can
    // benchmark against different versions of Error Prone
    implementation deps.build.errorProneCoreForApi


    // Source jars for our desired benchmarks
    caffeineSources('com.github.ben-manes.caffeine:caffeine:3.0.2:sources') {
        transitive = false
    }
    autodisposeSources('com.uber.autodispose2:autodispose:2.1.0:sources') {
        transitive = false
    }

    caffeineDeps 'com.github.ben-manes.caffeine:caffeine:3.0.2'
    autodisposeDeps 'com.uber.autodispose2:autodispose:2.1.0'

    testImplementation deps.test.junit4
}

def caffeineSourceDir = project.layout.buildDirectory.dir('caffeineSources')
def autodisposeSourceDir = project.layout.buildDirectory.dir('autodisposeSources')

task extractCaffeineSources(type: Copy) {
    from zipTree(configurations.caffeineSources.singleFile)
    into caffeineSourceDir
}

task extractAutodisposeSources(type: Copy) {
    from zipTree(configurations.autodisposeSources.singleFile)
    into autodisposeSourceDir
}

compileJava.dependsOn(extractCaffeineSources)
compileJava.dependsOn(extractAutodisposeSources)

// always run jmh
tasks.getByName('jmh').outputs.upToDateWhen { false }

jmh {
    // seems we need more iterations to fully warm up the JIT
    warmupIterations = 10

    // a trick: to get the classpath for a benchmark, create a configuration that depends on the benchmark, and
    // then filter out the benchmark itself
    def caffeineClasspath = configurations.caffeineDeps.filter({f -> !f.toString().contains("caffeine-3.0.2")}).asPath
    def autodisposeClasspath = configurations.autodisposeDeps.filter({f -> !f.toString().contains("autodispose-2.1.0")}).asPath

    jvmArgsAppend = [
            "-Dnullaway.caffeine.sources=${caffeineSourceDir.get()}",
            "-Dnullaway.caffeine.classpath=$caffeineClasspath",
            "-Dnullaway.autodispose.sources=${autodisposeSourceDir.get()}",
            "-Dnullaway.autodispose.classpath=$autodisposeClasspath",
    ]

    // commented-out examples of how to tweak other jmh parameters; they show the default values
    // for more examples see https://github.com/melix/jmh-gradle-plugin/blob/master/README.adoc#configuration-options
    // iterations = 5
    // fork = 5
}

// don't run test task on pre-JDK-11 VMs
test.onlyIf { JavaVersion.current() >= JavaVersion.VERSION_11 }