/*
 * Copyright 2017 the original author or authors.
 *
 * 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.
 */


import org.gradle.workers.WorkerExecutor

import javax.inject.Inject

// The implementation of a single unit of work
class ReverseFile implements Runnable {
    File fileToReverse
    File destinationFile

    @Inject
    public ReverseFile(File fileToReverse, File destinationFile) {
        this.fileToReverse = fileToReverse
        this.destinationFile = destinationFile
    }

    @Override
    public void run() {
        destinationFile.text = fileToReverse.text.reverse()
        if (Boolean.getBoolean("org.gradle.sample.showFileSize")) {
            println "Reversed ${fileToReverse.size()} bytes from ${fileToReverse.name}"
        }
    }
}

class ReverseFiles extends SourceTask {
    final WorkerExecutor workerExecutor

    @OutputDirectory
    File outputDir

    // The WorkerExecutor will be injected by Gradle at runtime
    @Inject
    public ReverseFiles(WorkerExecutor workerExecutor) {
        this.workerExecutor = workerExecutor
    }

    @TaskAction
    void reverseFiles() {
        // Create and submit a unit of work for each file
        source.files.each { file ->
            workerExecutor.submit(ReverseFile.class) { WorkerConfiguration config ->
                // Run this work in an isolated process
                config.isolationMode = IsolationMode.PROCESS

                // Configure the options for the forked process
                config.forkOptions { JavaForkOptions options ->
                    options.maxHeapSize = "512m"
                    options.systemProperty "org.gradle.sample.showFileSize", "true"
                }

                // Constructor parameters for the unit of work implementation
                config.params file, project.file("${outputDir}/${file.name}")
            }
        }
    }
}

task reverseFiles(type: ReverseFiles) {
    outputDir = file("${buildDir}/reversed")
    source("sources")
}