registerJextractTask.kt

package utilities

import org.gradle.api.Project
import org.gradle.api.tasks.Exec
import org.gradle.api.tasks.TaskProvider
import org.gradle.kotlin.dsl.register
import java.io.File
import java.nio.file.Files

private fun Project.swiftProductsWithJExtractPlugin(): List<String> = swiftPMPackage().targets.filter {
    it.productDependencies.contains("JExtractSwiftPlugin")
}.flatMap {
    it.productMemberships
}

private fun Project.registerSwiftCheckValidTask(): TaskProvider<*> = tasks.register<Exec>("swift-check-valid") {
    commandLine("swift")
    args("-version")
}

fun Project.registerJextractTask(
    arguments: () -> List<String> = {
        listOf("build", "--disable-experimental-prebuilts")
    }
): TaskProvider<*> {
    val swiftCheckValid = registerSwiftCheckValidTask()
    return tasks.register<Exec>("jextract") {
        description = "Generate Java wrappers for swift target"
        dependsOn(swiftCheckValid)

        // only because we depend on "live developing" the plugin while using this project to test it
        inputs.file(File(rootDir, "Package.swift"))
        inputs.dir(File(rootDir, "Sources"))

        // If the package description changes, we should execute jextract again, maybe we added jextract to new targets
        inputs.file(File(projectDir, "Package.swift"))

        // monitor all targets/products which depend on the JExtract plugin
        swiftProductsWithJExtractPlugin().forEach {
            logger.info("[swift-java:jextract (Gradle)] Swift input target: ${it}")
            inputs.dir(File(layout.projectDirectory.asFile, "Sources/${it}"))
        }
        outputs.dir(layout.buildDirectory.dir("../.build/plugins/outputs/${layout.projectDirectory.asFile.getName().lowercase()}"))

        val baseSwiftPluginOutputsDir = layout.buildDirectory.dir("../.build/plugins/outputs/").get().asFile
        if (!baseSwiftPluginOutputsDir.exists()) {
            baseSwiftPluginOutputsDir.mkdirs()
        }
        Files.walk(layout.buildDirectory.dir("../.build/plugins/outputs/").get().asFile.toPath()).forEach {
            // Add any Java sources generated by the plugin to our sourceSet
            if (it.endsWith("JExtractSwiftPlugin/src/generated/java")) {
                outputs.dir(it)
            }
        }

        workingDir = layout.projectDirectory.asFile
        commandLine("swift")
        // FIXME: disable prebuilts until swift-syntax isn't broken on 6.2 anymore: https://github.com/swiftlang/swift-java/issues/418
        args(arguments()) // since Swift targets which need to be jextract-ed have the jextract build plugin, we just need to build
        // If we wanted to execute a specific subcommand, we can like this:
        //     args("run",/*
        //             "swift-java", "jextract",
        //             "--swift-module", "MySwiftLibrary",
        //             // java.package is obtained from the swift-java.config in the swift module
        //             "--output-java", "${layout.buildDirectory.dir(".build/plugins/outputs/${layout.projectDirectory.asFile.getName().toLowerCase()}/JExtractSwiftPlugin/src/generated/java").get()}",
        //             "--output-swift", "${layout.buildDirectory.dir(".build/plugins/outputs/${layout.projectDirectory.asFile.getName().toLowerCase()}/JExtractSwiftPlugin/Sources").get()}",
        //             "--log-level", (logging.level <= LogLevel.INFO ? "debug" :  */"info")
        //     )
    }
}