project.plugins.withType(AppPlugin::class.java) {
    // Queries for the extension set by the Android Application plugin.
    // This is the second of two entry points into the Android Gradle plugin
    val androidComponents =
        project.extensions.getByType(ApplicationAndroidComponentsExtension::class.java)
    // Registers a callback to be called, when a new variant is configured
    androidComponents.onVariants { variant ->
        val taskProvider = project.tasks.register<ModifyClassesTask>("${variant.name}ModifyClasses")

        // Register modify classes task
        variant.artifacts.forScope(ScopedArtifacts.Scope.PROJECT)
            .use(taskProvider)
            .toTransform(
                ScopedArtifact.CLASSES,
                ModifyClassesTask::allJars,
                ModifyClassesTask::allDirectories,
                ModifyClassesTask::output
            )
    }
}

/**
 * Transform the current version of the [type] artifact into a new version. The order in which
 * the transforms are applied is directly set by the order of this method call. First come,
 * first served, last one provides the final version of the artifacts.
 *
 * @param type the [ScopedArtifact] to transform.
 * @param inputJars lambda that returns a [ListProperty] or [RegularFile] that will be used to
 * set all incoming files for this artifact type.
 * @param inputDirectories lambda that returns a [ListProperty] or [Directory] that will be used
 * to set all incoming directories for this artifact type.
 * @param into lambda that returns the [Property] used by the [Task] to save the transformed
 * element. The [Property] value will be automatically set by the Android Gradle Plugin and its
 * location should not be considered part of the API and can change in the future.
 */
fun toTransform(
    type: ScopedArtifact,
    inputJars: (T) -> ListProperty<RegularFile>,
    inputDirectories: (T) -> ListProperty<Directory>,
    into: (T) -> RegularFileProperty)

/**
 * Set the final version of the [type] artifact to the input fields of the [Task] [T].
 * Those input fields should be annotated with [org.gradle.api.tasks.InputFiles] for Gradle to
 * property set the task dependency.
 *
 * @param type the [ScopedArtifact] to obtain the final value of.
 * @param inputJars lambda that returns a [ListProperty] or [RegularFile] that will be used to
 * set all incoming files for this artifact type.
 * @param inputDirectories lambda that returns a [ListProperty] or [Directory] that will be used
 * to set all incoming directories for this artifact type.
 */
fun toGet(
    type: ScopedArtifact,
    inputJars: (T) -> ListProperty<RegularFile>,
    inputDirectories: (T) -> ListProperty<Directory>)

variant.artifacts
    .forScope(ScopedArtifacts.Scope.PROJECT)
    .use(taskProvider)
    .toGet(
        ScopedArtifact.CLASSES,
        CheckClassesTask::projectJars,
        CheckClassesTask::projectDirectories,
    )