build-system/gradle-core/src/main/java/com/android/build/gradle/internal/dependency/IdentityTransform.kt

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * 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.
 */

package com.android.build.gradle.internal.dependency

import org.gradle.api.artifacts.transform.InputArtifact
import org.gradle.api.artifacts.transform.TransformAction
import org.gradle.api.artifacts.transform.TransformOutputs
import org.gradle.api.file.FileSystemLocation
import org.gradle.api.provider.Provider
import org.gradle.api.tasks.Classpath
import java.io.IOException

/**
 * Transform to go from one artifact type to one or multiple other artifact types without changing
 * the artifact's contents.
 */
abstract class IdentityTransform : TransformAction<GenericTransformParameters> {

    @get:Classpath
    @get:InputArtifact
    abstract val inputArtifact: Provider<FileSystemLocation>

    override fun transform(transformOutputs: TransformOutputs) {
        val input = inputArtifact.get().asFile
        when {
            input.isDirectory -> transformOutputs.dir(input)
            input.isFile -> transformOutputs.file(input)
            else -> throw IOException("Expecting a file or a directory: ${input.canonicalPath}")
        }
    }
}