/*
 * Copyright 2019 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.
 */

package org.gradle.kotlin.dsl.provider.plugins.precompiled.tasks

import org.gradle.api.DefaultTask
import org.gradle.api.JavaVersion
import org.gradle.api.file.ConfigurableFileCollection
import org.gradle.api.file.Directory
import org.gradle.api.file.DirectoryProperty
import org.gradle.api.internal.properties.GradleProperties
import org.gradle.api.provider.Property
import org.gradle.api.provider.Provider
import org.gradle.api.tasks.CacheableTask
import org.gradle.api.tasks.IgnoreEmptyDirectories
import org.gradle.api.tasks.Input
import org.gradle.api.tasks.InputFiles
import org.gradle.api.tasks.Nested
import org.gradle.api.tasks.OutputDirectory
import org.gradle.api.tasks.PathSensitive
import org.gradle.api.tasks.PathSensitivity
import org.gradle.api.tasks.TaskAction
import org.gradle.jvm.toolchain.JavaLauncher
import org.gradle.kotlin.dsl.precompile.v1.PrecompiledPluginsBlock
import org.gradle.kotlin.dsl.support.ImplicitImports
import org.gradle.kotlin.dsl.support.KotlinCompilerOptions
import org.gradle.kotlin.dsl.support.compileKotlinScriptModuleForPrecompiledScriptPluginsTo
import org.gradle.kotlin.dsl.support.kotlinCompilerOptions
import org.gradle.kotlin.dsl.support.scriptDefinitionFromTemplate
import javax.inject.Inject


/**
 * Compiles the extracted `plugins {}` blocks from precompiled scripts of all targets.
 */
@CacheableTask
abstract class CompilePrecompiledScriptPluginPlugins @Inject constructor(

    private
    val implicitImports: ImplicitImports,

    private
    val gradleProperties: GradleProperties

) : DefaultTask(), SharedAccessorsPackageAware {

    private
    companion object {
        const val kotlinModuleName = "precompiled-script-plugin-plugins"
    }

    @get:OutputDirectory
    abstract val outputDir: DirectoryProperty

    @get:InputFiles
    @get:IgnoreEmptyDirectories
    @get:PathSensitive(PathSensitivity.RELATIVE)
    val sourceFiles: ConfigurableFileCollection = project.files(
        project.objects.sourceDirectorySet(
            kotlinModuleName,
            "Precompiled script plugin plugins"
        )
    )

    fun sourceDir(dir: Provider<Directory>) {
        sourceFiles.from(dir)
    }

    @get:Nested
    internal
    abstract val javaLauncher: Property<JavaLauncher>

    @get:Input
    protected
    val compilerOptions: Provider<KotlinCompilerOptions> = project.provider {
        kotlinCompilerOptions(gradleProperties).copy(jvmTarget = resolveJvmTarget())
    }

    @TaskAction
    fun compile() {
        outputDir.withOutputDirectory { outputDir ->
            val scriptFiles = sourceFiles.map { it.path }
            if (scriptFiles.isNotEmpty())
                compileKotlinScriptModuleForPrecompiledScriptPluginsTo(
                    outputDir,
                    compilerOptions.get(),
                    kotlinModuleName,
                    scriptFiles,
                    scriptDefinitionFromTemplate(
                        PrecompiledPluginsBlock::class,
                        implicitImportsForPrecompiledScriptPlugins(implicitImports)
                    ),
                    classPathFiles.filter { it.exists() },
                    logger,
                ) { it } // TODO: translate paths
        }
    }

    private
    fun resolveJvmTarget(): JavaVersion =
        JavaVersion.toVersion(javaLauncher.get().metadata.languageVersion.asInt())
}
