/*
 * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
 * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
 */

package org.jetbrains.kotlin.gradle.targets.js.webpack

import org.gradle.api.Action
import org.gradle.api.DefaultTask
import org.gradle.api.Incubating
import org.gradle.api.file.*
import org.gradle.api.logging.Logging
import org.gradle.api.model.ObjectFactory
import org.gradle.api.provider.Property
import org.gradle.api.provider.Provider
import org.gradle.api.tasks.*
import org.gradle.deployment.internal.Deployment
import org.gradle.deployment.internal.DeploymentHandle
import org.gradle.deployment.internal.DeploymentRegistry
import org.gradle.process.ExecOperations
import org.gradle.work.NormalizeLineEndings
import org.jetbrains.kotlin.build.report.metrics.BuildMetricsReporter
import org.jetbrains.kotlin.build.report.metrics.BuildMetricsReporterImpl
import org.jetbrains.kotlin.build.report.metrics.GradleBuildPerformanceMetric
import org.jetbrains.kotlin.build.report.metrics.GradleBuildTime
import org.jetbrains.kotlin.gradle.plugin.KotlinPlatformType
import org.jetbrains.kotlin.gradle.report.UsesBuildMetricsService
import org.jetbrains.kotlin.gradle.targets.js.NpmVersions
import org.jetbrains.kotlin.gradle.targets.js.RequiredKotlinJsDependency
import org.jetbrains.kotlin.gradle.targets.js.dsl.KotlinWebpackRulesContainer
import org.jetbrains.kotlin.gradle.targets.js.dsl.WebpackRulesDsl
import org.jetbrains.kotlin.gradle.targets.js.dsl.WebpackRulesDsl.Companion.webpackRulesContainer
import org.jetbrains.kotlin.gradle.targets.js.ir.KotlinJsIrCompilation
import org.jetbrains.kotlin.gradle.targets.js.npm.RequiresNpmDependencies
import org.jetbrains.kotlin.gradle.targets.js.npm.npmProject
import org.jetbrains.kotlin.gradle.targets.js.webpack.KotlinWebpackConfig.Mode
import org.jetbrains.kotlin.gradle.utils.*
import org.jetbrains.kotlin.gradle.utils.processes.ExecAsyncHandle
import java.io.File
import javax.inject.Inject

@CacheableTask
abstract class KotlinWebpack
@Inject
internal constructor(
    @Internal
    @Transient
    final override val compilation: KotlinJsIrCompilation,
    private val objects: ObjectFactory,
    private val execOps: ExecOperations,
) : DefaultTask(), RequiresNpmDependencies, WebpackRulesDsl, UsesBuildMetricsService {

    @Deprecated("Extending this class is deprecated. Scheduled for removal in Kotlin 2.4.")
    @Suppress("DEPRECATION")
    constructor(
        compilation: KotlinJsIrCompilation,
    ) : this(
        compilation = compilation,
        objects = compilation.project.objects,
        execOps = compilation.project.getExecOperations(),
    )

    @get:Internal
    internal abstract val versions: Property<NpmVersions>

    @get:Internal
    internal val rootPackageDir: Property<Directory> = project.objects.directoryProperty()

    private val npmProject = compilation.npmProject

    override val rules: KotlinWebpackRulesContainer =
        project.objects.webpackRulesContainer()

    @get:Internal
    @Deprecated(
        "ExecHandleFactory is an internal Gradle API and must be removed to support Gradle 9.0. Please remove usages of this property. Scheduled for removal in Kotlin 2.4.",
        ReplaceWith("TODO(\"ExecHandleFactory is an internal Gradle API and must be removed to support Gradle 9.0. Please remove usages of this property.\")"),
    )
    @Suppress("unused")
    open val execHandleFactory: Nothing
        get() = injected

    private val metrics: Property<BuildMetricsReporter<GradleBuildTime, GradleBuildPerformanceMetric>> = project.objects
        .property(BuildMetricsReporterImpl())

    @Suppress("unused")
    @get:Input
    val compilationId: String by lazy {
        compilation.let {
            val target = it.target
            target.project.path + "@" + target.name + ":" + it.compilationName
        }
    }

    @Input
    var mode: Mode = Mode.DEVELOPMENT

    @get:Internal
    internal abstract val getIsWasm: Property<Boolean>

    @get:Internal
    internal abstract val npmToolingEnvDir: DirectoryProperty

    @get:Internal
    abstract val inputFilesDirectory: DirectoryProperty

    @get:Input
    abstract val entryModuleName: Property<String>

    @get:Internal
    val npmProjectDir: Provider<File>
        get() = inputFilesDirectory.map { it.asFile.parentFile }

    @get:PathSensitive(PathSensitivity.RELATIVE)
    @get:InputFiles
    @get:NormalizeLineEndings
    val inputFiles: FileTree
        get() = objects.fileTree()
            .let { fileTree ->
                // in webpack.config.js there is path relative to npmProjectDir (kotlin/<module>.js).
                // And we need have relative path in build cache
                // That's why we use npmProjectDir with filter instead of just inputFilesDirectory,
                // if we would use inputFilesDirectory, we will get in cache just file names,
                // and if directory is changed to kotlin2, webpack config will be invalid.
                fileTree.from(npmProjectDir)
                    .matching {
                        it.include { element: FileTreeElement ->
                            this.inputFilesDirectory.get().asFile.isParentOf(element.file)
                        }
                    }
            }

    @get:Input
    abstract val esModules: Property<Boolean>

    @get:Internal
    val entry: Provider<RegularFile>
        get() = inputFilesDirectory.map {
            it.file(entryModuleName.get() + if (esModules.get()) ".mjs" else ".js")
        }

    init {
        this.onlyIf {
            entry.get().asFile.exists()
        }
    }

    @get:Internal
    internal var resolveFromModulesFirst: Boolean = false

    @get:OutputFile
    open val configFile: Provider<File> =
        npmProjectDir.map { it.resolve("webpack.config.js") }

    @Nested
    val output: KotlinWebpackOutput = KotlinWebpackOutput(
        library = project.archivesName.orNull,
        libraryTarget = KotlinWebpackOutput.Target.UMD,
        clean = true,
    )

    @get:Internal
    @Deprecated(
        "Use `outputDirectory` instead. Scheduled for removal in Kotlin 2.3.",
        ReplaceWith("outputDirectory"),
        level = DeprecationLevel.ERROR
    )
    var destinationDirectory: File
        get() = outputDirectory.asFile.get()
        set(value) {
            outputDirectory.set(value)
        }

    @get:OutputDirectory
    @get:Optional
    abstract val outputDirectory: DirectoryProperty

    @get:Internal
    @Deprecated(
        "Use `mainOutputFileName` instead. Scheduled for removal in Kotlin 2.3.",
        ReplaceWith("mainOutputFileName"),
        level = DeprecationLevel.ERROR
    )
    var outputFileName: String
        get() = mainOutputFileName.get()
        set(value) {
            mainOutputFileName.set(value)
        }

    @get:Internal
    abstract val mainOutputFileName: Property<String>

    @get:Internal
    @Deprecated(
        "Use `mainOutputFile` instead. Scheduled for removal in Kotlin 2.3.",
        ReplaceWith("mainOutputFile"),
        level = DeprecationLevel.ERROR
    )
    open val outputFile: File
        get() = mainOutputFile.get().asFile

    @get:Internal
    val mainOutputFile: Provider<RegularFile> =
        objects.providerWithLazyConvention { outputDirectory.file(mainOutputFileName) }.flatMap { it }

    private val projectDir = project.projectDir

    @get:PathSensitive(PathSensitivity.NAME_ONLY)
    @get:Optional
    @get:IgnoreEmptyDirectories
    @get:NormalizeLineEndings
    @get:InputDirectory
    open val configDirectory: File?
        get() = projectDir.resolve("webpack.config.d").takeIf { it.isDirectory }

    @Input
    var debug: Boolean = false

    @Input
    var bin: String = "webpack/bin/webpack.js"

    @Input
    var args: MutableList<String> = mutableListOf()

    @Input
    var nodeArgs: MutableList<String> = mutableListOf()

    @Input
    var sourceMaps: Boolean = true

    @Input
    @Optional
    val devServerProperty: Property<KotlinWebpackConfig.DevServer> = project.objects.property(KotlinWebpackConfig.DevServer::class.java)

    @get:Internal
    @Deprecated(
        "Use devServerProperty instead. Scheduled for removal in Kotlin 2.3.",
        replaceWith = ReplaceWith("devServerProperty"),
        level = DeprecationLevel.ERROR,
    )
    var devServer: KotlinWebpackConfig.DevServer
        get() = devServerProperty.get()
        set(value) = devServerProperty.set(value)

    @Input
    @Optional
    var watchOptions: KotlinWebpackConfig.WatchOptions? = null

    @Input
    var devtool: String = WebpackDevtool.EVAL_SOURCE_MAP

    @Incubating
    @Internal
    var generateConfigOnly: Boolean = false

    private val fakeWebpackConfig: KotlinWebpackConfig = KotlinWebpackConfig(
        rules = project.objects.webpackRulesContainer()
    )

    fun webpackConfigApplier(body: Action<KotlinWebpackConfig>) {
        body.execute(fakeWebpackConfig)
        fakeWebpackConfig.let {
            it.outputFileName?.let { mainOutputFileName.set(it) }
        }
        webpackConfigAppliers.add(body)
    }

    @get:Nested
    internal val webpackConfigAppliers: MutableList<Action<KotlinWebpackConfig>> =
        mutableListOf()

    private val platformType by project.provider {
        compilation.platformType
    }

    /**
     * [forNpmDependencies] is used to avoid querying [outputDirectory] before task execution.
     * Otherwise, Gradle will fail the build.
     */
    private fun createWebpackConfig(forNpmDependencies: Boolean = false) = KotlinWebpackConfig(
        npmProjectDir = npmProjectDir,
        mode = mode,
        entry = if (forNpmDependencies) null else entry.get().asFile,
        output = output,
        outputPath = if (forNpmDependencies) null else outputDirectory.getOrNull()?.asFile,
        outputFileName = mainOutputFileName.get(),
        configDirectory = configDirectory,
        rules = rules,
        watchOptions = watchOptions,
        devServer = devServerProperty.orNull,
        devtool = devtool,
        sourceMaps = sourceMaps,
        resolveFromModulesFirst = resolveFromModulesFirst,
        resolveLoadersFromKotlinToolingDir = getIsWasm.get()
    )

    private fun createRunner(): KotlinWebpackRunner {
        val config = createWebpackConfig()

        if (platformType == KotlinPlatformType.wasm) {
            config.experiments += listOf(
                "asyncWebAssembly",
                "topLevelAwait"
            )
        }

        webpackConfigAppliers
            .forEach { it.execute(config) }

        val webpackArgs = args.run {
            val port = devServerProperty.orNull?.port
            if (debug && port != null) plus(listOf("--port", port.toString()))
            else this
        }

        return KotlinWebpackRunner(
            npmProject = npmProject,
            logger = logger,
            configFile = configFile.get(),
            tool = bin,
            args = webpackArgs,
            nodeArgs = nodeArgs,
            config = config,
            objects = objects,
            execOps = execOps,
            npmToolingEnvDir = npmToolingEnvDir.getFile(),
            resolveModulesFromKotlinToolingDir = getIsWasm.get(),
        )
    }

    override val requiredNpmDependencies: Set<RequiredKotlinJsDependency>
        @Internal get() = createWebpackConfig(true).getRequiredDependencies(versions.get())

    private val isContinuous = project.gradle.startParameter.isContinuous

    @TaskAction
    fun doExecute() {
        val runner = createRunner()

        if (generateConfigOnly) {
            runner.config.save(configFile.get())
            return
        }

        if (isContinuous) {
            val deploymentRegistry = services.get(DeploymentRegistry::class.java)
            val deploymentHandle = deploymentRegistry.get("webpack", Handle::class.java)
            if (deploymentHandle == null) {
                deploymentRegistry.start("webpack", DeploymentRegistry.ChangeBehavior.BLOCK, Handle::class.java, runner, path)
            }
        } else {
            runner.copy(
                config = runner.config.copy(
                    progressReporter = true,
                )
            ).execute()

            val buildMetrics = metrics.get()
            outputDirectory.get().asFile.walkTopDown()
                .filter { it.isFile }
                .filter { it.extension == "js" }
                .map { it.length() }
                .sum()
                .let {
                    buildMetrics.addMetric(GradleBuildPerformanceMetric.BUNDLE_SIZE, it)
                }

            buildMetricsService.orNull?.also { it.addTask(path, this.javaClass, buildMetrics) }
        }
    }

    internal abstract class Handle @Inject constructor(
        private val runner: KotlinWebpackRunner,
        /** [KotlinWebpack.getPath], used for logging. */
        private val taskPath: String,
    ) : DeploymentHandle {
        private var process: ExecAsyncHandle? = null

        private val logger = Logging.getLogger(Handle::class.java)

        override fun isRunning(): Boolean =
            process?.isAlive() == true

        override fun start(deployment: Deployment) {
            process = runner.start()
            logger.info("[$taskPath] webpack-dev-server started ${process?.displayName}")
        }

        override fun stop() {
            process?.abort()
            logger.info("[$taskPath] webpack-dev-server stopped ${process?.displayName}")
        }
    }
}
