@file:Suppress("UNCHECKED_CAST")

import org.gradle.api.Project
import org.gradle.api.plugins.ExtensionAware
import org.gradle.kotlin.dsl.get
import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
import org.jetbrains.kotlin.gradle.plugin.*
import org.jetbrains.kotlin.gradle.plugin.mpp.*
import org.jetbrains.kotlin.gradle.plugin.sources.DefaultKotlinSourceSet
import kotlin.reflect.KProperty
import org.gradle.api.NamedDomainObjectCollection as NdoCollection
import org.gradle.api.NamedDomainObjectContainer as NdoContainer

internal typealias Presets = NdoCollection<KotlinTargetPreset<*>>
internal typealias Targets = NdoCollection<KotlinTarget>

val Presets.jvm get() = this["jvm"] as KotlinJvmTargetPreset
val Presets.js get() = this["js"] as KotlinJsTargetPreset
val Presets.linuxX64 get() = this["linuxX64"] as KotlinNativeTargetPreset
val Presets.macosX64 get() = this["macosX64"] as KotlinNativeTargetPreset
val Presets.mingwX64 get() = this["mingwX64"] as KotlinNativeTargetPreset
val Presets.iosX64 get() = this["iosX64"] as KotlinNativeTargetPreset
val <T : KotlinCompilation> NdoCollection<T>.main get() = this["main"]

internal val hostOs by lazy { System.getProperty("os.name") }

val isLinux get() = hostOs == "Linux"
val isMacos get() = hostOs == "Mac OS X"
val isWindows get() = hostOs.startsWith("Windows")

val Presets.host
    get() = when {
        isLinux -> linuxX64
        isMacos -> macosX64
        isWindows -> mingwX64
        else -> error("Unknown host platform '$hostOs'")
    }

fun <T : KotlinTarget> Targets.fromPreset(preset: KotlinTargetPreset<T>, name: String, handler: T.() -> Unit = {}): T {
    val target = preset.createTarget(name)
    add(target)
    handler(target)
    return target
}

fun <T : KotlinTarget> Targets.gettingTyped(configure: T.() -> Unit) =
        KotlinTargetDelegateProvider(this, configure)

class KotlinTargetDelegateProvider<T : KotlinTarget>(val targets: Targets, val configure: T.() -> Unit) {
    operator fun getValue(thisRef: Any?, property: KProperty<*>): T =
            (targets.getByName(property.name) as T).apply(configure)
}


val KotlinMultiplatformExtension.extensions get() = (this as ExtensionAware).extensions

fun KotlinMultiplatformExtension.`sourceSets`(configure: NdoContainer<KotlinSourceSet>.() -> Unit): Unit =
        extensions.configure("sourceSets", configure)

fun KotlinMultiplatformExtension.`targets`(configure: NdoContainer<KotlinTarget>.() -> Unit): Unit =
        extensions.configure("targets", configure)

val NdoContainer<KotlinSourceSet>.commonMain get() = getByName("commonMain")
val NdoContainer<KotlinSourceSet>.iosMain get() = getByName("iosMain")
val NdoContainer<KotlinSourceSet>.jvmMain get() = getByName("jvmMain")

operator fun KotlinSourceSet.invoke(configure: KotlinSourceSet.() -> Unit) {
    configure()
}


class KotlinDefaultConfigureProperties(val presets: Presets) {
    var hasJvm = true
    var hasIos = true
    val dependencyProjects = mutableListOf<Project>()

    fun dependsOn(project: Project) {
        dependencyProjects.add(project)
    }

    /*
    fun dependencies(configure: KotlinDependencyHandler.() -> Unit) {
        TODO("not implemented")
    }
    */
}

private val KotlinDefaultConfigureProperties.targets
    get() = listOf(presets.jvm.takeIf { hasJvm }, presets.iosX64.takeIf { hasIos }).filterNotNull()

fun KotlinMultiplatformExtension.defaultConfigure(configure: KotlinDefaultConfigureProperties.() -> Unit = {}) {
    val props = KotlinDefaultConfigureProperties(presets).apply(configure)

    targets {
        for (preset in props.targets) {
            val name = when (preset.name) {
                "jvm", "androidJvm" -> "jvm"
                "iosX64", "iosArm64" -> "ios"
                else -> throw IllegalArgumentException()
            }

            fromPreset(preset, name) {
                if (platformType == KotlinPlatformType.native) {
                    this as KotlinNativeTarget
                    compilations.main.outputKinds(NativeOutputKind.FRAMEWORK)
                }
            }
        }
    }

    sourceSets {
        forEach {
            it.languageSettings.apply {
                apiVersion = "1.3"
                languageVersion = "1.3"

                useExperimentalAnnotation("kotlin.Experimental")
            }
        }

        getByName("commonMain").apply {
            dependencies {
                commonDependencies()

                for (project in props.dependencyProjects) {
                    api(project)
                }
            }
        }

        for (target in targets) {
            if (target.platformType == KotlinPlatformType.common) continue

            target.compilations.main.apply {

                for (sourceSet in sourceSets) {
                    sourceSet as DefaultKotlinSourceSet
                    if (!sourceSet.displayName.startsWith(name)) continue
                    val compilationName = sourceSet.displayName.substring(name.length)
                    sourceSet.dependsOn(getByName("common$compilationName"))
                }

                dependencies {
                    when (target.name) {
                        "jvm" -> jvmDependencies()
                        "androidJvm" -> androidDependencies()
                        "iosX64", "iosArm64" -> nativeDependencies()
                    }
                }
            }
        }
    }

}

private fun KotlinDependencyHandler.commonDependencies() {
    api("org.jetbrains.kotlin:kotlin-stdlib-common")
    api("org.jetbrains.kotlinx:kotlinx-coroutines-core-common:$coroutinesVersion")
}

private fun KotlinDependencyHandler.jvmDependencies() {
    api("org.jetbrains.kotlin:kotlin-stdlib")
    api("org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutinesVersion")
}

private fun KotlinDependencyHandler.androidDependencies() {
    api("org.jetbrains.kotlin:kotlin-stdlib-android")
    api("org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutinesVersion")
}

private fun KotlinDependencyHandler.nativeDependencies() {
    api("org.jetbrains.kotlin:kotlin-stdlib-native")
    api("org.jetbrains.kotlinx:kotlinx-coroutines-core-native:$coroutinesVersion")
}