package kotlinx.coroutines

import kotlinx.coroutines.internal.*
import org.w3c.dom.*
import kotlin.coroutines.*

internal external interface JsProcess : JsAny {
    fun nextTick(handler: () -> Unit)
}

internal fun tryGetProcess(): JsProcess? =
    js("(typeof(process) !== 'undefined' && typeof(process.nextTick) === 'function') ? process : null")

internal fun tryGetWindow(): Window? =
    js("(typeof(window) !== 'undefined' && window != null && typeof(window.addEventListener) === 'function') ? window : null")

internal actual fun createDefaultDispatcher(): CoroutineDispatcher =
    tryGetProcess()?.let(::NodeDispatcher)
        ?: tryGetWindow()?.let(::WindowDispatcher)
        ?: SetTimeoutDispatcher

@PublishedApi // Used from kotlinx-coroutines-test via suppress, not part of ABI
internal actual val DefaultDelay: Delay
    get() = Dispatchers.Default as Delay

public actual fun CoroutineScope.newCoroutineContext(context: CoroutineContext): CoroutineContext {
    val combined = coroutineContext + context
    return if (combined !== Dispatchers.Default && combined[ContinuationInterceptor] == null)
        combined + Dispatchers.Default else combined
}

public actual fun CoroutineContext.newCoroutineContext(addedContext: CoroutineContext): CoroutineContext {
    return this + addedContext
}

// No debugging facilities on Wasm
internal actual inline fun <T> withCoroutineContext(context: CoroutineContext, countOrElement: Any?, block: () -> T): T = block()
internal actual inline fun <T> withContinuationContext(continuation: Continuation<*>, countOrElement: Any?, block: () -> T): T = block()
internal actual fun Continuation<*>.toDebugString(): String = toString()
internal actual val CoroutineContext.coroutineName: String? get() = null // not supported on Wasm

internal actual class UndispatchedCoroutine<in T> actual constructor(
    context: CoroutineContext,
    uCont: Continuation<T>
) : ScopeCoroutine<T>(context, uCont) {
    override fun afterResume(state: Any?) = uCont.resumeWith(recoverResult(state, uCont))
}