package net.sergeych.synctools

import kotlinx.coroutines.TimeoutCancellationException
import kotlinx.coroutines.channels.Channel
import kotlinx.coroutines.runBlocking
import kotlinx.coroutines.withTimeout

/**
 * Platform-independent interface to thread wait/notify. Does nothing in JS/browser,
 * and uses appropriate mechanics on other platforms.
 */
@Suppress("EXPECT_ACTUAL_CLASSIFIERS_ARE_IN_BETA_WARNING")
actual class WaitHandle {
    private val channel = Channel<Unit>()
    actual fun await(milliseconds: Long): Boolean {
        return runBlocking {
            try {
                if( milliseconds > 0) {
                    withTimeout(milliseconds) {
                        channel.receive()
                        true
                    }
                }
                else {
                    channel.receive()
                    true
                }
            }
            catch(_: TimeoutCancellationException) {
                false
            }
        }
    }

    actual fun wakeUp() {
        runBlocking { channel.send(Unit) }
    }
}