package com.peachpasswords.sync

import org.junit.Assert.assertEquals
import org.junit.Assert.assertFalse
import org.junit.Assert.assertTrue
import org.junit.Test
import java.util.concurrent.CountDownLatch
import java.util.concurrent.TimeUnit
import kotlin.concurrent.thread

class PairedDeviceStoreConcurrencyTest {
    @Test
    fun `a pairing snapshot cannot overwrite a concurrent sync update`() {
        val gate = RegistryMutationGate()
        val devices = mutableListOf("firefox")
        val pairingRead = CountDownLatch(1)
        val releasePairing = CountDownLatch(1)
        val syncEntered = CountDownLatch(1)

        val pairing = thread {
            gate.withLock {
                val snapshot = devices.toList()
                pairingRead.countDown()
                assertTrue(releasePairing.await(5, TimeUnit.SECONDS))
                devices.clear()
                devices += snapshot + "chrome"
            }
        }

        assertTrue(pairingRead.await(5, TimeUnit.SECONDS))
        val sync = thread {
            gate.withLock {
                syncEntered.countDown()
                val snapshot = devices.toList()
                devices.clear()
                devices += snapshot.map { if (it == "firefox") "firefox-synced" else it }
            }
        }

        assertFalse(syncEntered.await(100, TimeUnit.MILLISECONDS))
        releasePairing.countDown()
        pairing.join(5_000)
        sync.join(5_000)

        assertEquals(setOf("firefox-synced", "chrome"), devices.toSet())
    }
}