package com.peachpasswords.vault

import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.test.StandardTestDispatcher
import kotlinx.coroutines.test.advanceTimeBy
import kotlinx.coroutines.test.runCurrent
import kotlinx.coroutines.test.runTest
import org.junit.Assert.assertFalse
import org.junit.Assert.assertTrue
import org.junit.Test

/** In-memory [VaultStorage] so the timer can drive a real repository off-device. */
private class LockTimerFakeStorage : VaultStorage {
    private var slotA: StoredVault? = null
    private var slotB: String? = null
    private var ver: Long = 0
    private var settings = VaultSettings()
    override fun loadSlotA() = slotA
    override fun hasVault() = slotA != null
    override fun writeSlotA(slot: StoredVault): Boolean { slotA = slot; return true }
    override fun writeSlotB(blobBase64: String): Boolean { slotB = blobBase64; return true }
    private var decoy: StoredVault? = null
    override fun loadDecoySlot() = decoy
    override fun writeDecoySlot(slot: StoredVault): Boolean { decoy = slot; return true }
    override fun hasDecoySlot() = decoy != null
    override fun clearDecoySlot() { decoy = null }
    override fun version() = ver
    override fun stampLocalMutation(): Long { ver = maxOf(System.currentTimeMillis(), ver + 1); return ver }
    override fun loadSettings() = settings
    override fun writeSettings(s: VaultSettings): Boolean { settings = s; return true }
    override fun clearVault(): Boolean { slotA = null; slotB = null; ver = 0; settings = VaultSettings(); return true }
}

/**
 * Drives [VaultLockTimer] on virtual time. The timer's coroutine scope is replaced
 * with one backed by the test scheduler, so [advanceTimeBy] moves the idle clock
 * deterministically without real waiting.
 */
@OptIn(kotlinx.coroutines.ExperimentalCoroutinesApi::class)
class VaultLockTimerTest {

    private suspend fun unlockedRepo(autoLockMinutes: Int?): VaultRepository {
        val repo = VaultRepository(LockTimerFakeStorage())
        repo.createVault("correct horse battery staple")
        repo.updateSettings(VaultSettings(autoLockMinutes = autoLockMinutes))
        assertTrue(repo.isUnlocked.value)
        return repo
    }

    @Test fun timer_locks_after_configured_delay() = runTest {
        val repo = unlockedRepo(autoLockMinutes = 1)
        val timer = VaultLockTimer(repo).also { it.scope = CoroutineScope(StandardTestDispatcher(testScheduler)) }
        timer.start()
        advanceTimeBy(59_000); runCurrent()
        assertTrue("still unlocked before the window elapses", repo.isUnlocked.value)
        advanceTimeBy(2_000); runCurrent()
        assertFalse("locked once the idle window elapses", repo.isUnlocked.value)
    }

    @Test fun poke_resets_the_countdown() = runTest {
        val repo = unlockedRepo(autoLockMinutes = 1)
        val timer = VaultLockTimer(repo).also { it.scope = CoroutineScope(StandardTestDispatcher(testScheduler)) }
        timer.start()
        advanceTimeBy(50_000); runCurrent()
        timer.poke() // 50s in — restart the 60s window
        advanceTimeBy(50_000); runCurrent()
        assertTrue("poke pushed the lock past the original deadline", repo.isUnlocked.value)
        advanceTimeBy(11_000); runCurrent()
        assertFalse("locks 60s after the last poke", repo.isUnlocked.value)
    }

    @Test fun cancel_prevents_firing() = runTest {
        val repo = unlockedRepo(autoLockMinutes = 1)
        val timer = VaultLockTimer(repo).also { it.scope = CoroutineScope(StandardTestDispatcher(testScheduler)) }
        timer.start()
        timer.cancel()
        advanceTimeBy(120_000); runCurrent()
        assertTrue("cancelled timer never locks", repo.isUnlocked.value)
    }

    @Test fun null_auto_lock_never_fires() = runTest {
        val repo = unlockedRepo(autoLockMinutes = null)
        val timer = VaultLockTimer(repo).also { it.scope = CoroutineScope(StandardTestDispatcher(testScheduler)) }
        timer.start()
        advanceTimeBy(3_600_000); runCurrent()
        assertTrue("null autoLockMinutes means never lock", repo.isUnlocked.value)
    }
}