Keep the migration screen up for at least a second

app/src/main/java/eu/kanade/tachiyomi/ui/main/MainActivity.kt

@@ -97,6 +97,7 @@ import eu.kanade.tachiyomi.util.system.updaterEnabled
 import eu.kanade.tachiyomi.util.view.setComposeContent
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.callbackFlow
 import kotlinx.coroutines.flow.collectLatest
@@ -126,7 +127,9 @@ import tachiyomi.presentation.core.i18n.stringResource
 import tachiyomi.presentation.core.util.collectAsState
 import kotlin.time.Clock
 import kotlin.time.Duration.Companion.days
+import kotlin.time.Duration.Companion.seconds
 import kotlin.time.Instant
+import kotlin.time.TimeSource
 import kotlin.time.times
 
 class MainActivity : BaseActivity() {
@@ -181,7 +184,19 @@ class MainActivity : BaseActivity() {
         setComposeContent {
             val appMigrating by isAppMigrating.collectAsState()
             val databaseMigrating by databaseRepository.isMigrating.collectAsState()
-            if (appMigrating || databaseMigrating) {
+            val migrating = appMigrating || databaseMigrating
+            var migratingSince by remember { mutableStateOf(if (migrating) TimeSource.Monotonic.markNow() else null) }
+            LaunchedEffect(migrating) {
+                val since = migratingSince
+                if (migrating) {
+                    if (since == null) migratingSince = TimeSource.Monotonic.markNow()
+                } else if (since != null) {
+                    // A migration that finishes right away would otherwise only flash the screen
+                    delay(MIGRATING_SCREEN_MIN_DURATION - since.elapsedNow())
+                    migratingSince = null
+                }
+            }
+            if (migrating || migratingSince != null) {
                 AppMigratingScreen()
                 // Release the splash screen so the reason for the wait shows
                 LaunchedEffect(Unit) { ready = true }
@@ -633,3 +648,5 @@ class MainActivity : BaseActivity() {
 private const val SPLASH_MIN_DURATION = 500 // ms
 private const val SPLASH_MAX_DURATION = 5000 // ms
 private const val SPLASH_EXIT_ANIM_DURATION = 400L // ms
+
+private val MIGRATING_SCREEN_MIN_DURATION = 1.seconds