refactor(main): expose cold-start preferences as an InitialLaunch flow

Read the theme, locale, empty-library seed and section expansion
once in the application and collect them as state, instead of
blocking the UI thread with synchronous reads before setContent.

app/src/main/java/com/example/research/MainActivity.kt

@@ -31,8 +31,6 @@ import com.example.research.feature.search.SearchAction
 import com.example.research.feature.search.SearchViewModel
 import com.example.research.ui.navigation.AppNavigation
 import com.example.research.ui.settings.SettingsViewModel
-import kotlinx.coroutines.flow.first
-import kotlinx.coroutines.runBlocking
 
 class MainActivity : ComponentActivity() {
     companion object {
@@ -52,8 +50,6 @@ class MainActivity : ComponentActivity() {
         }
     }
 
-    private var initialSectionExpansion: SectionExpansionStates? = null
-
     private val settingsViewModel: SettingsViewModel by viewModels {
         val app = application as ReSearchApplication
         val versionName = try {
@@ -72,7 +68,7 @@ class MainActivity : ComponentActivity() {
                     app.dictionaryImportManager,
                     app.dictionaryProgressStateHolder,
                     versionName,
-                    initialSectionExpansion ?: SectionExpansionStates(
+                    app.initialLaunch.value?.sectionExpansion ?: SectionExpansionStates(
                         isThemeExpanded = false,
                         isLanguageExpanded = false,
                         isDictionariesExpanded = true,
@@ -87,19 +83,16 @@ class MainActivity : ComponentActivity() {
         super.onCreate(savedInstanceState)
         requestNotificationPermissionIfNeeded()
 
-        // Load theme and language synchronously before setContent to prevent flashing
         val app = application as ReSearchApplication
-        val initialTheme = loadInitialTheme(app)
-        val initialLanguage = loadInitialLanguage(app)
-        val initialHadNoDictionaries = loadInitialHadNoDictionaries(app)
-        initialSectionExpansion = loadInitialSectionExpansion(app)
-
         handleIntent(intent)
         setContent {
+            val initialLaunch by app.initialLaunch.collectAsStateWithLifecycle()
+            val launch = initialLaunch ?: return@setContent
+
             val settingsState by settingsViewModel.uiState.collectAsStateWithLifecycle()
             // Use loaded values initially, then switch to state values when ready
-            val theme = settingsState.theme.takeIf { it != AppTheme.SYSTEM } ?: initialTheme
+            val theme = settingsState.theme.takeIf { it != AppTheme.SYSTEM } ?: launch.theme
-            val language = settingsState.language.takeIf { it != "system" } ?: initialLanguage
+            val language = settingsState.language.takeIf { it != "system" } ?: launch.language
             val darkTheme = when (theme) {
                 AppTheme.LIGHT -> false
                 AppTheme.DARK -> true
@@ -115,7 +108,7 @@ class MainActivity : ComponentActivity() {
                             AppNavigation(
                                 searchViewModel = searchViewModel,
                                 settingsViewModel = settingsViewModel,
-                                seedNoDictionaries = initialHadNoDictionaries
+                                seedNoDictionaries = launch.seedNoDictionaries
                             )
                         }
                     }
@@ -138,69 +131,6 @@ class MainActivity : ComponentActivity() {
         }
     }
 
-    /**
-     * Load initial theme synchronously from DataStore to prevent theme flashing.
-     * This is called before setContent to ensure the correct theme is applied immediately.
-     * Uses runBlocking to synchronously read from DataStore.
-     */
-    private fun loadInitialTheme(app: ReSearchApplication): AppTheme {
-        return try {
-            runBlocking {
-                val themeString = app.preferencesManager.themeMode.first()
-                try {
-                    AppTheme.valueOf(themeString)
-                } catch (_: Exception) {
-                    android.util.Log.w("MainActivity", "Invalid theme value: $themeString, using SYSTEM")
-                    AppTheme.SYSTEM
-                }
-            }
-        } catch (e: Exception) {
-            android.util.Log.e("MainActivity", "Failed to load theme preference: ${e.message}")
-            AppTheme.SYSTEM
-        }
-    }
-
-    /**
-     * Load initial language synchronously from DataStore to prevent language flashing.
-     * This is called before setContent to ensure the correct language is applied immediately.
-     * Uses runBlocking to synchronously read from DataStore.
-     */
-    private fun loadInitialLanguage(app: ReSearchApplication): String {
-        return try {
-            runBlocking {
-                app.preferencesManager.language.first()
-            }
-        } catch (e: Exception) {
-            android.util.Log.e("MainActivity", "Failed to load language preference: ${e.message}")
-            "system"
-        }
-    }
-
-    private fun loadInitialHadNoDictionaries(app: ReSearchApplication): Boolean {
-        return try {
-            runBlocking {
-                app.preferencesManager.hadNoDictionaries.first()
-            }
-        } catch (_: Exception) {
-            true
-        }
-    }
-
-    private fun loadInitialSectionExpansion(app: ReSearchApplication): SectionExpansionStates {
-        return try {
-            runBlocking {
-                app.preferencesManager.sectionExpansionStates()
-            }
-        } catch (e: Exception) {
-            android.util.Log.e("MainActivity", "Failed to load section expansion states: ${e.message}")
-            SectionExpansionStates(
-                isThemeExpanded = false,
-                isLanguageExpanded = false,
-                isDictionariesExpanded = true,
-            )
-        }
-    }
-
     override fun onNewIntent(intent: Intent) {
         super.onNewIntent(intent)
         handleIntent(intent)

app/src/main/java/com/example/research/ReSearchApplication.kt

@@ -3,7 +3,9 @@ package com.example.research
 import android.app.Application
 import com.example.research.common.progress.DictionaryProgressStateHolder
 import com.example.research.common.util.NotificationHelper
+import com.example.research.core.domain.model.AppTheme
 import com.example.research.data.local.preferences.PreferencesManager
+import com.example.research.data.local.preferences.SectionExpansionStates
 import com.example.research.data.repository.LocalDictionaryRepository
 import com.example.research.feature.download.DownloadManager
 import com.example.research.feature.download.repository.DictionaryRepository
@@ -12,10 +14,25 @@ import com.example.research.feature.import.DictionaryImportManager
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
 import okhttp3.OkHttpClient
 import okhttp3.Protocol
 
+/**
+ * Values a cold start needs before the first composed frame: the initial
+ * theme, locale, empty-library navigation seed, and settings expansion state.
+ */
+data class InitialLaunch(
+    val theme: AppTheme,
+    val language: String,
+    val seedNoDictionaries: Boolean,
+    val sectionExpansion: SectionExpansionStates,
+)
+
 class ReSearchApplication : Application() {
 
     lateinit var preferencesManager: PreferencesManager
@@ -43,6 +60,9 @@ class ReSearchApplication : Application() {
         private set
     private val applicationScope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
 
+    private val _initialLaunch = MutableStateFlow<InitialLaunch?>(null)
+    val initialLaunch: StateFlow<InitialLaunch?> = _initialLaunch.asStateFlow()
+
     override fun onCreate() {
         super.onCreate()
 
@@ -53,6 +73,9 @@ class ReSearchApplication : Application() {
         applicationScope.launch(Dispatchers.IO) {
             preferencesManager.sanitizeDictionarySources()
         }
+        applicationScope.launch(Dispatchers.IO) {
+            _initialLaunch.value = loadInitialLaunch()
+        }
         localDictionaryRepository = LocalDictionaryRepository(this, preferencesManager = preferencesManager)
 
         okHttpClient = OkHttpClient.Builder()
@@ -121,6 +144,23 @@ class ReSearchApplication : Application() {
         downloadManager.onTerminal = dictionaryPipelineCoordinator::onDownloadTerminal
     }
 
+    private suspend fun loadInitialLaunch(): InitialLaunch {
+        val defaultExpansions = SectionExpansionStates(
+            isThemeExpanded = false,
+            isLanguageExpanded = false,
+            isDictionariesExpanded = true,
+        )
+        return InitialLaunch(
+            theme = runCatching { AppTheme.valueOf(preferencesManager.themeMode.first()) }
+                .getOrDefault(AppTheme.SYSTEM),
+            language = runCatching { preferencesManager.language.first() }.getOrDefault("system"),
+            seedNoDictionaries = runCatching { preferencesManager.hadNoDictionaries.first() }
+                .getOrDefault(true),
+            sectionExpansion = runCatching { preferencesManager.sectionExpansionStates() }
+                .getOrDefault(defaultExpansions),
+        )
+    }
+
     override fun onTrimMemory(level: Int) {
         super.onTrimMemory(level)
         if (::localDictionaryRepository.isInitialized) {