improve error handling

composeApp/src/androidMain/kotlin/su/reya/coop/App.kt

@@ -3,6 +3,7 @@ package su.reya.coop
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.material3.ExperimentalMaterial3ExpressiveApi
 import androidx.compose.material3.MaterialExpressiveTheme
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.darkColorScheme
 import androidx.compose.material3.dynamicDarkColorScheme
 import androidx.compose.material3.dynamicLightColorScheme
@@ -32,6 +33,10 @@ val LocalNostrViewModel = staticCompositionLocalOf<NostrViewModel> {
     error("No NostrViewModel provided")
 }
 
+val LocalSnackbarHostState = staticCompositionLocalOf<SnackbarHostState> {
+    error("No SnackbarHostState provided")
+}
+
 @OptIn(ExperimentalMaterial3ExpressiveApi::class)
 @Composable
 fun App(dbPath: String) {
@@ -53,24 +58,32 @@ fun App(dbPath: String) {
         else -> expressiveLightColorScheme()
     }
 
+    // Snackbar
+    val snackbarHostState = remember { SnackbarHostState() }
+
     LaunchedEffect(Unit) {
         viewModel.initAndConnect(dbPath)
+        viewModel.startNotificationHandler()
         viewModel.getChatRooms()
+        viewModel.errorEvents.collect { message ->
+            snackbarHostState.showSnackbar(message)
+        }
     }
 
     MaterialExpressiveTheme(
         colorScheme = colorScheme,
     ) {
-        CompositionLocalProvider(LocalNostrViewModel provides viewModel) {
+        CompositionLocalProvider(
+            LocalNostrViewModel provides viewModel,
+            LocalSnackbarHostState provides snackbarHostState,
+        ) {
             rememberCoroutineScope()
             val navController = rememberNavController()
-            val hasSecret by viewModel.hasSecret.collectAsState(initial = null)
+            val emptySecret by viewModel.emptySecret.collectAsState(initial = null)
 
-            LaunchedEffect(hasSecret) {
+            LaunchedEffect(emptySecret) {
                 // Navigate to the home screen if the secret is already set
-                if (hasSecret == true) {
-                    // Start a background notification handler
-                    viewModel.startNotificationHandler()
+                if (emptySecret == false) {
                     // Get chat rooms
                     viewModel.getChatRooms()
                     // Navigate to the home screen
@@ -81,11 +94,11 @@ fun App(dbPath: String) {
             }
 
             // Show loading screen while initializing
-            if (hasSecret == null) return@CompositionLocalProvider
+            if (emptySecret == null) return@CompositionLocalProvider
 
             NavHost(
                 navController = navController,
-                startDestination = if (hasSecret == true) Screen.Home else Screen.Onboarding
+                startDestination = if (emptySecret == false) Screen.Home else Screen.Onboarding
             ) {
                 composable<Screen.Onboarding> { backStackEntry ->
                     OnboardingScreen(