Offline Support

lib/utils/snackbar.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:awesome_snackbar_content/awesome_snackbar_content.dart';
 import 'package:flutter/foundation.dart';
+import 'package:supabase_flutter/supabase_flutter.dart' show PostgrestException;
 
 /// A global messenger key used to show snackbars from contexts without a
 /// Scaffold (e.g. dialogs, background callbacks, or tests).
@@ -218,3 +219,55 @@ void showWarningSnackBarGlobal(String message) => showAwesomeSnackBarGlobal(
   message: message,
   snackType: SnackType.warning,
 );
+
+/// Returns true when [error] is a network-connectivity failure (socket closed,
+/// no route to host, failed DNS lookup, etc.).
+///
+/// When this is true in a Brick-enabled app, the write was already queued in
+/// the offline SQLite store and will sync automatically when the device
+/// reconnects — so the UI should treat it as a success rather than an error.
+bool isOfflineSaveError(Object error) {
+  if (error is PostgrestException) {
+    // Null code = no HTTP response received at all (pure network failure).
+    if (error.code == null) return true;
+
+    // Brick's RestOfflineQueueClient catches network errors and returns a
+    // synthetic StreamedResponse(501, body: 'unknown internal error') rather
+    // than rethrowing. PostgREST then parses this as
+    // PostgrestException(code: '501', message: 'unknown internal error').
+    // This is the primary offline indicator when Supabase is used with Brick.
+    if (error.code == '501' && error.message == 'unknown internal error') {
+      return true;
+    }
+
+    // Fallback: Supabase may wrap a SocketException in a PostgrestException
+    // message field before it reaches Brick's queue (rare, but defensive).
+    final pmsg = error.message.toLowerCase();
+    if (pmsg.contains('socketexception') ||
+        pmsg.contains('failed host lookup') ||
+        pmsg.contains('connection refused') ||
+        pmsg.contains('network is unreachable') ||
+        pmsg.contains('no route to host') ||
+        pmsg.contains('connection timed out') ||
+        pmsg.contains('failed to connect')) {
+      return true;
+    }
+  }
+
+  // Non-PostgrestException network errors (SocketException, ClientException)
+  // that propagate before Brick's HTTP interceptor can catch them.
+  final msg = error.toString().toLowerCase();
+  return msg.contains('socketexception') ||
+      msg.contains('socket') && msg.contains('exception') ||
+      msg.contains('connection refused') ||
+      msg.contains('network is unreachable') ||
+      msg.contains('no route to host') ||
+      msg.contains('failed host lookup') ||
+      msg.contains('connection reset') ||
+      msg.contains('broken pipe') ||
+      msg.contains('connection timed out') ||
+      msg.contains('clientexception') && msg.contains('network') ||
+      msg.contains('failed to connect') ||
+      msg.contains('errno = 111') || // ECONNREFUSED
+      msg.contains('errno = 101'); // ENETUNREACH
+}