fix user discovery not working some times

rust/src/bridge/callbacks.rs

@@ -7,9 +7,10 @@ use protocols::user_discovery::traits::{AnnouncedUser, OtherPromotion};
 
 use crate::error::{Result, TwonlyError};
 use crate::{callback_generator, frb_generated::StreamSink};
-use std::sync::{Arc, OnceLock};
+use std::sync::Arc;
 
-static FLUTTER_CALLBACKS: OnceLock<FlutterCallbacks> = OnceLock::new();
+static FLUTTER_CALLBACKS: std::sync::RwLock<Option<FlutterCallbacks>> =
+    std::sync::RwLock::new(None);
 
 // This will also generate the function init_flutter_callbacks which MUST be called from Flutter to initialize the callbacks
 callback_generator! {
@@ -39,8 +40,10 @@ callback_generator! {
     }
 }
 
-pub(crate) fn get_callbacks() -> Result<&'static FlutterCallbacks> {
+pub(crate) fn get_callbacks() -> Result<FlutterCallbacks> {
     FLUTTER_CALLBACKS
-        .get()
+        .read()
+        .unwrap()
+        .clone()
         .ok_or(TwonlyError::MissingCallbackInitialization)
 }

rust/src/bridge/callbacks/macros.rs

@@ -13,6 +13,7 @@ macro_rules! callback_generator {
     ) => {
         // 1. Generate the Nested Sub-Structs
         $(
+            #[derive(Clone)]
             pub(crate) struct $sub_struct_name {
                 $(
                     pub(crate) $fn_name: Arc<dyn Fn($($input),*) -> DartFnFuture<$output> + Send + Sync + 'static>,
@@ -21,6 +22,7 @@ macro_rules! callback_generator {
         )*
 
         // 2. Generate the Main Container Struct
+        #[derive(Clone)]
         pub(crate) struct $struct_name {
             $(
                 pub(crate) $sub_struct_field: $sub_struct_name,
@@ -48,9 +50,8 @@ macro_rules! callback_generator {
                 };
 
                 // Use the static global strictly named FLUTTER_CALLBACKS
-                FLUTTER_CALLBACKS.set(callbacks).unwrap_or_else(|_| {
-                    println!("Callbacks were already initialized!");
-                });
+                let mut lock = FLUTTER_CALLBACKS.write().unwrap();
+                *lock = Some(callbacks);
             }
         }
     };