allow user to stop syncing propagation node

meshchat.py

@@ -224,12 +224,24 @@ class ReticulumMeshChat:
                 self.message_router.set_outbound_propagation_node(bytes.fromhex(destination_hash))
             except:
                 # failed to set propagation node, clear it to ensure we don't use an old one by mistake
-                self.message_router.outbound_propagation_node = None
+                self.remove_active_propagation_node()
                 pass
 
         # stop using propagation node
         else:
-            self.message_router.outbound_propagation_node = None
+            self.remove_active_propagation_node()
+
+    # stops the in progress propagation node sync
+    def stop_propagation_node_sync(self):
+        self.message_router.cancel_propagation_node_requests()
+
+    # stops and removes the active propagation node
+    def remove_active_propagation_node(self):
+        # fixme: it's possible for internal transfer state to get stuck if we change propagation node during a sync
+        # this still happens even if we cancel the propagation node requests
+        # for now, the user can just manually cancel syncing in the ui if they think it's stuck...
+        self.stop_propagation_node_sync()
+        self.message_router.outbound_propagation_node = None
 
     # handle receiving a new audio call
     def on_incoming_audio_call(self, audio_call: AudioCall):
@@ -890,6 +902,16 @@ class ReticulumMeshChat:
                 "message": "Sync is starting",
             })
 
+        # stop syncing propagation node
+        @routes.get("/api/v1/lxmf/propagation-node/stop-sync")
+        async def index(request):
+
+            self.stop_propagation_node_sync()
+
+            return web.json_response({
+                "message": "Sync is stopping",
+            })
+
         # serve propagation nodes
         @routes.get("/api/v1/lxmf/propagation-nodes")
         async def index(request):

src/frontend/components/App.vue

@@ -398,8 +398,11 @@ export default {
         },
         async syncPropagationNode() {
 
-            // do nothing if already syncing
+            // ask to stop syncing if already syncing
             if(this.isSyncingPropagationNode){
+                if(confirm("Are you sure you want to stop syncing?")){
+                    await this.stopSyncingPropagationNode();
+                }
                 return;
             }
 
@@ -429,7 +432,7 @@ export default {
                 // show result
                 const status = this.propagationNodeStatus?.state;
                 const messagesReceived = this.propagationNodeStatus?.messages_received ?? 0;
-                if(status === "complete"){
+                if(status === "complete" || status === "idle"){
                     DialogUtils.alert(`Sync complete. ${messagesReceived} messages received.`);
                 } else {
                     DialogUtils.alert(`Sync error: ${status}`);
@@ -437,6 +440,19 @@ export default {
 
             }, 500);
 
+        },
+        async stopSyncingPropagationNode() {
+
+            // stop sync
+            try {
+                await axios.get("/api/v1/lxmf/propagation-node/stop-sync");
+            } catch(e) {
+                // do nothing on error
+            }
+
+            // update propagation status
+            await this.updatePropagationNodeStatus();
+
         },
         async updatePropagationNodeStatus() {
             try {