Fixed real time updates not working after internet drops.

src/frontend/app/src/main/kotlin/pt/ulisboa/ist/pharmacist/service/real_time_updates/RealTimeUpdatesService.kt

@@ -2,7 +2,10 @@ package pt.ulisboa.ist.pharmacist.service.real_time_updates
 
 import android.util.Log
 import com.google.gson.Gson
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.callbackFlow
@@ -27,6 +30,18 @@ class RealTimeUpdatesService(
     private val updateSubscribeFlow = MutableSharedFlow<Array<RealTimeUpdateSubscription>>()
     private val updatePublishFlow = MutableSharedFlow<RealTimeUpdatePublishingDto>()
 
+    private val currentSubscriptions = mutableListOf<RealTimeUpdateSubscription>()
+
+    private val subscribeScope = CoroutineScope(Dispatchers.Default)
+
+    init {
+        subscribeScope.launch {
+            updateSubscribeFlow.collect { subscriptions ->
+                currentSubscriptions.addAll(subscriptions)
+            }
+        }
+    }
+
     /**
      * Starts the real time updates service, opening the web socket and listening for
      * log in and log out events to determine if a new web socket should open.
@@ -38,12 +53,23 @@ class RealTimeUpdatesService(
                 Log.d(TAG, "Already logged in. Starting WebSocket listener flow")
                 getWebSocketListenerFlow().collect(updatePublishFlow::emit)
             }
+            while (sessionManager.isLoggedIn()) {
+                Log.d(TAG, "User is still logged in. Starting new WebSocket listener flow")
+                getWebSocketListenerFlow().collect(updatePublishFlow::emit)
+                delay(2000)
+            }
+
             Log.d(TAG, "Listening to logInFlow")
             sessionManager.logInFlow.collect { loggedIn ->
-                if (loggedIn && sessionManager.isLoggedIn()) {
+                if (loggedIn) {
                     Log.d(TAG, "Became logged in (logInFlow). Starting WebSocket listener flow")
                     getWebSocketListenerFlow().collect(updatePublishFlow::emit)
                 }
+                while (sessionManager.isLoggedIn()) {
+                    Log.d(TAG, "User is still logged in. Starting new WebSocket listener flow")
+                    getWebSocketListenerFlow().collect(updatePublishFlow::emit)
+                    delay(2000)
+                }
             }
         }
     }
@@ -53,6 +79,11 @@ class RealTimeUpdatesService(
             override fun onOpen(webSocket: WebSocket, response: Response) {
                 super.onOpen(webSocket, response)
                 Log.d(TAG, "WebSocket opened")
+
+                Log.d(TAG, "Sending subscriptions to WebSocket")
+                val json = Gson().toJson(currentSubscriptions.map { it.toDto() }.toTypedArray())
+                val sent = webSocket.send(json)
+                Log.d(TAG, "Successfully sent subscriptions to WebSocket: $sent")
             }
 
             override fun onMessage(webSocket: WebSocket, text: String) {