fix: change loading from 60s to 30s for quicker error response, add better error messages for empty vs backend failure

Author: RyanCheung555

app/src/main/java/com/cornellappdev/transit/models/RouteRepository.kt

@@ -7,6 +7,7 @@ import com.cornellappdev.transit.networking.EcosystemNetworkApi
 import com.cornellappdev.transit.networking.RoutesNetworkApi
 import com.cornellappdev.transit.util.ECOSYSTEM_FLAG
 import com.google.android.gms.maps.model.LatLng
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -165,7 +166,7 @@ class RouteRepository @Inject constructor(
      * @param arriveBy Whether the route must complete by a certain time
      * @param originName The name of the origin
      */
-    fun fetchRoute(
+    suspend fun fetchRoute(
         end: LatLng,
         time: Double,
         destinationName: String,
@@ -174,22 +175,23 @@ class RouteRepository @Inject constructor(
         originName: String
     ) {
         _lastRouteFlow.value = ApiResponse.Pending
-        CoroutineScope(Dispatchers.IO).launch {
-            try {
-                val routeResponse = getRoute(
-                    RouteRequest(
-                        end = "${end.latitude}, ${end.longitude}",
-                        time = time,
-                        destinationName = destinationName,
-                        start = "${start.latitude}, ${start.longitude}",
-                        arriveBy = arriveBy,
-                        originName = originName
-                    )
+        try {
+            val routeResponse = getRoute(
+                RouteRequest(
+                    end = "${end.latitude}, ${end.longitude}",
+                    time = time,
+                    destinationName = destinationName,
+                    start = "${start.latitude}, ${start.longitude}",
+                    arriveBy = arriveBy,
+                    originName = originName
                 )
-                _lastRouteFlow.value = ApiResponse.Success(routeResponse.unwrap())
-            } catch (e: Exception) {
-                _lastRouteFlow.value = ApiResponse.Error
-            }
+            )
+            _lastRouteFlow.value = ApiResponse.Success(routeResponse.unwrap())
+        } catch (e: CancellationException) {
+            // Latest-only callers cancel stale requests; do not publish error for cancellations.
+            throw e
+        } catch (e: Exception) {
+            _lastRouteFlow.value = ApiResponse.Error
         }
     }
 

app/src/main/java/com/cornellappdev/transit/networking/NetworkModule.kt

@@ -45,8 +45,8 @@ object NetworkModule {
             .Builder()
             .connectionPool(ConnectionPool(0, 1, TimeUnit.NANOSECONDS))
             .protocols(listOf(Protocol.HTTP_1_1))
-            .readTimeout(60, TimeUnit.SECONDS)
-            .connectTimeout(60, TimeUnit.SECONDS)
+            .readTimeout(30, TimeUnit.SECONDS)
+            .connectTimeout(30, TimeUnit.SECONDS)
             .addInterceptor(logging)
             .build()
     }

app/src/main/java/com/cornellappdev/transit/ui/screens/RouteScreen.kt

@@ -579,6 +579,12 @@ private fun RouteList(
     onClick: (Route) -> Unit,
     onRefresh: () -> Unit,
 ) {
+    fun hasNoRoutes(options: RouteOptions): Boolean {
+        return options.fromStop.isNullOrEmpty() &&
+            options.boardingSoon.isNullOrEmpty() &&
+            options.walking.isNullOrEmpty()
+    }
+
     TransitPullToRefreshBox(
         isRefreshing = lastRouteResponse is ApiResponse.Pending,
         onRefresh = onRefresh
@@ -593,7 +599,7 @@ private fun RouteList(
                     item {
                         Spacer(modifier = Modifier.height(80.dp))
                         Text(
-                            text = "No Routes Found",
+                            text = "Unable to load routes",
                             fontFamily = robotoFamily,
                             fontWeight = FontWeight.Normal,
                             color = MetadataGray,
@@ -603,6 +609,15 @@ private fun RouteList(
                                 .fillMaxWidth(),
                             textAlign = TextAlign.Center
                         )
+                        Text(
+                            text = "Check your connection and pull to refresh.",
+                            style = Style.heading4,
+                            color = MetadataGray,
+                            modifier = Modifier
+                                .padding(horizontal = 12.dp)
+                                .fillMaxWidth(),
+                            textAlign = TextAlign.Center
+                        )
                     }
 
                 }
@@ -612,6 +627,31 @@ private fun RouteList(
                 }
 
                 is ApiResponse.Success -> {
+                    if (hasNoRoutes(lastRouteResponse.data)) {
+                        item {
+                            Spacer(modifier = Modifier.height(80.dp))
+                            Text(
+                                text = "No Routes Found",
+                                fontFamily = robotoFamily,
+                                fontWeight = FontWeight.Normal,
+                                color = MetadataGray,
+                                fontSize = 24.sp,
+                                modifier = Modifier
+                                    .padding(12.dp)
+                                    .fillMaxWidth(),
+                                textAlign = TextAlign.Center
+                            )
+                            Text(
+                                text = "Try a nearby stop, different time, or switch Arrive By/Leave At.",
+                                style = Style.heading4,
+                                color = MetadataGray,
+                                modifier = Modifier
+                                    .padding(horizontal = 12.dp)
+                                    .fillMaxWidth(),
+                                textAlign = TextAlign.Center
+                            )
+                        }
+                    }
                     lastRouteResponse.data.fromStop?.let {
                         items(it) { item ->
                             PaddedRouteCell(item.toTransport()) {

app/src/main/java/com/cornellappdev/transit/ui/viewmodels/RouteViewModel.kt

@@ -21,6 +21,7 @@ import com.google.android.gms.maps.model.LatLng
 import com.google.android.gms.maps.model.LatLngBounds
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
@@ -47,6 +48,8 @@ class RouteViewModel @Inject constructor(
     private val selectedRouteRepository: SelectedRouteRepository
 ) : ViewModel() {
 
+    private var fetchRouteJob: Job? = null
+
     /**
      * Value of the current location. Can be null
      */
@@ -263,7 +266,8 @@ class RouteViewModel @Inject constructor(
         arriveBy: Boolean,
         originName: String
     ) {
-        viewModelScope.launch {
+        fetchRouteJob?.cancel()
+        fetchRouteJob = viewModelScope.launch {
             routeRepository.fetchRoute(
                 end = end,
                 time = time,