Surface conditions API errors as Snackbar

Adds _conditionsError SharedFlow to MainViewModel that emits the
exception class + message on fetchCurrentConditions failure.
MainActivity collects it and shows a LENGTH_LONG Snackbar — no adb
required to see why conditions aren't loading.

https://claude.ai/code/session_01HXPjBsogsJVRwCiekDGkJX

2 files changed, 16 insertions, 1 deletions

diff --git a/android-app/app/src/main/kotlin/org/terst/nav/MainActivity.kt b/android-app/app/src/main/kotlin/org/terst/nav/MainActivity.kt
index ecf2254..7a00748 100644
--- a/android-app/app/src/main/kotlin/org/terst/nav/MainActivity.kt
+++ b/android-app/app/src/main/kotlin/org/terst/nav/MainActivity.kt
@@ -529,6 +529,13 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
             }
         }
         lifecycleScope.launch {
+            viewModel.conditionsError.collect { msg ->
+                com.google.android.material.snackbar.Snackbar
+                    .make(findViewById(android.R.id.content), msg, com.google.android.material.snackbar.Snackbar.LENGTH_LONG)
+                    .show()
+            }
+        }
+        lifecycleScope.launch {
             LocationService.nmeaDepthDataFlow.collect { depthData ->
                 lastDepthMeters = depthData.depthMeters
                 hudDepth.text = unitPrefs.formatDepth(depthData.depthMeters)
diff --git a/android-app/app/src/main/kotlin/org/terst/nav/ui/MainViewModel.kt b/android-app/app/src/main/kotlin/org/terst/nav/ui/MainViewModel.kt
index b2d5529..e65cbd1 100644
--- a/android-app/app/src/main/kotlin/org/terst/nav/ui/MainViewModel.kt
+++ b/android-app/app/src/main/kotlin/org/terst/nav/ui/MainViewModel.kt
@@ -55,6 +55,10 @@ class MainViewModel(
 
     private val _conditionsLoading = MutableStateFlow(false)
     val conditionsLoading: StateFlow<Boolean> = _conditionsLoading.asStateFlow()
+
+    private val _conditionsError = MutableSharedFlow<String>(replay = 0)
+    val conditionsError: SharedFlow<String> = _conditionsError.asSharedFlow()
+
     private var conditionsJob: Job? = null
 
     private val _aisTargets = MutableStateFlow<List<AisVessel>>(emptyList())
@@ -177,7 +181,11 @@ class MainViewModel(
             try {
                 repository.fetchCurrentConditions(lat, lon)
                     .onSuccess { _marineConditions.value = it }
-                    .onFailure { android.util.Log.e("Nav", "fetchCurrentConditions failed: ${it.javaClass.simpleName} — ${it.message}", it) }
+                    .onFailure {
+                        val msg = "${it.javaClass.simpleName}: ${it.message}"
+                        android.util.Log.e("Nav", "fetchCurrentConditions failed: $msg", it)
+                        _conditionsError.emit(msg)
+                    }
             } finally {
                 _conditionsLoading.value = false
             }