refactor: extract GeoThrottle, fix fully-qualified refs, harden enum parsing

- Extract GeoThrottle inner class in MainViewModel; eliminates 6 state
  vars and duplicate throttle logic in loadConditions/loadWindGrid
- Fix android.util.Log.e and kotlin.math.* fully-qualified refs now that
  imports are present
- UnitPrefs: wrap valueOf() in runCatching to handle corrupt pref values
- VesselRepository.init: forEach { add() } → mapTo() for both lists
- TrackRepository: remove noisy cached-log else-branch that fired on
  every stopTrack() call

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

5 files changed, 40 insertions, 40 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 5b219c4..39e0696 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
@@ -27,6 +27,8 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.firstOrNull
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
 import kotlinx.coroutines.launch
 import java.util.Locale
 import org.maplibre.android.MapLibre
@@ -60,7 +62,7 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
     private lateinit var layerManager: MapLayerManager
     private var particleWindView: ParticleWindView? = null
     private var weatherLoaded = false
-    private var cameraIdleJob: kotlinx.coroutines.Job? = null
+    private var cameraIdleJob: Job? = null
 
     private lateinit var bottomSheetBehavior: BottomSheetBehavior<View>
     private lateinit var fragmentContainer: FrameLayout
@@ -497,7 +499,7 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
             maplibreMap.addOnCameraIdleListener {
                 cameraIdleJob?.cancel()
                 cameraIdleJob = lifecycleScope.launch {
-                    kotlinx.coroutines.delay(1_500)
+                    delay(1_500)
                     val corners = listOfNotNull(
                         maplibreMap.projection.visibleRegion.nearLeft,
                         maplibreMap.projection.visibleRegion.nearRight,
diff --git a/android-app/app/src/main/kotlin/org/terst/nav/UnitPrefs.kt b/android-app/app/src/main/kotlin/org/terst/nav/UnitPrefs.kt
index c0745f8..c676390 100644
--- a/android-app/app/src/main/kotlin/org/terst/nav/UnitPrefs.kt
+++ b/android-app/app/src/main/kotlin/org/terst/nav/UnitPrefs.kt
@@ -17,19 +17,19 @@ class UnitPrefs(context: Context) {
     private val prefs = context.getSharedPreferences("unit_prefs", Context.MODE_PRIVATE)
 
     var tempUnit: TempUnit
-        get() = TempUnit.valueOf(prefs.getString(KEY_TEMP, null) ?: TempUnit.FAHRENHEIT.name)
+        get() = runCatching { TempUnit.valueOf(prefs.getString(KEY_TEMP, null) ?: "") }.getOrDefault(TempUnit.FAHRENHEIT)
         set(v) { prefs.edit().putString(KEY_TEMP, v.name).apply() }
 
     var depthUnit: DepthUnit
-        get() = DepthUnit.valueOf(prefs.getString(KEY_DEPTH, null) ?: DepthUnit.FEET.name)
+        get() = runCatching { DepthUnit.valueOf(prefs.getString(KEY_DEPTH, null) ?: "") }.getOrDefault(DepthUnit.FEET)
         set(v) { prefs.edit().putString(KEY_DEPTH, v.name).apply() }
 
     var pressureUnit: PressureUnit
-        get() = PressureUnit.valueOf(prefs.getString(KEY_PRESSURE, null) ?: PressureUnit.HPA.name)
+        get() = runCatching { PressureUnit.valueOf(prefs.getString(KEY_PRESSURE, null) ?: "") }.getOrDefault(PressureUnit.HPA)
         set(v) { prefs.edit().putString(KEY_PRESSURE, v.name).apply() }
 
     var speedUnit: SpeedUnit
-        get() = SpeedUnit.valueOf(prefs.getString(KEY_SPEED, null) ?: SpeedUnit.KNOTS.name)
+        get() = runCatching { SpeedUnit.valueOf(prefs.getString(KEY_SPEED, null) ?: "") }.getOrDefault(SpeedUnit.KNOTS)
         set(v) { prefs.edit().putString(KEY_SPEED, v.name).apply() }
 
     fun formatTemp(tempC: Double): String = when (tempUnit) {
diff --git a/android-app/app/src/main/kotlin/org/terst/nav/track/TrackRepository.kt b/android-app/app/src/main/kotlin/org/terst/nav/track/TrackRepository.kt
index bf25dfc..1b4cf34 100644
--- a/android-app/app/src/main/kotlin/org/terst/nav/track/TrackRepository.kt
+++ b/android-app/app/src/main/kotlin/org/terst/nav/track/TrackRepository.kt
@@ -96,8 +96,6 @@ class TrackRepository(context: Context) {
             // Merge: put stored tracks behind any in-memory tracks from this session
             _pastTracks.addAll(stored)
             NavLogger.i("track", "getPastTracks: total in memory=${_pastTracks.size}")
-        } else {
-            NavLogger.i("track", "getPastTracks: returning cached ${_pastTracks.size} tracks")
         }
         _pastTracks.toList()
     }
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 c648fab..0dc1705 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
@@ -1,7 +1,9 @@
 package org.terst.nav.ui
 
+import android.util.Log
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import org.terst.nav.NavApplication
 import org.terst.nav.ais.AisHubSource
 import org.terst.nav.ais.AisRepository
 import org.terst.nav.ais.AisVessel
@@ -37,8 +39,10 @@ import kotlinx.coroutines.launch
 import org.terst.nav.track.TrackSummary
 import retrofit2.Retrofit
 import retrofit2.converter.moshi.MoshiConverterFactory
+import kotlin.math.asin
 import kotlin.math.cos
 import kotlin.math.sin
+import kotlin.math.sqrt
 
 sealed class UiState {
     object Loading : UiState()
@@ -87,9 +91,9 @@ class MainViewModel(
 
     private val aisRepository = AisRepository()
 
-    private val trackRepository = org.terst.nav.NavApplication.trackRepository
+    private val trackRepository = NavApplication.trackRepository
 
-    val vesselRepository get() = org.terst.nav.NavApplication.vesselRepository
+    val vesselRepository get() = NavApplication.vesselRepository
 
     init {
         viewModelScope.launch {
@@ -240,30 +244,16 @@ class MainViewModel(
             .create(AisHubApiService::class.java)
     }
 
-    private var lastConditionsLat = Double.NaN
-    private var lastConditionsLon = Double.NaN
-    private var lastConditionsMs  = 0L
-
-    private var lastWindGridLat = Double.NaN
-    private var lastWindGridLon = Double.NaN
-    private var lastWindGridMs  = 0L
+    private val conditionsThrottle = GeoThrottle(minAgeMs = 20 * 60_000L, minDistNm = 10.0)
+    private val windGridThrottle   = GeoThrottle(minAgeMs = 15 * 60_000L, minDistNm = 10.0)
 
     /**
      * Fetches current conditions snapshot for [lat]/[lon] and exposes it via [marineConditions].
      * Throttled: skips unless the position moved >= 10 nm OR data is >= 20 min old.
      */
     fun loadConditions(lat: Double, lon: Double) {
-        val nowMs  = System.currentTimeMillis()
-        val ageMs  = nowMs - lastConditionsMs
-        val distNm = if (lastConditionsLat.isNaN()) Double.MAX_VALUE
-                     else distanceNm(lastConditionsLat, lastConditionsLon, lat, lon)
-        if (ageMs < 20 * 60_000L && distNm < 10.0) {
-            NavLogger.i("conditions", "skip age=${ageMs / 1000}s dist=%.1fnm".format(distNm))
-            return
-        }
-        lastConditionsLat = lat
-        lastConditionsLon = lon
-        lastConditionsMs  = nowMs
+        if (!conditionsThrottle.shouldFetch(lat, lon)) return
+        conditionsThrottle.update(lat, lon)
 
         conditionsJob?.cancel()
         conditionsJob = viewModelScope.launch {
@@ -273,7 +263,7 @@ class MainViewModel(
                     .onSuccess { _marineConditions.value = it }
                     .onFailure {
                         val msg = "${it.javaClass.simpleName}: ${it.message}"
-                        android.util.Log.e("Nav", "fetchCurrentConditions failed: $msg", it)
+                        Log.e("Nav", "fetchCurrentConditions failed: $msg", it)
                         _conditionsError.emit(msg)
                     }
             } finally {
@@ -288,7 +278,7 @@ class MainViewModel(
         val a = sin(dLat / 2) * sin(dLat / 2) +
                 cos(Math.toRadians(lat1)) * cos(Math.toRadians(lat2)) *
                 sin(dLon / 2) * sin(dLon / 2)
-        return 3440.065 * 2 * kotlin.math.asin(kotlin.math.sqrt(a))
+        return 3440.065 * 2 * asin(sqrt(a))
     }
 
     /**
@@ -330,14 +320,8 @@ class MainViewModel(
     fun loadWindGrid(latMin: Double, latMax: Double, lonMin: Double, lonMax: Double) {
         val centerLat = (latMin + latMax) / 2.0
         val centerLon = (lonMin + lonMax) / 2.0
-        val nowMs  = System.currentTimeMillis()
-        val ageMs  = nowMs - lastWindGridMs
-        val distNm = if (lastWindGridLat.isNaN()) Double.MAX_VALUE
-                     else distanceNm(lastWindGridLat, lastWindGridLon, centerLat, centerLon)
-        if (ageMs < 15 * 60_000L && distNm < 10.0) return
-        lastWindGridLat = centerLat
-        lastWindGridLon = centerLon
-        lastWindGridMs  = nowMs
+        if (!windGridThrottle.shouldFetch(centerLat, centerLon)) return
+        windGridThrottle.update(centerLat, centerLon)
         viewModelScope.launch {
             val points = buildGrid(latMin, latMax, lonMin, lonMax, cols = 4, rows = 5)
             repository.fetchWindGrid(points).getOrNull()?.let { _windGrid.value = it }
@@ -406,4 +390,20 @@ class MainViewModel(
             }
         }
     }
+
+    private inner class GeoThrottle(private val minAgeMs: Long, private val minDistNm: Double) {
+        private var lastLat = Double.NaN
+        private var lastLon = Double.NaN
+        private var lastMs  = 0L
+
+        fun shouldFetch(lat: Double, lon: Double): Boolean {
+            val dist = if (lastLat.isNaN()) Double.MAX_VALUE
+                       else distanceNm(lastLat, lastLon, lat, lon)
+            return (System.currentTimeMillis() - lastMs) >= minAgeMs || dist >= minDistNm
+        }
+
+        fun update(lat: Double, lon: Double) {
+            lastLat = lat; lastLon = lon; lastMs = System.currentTimeMillis()
+        }
+    }
 }
diff --git a/android-app/app/src/main/kotlin/org/terst/nav/vessel/VesselRepository.kt b/android-app/app/src/main/kotlin/org/terst/nav/vessel/VesselRepository.kt
index 7ebd2f6..faff0cb 100644
--- a/android-app/app/src/main/kotlin/org/terst/nav/vessel/VesselRepository.kt
+++ b/android-app/app/src/main/kotlin/org/terst/nav/vessel/VesselRepository.kt
@@ -23,10 +23,10 @@ class VesselRepository(context: Context) {
     init {
         prefs.getString(KEY_VESSELS, null)
             ?.let { runCatching { vesselAdapter.fromJson(it) }.getOrNull() }
-            ?.forEach { vessels.add(it.toDomain()) }
+            ?.mapTo(vessels) { it.toDomain() }
         prefs.getString(KEY_CREW, null)
             ?.let { runCatching { crewAdapter.fromJson(it) }.getOrNull() }
-            ?.forEach { crew.add(it.toDomain()) }
+            ?.mapTo(crew) { it.toDomain() }
     }
 
     // --- Vessel CRUD ---