feat(map): layer manager — satellite/charts/hybrid + wind toggle, long-press picker

MapLayerManager: all raster sources registered at style-build time,
visibility toggled on demand. Persists base preset and wind state to
SharedPreferences. Sources: Google satellite, NOAA RNC charts
(tileservice.charts.noaa.gov), OWM wind, OpenSeaMap seamarks.

LayerPickerSheet: bottom sheet with chip group (Satellite/Charts/Hybrid)
and wind toggle, launched from map long-press.

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

4 files changed, 303 insertions, 22 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 06c45ca..de1f4dd 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
@@ -30,10 +30,6 @@ import java.util.Locale
 import org.maplibre.android.MapLibre
 import org.maplibre.android.maps.MapView
 import org.maplibre.android.maps.Style
-import org.maplibre.android.style.layers.PropertyFactory
-import org.maplibre.android.style.layers.RasterLayer
-import org.maplibre.android.style.sources.RasterSource
-import org.maplibre.android.style.sources.TileSet
 import org.terst.nav.ui.*
 import org.terst.nav.ui.doc.DocFragment
 import org.terst.nav.ui.safety.SafetyFragment
@@ -48,6 +44,7 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
     private var instrumentHandler: InstrumentHandler? = null
     private var mapHandler: MapHandler? = null
     private val loadedStyleFlow = MutableStateFlow<Style?>(null)
+    private lateinit var layerManager: MapLayerManager
 
     private lateinit var bottomSheetBehavior: BottomSheetBehavior<View>
     private lateinit var fragmentContainer: FrameLayout
@@ -265,9 +262,10 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
     }
 
     private fun setupMap() {
+        layerManager = MapLayerManager(this)
         mapView = findViewById(R.id.mapView)
         if (NavApplication.isTesting) return
-        
+
         mapView?.onCreate(null)
         mapView?.getMapAsync { maplibreMap ->
             mapHandler = MapHandler(maplibreMap)
@@ -282,29 +280,28 @@ class MainActivity : AppCompatActivity(), SafetyFragment.SafetyListener {
                     }
                 }
             }
-            val style = Style.Builder()
-                .fromUri("https://tiles.openfreemap.org/styles/bright") // Base for labels if needed, or use satellite only
-                .withSource(RasterSource("satellite-source",
-                    TileSet("2.2.0", "https://mt1.google.com/vt/lyrs=s&x={x}&y={y}&z={z}"), 256))
-                .withLayer(RasterLayer("satellite-layer", "satellite-source"))
-                .withSource(RasterSource("wind-source",
-                    TileSet("2.2.0", "https://tile.openweathermap.org/map/wind_new/{z}/{x}/{y}.png?appid=ae2a038149aa0900d1bc74160aa2a37e"), 256))
-                .withLayer(RasterLayer("wind-layer", "wind-source").apply {
-                    setProperties(PropertyFactory.rasterOpacity(0.6f))
-                })
-                .withSource(RasterSource("openseamap-source",
-                    TileSet("2.2.0", "https://tiles.openseamap.org/seamark/{z}/{x}/{y}.png").also {
-                        it.setMaxZoom(18f)
-                    }, 256))
-                .withLayer(RasterLayer("openseamap-layer", "openseamap-source"))
-            
-            maplibreMap.setStyle(style) { style ->
+
+            val styleBuilder = Style.Builder()
+                .fromUri("https://tiles.openfreemap.org/styles/bright")
+            layerManager.addToStyleBuilder(styleBuilder)
+
+            maplibreMap.setStyle(styleBuilder) { style ->
                 loadedStyleFlow.value = style
                 val anchorBitmap = rasterizeDrawable(R.drawable.ic_anchor)
                 val arrowBitmap = rasterizeDrawable(R.drawable.ic_tidal_arrow)
                 val userBitmap = rasterizeDrawable(R.drawable.ic_ship_arrow)
                 mapHandler?.setupLayers(style, anchorBitmap, arrowBitmap, userBitmap)
             }
+
+            maplibreMap.addOnMapLongClickListener { _ ->
+                val currentStyle = loadedStyleFlow.value ?: return@addOnMapLongClickListener true
+                LayerPickerSheet(
+                    manager = layerManager,
+                    onBaseChanged = { preset -> layerManager.setBasePreset(currentStyle, preset) },
+                    onWindChanged = { enabled -> layerManager.setWindEnabled(currentStyle, enabled) }
+                ).show(supportFragmentManager, "layer_picker")
+                true
+            }
         }
     }
 
diff --git a/android-app/app/src/main/kotlin/org/terst/nav/ui/LayerPickerSheet.kt b/android-app/app/src/main/kotlin/org/terst/nav/ui/LayerPickerSheet.kt
new file mode 100644
index 0000000..48dc808
--- /dev/null
+++ b/android-app/app/src/main/kotlin/org/terst/nav/ui/LayerPickerSheet.kt
@@ -0,0 +1,48 @@
+package org.terst.nav.ui
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import com.google.android.material.bottomsheet.BottomSheetDialogFragment
+import com.google.android.material.chip.ChipGroup
+import com.google.android.material.switchmaterial.SwitchMaterial
+import org.terst.nav.R
+
+class LayerPickerSheet(
+    private val manager: MapLayerManager,
+    private val onBaseChanged: (MapBasePreset) -> Unit,
+    private val onWindChanged: (Boolean) -> Unit
+) : BottomSheetDialogFragment() {
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View =
+        inflater.inflate(R.layout.layout_layer_picker_sheet, container, false)
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        val chipGroup  = view.findViewById<ChipGroup>(R.id.chip_group_base)
+        val windSwitch = view.findViewById<SwitchMaterial>(R.id.switch_wind)
+
+        // Set initial state from manager
+        val chipId = when (manager.basePreset) {
+            MapBasePreset.SATELLITE -> R.id.chip_satellite
+            MapBasePreset.CHARTS    -> R.id.chip_charts
+            MapBasePreset.HYBRID    -> R.id.chip_hybrid
+        }
+        chipGroup.check(chipId)
+        windSwitch.isChecked = manager.windEnabled
+
+        chipGroup.setOnCheckedStateChangeListener { _, checkedIds ->
+            val preset = when (checkedIds.firstOrNull()) {
+                R.id.chip_satellite -> MapBasePreset.SATELLITE
+                R.id.chip_charts    -> MapBasePreset.CHARTS
+                R.id.chip_hybrid    -> MapBasePreset.HYBRID
+                else -> return@setOnCheckedStateChangeListener
+            }
+            onBaseChanged(preset)
+        }
+
+        windSwitch.setOnCheckedChangeListener { _, checked ->
+            onWindChanged(checked)
+        }
+    }
+}
diff --git a/android-app/app/src/main/kotlin/org/terst/nav/ui/MapLayerManager.kt b/android-app/app/src/main/kotlin/org/terst/nav/ui/MapLayerManager.kt
new file mode 100644
index 0000000..cf78ec2
--- /dev/null
+++ b/android-app/app/src/main/kotlin/org/terst/nav/ui/MapLayerManager.kt
@@ -0,0 +1,132 @@
+package org.terst.nav.ui
+
+import android.content.Context
+import org.maplibre.android.maps.Style
+import org.maplibre.android.style.layers.PropertyFactory
+import org.maplibre.android.style.layers.RasterLayer
+import org.maplibre.android.style.sources.RasterSource
+import org.maplibre.android.style.sources.TileSet
+
+enum class MapBasePreset { SATELLITE, CHARTS, HYBRID }
+
+/**
+ * Manages the raster layer stack: base imagery (satellite / NOAA charts / hybrid)
+ * and the wind overlay. Persists selections across sessions.
+ *
+ * All sources are registered at style-build time; this class only toggles
+ * layer visibility — no runtime source swapping required.
+ */
+class MapLayerManager(context: Context) {
+
+    private val prefs = context.getSharedPreferences("map_layers", Context.MODE_PRIVATE)
+
+    var basePreset: MapBasePreset = loadBasePreset()
+        private set
+
+    var windEnabled: Boolean = prefs.getBoolean(KEY_WIND, true)
+        private set
+
+    // ── Source / Layer IDs ────────────────────────────────────────────────────
+
+    companion object {
+        const val SOURCE_SATELLITE  = "satellite-source"
+        const val SOURCE_CHARTS     = "charts-source"
+        const val SOURCE_WIND       = "wind-source"
+        const val SOURCE_SEAMARKS   = "openseamap-source"
+
+        const val LAYER_SATELLITE   = "satellite-layer"
+        const val LAYER_CHARTS      = "charts-layer"
+        const val LAYER_WIND        = "wind-layer"
+        const val LAYER_SEAMARKS    = "openseamap-layer"
+
+        private const val KEY_BASE  = "base_preset"
+        private const val KEY_WIND  = "wind_enabled"
+
+        // Tile URLs
+        private const val URL_SATELLITE =
+            "https://mt1.google.com/vt/lyrs=s&x={x}&y={y}&z={z}"
+        private const val URL_CHARTS =
+            "https://tileservice.charts.noaa.gov/tiles/50000_1/{z}/{x}/{y}.png"
+        private const val URL_WIND =
+            "https://tile.openweathermap.org/map/wind_new/{z}/{x}/{y}.png?appid=ae2a038149aa0900d1bc74160aa2a37e"
+        private const val URL_SEAMARKS =
+            "https://tiles.openseamap.org/seamark/{z}/{x}/{y}.png"
+    }
+
+    /**
+     * Registers all raster sources and layers into the [Style.Builder].
+     * Call this before [Style.Builder.build]. Layers are added in the correct
+     * order; MapHandler's vector layers go on top after style loads.
+     */
+    fun addToStyleBuilder(builder: Style.Builder) {
+        // ── Sources ───────────────────────────────────────────────────────────
+        builder.withSource(RasterSource(SOURCE_SATELLITE,
+            TileSet("2.2.0", URL_SATELLITE), 256))
+
+        builder.withSource(RasterSource(SOURCE_CHARTS,
+            TileSet("2.2.0", URL_CHARTS), 256))
+
+        builder.withSource(RasterSource(SOURCE_WIND,
+            TileSet("2.2.0", URL_WIND), 256))
+
+        builder.withSource(RasterSource(SOURCE_SEAMARKS,
+            TileSet("2.2.0", URL_SEAMARKS).also { it.setMaxZoom(18f) }, 256))
+
+        // ── Layers (bottom → top within raster stack) ─────────────────────────
+        builder.withLayer(RasterLayer(LAYER_SATELLITE, SOURCE_SATELLITE).apply {
+            setProperties(PropertyFactory.rasterOpacity(1f))
+            setProperties(PropertyFactory.visibility(visibilityFor(basePreset, LAYER_SATELLITE)))
+        })
+
+        builder.withLayer(RasterLayer(LAYER_CHARTS, SOURCE_CHARTS).apply {
+            setProperties(PropertyFactory.rasterOpacity(opacityFor(basePreset)))
+            setProperties(PropertyFactory.visibility(visibilityFor(basePreset, LAYER_CHARTS)))
+        })
+
+        builder.withLayer(RasterLayer(LAYER_WIND, SOURCE_WIND).apply {
+            setProperties(PropertyFactory.rasterOpacity(0.6f))
+            setProperties(PropertyFactory.visibility(if (windEnabled) "visible" else "none"))
+        })
+
+        builder.withLayer(RasterLayer(LAYER_SEAMARKS, SOURCE_SEAMARKS).apply {
+            setProperties(PropertyFactory.visibility("visible"))
+        })
+    }
+
+    /** Apply a new base preset to a live style. */
+    fun setBasePreset(style: Style, preset: MapBasePreset) {
+        basePreset = preset
+        prefs.edit().putString(KEY_BASE, preset.name).apply()
+
+        style.getLayer(LAYER_SATELLITE)?.setProperties(
+            PropertyFactory.visibility(visibilityFor(preset, LAYER_SATELLITE)))
+        style.getLayer(LAYER_CHARTS)?.let {
+            it.setProperties(PropertyFactory.visibility(visibilityFor(preset, LAYER_CHARTS)))
+            (it as? RasterLayer)?.setProperties(PropertyFactory.rasterOpacity(opacityFor(preset)))
+        }
+    }
+
+    /** Toggle wind overlay on a live style. */
+    fun setWindEnabled(style: Style, enabled: Boolean) {
+        windEnabled = enabled
+        prefs.edit().putBoolean(KEY_WIND, enabled).apply()
+        style.getLayer(LAYER_WIND)?.setProperties(
+            PropertyFactory.visibility(if (enabled) "visible" else "none"))
+    }
+
+    // ── Helpers ───────────────────────────────────────────────────────────────
+
+    private fun visibilityFor(preset: MapBasePreset, layerId: String): String = when (layerId) {
+        LAYER_SATELLITE -> if (preset == MapBasePreset.SATELLITE || preset == MapBasePreset.HYBRID) "visible" else "none"
+        LAYER_CHARTS    -> if (preset == MapBasePreset.CHARTS    || preset == MapBasePreset.HYBRID) "visible" else "none"
+        else -> "visible"
+    }
+
+    private fun opacityFor(preset: MapBasePreset): Float =
+        if (preset == MapBasePreset.HYBRID) 0.75f else 1f
+
+    private fun loadBasePreset(): MapBasePreset =
+        prefs.getString(KEY_BASE, null)?.let {
+            runCatching { MapBasePreset.valueOf(it) }.getOrNull()
+        } ?: MapBasePreset.SATELLITE
+}
diff --git a/android-app/app/src/main/res/layout/layout_layer_picker_sheet.xml b/android-app/app/src/main/res/layout/layout_layer_picker_sheet.xml
new file mode 100644
index 0000000..c424606
--- /dev/null
+++ b/android-app/app/src/main/res/layout/layout_layer_picker_sheet.xml
@@ -0,0 +1,104 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:orientation="vertical"
+    android:paddingStart="24dp"
+    android:paddingEnd="24dp"
+    android:paddingBottom="32dp"
+    android:background="?attr/colorSurface">
+
+    <View
+        android:layout_width="36dp"
+        android:layout_height="4dp"
+        android:layout_gravity="center_horizontal"
+        android:layout_marginTop="12dp"
+        android:layout_marginBottom="20dp"
+        android:background="@color/md_theme_outline" />
+
+    <TextView
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="16dp"
+        android:text="MAP LAYERS"
+        android:textSize="11sp"
+        android:textAllCaps="true"
+        android:letterSpacing="0.12"
+        android:fontFamily="sans-serif-light"
+        android:textColor="@color/instrument_text_secondary" />
+
+    <!-- Base map selection -->
+    <com.google.android.material.chip.ChipGroup
+        android:id="@+id/chip_group_base"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="24dp"
+        app:singleSelection="true"
+        app:selectionRequired="true"
+        xmlns:app="http://schemas.android.com/apk/res-auto">
+
+        <com.google.android.material.chip.Chip
+            android:id="@+id/chip_satellite"
+            style="@style/Widget.Material3.Chip.Filter"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="Satellite" />
+
+        <com.google.android.material.chip.Chip
+            android:id="@+id/chip_charts"
+            style="@style/Widget.Material3.Chip.Filter"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="Charts" />
+
+        <com.google.android.material.chip.Chip
+            android:id="@+id/chip_hybrid"
+            style="@style/Widget.Material3.Chip.Filter"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="Hybrid" />
+
+    </com.google.android.material.chip.ChipGroup>
+
+    <!-- Wind divider -->
+    <View
+        android:layout_width="match_parent"
+        android:layout_height="1dp"
+        android:layout_marginBottom="16dp"
+        android:background="@color/md_theme_surfaceVariant" />
+
+    <!-- Wind toggle -->
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal"
+        android:gravity="center_vertical">
+
+        <LinearLayout
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:orientation="vertical">
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="Wind overlay"
+                android:textSize="15sp"
+                android:textColor="@color/instrument_text_normal" />
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="OpenWeatherMap wind speed"
+                android:textSize="12sp"
+                android:textColor="@color/instrument_text_secondary" />
+        </LinearLayout>
+
+        <com.google.android.material.switchmaterial.SwitchMaterial
+            android:id="@+id/switch_wind"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content" />
+
+    </LinearLayout>
+
+</LinearLayout>