OSM fallback for geocoding (#611)

* OSM fallback for geocoding

* fallback to city for missing province

AGENTS.md

@@ -0,0 +1,74 @@
+# Bitchat Android - Agent Guide
+
+This document provides context, architectural insights, and development standards for AI agents working on the Bitchat Android codebase.
+
+## 1. Project Overview
+**Bitchat** is a decentralized, off-grid communication application focused on privacy and censorship resistance. It utilizes mesh networking (primarily Bluetooth LE and Tor/Arti) to enable peer-to-peer messaging without centralized servers.
+
+**Key Technologies:**
+- **Language:** Kotlin (JVM Target 1.8)
+- **UI Framework:** Jetpack Compose (Material 3)
+- **Asynchronous:** Kotlin Coroutines & Flow
+- **Networking:** Bluetooth Low Energy (BLE), Tor (Arti Rust bridge), OkHttp
+- **Architecture:** MVVM with Clean Architecture principles
+- **Build System:** Gradle (Kotlin DSL)
+
+## 2. Architecture & Directory Structure
+The application follows a clean architecture pattern, heavily modularized by feature within the `app` module.
+
+**Root Package:** `com.bitchat.android`
+
+| Directory | Purpose |
+|-----------|---------|
+| `ui/` | **Presentation Layer**: Jetpack Compose screens, themes, and ViewModels. |
+| `service/` | **Core Service**: Contains `MeshForegroundService`, managing persistent background connectivity. |
+| `mesh/` | **Mesh Networking**: Logic for peer discovery, advertising, and message routing. |
+| `protocol/` | **Wire Protocol**: Definitions of messages exchanged between peers. |
+| `crypto/` | **Security**: Cryptographic primitives and key management. |
+| `noise/` | **Encryption**: Implementation of the Noise Protocol Framework for secure channels. |
+| `identity/` | **User Identity**: Management of user profiles and public/private keys. |
+| `features/` | **App Features**: Sub-modules for `voice`, `file`, and `media` handling. |
+| `nostr/` | **Relay Integration**: Logic for Nostr protocol integration and relay management. |
+| `geohash/` | **Location**: Utilities for location-based features and geohashing. |
+| `net/` | **Networking**: General network utilities and abstractions. |
+
+## 3. Key Components
+
+### UI Layer (Jetpack Compose)
+- **Activity**: Single-Activity architecture (`MainActivity.kt`).
+- **Navigation**: Jetpack Compose Navigation.
+- **State Management**: `ViewModel` exposing `StateFlow` to Composables.
+- **Theme**: Custom theme definitions in `ui/theme`.
+
+### Networking & Connectivity
+- **MeshForegroundService**: The critical component that keeps the mesh network alive. It manages the lifecycle of BLE scanning/advertising and other transport layers.
+- **BLE Stack**: Located in `mesh/` and `net/`, handles the intricacies of Android Bluetooth interactions.
+- **Tor/Arti**: Integrated via JNI (`jniLibs`) to provide anonymous internet routing where available.
+
+## 4. Development Standards
+
+### Code Style
+- **Kotlin**: Adhere to official Kotlin coding conventions.
+- **Compose**: Use functional components. Hoist state to ViewModels where possible.
+- **Coroutines**: Use `suspend` functions for all I/O operations. strictly avoid blocking the main thread.
+- **Naming**: Clear, descriptive names. Follow standard Android naming patterns (e.g., `*ViewModel`, `*Repository`, `*Screen`).
+
+### Testing
+- **Unit Tests**: Located in `app/src/test/`. Use for business logic, protocols, and utility testing.
+- **Instrumented Tests**: Located in `app/src/androidTest/`. Use for UI and permission integration testing.
+- **Execution**:
+  - Unit: `./gradlew test`
+  - Instrumented: `./gradlew connectedAndroidTest`
+
+## 5. Critical Constraints & Gotchas
+1.  **Permissions**: The app relies heavily on dangerous runtime permissions (Location, Bluetooth Scan/Connect/Advertise, Audio Recording). Always verify permission handling patterns in `MainActivity` or permission wrappers before adding new hardware features.
+2.  **Hardware Dependency**: Features like BLE are difficult to emulate. When writing code for these, focus on robust error handling and defensive programming as hardware behavior can be flaky.
+3.  **Background Limits**: Android enforces strict background execution limits. Network operations intended to persist must be tied to the `MeshForegroundService`.
+
+## 6. Common Tasks
+- **Build Debug APK**: `./gradlew assembleDebug`
+- **Lint Check**: `./gradlew lint`
+- **Clean Build**: `./gradlew clean`
+
+---
+*Note: This file is intended to assist AI agents in navigating and modifying the codebase efficiently. Always verify context by reading the actual files before making changes.*

app/src/main/java/com/bitchat/android/geohash/AndroidGeocoderProvider.kt

@@ -0,0 +1,52 @@
+package com.bitchat.android.geohash
+
+import android.content.Context
+import android.location.Address
+import android.location.Geocoder
+import android.os.Build
+import android.util.Log
+import kotlinx.coroutines.suspendCancellableCoroutine
+import java.util.Locale
+import kotlin.coroutines.resume
+import kotlin.coroutines.resumeWithException
+
+class AndroidGeocoderProvider(context: Context) : GeocoderProvider {
+    private val geocoder = Geocoder(context, Locale.getDefault())
+    private val TAG = "AndroidGeocoderProvider"
+
+    override suspend fun getFromLocation(latitude: Double, longitude: Double, maxResults: Int): List<Address> {
+        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            suspendCancellableCoroutine { cont ->
+                try {
+                    geocoder.getFromLocation(
+                        latitude,
+                        longitude,
+                        maxResults,
+                        object : Geocoder.GeocodeListener {
+                            override fun onGeocode(addresses: MutableList<Address>) {
+                                if (cont.isActive) cont.resume(addresses)
+                            }
+
+                            override fun onError(errorMessage: String?) {
+                                if (cont.isActive) {
+                                    Log.e(TAG, "Geocode error: $errorMessage")
+                                    cont.resume(emptyList())
+                                }
+                            }
+                        }
+                    )
+                } catch (e: Exception) {
+                    if (cont.isActive) cont.resumeWithException(e)
+                }
+            }
+        } else {
+            @Suppress("DEPRECATION")
+            try {
+                geocoder.getFromLocation(latitude, longitude, maxResults) ?: emptyList()
+            } catch (e: Exception) {
+                Log.e(TAG, "Geocode failed", e)
+                emptyList()
+            }
+        }
+    }
+}

app/src/main/java/com/bitchat/android/geohash/GeocoderFactory.kt

@@ -0,0 +1,19 @@
+package com.bitchat.android.geohash
+
+import android.content.Context
+import android.location.Geocoder
+
+/**
+ * Factory to provide the best available geocoder.
+ */
+object GeocoderFactory {
+    fun get(context: Context): GeocoderProvider {
+        // If Google Play Services Geocoder is present, use it.
+        // Otherwise, fall back to OpenStreetMap.
+        return if (Geocoder.isPresent()) {
+            AndroidGeocoderProvider(context)
+        } else {
+            OpenStreetMapGeocoderProvider()
+        }
+    }
+}

app/src/main/java/com/bitchat/android/geohash/GeocoderProvider.kt

@@ -0,0 +1,13 @@
+package com.bitchat.android.geohash
+
+import android.location.Address
+
+/**
+ * Interface for reverse geocoding providers.
+ */
+interface GeocoderProvider {
+    /**
+     * Get a list of Address objects from latitude and longitude.
+     */
+    suspend fun getFromLocation(latitude: Double, longitude: Double, maxResults: Int): List<Address>
+}

app/src/main/java/com/bitchat/android/geohash/GeohashBookmarksStore.kt

@@ -167,12 +167,11 @@ class GeohashBookmarksStore private constructor(private val context: Context) {
         if (gh.isEmpty()) return
         if (_bookmarkNames.value?.containsKey(gh) == true) return
         if (resolving.contains(gh)) return
-        if (!Geocoder.isPresent()) return
 
         resolving.add(gh)
         CoroutineScope(Dispatchers.IO).launch {
             try {
-                val geocoder = Geocoder(context, Locale.getDefault())
+                val geocoderProvider = GeocoderFactory.get(context)
                 val name: String? = if (gh.length <= 2) {
                     // Composite admin name from multiple points
                     val b = Geohash.decodeToBounds(gh)
@@ -186,9 +185,8 @@ class GeohashBookmarksStore private constructor(private val context: Context) {
                     val admins = linkedSetOf<String>()
                     for (loc in points) {
                         try {
-                            @Suppress("DEPRECATION")
-                            val list = geocoder.getFromLocation(loc.latitude, loc.longitude, 1)
-                            val a = list?.firstOrNull()
+                            val list = geocoderProvider.getFromLocation(loc.latitude, loc.longitude, 1)
+                            val a = list.firstOrNull()
                             val admin = a?.adminArea?.takeIf { !it.isNullOrEmpty() }
                             val country = a?.countryName?.takeIf { !it.isNullOrEmpty() }
                             if (admin != null) admins.add(admin)
@@ -203,9 +201,8 @@ class GeohashBookmarksStore private constructor(private val context: Context) {
                     }
                 } else {
                     val center = Geohash.decodeToCenter(gh)
-                    @Suppress("DEPRECATION")
-                    val list = geocoder.getFromLocation(center.first, center.second, 1)
-                    val a = list?.firstOrNull()
+                    val list = geocoderProvider.getFromLocation(center.first, center.second, 1)
+                    val a = list.firstOrNull()
                     pickNameForLength(gh.length, a)
                 }
 

app/src/main/java/com/bitchat/android/geohash/LocationChannelManager.kt

@@ -47,7 +47,7 @@ class LocationChannelManager private constructor(private val context: Context) {
     }
 
     private val locationManager: LocationManager = context.getSystemService(Context.LOCATION_SERVICE) as LocationManager
-    private val geocoder: Geocoder = Geocoder(context, Locale.getDefault())
+    private val geocoderProvider: GeocoderProvider = GeocoderFactory.get(context)
     private var lastLocation: Location? = null
     private var geocodingJob: Job? = null
     private val gson = Gson()
@@ -538,11 +538,6 @@ class LocationChannelManager private constructor(private val context: Context) {
     }
 
     private fun reverseGeocodeIfNeeded(location: Location) {
-        if (!Geocoder.isPresent()) {
-            Log.w(TAG, "Geocoder not present on this device")
-            return
-        }
-        
         // Cancel any pending geocoding job to avoid race conditions
         geocodingJob?.cancel()
 
@@ -550,17 +545,10 @@ class LocationChannelManager private constructor(private val context: Context) {
             try {
                 Log.d(TAG, "Starting reverse geocoding")
                 
-                if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.TIRAMISU) {
-                    // Use new listener-based API for Android 13+
-                    suspendCancellableCoroutine<Unit> { cont ->
-                        try {
-                            geocoder.getFromLocation(
-                                location.latitude,
-                                location.longitude,
-                                1,
-                                object : Geocoder.GeocodeListener {
-                                    override fun onGeocode(addresses: MutableList<android.location.Address>) {
-                                        if (!cont.isActive) return
+                val addresses = geocoderProvider.getFromLocation(location.latitude, location.longitude, 1)
+
+                if (!isActive) return@launch
+
                 if (addresses.isNotEmpty()) {
                     val address = addresses[0]
                     val names = namesByLevel(address)
@@ -569,40 +557,6 @@ class LocationChannelManager private constructor(private val context: Context) {
                 } else {
                     Log.w(TAG, "No reverse geocoding results")
                 }
-                                        cont.resume(Unit) {}
-                                    }
-
-                                    override fun onError(errorMessage: String?) {
-                                        if (!cont.isActive) return
-                                        Log.e(TAG, "Reverse geocoding failed: $errorMessage")
-                                        cont.resume(Unit) {}
-                                    }
-                                }
-                            )
-                        } catch (e: Exception) {
-                            if (!cont.isActive) return@suspendCancellableCoroutine
-                            Log.e(TAG, "Error initiating geocoding listener: ${e.message}")
-                            cont.resume(Unit) {}
-                        }
-                        cont.invokeOnCancellation {
-                            // Listener-based API has no explicit unregister, so we just ignore callbacks
-                        }
-                    }
-                } else {
-                    @Suppress("DEPRECATION")
-                    val addresses = geocoder.getFromLocation(location.latitude, location.longitude, 1)
-                    
-                    if (!isActive) return@launch
-                    
-                    if (!addresses.isNullOrEmpty()) {
-                        val address = addresses[0]
-                        val names = namesByLevel(address)
-                        Log.d(TAG, "Reverse geocoding result: $names")
-                        _locationNames.value = names
-                    } else {
-                        Log.w(TAG, "No reverse geocoding results")
-                    }
-                }
             } catch (e: Exception) {
                 if (e !is CancellationException) {
                     Log.e(TAG, "Reverse geocoding failed: ${e.message}")
@@ -619,11 +573,13 @@ class LocationChannelManager private constructor(private val context: Context) {
             dict[GeohashChannelLevel.REGION] = it
         }
         
-        // Province (state/province or county)
+        // Province (state/province or county or city)
         address.adminArea?.takeIf { it.isNotEmpty() }?.let {
             dict[GeohashChannelLevel.PROVINCE] = it
         } ?: address.subAdminArea?.takeIf { it.isNotEmpty() }?.let {
             dict[GeohashChannelLevel.PROVINCE] = it
+        } ?: address.locality?.takeIf { it.isNotEmpty() }?.let {
+            dict[GeohashChannelLevel.PROVINCE] = it
         }
         
         // City (locality)

app/src/main/java/com/bitchat/android/geohash/OpenStreetMapGeocoderProvider.kt

@@ -0,0 +1,106 @@
+package com.bitchat.android.geohash
+
+import android.location.Address
+import android.util.Log
+import com.bitchat.android.net.OkHttpProvider
+import com.google.gson.Gson
+import okhttp3.Request
+import java.util.Locale
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+class OpenStreetMapGeocoderProvider : GeocoderProvider {
+    private val TAG = "OSMGeocoderProvider"
+    private val gson = Gson()
+    private val userAgent = "Bitchat-Android/1.0"
+
+    override suspend fun getFromLocation(latitude: Double, longitude: Double, maxResults: Int): List<Address> {
+        return withContext(Dispatchers.IO) {
+            val lang = Locale.getDefault().toLanguageTag()
+            // Using format=jsonv2 for structured address breakdown
+            val url = "https://nominatim.openstreetmap.org/reverse?format=jsonv2&lat=$latitude&lon=$longitude&zoom=18&addressdetails=1&accept-language=$lang"
+
+            try {
+                val request = Request.Builder()
+                    .url(url)
+                    .header("User-Agent", userAgent)
+                    .build()
+
+                val response = OkHttpProvider.httpClient().newCall(request).execute()
+                if (!response.isSuccessful) {
+                    Log.e(TAG, "OSM Request failed: ${response.code}")
+                    response.close()
+                    return@withContext emptyList<Address>()
+                }
+
+                val body = response.body?.string()
+                response.close()
+
+                if (body.isNullOrEmpty()) return@withContext emptyList<Address>()
+
+                try {
+                    val osmResponse = gson.fromJson(body, OsmResponse::class.java)
+                    if (osmResponse?.address == null) return@withContext emptyList<Address>()
+                    
+                    val address = mapToAddress(osmResponse, latitude, longitude)
+                    listOf(address)
+                } catch (e: Exception) {
+                     Log.e(TAG, "OSM Parse failed: ${e.message}")
+                     emptyList<Address>()
+                }
+            } catch (e: Exception) {
+                Log.e(TAG, "OSM Geocoding failed", e)
+                emptyList<Address>()
+            }
+        }
+    }
+
+    private fun mapToAddress(res: OsmResponse, lat: Double, lon: Double): Address {
+        val address = Address(Locale.getDefault())
+        address.latitude = lat
+        address.longitude = lon
+        
+        val a = res.address ?: return address
+
+        address.countryName = a.country
+        address.adminArea = a.state
+        address.subAdminArea = a.county
+        
+        // City logic similar to Google's mapping
+        address.locality = a.city ?: a.town ?: a.village ?: a.hamlet
+        
+        // Neighborhood logic
+        address.subLocality = a.suburb ?: a.neighbourhood ?: a.residential ?: a.quarter
+        
+        address.postalCode = a.postcode
+        address.thoroughfare = a.road
+        
+        // Feature name
+        address.featureName = res.name
+
+        return address
+    }
+
+    // Data classes for JSON parsing
+    private data class OsmResponse(
+        val name: String?,
+        val display_name: String?,
+        val address: OsmAddress?
+    )
+
+    private data class OsmAddress(
+        val country: String?,
+        val state: String?,
+        val county: String?,
+        val city: String?,
+        val town: String?,
+        val village: String?,
+        val hamlet: String?,
+        val suburb: String?,
+        val neighbourhood: String?,
+        val residential: String?,
+        val quarter: String?,
+        val postcode: String?,
+        val road: String?
+    )
+}