Wire up FCM push notification service

- ClippyFCMService: Receives FCM data messages, routes to TTS pipeline
- FCMTokenManager: Stores FCM token in Matrix account data for n8n
- Enable Google Services plugin and Firebase dependencies
- Add FCM service to AndroidManifest.xml
- Register FCM token on app init in ClippySession and SetupActivity

Token stored at: /_matrix/client/v3/user/@clippyauto:hobbs.farm/account_data/farm.hobbs.clippy.fcm_token

Co-authored-by: Spirit <spirit@hobbs.farm>

app/build.gradle.kts

@@ -2,8 +2,7 @@ plugins {
     id("com.android.application")
     id("org.jetbrains.kotlin.android")
     id("org.jetbrains.kotlin.plugin.serialization")
-    // Firebase deferred to Sprint 2
-    // id("com.google.gms.google-services")
+    id("com.google.gms.google-services")
 }
 
 android {
@@ -40,9 +39,9 @@ dependencies {
     implementation("androidx.car.app:app:1.7.0")
     implementation("androidx.car.app:app-projected:1.7.0")
 
-    // Firebase Cloud Messaging — Sprint 2
-    // implementation(platform("com.google.firebase:firebase-bom:33.9.0"))
-    // implementation("com.google.firebase:firebase-messaging-ktx")
+    // Firebase Cloud Messaging
+    implementation(platform("com.google.firebase:firebase-bom:33.1.0"))
+    implementation("com.google.firebase:firebase-messaging-ktx")
 
     // HTTP client for Matrix REST API
     implementation("io.ktor:ktor-client-okhttp:3.0.3")
@@ -51,6 +50,7 @@ dependencies {
 
     // Coroutines
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.9.0")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-play-services:1.7.3")
 
     // Lifecycle
     implementation("androidx.lifecycle:lifecycle-runtime-ktx:2.8.7")

app/src/main/AndroidManifest.xml

@@ -29,14 +29,14 @@
             android:name="com.google.android.gms.car.application"
             android:resource="@xml/automotive_app_desc" />
 
-        <!-- FCM Service — Sprint 2 (needs Firebase project) -->
-        <!-- <service
+        <!-- FCM push service for fast Clippy response delivery -->
+        <service
             android:name=".push.ClippyFCMService"
             android:exported="false">
             <intent-filter>
                 <action android:name="com.google.firebase.MESSAGING_EVENT" />
             </intent-filter>
-        </service> -->
+        </service>
 
         <!-- Phone UI -->
         <activity

app/src/main/java/farm/hobbs/clippyauto/auto/ClippySession.kt

@@ -8,6 +8,7 @@ import androidx.lifecycle.LifecycleOwner
 import farm.hobbs.clippyauto.VoiceLoop
 import farm.hobbs.clippyauto.config.AppConfig
 import farm.hobbs.clippyauto.matrix.MatrixRestClient
+import farm.hobbs.clippyauto.push.FCMTokenManager
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
@@ -62,6 +63,8 @@ class ClippySession : Session(), DefaultLifecycleObserver {
             withContext(Dispatchers.Main) {
                 if (loggedIn) {
                     voiceLoop?.initialize()
+                    // Register FCM token for push delivery
+                    FCMTokenManager.ensureTokenRegistered(scope)
                     voiceLoop?.startSession()
                     screen?.attachVoiceLoop(voiceLoop!!)
                 } else {

app/src/main/java/farm/hobbs/clippyauto/push/ClippyFCMService.kt

@@ -1,40 +1,124 @@
 package farm.hobbs.clippyauto.push
 
-// Firebase FCM Service — Sprint 2
-// Requires google-services.json and Firebase project setup.
-// For now, only the dedup + bus infrastructure is active.
-// The actual FirebaseMessagingService subclass will be added in Sprint 2.
+import android.util.Log
+import com.google.firebase.messaging.FirebaseMessagingService
+import com.google.firebase.messaging.RemoteMessage
+import farm.hobbs.clippyauto.config.AppConfig
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.launch
+import io.ktor.client.*
+import io.ktor.client.engine.cio.*
+import io.ktor.client.request.*
+import io.ktor.http.*
 
 /**
- * Simple dedup cache — keeps last N response hashes.
- * Prevents double-TTS when both FCM and Matrix sync deliver the same message.
+ * Firebase Cloud Messaging service for ClippyAuto.
+ *
+ * Receives push messages from the n8n webhook bridge:
+ *   Clippy sends Matrix message → Synapse push gateway → n8n → FCM data message → here
+ *
+ * Data message format (from n8n):
+ *   {
+ *     "sender": "@clippy:hobbs.farm",
+ *     "room_id": "!KSovCtghshGUfVDbQg:hobbs.farm",
+ *     "event_id": "$abc123",
+ *     "body": "Hey Jeremy. You've got three things on deck today."
+ *   }
+ *
+ * Routes messages to ClippyResponseBus for dedup + TTS pipeline.
+ * Latency target: ~300ms from FCM delivery to TTS start.
  */
-object ResponseDedup {
-    private val cache = LinkedHashSet<String>()
-    private const val MAX_SIZE = 50
+class ClippyFCMService : FirebaseMessagingService() {
 
-    fun seen(hash: String): Boolean = hash in cache
+    companion object {
+        private const val TAG = "ClippyFCM"
 
-    fun mark(hash: String) {
-        cache.add(hash)
-        if (cache.size > MAX_SIZE) {
-            cache.remove(cache.first())
+        /** Key for storing the FCM token in Matrix account data */
+        const val ACCOUNT_DATA_TYPE = "farm.hobbs.clippy.fcm_token"
+    }
+
+    private val scope = CoroutineScope(Dispatchers.IO + SupervisorJob())
+
+    /**
+     * Called when a data message is received from FCM.
+     * This is the fast path — should beat the Matrix sync poll.
+     */
+    override fun onMessageReceived(message: RemoteMessage) {
+        super.onMessageReceived(message)
+
+        val data = message.data
+        val sender = data["sender"] ?: return
+        val body = data["body"] ?: return
+        val eventId = data["event_id"] ?: ""
+        val roomId = data["room_id"] ?: ""
+
+        Log.d(TAG, "FCM message from $sender (event: $eventId)")
+
+        // Only process messages from Clippy in the voice room
+        if (sender != AppConfig.clippyUserId) {
+            Log.d(TAG, "Ignoring message from non-Clippy sender: $sender")
+            return
+        }
+
+        if (roomId.isNotEmpty() && roomId != AppConfig.roomId) {
+            Log.d(TAG, "Ignoring message from different room: $roomId")
+            return
+        }
+
+        // Route to the response bus — VoiceLoop picks it up via ClippyResponseBus
+        // ResponseDedup handles the case where sync also delivers the same message
+        ClippyResponseBus.emit(body, "fcm")
+        Log.d(TAG, "FCM → ResponseBus: ${body.take(50)}...")
+    }
+
+    /**
+     * Called when a new FCM token is generated.
+     * Stores the token in Matrix account data so n8n can retrieve it.
+     */
+    override fun onNewToken(token: String) {
+        super.onNewToken(token)
+        Log.d(TAG, "New FCM token: ${token.take(20)}...")
+        registerTokenWithMatrix(token)
+    }
+
+    /**
+     * Register the FCM token with Matrix via account data.
+     *
+     * Stores at: PUT /_matrix/client/v3/user/{userId}/account_data/{type}
+     * n8n reads this to know where to send FCM pushes.
+     */
+    private fun registerTokenWithMatrix(token: String) {
+        scope.launch {
+            try {
+                val accessToken = AppConfig.matrixAccessToken ?: run {
+                    Log.w(TAG, "No Matrix access token — can't register FCM token")
+                    return@launch
+                }
+
+                val userId = "@${AppConfig.matrixUser}:hobbs.farm"
+                val client = HttpClient(CIO)
+
+                val response = client.put(
+                    "${AppConfig.homeserverUrl}/_matrix/client/v3/user/" +
+                    "${userId}/account_data/${ACCOUNT_DATA_TYPE}"
+                ) {
+                    header("Authorization", "Bearer $accessToken")
+                    contentType(ContentType.Application.Json)
+                    setBody("""{"fcm_token":"$token","updated_at":"${System.currentTimeMillis()}"}""")
+                }
+
+                if (response.status.isSuccess()) {
+                    Log.d(TAG, "FCM token registered in Matrix account data")
+                } else {
+                    Log.e(TAG, "Failed to register FCM token: ${response.status}")
+                }
+
+                client.close()
+            } catch (e: Exception) {
+                Log.e(TAG, "Error registering FCM token", e)
+            }
         }
     }
 }
-
-/**
- * Simple event bus for FCM → voice pipeline communication.
- * In production, consider using SharedFlow or LiveData.
- */
-object ClippyResponseBus {
-    private val listeners = mutableListOf<(String, String) -> Unit>()
-
-    fun subscribe(listener: (response: String, sessionId: String) -> Unit) {
-        listeners.add(listener)
-    }
-
-    fun emit(response: String, sessionId: String) {
-        listeners.forEach { it(response, sessionId) }
-    }
-}

app/src/main/java/farm/hobbs/clippyauto/push/FCMTokenManager.kt

@@ -0,0 +1,79 @@
+package farm.hobbs.clippyauto.push
+
+import android.content.Context
+import android.util.Log
+import com.google.firebase.messaging.FirebaseMessaging
+import farm.hobbs.clippyauto.config.AppConfig
+import io.ktor.client.*
+import io.ktor.client.engine.cio.*
+import io.ktor.client.request.*
+import io.ktor.http.*
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.tasks.await
+
+/**
+ * Handles FCM token lifecycle.
+ *
+ * Call [ensureTokenRegistered] at app startup (after Matrix login)
+ * to make sure n8n has the current FCM token for push delivery.
+ *
+ * Token is stored in Matrix account data so n8n can read it:
+ *   GET /_matrix/client/v3/user/{userId}/account_data/farm.hobbs.clippy.fcm_token
+ *   → { "fcm_token": "...", "updated_at": 1741... }
+ */
+object FCMTokenManager {
+
+    private const val TAG = "FCMToken"
+
+    /**
+     * Ensure the current FCM token is registered with Matrix.
+     * Call after successful Matrix login.
+     */
+    fun ensureTokenRegistered(scope: CoroutineScope) {
+        scope.launch(Dispatchers.IO) {
+            try {
+                val token = FirebaseMessaging.getInstance().token.await()
+                Log.d(TAG, "Current FCM token: ${token.take(20)}...")
+                registerToken(token)
+            } catch (e: Exception) {
+                Log.e(TAG, "Failed to get FCM token", e)
+            }
+        }
+    }
+
+    /**
+     * Register a token with Matrix account data.
+     */
+    suspend fun registerToken(token: String) {
+        val accessToken = AppConfig.matrixAccessToken ?: run {
+            Log.w(TAG, "No Matrix access token available")
+            return
+        }
+
+        try {
+            val userId = "@${AppConfig.matrixUser}:hobbs.farm"
+            val client = HttpClient(CIO)
+
+            val response = client.put(
+                "${AppConfig.homeserverUrl}/_matrix/client/v3/user/" +
+                "${userId}/account_data/${ClippyFCMService.ACCOUNT_DATA_TYPE}"
+            ) {
+                header("Authorization", "Bearer $accessToken")
+                contentType(ContentType.Application.Json)
+                setBody("""{"fcm_token":"$token","updated_at":"${System.currentTimeMillis()}"}""")
+            }
+
+            if (response.status.isSuccess()) {
+                Log.d(TAG, "FCM token registered successfully")
+            } else {
+                Log.e(TAG, "Failed to register FCM token: ${response.status}")
+            }
+
+            client.close()
+        } catch (e: Exception) {
+            Log.e(TAG, "Error registering FCM token with Matrix", e)
+        }
+    }
+}

app/src/main/java/farm/hobbs/clippyauto/ui/SetupActivity.kt

@@ -13,6 +13,7 @@ import androidx.core.content.ContextCompat
 import farm.hobbs.clippyauto.VoiceLoop
 import farm.hobbs.clippyauto.config.AppConfig
 import farm.hobbs.clippyauto.matrix.MatrixRestClient
+import farm.hobbs.clippyauto.push.FCMTokenManager
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.SupervisorJob
@@ -135,6 +136,9 @@ class SetupActivity : AppCompatActivity() {
             if (loggedIn) {
                 log("✅ Logged in as @${AppConfig.matrixUser}:hobbs.farm")
                 voiceLoop?.initialize()
+                // Register FCM token for push delivery
+                FCMTokenManager.ensureTokenRegistered(scope)
+                log("📲 FCM token registration requested")
                 voiceLoop?.startSession()
                 talkButton.isEnabled = true
                 statusText.text = "Connected! Tap Talk to Clippy"

build.gradle.kts

@@ -2,6 +2,5 @@ plugins {
     id("com.android.application") version "8.7.3" apply false
     id("org.jetbrains.kotlin.android") version "2.1.10" apply false
     id("org.jetbrains.kotlin.plugin.serialization") version "2.1.10" apply false
-    // Firebase deferred to Sprint 2 (needs google-services.json)
-    // id("com.google.gms.google-services") version "4.4.2" apply false
+    id("com.google.gms.google-services") version "4.4.2" apply false
 }