feat: AI-powered Reply Drafter

.github/workflows/play-release.yml

@@ -51,6 +51,7 @@ jobs:
           SUPABASE_URL:             ${{ secrets.SUPABASE_URL }}
           SUPABASE_ANON_KEY:        ${{ secrets.SUPABASE_ANON_KEY }}
           GOOGLE_WEB_CLIENT_ID:     ${{ secrets.GOOGLE_WEB_CLIENT_ID }}
+          REPLY_DRAFTER_MODEL_URL:  ${{ secrets.REPLY_DRAFTER_MODEL_URL }}
         run: ./gradlew bundleRelease --no-daemon
 
       # Single upload that targets one or more Play tracks. Prereleases

app/build.gradle.kts

@@ -69,6 +69,11 @@ android {
             "GOOGLE_WEB_CLIENT_ID",
             "\"${configValue("GOOGLE_WEB_CLIENT_ID", "google.webClientId")}\""
         )
+        buildConfigField(
+            "String",
+            "REPLY_DRAFTER_MODEL_URL",
+            "\"${configValue("REPLY_DRAFTER_MODEL_URL", "replyDrafter.modelUrl")}\""
+        )
     }
 
     // CI-only release signing: activates when UPLOAD_KEYSTORE_PATH points at
@@ -165,6 +170,8 @@ dependencies {
     implementation(libs.androidx.camera.view)
     implementation(libs.accompanist.permissions)
     implementation(libs.mediapipe.tasks.vision)
+    implementation(libs.mediapipe.tasks.genai)
+    implementation(libs.androidx.work.runtime)
     implementation(libs.room.runtime)
     implementation(libs.room.ktx)
     ksp(libs.room.compiler)

app/src/main/AndroidManifest.xml

@@ -21,6 +21,8 @@
         tools:ignore="ProtectedPermissions" /> <!-- Required for recent apps -->
     <uses-permission android:name="com.google.android.gms.permission.AD_ID" /> <!-- Required for advertising identifier access -->
     <uses-permission android:name="android.permission.WAKE_LOCK" /> <!-- Required for camera service wake lock -->
+    <uses-permission android:name="android.permission.INTERNET" /> <!-- Required for downloading the Reply Drafter model -->
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" /> <!-- Required for the model download foreground worker -->
 
     <application
         android:name=".SwitchifyApplication"
@@ -63,6 +65,12 @@
             android:exported="false"
             android:foregroundServiceType="camera"></service>
 
+        <!-- dataSync type for the model download foreground worker -->
+        <service
+            android:name="androidx.work.impl.foreground.SystemForegroundService"
+            android:foregroundServiceType="dataSync"
+            tools:node="merge" />
+
     </application>
 
 </manifest>

app/src/main/java/com/enaboapps/switchify/backend/preferences/PreferenceManager.kt

@@ -80,6 +80,10 @@ class PreferenceManager(context: Context) {
         const val PREFERENCE_KEY_CAMERA_HEAD_TURN_DOWN_SENSITIVITY =
             "camera_head_turn_down_sensitivity"
 
+        // Reply Drafter (on-device LLM) Gemma terms acceptance
+        const val PREFERENCE_KEY_REPLY_DRAFTER_GEMMA_TERMS_ACCEPTED =
+            "reply_drafter_gemma_terms_accepted"
+
         private const val PREFERENCE_FILE_NAME = "switchify_preferences"
 
         /**
@@ -90,7 +94,8 @@ class PreferenceManager(context: Context) {
             PREFERENCE_KEY_ACCESS_TECHNIQUE,
             PREFERENCE_KEY_SETUP_COMPLETE,
             PREFERENCE_KEY_REVIEW_LAST_SHOWN,
-            PREFERENCE_KEY_TELEMETRY_ENABLED
+            PREFERENCE_KEY_TELEMETRY_ENABLED,
+            PREFERENCE_KEY_REPLY_DRAFTER_GEMMA_TERMS_ACCEPTED
         )
     }
 

app/src/main/java/com/enaboapps/switchify/nav/NavGraph.kt

@@ -16,6 +16,8 @@ import com.enaboapps.switchify.screens.paywall.AppPaywallScreen
 import com.enaboapps.switchify.screens.settings.CameraSettingsScreen
 import com.enaboapps.switchify.screens.settings.HeadControlSettingsScreen
 import com.enaboapps.switchify.screens.settings.SettingsScreen
+import com.enaboapps.switchify.screens.settings.replydrafter.GemmaTermsScreen
+import com.enaboapps.switchify.screens.settings.replydrafter.ReplyDrafterSettingsScreen
 import com.enaboapps.switchify.screens.settings.gestures.ScrollingSettingsScreen
 import com.enaboapps.switchify.screens.settings.patterns.GesturePatternsScreen
 import com.enaboapps.switchify.screens.settings.scanning.AutoScanSettingsScreen
@@ -144,6 +146,12 @@ fun NavGraph(navController: NavHostController) {
         composable(NavigationRoute.FavouriteApps.name) {
             FavouriteAppsScreen(navController)
         }
+        composable(NavigationRoute.ReplyDrafterSettings.name) {
+            ReplyDrafterSettingsScreen(navController)
+        }
+        composable(NavigationRoute.GemmaTerms.name) {
+            GemmaTermsScreen(navController)
+        }
         composable("${NavigationRoute.SwitchActionSelection.name}/{currentActionId}") {
             it.arguments?.getString("currentActionId")?.toIntOrNull()?.let { actionId ->
                 SwitchActionSelectionScreen(navController, actionId)

app/src/main/java/com/enaboapps/switchify/nav/NavigationRoute.kt

@@ -35,4 +35,6 @@ sealed class NavigationRoute(val name: String) {
     data object SwitchActionSelection : NavigationRoute("SwitchActionSelection")
     data object LongPressActions : NavigationRoute("LongPressActions")
     data object FavouriteApps : NavigationRoute("FavouriteApps")
+    data object ReplyDrafterSettings : NavigationRoute("ReplyDrafterSettings")
+    data object GemmaTerms : NavigationRoute("GemmaTerms")
 }

app/src/main/java/com/enaboapps/switchify/screens/settings/SettingsScreen.kt

@@ -128,6 +128,14 @@ fun GeneralSettingsTab(menuSettingsModel: MenuSettingsModel, navController: NavC
         BehaviourSection(navController)
         GesturesSettingsSection(navController)
         MenuSection(menuSettingsModel, navController)
+        Section(titleResId = R.string.settings_section_reply_drafter) {
+            NavRouteLink(
+                titleResId = R.string.settings_title_reply_drafter,
+                summaryResId = R.string.settings_summary_reply_drafter,
+                navController = navController,
+                route = NavigationRoute.ReplyDrafterSettings.name
+            )
+        }
     }
 }
 

app/src/main/java/com/enaboapps/switchify/screens/settings/replydrafter/GemmaTermsScreen.kt

@@ -0,0 +1,72 @@
+package com.enaboapps.switchify.screens.settings.replydrafter
+
+import android.content.Context
+import android.content.Intent
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.platform.LocalContext
+import androidx.core.net.toUri
+import androidx.navigation.NavController
+import com.enaboapps.switchify.R
+import com.enaboapps.switchify.backend.preferences.PreferenceManager
+import com.enaboapps.switchify.components.ActionButton
+import com.enaboapps.switchify.components.ActionButtonType
+import com.enaboapps.switchify.components.BaseView
+import com.enaboapps.switchify.components.InfoCard
+import com.enaboapps.switchify.service.llm.model.ReplyDrafterModelConfig
+import com.enaboapps.switchify.theme.Dimens
+
+@Composable
+fun GemmaTermsScreen(navController: NavController) {
+    val context = LocalContext.current
+    val preferenceManager = remember { PreferenceManager(context) }
+    val alreadyAccepted = remember {
+        preferenceManager.getBooleanValue(
+            PreferenceManager.PREFERENCE_KEY_REPLY_DRAFTER_GEMMA_TERMS_ACCEPTED
+        )
+    }
+
+    BaseView(
+        titleResId = R.string.screen_title_gemma_terms,
+        navController = navController
+    ) {
+        InfoCard(
+            titleResId = R.string.gemma_terms_intro_title,
+            descriptionResId = R.string.gemma_terms_intro
+        )
+        Spacer(modifier = Modifier.height(Dimens.spaceM))
+        ActionButton(
+            textResId = R.string.gemma_terms_view_terms,
+            onClick = { openUrl(context, ReplyDrafterModelConfig.GEMMA_TERMS_URL) },
+            type = ActionButtonType.SECONDARY
+        )
+        ActionButton(
+            textResId = R.string.gemma_terms_view_policy,
+            onClick = { openUrl(context, ReplyDrafterModelConfig.GEMMA_USE_POLICY_URL) },
+            type = ActionButtonType.SECONDARY
+        )
+        if (!alreadyAccepted) {
+            Spacer(modifier = Modifier.height(Dimens.spaceL))
+            ActionButton(
+                textResId = R.string.gemma_terms_accept,
+                onClick = {
+                    preferenceManager.setBooleanValue(
+                        PreferenceManager.PREFERENCE_KEY_REPLY_DRAFTER_GEMMA_TERMS_ACCEPTED,
+                        true
+                    )
+                    navController.popBackStack()
+                }
+            )
+        }
+    }
+}
+
+private fun openUrl(context: Context, url: String) {
+    if (url.isBlank()) return
+    runCatching {
+        context.startActivity(Intent(Intent.ACTION_VIEW, url.toUri()))
+    }
+}

app/src/main/java/com/enaboapps/switchify/screens/settings/replydrafter/ModelDownloadViewModel.kt

@@ -0,0 +1,70 @@
+package com.enaboapps.switchify.screens.settings.replydrafter
+
+import android.content.Context
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MediatorLiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.work.WorkInfo
+import com.enaboapps.switchify.backend.preferences.PreferenceManager
+import com.enaboapps.switchify.service.llm.model.ModelDownloadManager
+import com.enaboapps.switchify.service.llm.model.ModelManager
+
+sealed interface ModelDownloadUiState {
+    data object NotDownloaded : ModelDownloadUiState
+    data object Ready : ModelDownloadUiState
+    data class Downloading(val bytesDownloaded: Long, val totalBytes: Long) : ModelDownloadUiState
+    data object Failed : ModelDownloadUiState
+}
+
+class ModelDownloadViewModel(context: Context) : ViewModel() {
+    private val appContext = context.applicationContext
+    private val modelManager = ModelManager(appContext)
+    private val preferenceManager = PreferenceManager(appContext)
+
+    private val workInfos = ModelDownloadManager.getWorkInfoLiveData(appContext)
+    private val refreshTrigger = MutableLiveData(Unit)
+
+    val uiState: LiveData<ModelDownloadUiState> =
+        MediatorLiveData<ModelDownloadUiState>().apply {
+            val update = { value = deriveState(workInfos.value.orEmpty()) }
+            addSource(workInfos) { update() }
+            addSource(refreshTrigger) { update() }
+        }
+
+    fun hasEnoughFreeSpace(): Boolean = modelManager.hasEnoughFreeSpace()
+
+    fun isTermsAccepted(): Boolean = preferenceManager.getBooleanValue(
+        PreferenceManager.PREFERENCE_KEY_REPLY_DRAFTER_GEMMA_TERMS_ACCEPTED
+    )
+
+    fun startDownload() {
+        if (!isTermsAccepted()) return
+        ModelDownloadManager.enqueue(appContext)
+    }
+
+    fun cancelDownload() {
+        ModelDownloadManager.cancel(appContext)
+    }
+
+    fun deleteModel() {
+        modelManager.deleteModel()
+        refreshTrigger.value = Unit
+    }
+
+    private fun deriveState(infos: List<WorkInfo>): ModelDownloadUiState {
+        if (modelManager.isModelReady()) return ModelDownloadUiState.Ready
+        val latest = infos.lastOrNull()
+        return when (latest?.state) {
+            WorkInfo.State.ENQUEUED,
+            WorkInfo.State.RUNNING,
+            WorkInfo.State.BLOCKED -> ModelDownloadUiState.Downloading(
+                latest.progress.getLong(ModelDownloadManager.KEY_PROGRESS_BYTES, 0L),
+                latest.progress.getLong(ModelDownloadManager.KEY_PROGRESS_TOTAL, 0L)
+            )
+
+            WorkInfo.State.FAILED -> ModelDownloadUiState.Failed
+            else -> ModelDownloadUiState.NotDownloaded
+        }
+    }
+}