1 files changed, 231 insertions, 0 deletions
diff --git a/service/java/com/android/server/deviceconfig/BootNotificationCreator.java b/service/java/com/android/server/deviceconfig/BootNotificationCreator.java
new file mode 100644
index 0000000..d29f317
--- /dev/null
+++ b/service/java/com/android/server/deviceconfig/BootNotificationCreator.java
@@ -0,0 +1,231 @@
+package com.android.server.deviceconfig;
+
+import android.annotation.NonNull;
+import android.app.AlarmManager;
+import android.app.Notification;
+import android.app.Notification.Action;
+import android.app.NotificationChannel;
+import android.app.NotificationManager;
+import android.app.PendingIntent;
+import android.content.IntentFilter;
+import android.content.BroadcastReceiver;
+import android.content.Intent;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.Context;
+import android.graphics.drawable.Icon;
+import android.os.PowerManager;
+import android.provider.DeviceConfig.OnPropertiesChangedListener;
+import android.provider.DeviceConfig.Properties;
+import android.util.Slog;
+import com.android.server.deviceconfig.resources.R;
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.io.IOException;
+import java.util.Map;
+import java.util.Set;
+
+import static android.app.NotificationManager.IMPORTANCE_HIGH;
+import static java.time.temporal.ChronoUnit.SECONDS;
+
+/**
+ * Creates notifications when aconfig flags are staged on the device.
+ *
+ * The notification alerts the user to reboot, to apply the staged flags.
+ *
+ * @hide
+ */
+class BootNotificationCreator implements OnPropertiesChangedListener {
+    private static final String TAG = "DeviceConfigBootNotificationCreator";
+
+    private static final String RESOURCES_PACKAGE =
+        "com.android.server.deviceconfig.resources";
+
+    private static final String REBOOT_REASON = "DeviceConfig";
+
+    private static final String ACTION_TRIGGER_HARD_REBOOT =
+        "com.android.server.deviceconfig.TRIGGER_HARD_REBOOT";
+    private static final String ACTION_POST_NOTIFICATION =
+        "com.android.server.deviceconfig.POST_NOTIFICATION";
+
+    private static final String CHANNEL_ID = "trunk-stable-flags";
+    private static final String CHANNEL_NAME = "Trunkfood flags";
+    private static final int NOTIFICATION_ID = 111555;
+
+    private NotificationManager notificationManager;
+    private PowerManager powerManager;
+    private AlarmManager alarmManager;
+
+    private Context context;
+
+    private static final int REBOOT_HOUR = 10;
+    private static final int REBOOT_MINUTE = 0;
+    private static final int MIN_SECONDS_TO_SHOW_NOTIF = 86400;
+
+    private LocalDateTime lastReboot;
+
+    private Map<String, Set<String>> aconfigFlags;
+
+    public BootNotificationCreator(@NonNull Context context,
+                                   Map<String, Set<String>> aconfigFlags) {
+        this.context = context;
+        this.aconfigFlags = aconfigFlags;
+
+        this.context.registerReceiver(
+            new HardRebootBroadcastReceiver(),
+            new IntentFilter(ACTION_TRIGGER_HARD_REBOOT),
+            Context.RECEIVER_EXPORTED);
+        this.context.registerReceiver(
+            new PostNotificationBroadcastReceiver(),
+            new IntentFilter(ACTION_POST_NOTIFICATION),
+            Context.RECEIVER_EXPORTED);
+
+        this.lastReboot = LocalDateTime.now(ZoneId.systemDefault());
+    }
+
+    @Override
+    public void onPropertiesChanged(Properties properties) {
+        if (!containsAconfigChanges(properties)) {
+            return;
+        }
+
+        if (!tryInitializeDependenciesIfNeeded()) {
+            Slog.i(TAG, "not posting notif; service dependencies not ready");
+            return;
+        }
+
+        PendingIntent pendingIntent =
+            PendingIntent.getBroadcast(
+                context,
+                /* requestCode= */ 1,
+                new Intent(ACTION_POST_NOTIFICATION),
+                PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE);
+
+        ZonedDateTime now = Instant
+            .ofEpochMilli(System.currentTimeMillis())
+            .atZone(ZoneId.systemDefault());
+
+        LocalDateTime currentTime = now.toLocalDateTime();
+        LocalDateTime postTime = now.toLocalDate().atTime(REBOOT_HOUR, REBOOT_MINUTE);
+
+        LocalDateTime scheduledPostTime =
+            currentTime.isBefore(postTime) ? postTime : postTime.plusDays(1);
+        long scheduledPostTimeLong = scheduledPostTime
+            .atZone(ZoneId.systemDefault())
+            .toInstant()
+            .toEpochMilli();
+
+        alarmManager.setExact(
+            AlarmManager.RTC_WAKEUP, scheduledPostTimeLong, pendingIntent);
+    }
+
+    private boolean containsAconfigChanges(Properties properties) {
+        for (String namespaceAndFlag : properties.getKeyset()) {
+            int firstStarIndex = namespaceAndFlag.indexOf("*");
+            if (firstStarIndex == -1 || firstStarIndex == 0
+                || firstStarIndex == namespaceAndFlag.length() - 1) {
+                Slog.w(TAG, "detected malformed staged flag: " + namespaceAndFlag);
+                continue;
+            }
+
+            String namespace = namespaceAndFlag.substring(0, firstStarIndex);
+            String flag = namespaceAndFlag.substring(firstStarIndex + 1);
+
+            if (aconfigFlags.get(namespace) != null && aconfigFlags.get(namespace).contains(flag)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private class PostNotificationBroadcastReceiver extends BroadcastReceiver {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            LocalDateTime now = LocalDateTime.now(ZoneId.systemDefault());
+
+            if (lastReboot.until(now, SECONDS) < MIN_SECONDS_TO_SHOW_NOTIF) {
+                Slog.w(TAG, "not enough time passed, punting");
+                tryAgainIn24Hours(now);
+                return;
+            }
+
+            PendingIntent pendingIntent =
+                PendingIntent.getBroadcast(
+                    context,
+                    /* requestCode= */ 1,
+                    new Intent(ACTION_TRIGGER_HARD_REBOOT),
+                    PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE);
+
+            try {
+                Context resourcesContext = context.createPackageContext(RESOURCES_PACKAGE, 0);
+                Action action = new Action.Builder(
+                    Icon.createWithResource(resourcesContext, R.drawable.ic_restart),
+                    resourcesContext.getString(R.string.boot_notification_action_text),
+                    pendingIntent).build();
+                Notification notification = new Notification.Builder(context, CHANNEL_ID)
+                    .setContentText(resourcesContext.getString(R.string.boot_notification_content))
+                    .setContentTitle(resourcesContext.getString(R.string.boot_notification_title))
+                    .setSmallIcon(Icon.createWithResource(resourcesContext, R.drawable.ic_flag))
+                    .addAction(action)
+                    .build();
+                notificationManager.notify(NOTIFICATION_ID, notification);
+            } catch (NameNotFoundException e) {
+                Slog.e(TAG, "failed to post boot notification", e);
+            }
+        }
+
+        private void tryAgainIn24Hours(LocalDateTime currentTime) {
+            PendingIntent pendingIntent =
+                PendingIntent.getBroadcast(
+                    context,
+                    /* requestCode= */ 1,
+                    new Intent(ACTION_POST_NOTIFICATION),
+                    PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE);
+
+            LocalDateTime postTime =
+                currentTime.toLocalDate().atTime(REBOOT_HOUR, REBOOT_MINUTE).plusDays(1);
+            long scheduledPostTimeLong = postTime
+                .atZone(ZoneId.systemDefault())
+                .toInstant()
+                .toEpochMilli();
+            alarmManager.setExact(
+                AlarmManager.RTC_WAKEUP, scheduledPostTimeLong, pendingIntent);
+        }
+    }
+
+    private class HardRebootBroadcastReceiver extends BroadcastReceiver {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            powerManager.reboot(REBOOT_REASON);
+        }
+    }
+
+    /**
+     * If deps are not initialized yet, try to initialize them.
+     *
+     * @return true if the dependencies are newly or already initialized,
+     *         or false if they are not ready yet
+     */
+    private boolean tryInitializeDependenciesIfNeeded() {
+        if (notificationManager == null) {
+            notificationManager = context.getSystemService(NotificationManager.class);
+            if (notificationManager != null) {
+                notificationManager.createNotificationChannel(
+                    new NotificationChannel(CHANNEL_ID, CHANNEL_NAME, IMPORTANCE_HIGH));
+            }
+        }
+
+        if (alarmManager == null) {
+            alarmManager = context.getSystemService(AlarmManager.class);
+        }
+
+        if (powerManager == null) {
+            powerManager = context.getSystemService(PowerManager.class);
+        }
+
+        return notificationManager != null
+            && alarmManager != null
+            && powerManager != null;
+    }
+}