Handle session restoration.

src/org/thoughtcrime/securesms/conversation/ConversationActivity.java

@@ -3086,8 +3086,9 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
   @Override
   public void updateItemButtonPressed(@NonNull MessageRecord messageRecord) {
     // Loki - User clicked restore session
-    if (messageRecord.isNoRemoteSession() && !messageRecord.isLokiSessionRestoreSent()) {
-      // TODO: Send a message with `SESSION_RESTORE` flag
+    Recipient recipient = messageRecord.getRecipient();
+    if (!recipient.isGroupRecipient() && messageRecord.isNoRemoteSession() && !messageRecord.isLokiSessionRestoreSent()) {
+      MessageSender.sendRestoreSessionMessage(this, recipient.getAddress().serialize());
       DatabaseFactory.getSmsDatabase(this).markAsLokiSessionRestoreSent(messageRecord.id);
       TextSecurePreferences.setShowingSessionRestorePrompt(this, messageRecord.getIndividualRecipient().getAddress().serialize(), false);
     }

src/org/thoughtcrime/securesms/jobs/PushDecryptJob.java

@@ -74,6 +74,7 @@ import org.thoughtcrime.securesms.loki.LokiPreKeyBundleDatabase;
 import org.thoughtcrime.securesms.loki.LokiPreKeyRecordDatabase;
 import org.thoughtcrime.securesms.loki.LokiThreadDatabase;
 import org.thoughtcrime.securesms.loki.MultiDeviceUtilities;
+import org.thoughtcrime.securesms.loki.DebouncerCache;
 import org.thoughtcrime.securesms.mms.IncomingMediaMessage;
 import org.thoughtcrime.securesms.mms.MmsException;
 import org.thoughtcrime.securesms.mms.OutgoingExpirationUpdateMessage;
@@ -94,6 +95,7 @@ import org.thoughtcrime.securesms.sms.OutgoingEncryptedMessage;
 import org.thoughtcrime.securesms.sms.OutgoingEndSessionMessage;
 import org.thoughtcrime.securesms.sms.OutgoingTextMessage;
 import org.thoughtcrime.securesms.stickers.StickerLocator;
+import org.thoughtcrime.securesms.util.Debouncer;
 import org.thoughtcrime.securesms.util.GroupUtil;
 import org.thoughtcrime.securesms.util.Hex;
 import org.thoughtcrime.securesms.util.IdentityUtil;
@@ -337,6 +339,8 @@ public class PushDecryptJob extends BaseJob implements InjectableType {
             MultiDeviceUtilities.checkForRevocation(context);
           }
         } else {
+          // Loki - We shouldn't process session restore message any further
+          if (message.isSessionRestore()) { return; }
           if (message.isEndSession()) handleEndSessionMessage(content, smsMessageId);
           else if (message.isGroupUpdate()) handleGroupMessage(content, message, smsMessageId);
           else if (message.isExpirationUpdate())
@@ -1187,7 +1191,8 @@ public class PushDecryptJob extends BaseJob implements InjectableType {
   }
 
   private void storePreKeyBundleIfNeeded(@NonNull SignalServiceEnvelope envelope, @NonNull SignalServiceContent content) {
-    if (content.lokiServiceMessage.isPresent()) {
+    Recipient sender = Recipient.from(context, Address.fromSerialized(content.getSender()), false);
+    if (!sender.isGroupRecipient() && content.lokiServiceMessage.isPresent()) {
       LokiServiceMessage lokiMessage = content.lokiServiceMessage.get();
       if (lokiMessage.getPreKeyBundleMessage() != null) {
         int registrationID = TextSecurePreferences.getLocalRegistrationId(context);
@@ -1203,10 +1208,11 @@ public class PushDecryptJob extends BaseJob implements InjectableType {
 
           // If we got a friend request and we were friends with this user then we need to reset our session
           if (envelope.isFriendRequest()) {
-            Recipient sender = Recipient.from(context, Address.fromSerialized(content.getSender()), false);
             long threadID = threadDatabase.getThreadIdIfExistsFor(sender);
             if (lokiThreadDatabase.getFriendRequestStatus(threadID) == LokiThreadFriendRequestStatus.FRIENDS) {
               resetSession(content.getSender(), threadID);
+              // Let our other devices know that we have reset session
+              MessageSender.syncContact(context, sender.getAddress());
             }
           }
         }
@@ -1398,23 +1404,43 @@ public class PushDecryptJob extends BaseJob implements InjectableType {
   private void handleNoSessionMessage(@NonNull String sender, int senderDevice, long timestamp,
                                       @NonNull Optional<Long> smsMessageId)
   {
-    SmsDatabase smsDatabase = DatabaseFactory.getSmsDatabase(context);
-
-    if (!smsMessageId.isPresent()) {
-      if (!TextSecurePreferences.isShowingSessionRestorePrompt(context, sender)) {
-        Optional<InsertResult> insertResult = insertPlaceholder(sender, senderDevice, timestamp);
+    Recipient recipient = Recipient.from(context, Address.fromSerialized(sender), false);
+    if (recipient.isGroupRecipient()) { return; }
 
-        if (insertResult.isPresent()) {
-          smsDatabase.markAsNoSession(insertResult.get().getMessageId());
-          TextSecurePreferences.setShowingSessionRestorePrompt(context, sender, true);
-          //MessageNotifier.updateNotification(context, insertResult.get().getThreadId());
+    long threadID = DatabaseFactory.getThreadDatabase(context).getThreadIdIfExistsFor(recipient);
+    LokiThreadFriendRequestStatus friendRequestStatus = DatabaseFactory.getLokiThreadDatabase(context).getFriendRequestStatus(threadID);
+    /*
+    If we are friends with the user or we sent a friend request to them and we got a message back with no session then we want to try and restore the session automatically.
+    otherwise if we're not friends or our friend request expired then we need to prompt the user for action
+    */
+    if (friendRequestStatus == LokiThreadFriendRequestStatus.FRIENDS || friendRequestStatus == LokiThreadFriendRequestStatus.REQUEST_SENT) {
+      autoRestoreSession(sender);
+    } else if (friendRequestStatus == LokiThreadFriendRequestStatus.NONE || friendRequestStatus == LokiThreadFriendRequestStatus.REQUEST_EXPIRED) {
+      SmsDatabase smsDatabase = DatabaseFactory.getSmsDatabase(context);
+
+      if (!smsMessageId.isPresent()) {
+        if (!TextSecurePreferences.isShowingSessionRestorePrompt(context, sender)) {
+          Optional<InsertResult> insertResult = insertPlaceholder(sender, senderDevice, timestamp);
+
+          if (insertResult.isPresent()) {
+            smsDatabase.markAsNoSession(insertResult.get().getMessageId());
+            TextSecurePreferences.setShowingSessionRestorePrompt(context, sender, true);
+            //MessageNotifier.updateNotification(context, insertResult.get().getThreadId());
+          }
         }
+      } else {
+        smsDatabase.markAsNoSession(smsMessageId.get());
       }
-    } else {
-      smsDatabase.markAsNoSession(smsMessageId.get());
     }
   }
 
+  private void autoRestoreSession(@NonNull String sender) {
+    // We don't want to keep spamming the user for an auto restore
+    String key = "restore_session_" + sender;
+    Debouncer debouncer = DebouncerCache.getDebouncer(key, 10000);
+    debouncer.publish(() ->  MessageSender.sendRestoreSessionMessage(context, sender));
+  }
+
   private void handleLegacyMessage(@NonNull String sender, int senderDevice, long timestamp,
                                    @NonNull Optional<Long> smsMessageId)
   {

src/org/thoughtcrime/securesms/loki/DebouncerCache.kt

@@ -0,0 +1,18 @@
+package org.thoughtcrime.securesms.loki
+
+import org.thoughtcrime.securesms.util.Debouncer
+
+object DebouncerCache {
+  private val cache: HashMap<String, Debouncer> = hashMapOf()
+  @JvmStatic
+  fun getDebouncer(key: String, threshold: Long): Debouncer {
+    val throttler = cache[key] ?: Debouncer(threshold)
+    cache[key] = throttler
+    return throttler
+  }
+
+  @JvmStatic
+  fun remove(key: String) {
+    cache.remove(key)
+  }
+}

src/org/thoughtcrime/securesms/loki/FriendRequestHandler.kt

@@ -27,6 +27,15 @@ object FriendRequestHandler {
         ActionType.Sent -> LokiThreadFriendRequestStatus.REQUEST_SENT
       }
       DatabaseFactory.getLokiThreadDatabase(context).setFriendRequestStatus(threadId, threadFriendStatus)
+      // If we sent a friend request then we need to hide the session restore prompt
+      if (type == ActionType.Sent) {
+        val smsDatabase = DatabaseFactory.getSmsDatabase(context)
+        smsDatabase.getMessages(threadId)
+                .filter { it.isNoRemoteSession && !it.isLokiSessionRestoreSent }
+                .forEach {
+                  smsDatabase.markAsLokiSessionRestoreSent(it.id)
+                }
+      }
     }
 
     // Update message status

src/org/thoughtcrime/securesms/loki/PushBackgroundMessageSendJob.kt

@@ -13,30 +13,43 @@ import org.whispersystems.signalservice.api.messages.SignalServiceDataMessage
 import org.whispersystems.signalservice.api.push.SignalServiceAddress
 import org.whispersystems.signalservice.internal.util.JsonUtil
 import java.io.IOException
+import java.lang.IllegalStateException
 import java.util.concurrent.TimeUnit
 
-data class BackgroundMessage private constructor(val recipient: String, val body: String?, val friendRequest: Boolean, val unpairingRequest: Boolean) {
+data class BackgroundMessage private constructor(val data: Map<String, Any>) {
   companion object {
     @JvmStatic
-    fun create(recipient: String) = BackgroundMessage(recipient, null, false, false)
+    fun create(recipient: String) = BackgroundMessage(mapOf("recipient" to recipient))
     @JvmStatic
-    fun createFriendRequest(recipient: String, messageBody: String) = BackgroundMessage(recipient, messageBody, true, false)
+    fun createFriendRequest(recipient: String, messageBody: String) = BackgroundMessage(mapOf(
+            "recipient" to recipient,
+            "body" to messageBody,
+            "friendRequest" to true
+    ))
     @JvmStatic
-    fun createUnpairingRequest(recipient: String) = BackgroundMessage(recipient, null, false, true)
+    fun createUnpairingRequest(recipient: String) = BackgroundMessage(mapOf(
+            "recipient" to recipient,
+            "unpairingRequest" to true
+    ))
+    @JvmStatic
+    fun createSessionRestore(recipient: String) = BackgroundMessage(mapOf(
+            "recipient" to recipient,
+            "friendRequest" to true,
+            "sessionRestore" to true
+    ))
             
     internal fun parse(serialized: String): BackgroundMessage {
-      val node = JsonUtil.fromJson(serialized)
-      val recipient = node.get("recipient").asText()
-      val body = if (node.hasNonNull("body")) node.get("body").asText() else null
-      val friendRequest = node.get("friendRequest").asBoolean(false)
-      val unpairingRequest = node.get("unpairingRequest").asBoolean(false)
-      return BackgroundMessage(recipient, body, friendRequest, unpairingRequest)
+      val data = JsonUtil.fromJson(serialized, Map::class.java) as? Map<String, Any> ?: throw AssertionError("JSON parsing failed")
+      return BackgroundMessage(data)
     }
   }
 
+  fun <T> get(key: String, defaultValue: T): T {
+    return data[key] as? T ?: defaultValue
+  }
+
   fun serialize(): String {
-    val map = mapOf("recipient" to recipient, "body" to body, "friendRequest" to friendRequest, "unpairingRequest" to unpairingRequest)
-    return JsonUtil.toJson(map)
+    return JsonUtil.toJson(data)
   }
 }
 
@@ -71,24 +84,31 @@ class PushBackgroundMessageSendJob private constructor(
   }
 
   public override fun onRun() {
+    val recipient = message.get<String?>("recipient", null) ?: throw IllegalStateException()
     val dataMessage = SignalServiceDataMessage.newBuilder()
             .withTimestamp(System.currentTimeMillis())
-            .withBody(message.body)
+            .withBody(message.get<String?>("body", null))
 
-    if (message.friendRequest) {
-      val bundle = DatabaseFactory.getLokiPreKeyBundleDatabase(context).generatePreKeyBundle(message.recipient)
+    if (message.get("friendRequest", false)) {
+      val bundle = DatabaseFactory.getLokiPreKeyBundleDatabase(context).generatePreKeyBundle(recipient)
       dataMessage.withPreKeyBundle(bundle)
               .asFriendRequest(true)
-    } else if (message.unpairingRequest) {
+    }
+
+    if (message.get("unpairingRequest", false)) {
       dataMessage.asUnpairingRequest(true)
     }
 
+    if (message.get("sessionRestore", false)) {
+      dataMessage.asSessionRestore(true)
+    }
+
     val messageSender = ApplicationContext.getInstance(context).communicationModule.provideSignalMessageSender()
-    val address = SignalServiceAddress(message.recipient)
+    val address = SignalServiceAddress(recipient)
     try {
       messageSender.sendMessage(-1, address, Optional.absent<UnidentifiedAccessPair>(), dataMessage.build()) // The message ID doesn't matter
     } catch (e: Exception) {
-      Log.d("Loki", "Failed to send background message to: ${message.recipient}.")
+      Log.d("Loki", "Failed to send background message to: ${recipient}.")
       throw e
     }
   }

src/org/thoughtcrime/securesms/sms/MessageSender.java

@@ -139,6 +139,10 @@ public class MessageSender {
   public static void sendUnpairRequest(Context context, String contactHexEncodedPublicKey) {
     ApplicationContext.getInstance(context).getJobManager().add(new PushBackgroundMessageSendJob(BackgroundMessage.createUnpairingRequest(contactHexEncodedPublicKey)));
   }
+
+  public static void sendRestoreSessionMessage(Context context, String contactHexEncodedPublicKey) {
+    ApplicationContext.getInstance(context).getJobManager().add(new PushBackgroundMessageSendJob(BackgroundMessage.createSessionRestore(contactHexEncodedPublicKey)));
+  }
   // endregion
 
   public static long send(final Context context,