#608 WIP, NPE gone but creating cards doubles them...

10 files changed, 123 insertions, 68 deletions

diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/SyncManager.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/SyncManager.java
index 9466deca0..832fd776a 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/SyncManager.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/SyncManager.java
@@ -613,13 +613,13 @@ public class SyncManager {
                 List<AccessControl> aclList = originalBoard.getParticipants();
                 for (AccessControl acl : aclList) {
                     acl.setLocalId(null);
+                    acl.setId(null);
                     acl.setBoardId(newBoardId);
-                    acl.setUserId(newOwner.getLocalId());
                     dataBaseAdapter.createAccessControl(targetAccountId, acl);
                 }
             }
 
-            Map<Long, Long> oldToNewLabelIdsDictionary = isSameAccount ? null : new HashMap<>();
+            Map<Long, Long> oldToNewLabelIdsDictionary = new HashMap<>();
 
             for (Label label : originalBoard.getLabels()) {
                 Long oldLocalId = label.getLocalId();
@@ -628,10 +628,8 @@ public class SyncManager {
                 label.setAccountId(targetAccountId);
                 label.setStatusEnum(DBStatus.LOCAL_EDITED);
                 label.setBoardId(newBoardId);
-                long newLocalId = dataBaseAdapter.createLabel(targetAccountId, label);
-                if (!isSameAccount) {
-                    oldToNewLabelIdsDictionary.put(oldLocalId, newLocalId);
-                }
+                long newLocalId = dataBaseAdapter.createLabelDirectly(targetAccountId, label);
+                oldToNewLabelIdsDictionary.put(oldLocalId, newLocalId);
             }
 
             List<Stack> oldStacks = originalBoard.getStacks();
@@ -653,11 +651,13 @@ public class SyncManager {
                         newCard.setStackId(createdStackId);
                         newCard.setAccountId(targetAccountId);
                         newCard.setStatusEnum(DBStatus.LOCAL_EDITED);
-                        long createdCardId = dataBaseAdapter.createCard(targetAccountId, newCard);
+                        long createdCardId = dataBaseAdapter.createCardDirectly(targetAccountId, newCard);
                         if (oldCard.getLabels() != null) {
                             for (Label oldLabel : oldCard.getLabels()) {
-                                Long newLabelId = isSameAccount ? oldLabel.getLocalId() : oldToNewLabelIdsDictionary.get(oldLabel.getLocalId());
-                                dataBaseAdapter.createJoinCardWithLabel(newLabelId, createdCardId, DBStatus.LOCAL_EDITED);
+                                Long newLabelId = oldToNewLabelIdsDictionary.get(oldLabel.getLocalId());
+                                if (newLabelId != null) {
+                                    dataBaseAdapter.createJoinCardWithLabel(newLabelId, createdCardId, DBStatus.LOCAL_EDITED);
+                                } else DeckLog.error("ID of created Label is null! Skipping assignment of \"" + oldLabel.getTitle() + "\"...");
                             }
                         }
                         if (isSameAccount && oldCard.getAssignedUsers() != null) {
@@ -1041,7 +1041,7 @@ public class SyncManager {
             card.getCard().setAccountId(accountId);
             card.getCard().setStatusEnum(DBStatus.LOCAL_EDITED);
             card.getCard().setOrder(dataBaseAdapter.getHighestCardOrderInStack(localStackId) + 1);
-            long localCardId = dataBaseAdapter.createCard(accountId, card.getCard());
+            long localCardId = dataBaseAdapter.createCardDirectly(accountId, card.getCard());
             card.getCard().setLocalId(localCardId);
 
             List<User> assignedUsers = card.getAssignedUsers();
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/adapters/db/DataBaseAdapter.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/adapters/db/DataBaseAdapter.java
index 9e240909d..c659bb548 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/adapters/db/DataBaseAdapter.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/adapters/db/DataBaseAdapter.java
@@ -266,17 +266,20 @@ public class DataBaseAdapter {
         return db.getUserDao().getUserByUidDirectly(accountId, uid);
     }
 
+    @WorkerThread
     public long createUser(long accountId, User user) {
         user.setAccountId(accountId);
         return db.getUserDao().insert(user);
     }
 
+    @WorkerThread
     public void updateUser(long accountId, User user, boolean setStatus) {
         markAsEditedIfNeeded(user, setStatus);
         user.setAccountId(accountId);
         db.getUserDao().update(user);
     }
 
+    @AnyThread
     public LiveData<Label> getLabelByRemoteId(long accountId, long remoteId) {
         return distinctUntilChanged(db.getLabelDao().getLabelByRemoteId(accountId, remoteId));
     }
@@ -286,7 +289,8 @@ public class DataBaseAdapter {
         return db.getLabelDao().getLabelByRemoteIdDirectly(accountId, remoteId);
     }
 
-    public long createLabel(long accountId, @NonNull Label label) {
+    @WorkerThread
+    public long createLabelDirectly(long accountId, @NonNull Label label) {
         label.setAccountId(accountId);
         return db.getLabelDao().insert(label);
     }
@@ -545,7 +549,7 @@ public class DataBaseAdapter {
     }
 
     @WorkerThread
-    public long createCard(long accountId, Card card) {
+    public long createCardDirectly(long accountId, Card card) {
         card.setAccountId(accountId);
         long newCardId = db.getCardDao().insert(card);
 
@@ -816,8 +820,8 @@ public class DataBaseAdapter {
         return db.getJoinCardWithLabelDao().getRemoteIdsForJoin(localCardId, localLabelId);
     }
 
-    public List<JoinCardWithUser> getAllDeletedUserJoinsWithRemoteIDs() {
-        return db.getJoinCardWithUserDao().getDeletedJoinsWithRemoteIDs();
+    public List<JoinCardWithUser> getAllChangedUserJoinsWithRemoteIDs() {
+        return db.getJoinCardWithUserDao().getChangedJoinsWithRemoteIDs();
     }
 
     public void deleteJoinedLabelForCardPhysicallyByRemoteIDs(Long accountId, Long remoteCardId, Long remoteLabelId) {
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/adapters/db/dao/JoinCardWithUserDao.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/adapters/db/dao/JoinCardWithUserDao.java
index 46554685f..9d8e2cf9d 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/adapters/db/dao/JoinCardWithUserDao.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/adapters/db/dao/JoinCardWithUserDao.java
@@ -25,7 +25,7 @@ public interface JoinCardWithUserDao extends GenericDao<JoinCardWithUser> {
             "inner join card c on j.cardId = c.localId " +
             "inner join user u on j.userId = u.localId " +
             "WHERE j.status <> 1") // not UP_TO_DATE
-    List<JoinCardWithUser> getDeletedJoinsWithRemoteIDs();
+    List<JoinCardWithUser> getChangedJoinsWithRemoteIDs();
 
     @Query("delete from joincardwithuser " +
             "where cardId = (select c.localId from card c where c.accountId = :accountId and c.id = :remoteCardId) " +
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/AccessControlDataProvider.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/AccessControlDataProvider.java
index 36e5d9522..aab3aeb09 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/AccessControlDataProvider.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/AccessControlDataProvider.java
@@ -14,6 +14,7 @@ import it.niedermann.nextcloud.deck.model.ocs.user.GroupMemberUIDs;
 import it.niedermann.nextcloud.deck.model.ocs.user.OcsUser;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.ServerAdapter;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.DataBaseAdapter;
+import it.niedermann.nextcloud.deck.persistence.sync.helpers.util.AsyncUtil;
 
 public class AccessControlDataProvider extends AbstractSyncDataProvider<AccessControl> {
 
@@ -29,32 +30,29 @@ public class AccessControlDataProvider extends AbstractSyncDataProvider<AccessCo
 
     @Override
     public void getAllFromServer(ServerAdapter serverAdapter, DataBaseAdapter dataBaseAdapter, long accountId, IResponseCallback<List<AccessControl>> responder, Date lastSync) {
-        CountDownLatch latch = new CountDownLatch(acl.size());
-        for (AccessControl accessControl : acl) {
-            if (accessControl.getType() == TYPE_GROUP) {
-                serverAdapter.searchGroupMembers(accessControl.getUser().getUid(), new IResponseCallback<GroupMemberUIDs>(responder.getAccount()) {
-                    @Override
-                    public void onResponse(GroupMemberUIDs response) {
-                        accessControl.setGroupMemberUIDs(response);
-                        if (response.getUids().size() > 0) {
-                            ensureGroupMembersInDB(getAccount(), dataBaseAdapter, serverAdapter, response);
+        AsyncUtil.awaitAsyncWork(acl.size(), latch -> {
+            for (AccessControl accessControl : acl) {
+                if (accessControl.getType() == TYPE_GROUP) {
+                    serverAdapter.searchGroupMembers(accessControl.getUser().getUid(), new IResponseCallback<GroupMemberUIDs>(responder.getAccount()) {
+                        @Override
+                        public void onResponse(GroupMemberUIDs response) {
+                            accessControl.setGroupMemberUIDs(response);
+                            if (response.getUids().size() > 0) {
+                                ensureGroupMembersInDB(getAccount(), dataBaseAdapter, serverAdapter, response);
+                            }
+                            latch.countDown();
                         }
-                        latch.countDown();
-                    }
 
-                    @Override
-                    public void onError(Throwable throwable) {
-                        super.onError(throwable);
-                        latch.countDown();
-                    }
-                });
-            } else latch.countDown();
-        }
-        try {
-            latch.await();
-        } catch (InterruptedException e) {
-            DeckLog.logError(e);
-        }
+                        @Override
+                        public void onError(Throwable throwable) {
+                            super.onError(throwable);
+                            latch.countDown();
+                        }
+                    });
+                } else latch.countDown();
+            }
+        });
+
         responder.onResponse(acl);
     }
 
@@ -137,6 +135,7 @@ public class AccessControlDataProvider extends AbstractSyncDataProvider<AccessCo
     @Override
     public void updateInDB(DataBaseAdapter dataBaseAdapter, long accountId, AccessControl entity, boolean setStatus) {
         prepareUser(dataBaseAdapter, accountId, entity);
+        entity.setBoardId(board.getLocalId());
         dataBaseAdapter.updateAccessControl(entity, setStatus);
         handleGroupMemberships(dataBaseAdapter, entity);
     }
@@ -150,6 +149,9 @@ public class AccessControlDataProvider extends AbstractSyncDataProvider<AccessCo
     public void createOnServer(ServerAdapter serverAdapter, DataBaseAdapter dataBaseAdapter, long accountId, IResponseCallback<AccessControl> responder, AccessControl entity) {
         AccessControl acl = new AccessControl(entity);
         acl.setBoardId(board.getBoard().getId());
+        if (acl.getUser() == null && acl.getUserId() != null) {
+            acl.setUser(dataBaseAdapter.getUserByLocalIdDirectly(acl.getUserId()));
+        }
         serverAdapter.createAccessControl(board.getBoard().getId(), acl, responder);
     }
 
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/BoardDataProvider.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/BoardDataProvider.java
index 2f5629474..747502f26 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/BoardDataProvider.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/BoardDataProvider.java
@@ -6,9 +6,7 @@ import java.util.Date;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
-import java.util.concurrent.CountDownLatch;
 
-import it.niedermann.nextcloud.deck.DeckLog;
 import it.niedermann.nextcloud.deck.api.IResponseCallback;
 import it.niedermann.nextcloud.deck.model.AccessControl;
 import it.niedermann.nextcloud.deck.model.Board;
@@ -19,6 +17,7 @@ import it.niedermann.nextcloud.deck.model.full.FullStack;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.ServerAdapter;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.DataBaseAdapter;
 import it.niedermann.nextcloud.deck.persistence.sync.helpers.SyncHelper;
+import it.niedermann.nextcloud.deck.persistence.sync.helpers.util.AsyncUtil;
 
 public class BoardDataProvider extends AbstractSyncDataProvider<FullBoard> {
 
@@ -122,17 +121,13 @@ public class BoardDataProvider extends AbstractSyncDataProvider<FullBoard> {
     public void goDeeperForUpSync(SyncHelper syncHelper, ServerAdapter serverAdapter, DataBaseAdapter dataBaseAdapter, IResponseCallback<Boolean> callback) {
         Long accountId = callback.getAccount().getId();
         List<Label> locallyChangedLabels = dataBaseAdapter.getLocallyChangedLabels(accountId);
-        CountDownLatch countDownLatch = new CountDownLatch(locallyChangedLabels.size());
-        for (Label label : locallyChangedLabels) {
-            Board board = dataBaseAdapter.getBoardByLocalIdDirectly(label.getBoardId());
-            label.setBoardId(board.getId());
-            syncHelper.doUpSyncFor(new LabelDataProvider(this, board, Collections.singletonList(label)), countDownLatch);
-        }
-        try {
-            countDownLatch.await();
-        } catch (InterruptedException e) {
-            DeckLog.logError(e);
-        }
+        AsyncUtil.awaitAsyncWork(locallyChangedLabels.size(), (countDownLatch) -> {
+            for (Label label : locallyChangedLabels) {
+                Board board = dataBaseAdapter.getBoardByLocalIdDirectly(label.getBoardId());
+                label.setBoardId(board.getId());
+                syncHelper.doUpSyncFor(new LabelDataProvider(this, board, Collections.singletonList(label)), countDownLatch);
+            }
+        });
 
         List<Long> localBoardIDsWithChangedACL = dataBaseAdapter.getBoardIDsOfLocallyChangedAccessControl(accountId);
         for (Long boardId : localBoardIDsWithChangedACL) {
@@ -151,7 +146,11 @@ public class BoardDataProvider extends AbstractSyncDataProvider<FullBoard> {
                 if (added) {
                     FullBoard board = dataBaseAdapter.getFullBoardByLocalIdDirectly(accountId, boardId);
                     locallyChangedStack.getStack().setBoardId(board.getId());
-                    syncHelper.doUpSyncFor(new StackDataProvider(this, board));
+                    //TODO: maybe better with waits? shouldn't change anything, since the added flag should prevent concurrency...
+//                    AsyncUtil.awaitAsyncWork(1, (countDownLatch) -> {
+//                        syncHelper.doUpSyncFor(new StackDataProvider(this, board), countDownLatch);
+                        syncHelper.doUpSyncFor(new StackDataProvider(this, board));
+//                    });
                 }
             }
         }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/CardDataProvider.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/CardDataProvider.java
index 9d7284fe7..4c7cc4b57 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/CardDataProvider.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/CardDataProvider.java
@@ -70,7 +70,7 @@ public class CardDataProvider extends AbstractSyncDataProvider<FullCard> {
     @Override
     public long createInDB(DataBaseAdapter dataBaseAdapter, long accountId, FullCard entity) {
         fixRelations(dataBaseAdapter, accountId, entity);
-        return dataBaseAdapter.createCard(accountId, entity.getCard());
+        return dataBaseAdapter.createCardDirectly(accountId, entity.getCard());
     }
 
     protected CardUpdate toCardUpdate(FullCard card) {
@@ -150,7 +150,9 @@ public class CardDataProvider extends AbstractSyncDataProvider<FullCard> {
     @Override
     public void createOnServer(ServerAdapter serverAdapter, DataBaseAdapter dataBaseAdapter, long accountId, IResponseCallback<FullCard> responder, FullCard entity) {
         entity.getCard().setStackId(stack.getId());
-        serverAdapter.createCard(board.getId(), stack.getId(), entity.getCard(), responder);
+//        if (board != null && stack != null && board.getId() != null && stack.getId() != null) {
+            serverAdapter.createCard(board.getId(), stack.getId(), entity.getCard(), responder);
+//        } else DeckLog.error("Skipped card creation due to missing remote ID");
     }
 
     @Override
@@ -230,9 +232,14 @@ public class CardDataProvider extends AbstractSyncDataProvider<FullCard> {
 
             }
         }
-        List<JoinCardWithUser> deletedUsers = dataBaseAdapter.getAllDeletedUserJoinsWithRemoteIDs();
-        for (JoinCardWithUser deletedUser : deletedUsers) {
-            Card card = dataBaseAdapter.getCardByRemoteIdDirectly(account.getId(), deletedUser.getCardId());
+        List<JoinCardWithUser> changedUsers = dataBaseAdapter.getAllChangedUserJoinsWithRemoteIDs();
+        for (JoinCardWithUser changedUser : changedUsers) {
+            // not already known to server?
+            if (changedUser.getCardId() == null) {
+                //skip for now
+                continue;
+            }
+            Card card = dataBaseAdapter.getCardByRemoteIdDirectly(account.getId(), changedUser.getCardId());
             if (this.stack == null) {
                 stack = dataBaseAdapter.getFullStackByLocalIdDirectly(card.getStackId());
             } else {
@@ -244,16 +251,16 @@ public class CardDataProvider extends AbstractSyncDataProvider<FullCard> {
             } else {
                 board = this.board;
             }
-            User user = dataBaseAdapter.getUserByLocalIdDirectly(deletedUser.getUserId());
-            if (deletedUser.getStatusEnum() == DBStatus.LOCAL_DELETED) {
-                serverAdapter.unassignUserFromCard(board.getId(), stack.getId(), deletedUser.getCardId(), user.getUid(), new IResponseCallback<Void>(account) {
+            User user = dataBaseAdapter.getUserByLocalIdDirectly(changedUser.getUserId());
+            if (changedUser.getStatusEnum() == DBStatus.LOCAL_DELETED) {
+                serverAdapter.unassignUserFromCard(board.getId(), stack.getId(), changedUser.getCardId(), user.getUid(), new IResponseCallback<Void>(account) {
                     @Override
                     public void onResponse(Void response) {
-                        dataBaseAdapter.deleteJoinedUserForCardPhysicallyByRemoteIDs(account.getId(), deletedUser.getCardId(), user.getUid());
+                        dataBaseAdapter.deleteJoinedUserForCardPhysicallyByRemoteIDs(account.getId(), changedUser.getCardId(), user.getUid());
                     }
                 });
-            } else if (deletedUser.getStatusEnum() == DBStatus.LOCAL_EDITED) {
-                serverAdapter.assignUserToCard(board.getId(), stack.getId(), deletedUser.getCardId(), user.getUid(), new IResponseCallback<Void>(account) {
+            } else if (changedUser.getStatusEnum() == DBStatus.LOCAL_EDITED) {
+                serverAdapter.assignUserToCard(board.getId(), stack.getId(), changedUser.getCardId(), user.getUid(), new IResponseCallback<Void>(account) {
                     @Override
                     public void onResponse(Void response) {
                         dataBaseAdapter.setStatusForJoinCardWithUser(card.getLocalId(), user.getLocalId(), DBStatus.UP_TO_DATE.getId());
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/LabelDataProvider.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/LabelDataProvider.java
index 7510d9be3..90d633bce 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/LabelDataProvider.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/LabelDataProvider.java
@@ -45,7 +45,7 @@ public class LabelDataProvider extends AbstractSyncDataProvider<Label> {
             updateInDB(dataBaseAdapter, accountId, entity, false);
             return entity.getLocalId();
         } else {
-            return dataBaseAdapter.createLabel(accountId, entity);
+            return dataBaseAdapter.createLabelDirectly(accountId, entity);
         }
     }
 
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/StackDataProvider.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/StackDataProvider.java
index a3c123afd..7901cfedf 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/StackDataProvider.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/StackDataProvider.java
@@ -15,6 +15,7 @@ import it.niedermann.nextcloud.deck.model.full.FullStack;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.ServerAdapter;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.DataBaseAdapter;
 import it.niedermann.nextcloud.deck.persistence.sync.helpers.SyncHelper;
+import it.niedermann.nextcloud.deck.persistence.sync.helpers.util.AsyncUtil;
 
 public class StackDataProvider extends AbstractSyncDataProvider<FullStack> {
     private FullBoard board;
@@ -110,9 +111,14 @@ public class StackDataProvider extends AbstractSyncDataProvider<FullStack> {
                 boolean added = syncedStacks.add(stackId);
                 if (added) {
                     FullStack stack = dataBaseAdapter.getFullStackByLocalIdDirectly(stackId);
-                    Board board = dataBaseAdapter.getBoardByLocalIdDirectly(stack.getStack().getBoardId());
-                    changedCard.getCard().setStackId(stack.getId());
-                    syncHelper.doUpSyncFor(new CardDataProvider(this, board, stack));
+                    // already synced and known to server?
+                    if (stack.getStack().getId() != null) {
+                        AsyncUtil.awaitAsyncWork(1, latch -> {
+                            Board board = dataBaseAdapter.getBoardByLocalIdDirectly(stack.getStack().getBoardId());
+                            changedCard.getCard().setStackId(stack.getId());
+                            syncHelper.doUpSyncFor(new CardDataProvider(this, board, stack), latch);
+                        });
+                    }
                 }
             }
         } else {
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/partial/BoardWithStacksAndLabelsUpSyncDataProvider.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/partial/BoardWithStacksAndLabelsUpSyncDataProvider.java
index 278971a9d..3416e1b89 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/partial/BoardWithStacksAndLabelsUpSyncDataProvider.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/providers/partial/BoardWithStacksAndLabelsUpSyncDataProvider.java
@@ -5,6 +5,7 @@ import java.util.Date;
 import java.util.List;
 
 import it.niedermann.nextcloud.deck.api.IResponseCallback;
+import it.niedermann.nextcloud.deck.model.Label;
 import it.niedermann.nextcloud.deck.model.full.FullBoard;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.ServerAdapter;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.DataBaseAdapter;
@@ -20,6 +21,21 @@ public class BoardWithStacksAndLabelsUpSyncDataProvider extends BoardDataProvide
     }
 
     @Override
+    public void updateInDB(DataBaseAdapter dataBaseAdapter, long accountId, FullBoard entity, boolean setStatus) {
+        //merge labels (created at board creation)
+        if (entity!= null && entity.getLabels() != null) {
+            for (Label label : entity.getLabels()) {
+                Label existing = dataBaseAdapter.getLabelByBoardIdAndTitleDirectly(board.getLocalId(), label.getTitle());
+                if (existing != null) {
+                    existing.setId(label.getId());
+                    dataBaseAdapter.updateLabel(existing, false);
+                }
+            }
+        }
+        super.updateInDB(dataBaseAdapter, accountId, entity, setStatus);
+    }
+
+    @Override
     public List<FullBoard> getAllChangedFromDB(DataBaseAdapter dataBaseAdapter, long accountId, Date lastSync) {
         return Collections.singletonList(board);
     }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/util/AsyncUtil.java b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/util/AsyncUtil.java
new file mode 100644
index 000000000..faabda163
--- /dev/null
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/persistence/sync/helpers/util/AsyncUtil.java
@@ -0,0 +1,21 @@
+package it.niedermann.nextcloud.deck.persistence.sync.helpers.util;
+
+import java.util.concurrent.CountDownLatch;
+
+import it.niedermann.nextcloud.deck.DeckLog;
+
+public class AsyncUtil {
+    public interface LatchCallback {
+        void doWork(CountDownLatch latch);
+    }
+
+    public static void awaitAsyncWork(int count, LatchCallback worker){
+        CountDownLatch countDownLatch = new CountDownLatch(count);
+        worker.doWork(countDownLatch);
+        try {
+            countDownLatch.await();
+        } catch (InterruptedException e) {
+            DeckLog.logError(e);
+        }
+    }
+}