Decouple SyncManager from UIs and use ViewModel between them

Signed-off-by: Stefan Niedermann <info@niedermann.it>

37 files changed, 726 insertions, 296 deletions

diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainActivity.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainActivity.java
index 1aabeabdb..d7e726a7d 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainActivity.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainActivity.java
@@ -1,5 +1,6 @@
 package it.niedermann.nextcloud.deck.ui;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.Intent;
 import android.content.SharedPreferences;
@@ -88,6 +89,7 @@ import it.niedermann.nextcloud.deck.ui.exception.ExceptionDialogFragment;
 import it.niedermann.nextcloud.deck.ui.exception.ExceptionHandler;
 import it.niedermann.nextcloud.deck.ui.filter.FilterDialogFragment;
 import it.niedermann.nextcloud.deck.ui.filter.FilterViewModel;
+import it.niedermann.nextcloud.deck.ui.pickstack.PickStackViewModel;
 import it.niedermann.nextcloud.deck.ui.settings.SettingsActivity;
 import it.niedermann.nextcloud.deck.ui.stack.DeleteStackDialogFragment;
 import it.niedermann.nextcloud.deck.ui.stack.DeleteStackListener;
@@ -128,6 +130,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
 
     protected MainViewModel mainViewModel;
     private FilterViewModel filterViewModel;
+    private PickStackViewModel pickStackViewModel;
 
     protected static final int ACTIVITY_ABOUT = 1;
     protected static final int ACTIVITY_SETTINGS = 2;
@@ -136,7 +139,6 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
     @NonNull
     protected List<Account> accountsList = new ArrayList<>();
     protected SharedPreferences sharedPreferences;
-    private SyncManager syncManager;
     private StackAdapter stackAdapter;
     long lastBoardId;
     @NonNull
@@ -180,6 +182,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
 
         mainViewModel = new ViewModelProvider(this).get(MainViewModel.class);
         filterViewModel = new ViewModelProvider(this).get(FilterViewModel.class);
+        pickStackViewModel = new ViewModelProvider(this).get(PickStackViewModel.class);
 
         addList = getString(R.string.add_list);
         addBoard = getString(R.string.add_board);
@@ -193,12 +196,11 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
         toggle.syncState();
 
         binding.navigationView.setNavigationItemSelectedListener(this);
-        syncManager = new SyncManager(this);
         sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
 
-        switchMap(syncManager.hasAccounts(), hasAccounts -> {
+        switchMap(mainViewModel.hasAccounts(), hasAccounts -> {
             if (hasAccounts) {
-                return syncManager.readAccounts();
+                return mainViewModel.readAccounts();
             } else {
                 startActivityForResult(new Intent(this, ImportAccountActivity.class), ImportAccountActivity.REQUEST_CODE_IMPORT_ACCOUNT);
                 return null;
@@ -222,7 +224,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
                         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
                             registerAutoSyncOnNetworkAvailable();
                         } else {
-                            syncManager.synchronize(new IResponseCallback<Boolean>(mainViewModel.getCurrentAccount()) {
+                            mainViewModel.synchronize(new IResponseCallback<Boolean>(mainViewModel.getCurrentAccount()) {
                                 @Override
                                 public void onResponse(Boolean response) {
                                 }
@@ -242,7 +244,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
 
             mainViewModel.getCurrentAccountLiveData().observe(this, (currentAccount) -> {
                 SingleAccountHelper.setCurrentAccount(getApplicationContext(), mainViewModel.getCurrentAccount().getName());
-                syncManager = new SyncManager(this);
+                mainViewModel.recreateSyncManager();
 
                 saveCurrentAccountId(this, mainViewModel.getCurrentAccount().getId());
                 if (mainViewModel.getCurrentAccount().isMaintenanceEnabled()) {
@@ -255,7 +257,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
                     boardsLiveData.removeObserver(boardsLiveDataObserver);
                 }
 
-                boardsLiveData = syncManager.getBoards(currentAccount.getId(), false);
+                boardsLiveData = mainViewModel.getBoards(currentAccount.getId(), false);
                 boardsLiveDataObserver = (boards) -> {
                     if (boards == null) {
                         throw new IllegalStateException("List<Board> boards must not be null.");
@@ -287,7 +289,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
                     if (hasArchivedBoardsLiveData != null && hasArchivedBoardsLiveDataObserver != null) {
                         hasArchivedBoardsLiveData.removeObserver(hasArchivedBoardsLiveDataObserver);
                     }
-                    hasArchivedBoardsLiveData = syncManager.hasArchivedBoards(currentAccount.getId());
+                    hasArchivedBoardsLiveData = mainViewModel.hasArchivedBoards(currentAccount.getId());
                     hasArchivedBoardsLiveDataObserver = (hasArchivedBoards) -> {
                         mainViewModel.setCurrentAccountHasArchivedBoards(Boolean.TRUE.equals(hasArchivedBoards));
                         inflateBoardMenu();
@@ -326,7 +328,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
             CrossTabDragAndDrop<StackFragment, CardAdapter, FullCard> dragAndDrop = new CrossTabDragAndDrop<>(getResources(), ViewCompat.getLayoutDirection(binding.getRoot()) == ViewCompat.LAYOUT_DIRECTION_LTR);
             dragAndDrop.register(binding.viewPager, binding.stackTitles, getSupportFragmentManager());
             dragAndDrop.addItemMovedByDragListener((movedCard, stackId, position) -> {
-                syncManager.reorder(mainViewModel.getCurrentAccount().getId(), movedCard, stackId, position);
+                mainViewModel.reorder(mainViewModel.getCurrentAccount().getId(), movedCard, stackId, position);
                 DeckLog.info("Card \"" + movedCard.getCard().getTitle() + "\" was moved to Stack " + stackId + " on position " + position);
             });
 
@@ -399,7 +401,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
                     }
                 } else DeckLog.warn("ConnectivityManager is null");
                 refreshCapabilities(mainViewModel.getCurrentAccount());
-                syncManager.synchronize(new IResponseCallback<Boolean>(mainViewModel.getCurrentAccount()) {
+                mainViewModel.synchronize(new IResponseCallback<Boolean>(mainViewModel.getCurrentAccount()) {
                     @Override
                     public void onResponse(Boolean response) {
                         runOnUiThread(() -> binding.swipeRefreshLayout.setRefreshing(false));
@@ -445,7 +447,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
     @Override
     public void onCreateStack(String stackName) {
         DeckLog.info("Create Stack in account " + mainViewModel.getCurrentAccount().getName() + " on board " + mainViewModel.getCurrentBoardLocalId());
-        WrappedLiveData<FullStack> createLiveData = syncManager.createStack(mainViewModel.getCurrentAccount().getId(), stackName, mainViewModel.getCurrentBoardLocalId());
+        WrappedLiveData<FullStack> createLiveData = mainViewModel.createStack(mainViewModel.getCurrentAccount().getId(), stackName, mainViewModel.getCurrentBoardLocalId());
         observeOnce(createLiveData, this, (fullStack) -> {
             if (createLiveData.hasError()) {
                 final Throwable error = createLiveData.getError();
@@ -461,7 +463,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
 
     @Override
     public void onUpdateStack(long localStackId, String stackName) {
-        final WrappedLiveData<FullStack> liveData = syncManager.updateStackTitle(localStackId, stackName);
+        final WrappedLiveData<FullStack> liveData = mainViewModel.updateStackTitle(localStackId, stackName);
         observeOnce(liveData, this, (v) -> {
             if (liveData.hasError()) {
                 ExceptionDialogFragment.newInstance(liveData.getError(), mainViewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -479,7 +481,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
         boardToCreate.setPermissionEdit(true);
         boardToCreate.setPermissionManage(true);
 
-        final WrappedLiveData<FullBoard> createLiveData = syncManager.createBoard(mainViewModel.getCurrentAccount().getId(), boardToCreate);
+        final WrappedLiveData<FullBoard> createLiveData = mainViewModel.createBoard(mainViewModel.getCurrentAccount().getId(), boardToCreate);
         observeOnce(createLiveData, this, (createdBoard) -> {
             if (createLiveData.hasError()) {
                 BrandedSnackbar.make(binding.coordinatorLayout, R.string.synchronization_failed, Snackbar.LENGTH_LONG)
@@ -499,7 +501,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
 
     @Override
     public void onUpdateBoard(FullBoard fullBoard) {
-        final WrappedLiveData<FullBoard> updateLiveData = syncManager.updateBoard(fullBoard);
+        final WrappedLiveData<FullBoard> updateLiveData = mainViewModel.updateBoard(fullBoard);
         observeOnce(updateLiveData, this, (next) -> {
             if (updateLiveData.hasError()) {
                 ExceptionDialogFragment.newInstance(updateLiveData.getError(), mainViewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -508,7 +510,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
     }
 
     private void refreshCapabilities(final Account account) {
-        syncManager.refreshCapabilities(new IResponseCallback<Capabilities>(account) {
+        mainViewModel.refreshCapabilities(new IResponseCallback<Capabilities>(account) {
             @Override
             public void onResponse(Capabilities response) {
                 if (response.isMaintenanceEnabled()) {
@@ -565,7 +567,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
         binding.emptyContentViewBoards.setVisibility(View.GONE);
         binding.swipeRefreshLayout.setVisibility(View.VISIBLE);
 
-        stacksLiveData = syncManager.getStacksForBoard(mainViewModel.getCurrentAccount().getId(), board.getLocalId());
+        stacksLiveData = mainViewModel.getStacksForBoard(mainViewModel.getCurrentAccount().getId(), board.getLocalId());
         stacksLiveData.observe(this, (List<Stack> stacks) -> {
             if (stacks == null) {
                 throw new IllegalStateException("Given List<FullStack> must not be null");
@@ -671,7 +673,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
         if (itemId == R.id.archive_cards) {
             final Stack stack = stackAdapter.getItem(binding.viewPager.getCurrentItem());
             final long stackLocalId = stack.getLocalId();
-            observeOnce(syncManager.countCardsInStack(mainViewModel.getCurrentAccount().getId(), stackLocalId), MainActivity.this, (numberOfCards) -> {
+            observeOnce(mainViewModel.countCardsInStack(mainViewModel.getCurrentAccount().getId(), stackLocalId), MainActivity.this, (numberOfCards) -> {
                 new BrandedAlertDialogBuilder(this)
                         .setTitle(R.string.archive_cards)
                         .setMessage(getString(FilterInformation.hasActiveFilter(filterViewModel.getFilterInformation().getValue())
@@ -679,7 +681,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
                                 : R.string.do_you_want_to_archive_all_cards_of_the_list, stack.getTitle()))
                         .setPositiveButton(R.string.simple_archive, (dialog, whichButton) -> {
                             final FilterInformation filterInformation = filterViewModel.getFilterInformation().getValue();
-                            final WrappedLiveData<Void> archiveStackLiveData = syncManager.archiveCardsInStack(mainViewModel.getCurrentAccount().getId(), stackLocalId, filterInformation == null ? new FilterInformation() : filterInformation);
+                            final WrappedLiveData<Void> archiveStackLiveData = mainViewModel.archiveCardsInStack(mainViewModel.getCurrentAccount().getId(), stackLocalId, filterInformation == null ? new FilterInformation() : filterInformation);
                             observeOnce(archiveStackLiveData, this, (result) -> {
                                 if (archiveStackLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(archiveStackLiveData.getError())) {
                                     ExceptionDialogFragment.newInstance(archiveStackLiveData.getError(), mainViewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -696,7 +698,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
             return true;
         } else if (itemId == R.id.rename_list) {
             final long stackId = stackAdapter.getItem(binding.viewPager.getCurrentItem()).getLocalId();
-            observeOnce(syncManager.getStack(mainViewModel.getCurrentAccount().getId(), stackId), MainActivity.this, fullStack ->
+            observeOnce(mainViewModel.getStack(mainViewModel.getCurrentAccount().getId(), stackId), MainActivity.this, fullStack ->
                     EditStackDialogFragment.newInstance(fullStack.getLocalId(), fullStack.getStack().getTitle())
                             .show(getSupportFragmentManager(), EditStackDialogFragment.class.getCanonicalName()));
             return true;
@@ -705,7 +707,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
             // TODO error handling
             final int stackLeftPosition = binding.viewPager.getCurrentItem() - 1;
             final long stackLeftId = stackAdapter.getItem(stackLeftPosition).getLocalId();
-            syncManager.swapStackOrder(mainViewModel.getCurrentAccount().getId(), mainViewModel.getCurrentBoardLocalId(), new Pair<>(stackId, stackLeftId));
+            mainViewModel.swapStackOrder(mainViewModel.getCurrentAccount().getId(), mainViewModel.getCurrentBoardLocalId(), new Pair<>(stackId, stackLeftId));
             stackMoved = true;
             return true;
         } else if (itemId == R.id.move_list_right) {
@@ -713,12 +715,12 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
             // TODO error handling
             final int stackRightPosition = binding.viewPager.getCurrentItem() + 1;
             final long stackRightId = stackAdapter.getItem(stackRightPosition).getLocalId();
-            syncManager.swapStackOrder(mainViewModel.getCurrentAccount().getId(), mainViewModel.getCurrentBoardLocalId(), new Pair<>(stackId, stackRightId));
+            mainViewModel.swapStackOrder(mainViewModel.getCurrentAccount().getId(), mainViewModel.getCurrentBoardLocalId(), new Pair<>(stackId, stackRightId));
             stackMoved = true;
             return true;
         } else if (itemId == R.id.delete_list) {
             final long stackId = stackAdapter.getItem(binding.viewPager.getCurrentItem()).getLocalId();
-            observeOnce(syncManager.countCardsInStack(mainViewModel.getCurrentAccount().getId(), stackId), MainActivity.this, (numberOfCards) -> {
+            observeOnce(mainViewModel.countCardsInStack(mainViewModel.getCurrentAccount().getId(), stackId), MainActivity.this, (numberOfCards) -> {
                 if (numberOfCards != null && numberOfCards > 0) {
                     DeleteStackDialogFragment.newInstance(stackId, numberOfCards).show(getSupportFragmentManager(), DeleteStackDialogFragment.class.getCanonicalName());
                 } else {
@@ -772,7 +774,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
             default:
                 try {
                     AccountImporter.onActivityResult(requestCode, resultCode, data, this, (account) -> {
-                        final WrappedLiveData<Account> accountLiveData = this.syncManager.createAccount(new Account(account.name, account.userId, account.url));
+                        final WrappedLiveData<Account> accountLiveData = mainViewModel.createAccount(new Account(account.name, account.userId, account.url));
                         accountLiveData.observe(this, (createdAccount) -> {
                             if (!accountLiveData.hasError()) {
                                 if (createdAccount == null) {
@@ -781,12 +783,13 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
 
                                 final SyncManager importSyncManager = new SyncManager(this, account.name);
                                 importSyncManager.refreshCapabilities(new IResponseCallback<Capabilities>(createdAccount) {
+                                    @SuppressLint("StringFormatInvalid")
                                     @Override
                                     public void onResponse(Capabilities response) {
                                         if (!response.isMaintenanceEnabled()) {
                                             if (response.getDeckVersion().isSupported(getApplicationContext())) {
                                                 runOnUiThread(() -> {
-                                                    syncManager = importSyncManager;
+                                                    mainViewModel.setSyncManager(importSyncManager);
                                                     mainViewModel.setCurrentAccount(account);
 
                                                     final Snackbar importSnackbar = BrandedSnackbar.make(binding.coordinatorLayout, R.string.account_is_getting_imported, Snackbar.LENGTH_INDEFINITE);
@@ -819,7 +822,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
                                                             startActivity(openURL);
                                                             finish();
                                                         }).show());
-                                                syncManager.deleteAccount(createdAccount.getId());
+                                                mainViewModel.deleteAccount(createdAccount.getId());
                                             }
                                         } else {
                                             DeckLog.warn("Cannot import account because server version is currently in maintenance mode.");
@@ -828,14 +831,14 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
                                                     .setMessage(getString(R.string.maintenance_mode_explanation, createdAccount.getUrl()))
                                                     .setPositiveButton(R.string.simple_close, null)
                                                     .show());
-                                            syncManager.deleteAccount(createdAccount.getId());
+                                            mainViewModel.deleteAccount(createdAccount.getId());
                                         }
                                     }
 
                                     @Override
                                     public void onError(Throwable throwable) {
                                         super.onError(throwable);
-                                        syncManager.deleteAccount(createdAccount.getId());
+                                        mainViewModel.deleteAccount(createdAccount.getId());
                                         if (throwable instanceof OfflineException) {
                                             DeckLog.warn("Cannot import account because device is currently offline.");
                                             runOnUiThread(() -> new BrandedAlertDialogBuilder(MainActivity.this)
@@ -885,7 +888,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
                     @Override
                     public void onAvailable(@NonNull Network network) {
                         DeckLog.log("Got Network connection");
-                        syncManager.synchronize(new IResponseCallback<Boolean>(mainViewModel.getCurrentAccount()) {
+                        mainViewModel.synchronize(new IResponseCallback<Boolean>(mainViewModel.getCurrentAccount()) {
                             @Override
                             public void onResponse(Boolean response) {
                                 DeckLog.log("Auto-Sync after connection available successful");
@@ -916,7 +919,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
     @Override
     public void onStackDeleted(Long stackLocalId) {
         long stackId = stackAdapter.getItem(binding.viewPager.getCurrentItem()).getLocalId();
-        final WrappedLiveData<Void> deleteStackLiveData = syncManager.deleteStack(mainViewModel.getCurrentAccount().getId(), stackId, mainViewModel.getCurrentBoardLocalId());
+        final WrappedLiveData<Void> deleteStackLiveData = mainViewModel.deleteStack(mainViewModel.getCurrentAccount().getId(), stackId, mainViewModel.getCurrentBoardLocalId());
         observeOnce(deleteStackLiveData, this, (v) -> {
             if (deleteStackLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(deleteStackLiveData.getError())) {
                 ExceptionDialogFragment.newInstance(deleteStackLiveData.getError(), mainViewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -939,7 +942,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
             }
         }
 
-        final WrappedLiveData<Void> deleteLiveData = syncManager.deleteBoard(board);
+        final WrappedLiveData<Void> deleteLiveData = mainViewModel.deleteBoard(board);
         observeOnce(deleteLiveData, this, (next) -> {
             if (deleteLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(deleteLiveData.getError())) {
                 ExceptionDialogFragment.newInstance(deleteLiveData.getError(), mainViewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -965,7 +968,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
 
     @Override
     public void onArchive(@NonNull Board board) {
-        final WrappedLiveData<FullBoard> liveData = syncManager.archiveBoard(board);
+        final WrappedLiveData<FullBoard> liveData = mainViewModel.archiveBoard(board);
         observeOnce(liveData, this, (fullBoard) -> {
             if (liveData.hasError()) {
                 ExceptionDialogFragment.newInstance(liveData.getError(), mainViewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -984,7 +987,7 @@ public class MainActivity extends BrandedActivity implements DeleteStackListener
                     binding.drawerLayout.closeDrawer(GravityCompat.START);
                     final Snackbar snackbar = BrandedSnackbar.make(binding.coordinatorLayout, getString(R.string.cloning_board, board.getTitle()), Snackbar.LENGTH_INDEFINITE);
                     snackbar.show();
-                    final WrappedLiveData<FullBoard> liveData = syncManager.cloneBoard(board.getAccountId(), board.getLocalId(), board.getAccountId(), board.getColor(), checkedItems[0]);
+                    final WrappedLiveData<FullBoard> liveData = mainViewModel.cloneBoard(board.getAccountId(), board.getLocalId(), board.getAccountId(), board.getColor(), checkedItems[0]);
                     observeOnce(liveData, this, (fullBoard -> {
                         snackbar.dismiss();
                         if (liveData.hasError()) {
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainViewModel.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainViewModel.java
index fecbf78ab..ac244b88e 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainViewModel.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainViewModel.java
@@ -2,18 +2,31 @@ package it.niedermann.nextcloud.deck.ui;
 
 import android.app.Application;
 
+import androidx.annotation.ColorInt;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.core.util.Pair;
 import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
 import java.io.File;
+import java.util.List;
 
+import it.niedermann.nextcloud.deck.api.IResponseCallback;
+import it.niedermann.nextcloud.deck.model.AccessControl;
 import it.niedermann.nextcloud.deck.model.Account;
 import it.niedermann.nextcloud.deck.model.Attachment;
 import it.niedermann.nextcloud.deck.model.Board;
+import it.niedermann.nextcloud.deck.model.Card;
+import it.niedermann.nextcloud.deck.model.Label;
+import it.niedermann.nextcloud.deck.model.Stack;
+import it.niedermann.nextcloud.deck.model.User;
+import it.niedermann.nextcloud.deck.model.full.FullBoard;
 import it.niedermann.nextcloud.deck.model.full.FullCard;
+import it.niedermann.nextcloud.deck.model.full.FullStack;
+import it.niedermann.nextcloud.deck.model.internal.FilterInformation;
+import it.niedermann.nextcloud.deck.model.ocs.Capabilities;
 import it.niedermann.nextcloud.deck.model.ocs.comment.DeckComment;
 import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.WrappedLiveData;
@@ -21,7 +34,7 @@ import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.WrappedLiv
 @SuppressWarnings("WeakerAccess")
 public class MainViewModel extends AndroidViewModel {
 
-    private final SyncManager syncManager;
+    private SyncManager syncManager;
 
     private final MutableLiveData<Account> currentAccount = new MutableLiveData<>();
     @Nullable
@@ -82,6 +95,142 @@ public class MainViewModel extends AndroidViewModel {
         return currentAccountIsSupportedVersion;
     }
 
+    public void recreateSyncManager() {
+        this.syncManager = new SyncManager(getApplication());
+    }
+
+    public void setSyncManager(@NonNull SyncManager syncManager) {
+        this.syncManager = syncManager;
+    }
+
+    public void synchronize(@NonNull IResponseCallback<Boolean> responseCallback) {
+        syncManager.synchronize(responseCallback);
+    }
+
+    public void refreshCapabilities(@NonNull IResponseCallback<Capabilities> callback) {
+        syncManager.refreshCapabilities(callback);
+    }
+
+    public LiveData<Boolean> hasAccounts() {
+        return syncManager.hasAccounts();
+    }
+
+    public WrappedLiveData<Account> createAccount(@NonNull Account accout) {
+        return syncManager.createAccount(accout);
+    }
+
+    public void deleteAccount(long id) {
+        syncManager.deleteAccount(id);
+    }
+
+    public LiveData<List<Account>> readAccounts() {
+        return syncManager.readAccounts();
+    }
+
+    public WrappedLiveData<FullBoard> createBoard(long accountId, @NonNull Board board) {
+        return syncManager.createBoard(accountId, board);
+    }
+
+    public WrappedLiveData<FullBoard> updateBoard(@NonNull FullBoard board) {
+        return syncManager.updateBoard(board);
+    }
+
+    public LiveData<List<Board>> getBoards(long accountId, boolean archived) {
+        return syncManager.getBoards(accountId, archived);
+    }
+
+    public LiveData<FullBoard> getFullBoardById(Long accountId, Long localId) {
+        return syncManager.getFullBoardById(accountId, localId);
+    }
+
+    public WrappedLiveData<FullBoard> archiveBoard(@NonNull Board board) {
+        return syncManager.archiveBoard(board);
+    }
+
+    public WrappedLiveData<FullBoard> dearchiveBoard(@NonNull Board board) {
+        return syncManager.dearchiveBoard(board);
+    }
+
+    public WrappedLiveData<FullBoard> cloneBoard(long originAccountId, long originBoardLocalId, long targetAccountId, @ColorInt int targetBoardColor, boolean cloneCards) {
+        return syncManager.cloneBoard(originAccountId, originBoardLocalId, targetAccountId, targetBoardColor, cloneCards);
+    }
+
+    public WrappedLiveData<Void> deleteBoard(@NonNull Board board) {
+        return syncManager.deleteBoard(board);
+    }
+
+    public LiveData<Boolean> hasArchivedBoards(long accountId) {
+        return syncManager.hasArchivedBoards(accountId);
+    }
+
+    public WrappedLiveData<AccessControl> createAccessControl(long accountId, AccessControl entity) {
+        return syncManager.createAccessControl(accountId, entity);
+    }
+
+    public WrappedLiveData<AccessControl> updateAccessControl(@NonNull AccessControl entity) {
+        return syncManager.updateAccessControl(entity);
+    }
+
+    public LiveData<List<AccessControl>> getAccessControlByLocalBoardId(long accountId, Long id) {
+        return syncManager.getAccessControlByLocalBoardId(accountId, id);
+    }
+
+    public WrappedLiveData<Void> deleteAccessControl(@NonNull AccessControl entity) {
+        return syncManager.deleteAccessControl(entity);
+    }
+
+    public WrappedLiveData<Label> createLabel(long accountId, Label label, long localBoardId) {
+        return syncManager.createLabel(accountId, label, localBoardId);
+    }
+
+    public LiveData<Integer> countCardsWithLabel(long localLabelId) {
+        return syncManager.countCardsWithLabel(localLabelId);
+    }
+
+    public WrappedLiveData<Label> updateLabel(@NonNull Label label) {
+        return syncManager.updateLabel(label);
+    }
+
+    public WrappedLiveData<Void> deleteLabel(@NonNull Label label) {
+        return syncManager.deleteLabel(label);
+    }
+
+    public LiveData<List<Stack>> getStacksForBoard(long accountId, long localBoardId) {
+        return syncManager.getStacksForBoard(accountId, localBoardId);
+    }
+
+    public WrappedLiveData<FullStack> createStack(long accountId, @NonNull String title, long boardLocalId) {
+        return syncManager.createStack(accountId, title, boardLocalId);
+    }
+
+    public LiveData<FullStack> getStack(long accountId, long localStackId) {
+        return syncManager.getStack(accountId, localStackId);
+    }
+
+    public void swapStackOrder(long accountId, long boardLocalId, @NonNull Pair<Long, Long> stackLocalIds) {
+        syncManager.swapStackOrder(accountId, boardLocalId, stackLocalIds);
+    }
+
+    public WrappedLiveData<FullStack> updateStackTitle(long localStackId, @NonNull String newTitle) {
+        return syncManager.updateStackTitle(localStackId, newTitle);
+    }
+
+    public WrappedLiveData<Void> deleteStack(long accountId, long stackLocalId, long boardLocalId) {
+        return syncManager.deleteStack(accountId, stackLocalId, boardLocalId);
+    }
+
+    public void reorder(long accountId, @NonNull FullCard movedCard, long newStackId, int newIndex) {
+        syncManager.reorder(accountId, movedCard, newStackId, newIndex);
+    }
+
+    public LiveData<Integer> countCardsInStack(long accountId, long localStackId) {
+        return syncManager.countCardsInStack(accountId, localStackId);
+    }
+
+    public WrappedLiveData<Void> archiveCardsInStack(long accountId, long stackLocalId, @NonNull FilterInformation filterInformation) {
+        return syncManager.archiveCardsInStack(accountId, stackLocalId, filterInformation);
+    }
+
     public WrappedLiveData<FullCard> updateCard(@NonNull FullCard fullCard) {
         return syncManager.updateCard(fullCard);
     }
@@ -97,4 +246,40 @@ public class MainViewModel extends AndroidViewModel {
     public void addOrUpdateSingleCardWidget(int widgetId, long accountId, long boardId, long localCardId) {
         syncManager.addOrUpdateSingleCardWidget(widgetId, accountId, boardId, localCardId);
     }
+
+    public LiveData<List<FullCard>> getFullCardsForStack(long accountId, long localStackId, @Nullable FilterInformation filter) {
+        return syncManager.getFullCardsForStack(accountId, localStackId, filter);
+    }
+
+    public WrappedLiveData<Void> moveCard(long originAccountId, long originCardLocalId, long targetAccountId, long targetBoardLocalId, long targetStackLocalId) {
+        return syncManager.moveCard(originAccountId, originCardLocalId, targetAccountId, targetBoardLocalId, targetStackLocalId);
+    }
+
+    public LiveData<List<FullCard>> getArchivedFullCardsForBoard(long accountId, long localBoardId) {
+        return syncManager.getArchivedFullCardsForBoard(accountId, localBoardId);
+    }
+
+    public void assignUserToCard(@NonNull User user, @NonNull Card card) {
+        syncManager.assignUserToCard(user, card);
+    }
+
+    public void unassignUserFromCard(@NonNull User user, @NonNull Card card) {
+        syncManager.unassignUserFromCard(user, card);
+    }
+
+    public User getUserByUidDirectly(long accountId, String uid) {
+        return syncManager.getUserByUidDirectly(accountId, uid);
+    }
+
+    public WrappedLiveData<FullCard> archiveCard(@NonNull FullCard card) {
+        return syncManager.archiveCard(card);
+    }
+
+    public WrappedLiveData<FullCard> dearchiveCard(@NonNull FullCard card) {
+        return syncManager.dearchiveCard(card);
+    }
+
+    public WrappedLiveData<Void> deleteCard(@NonNull Card card) {
+        return syncManager.deleteCard(card);
+    }
 }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/PickStackActivity.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/PickStackActivity.java
index e6766a0ab..2339a8783 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/PickStackActivity.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/PickStackActivity.java
@@ -11,6 +11,7 @@ import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.content.ContextCompat;
 import androidx.core.graphics.drawable.DrawableCompat;
+import androidx.lifecycle.ViewModelProvider;
 
 import java.util.List;
 
@@ -21,11 +22,11 @@ import it.niedermann.nextcloud.deck.databinding.ActivityPickStackBinding;
 import it.niedermann.nextcloud.deck.model.Account;
 import it.niedermann.nextcloud.deck.model.Board;
 import it.niedermann.nextcloud.deck.model.Stack;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.branding.Branded;
 import it.niedermann.nextcloud.deck.ui.exception.ExceptionHandler;
 import it.niedermann.nextcloud.deck.ui.pickstack.PickStackFragment;
 import it.niedermann.nextcloud.deck.ui.pickstack.PickStackListener;
+import it.niedermann.nextcloud.deck.ui.pickstack.PickStackViewModel;
 
 import static androidx.lifecycle.Transformations.switchMap;
 import static it.niedermann.nextcloud.deck.DeckApplication.isDarkTheme;
@@ -36,8 +37,7 @@ import static it.niedermann.nextcloud.deck.util.DeckColorUtil.contrastRatioIsSuf
 public abstract class PickStackActivity extends AppCompatActivity implements Branded, PickStackListener {
 
     protected ActivityPickStackBinding binding;
-
-    protected SyncManager syncManager;
+    protected PickStackViewModel viewModel;
 
     private boolean brandingEnabled;
 
@@ -55,14 +55,14 @@ public abstract class PickStackActivity extends AppCompatActivity implements Bra
         brandingEnabled = isBrandingEnabled(this);
 
         binding = ActivityPickStackBinding.inflate(getLayoutInflater());
+        viewModel = new ViewModelProvider(this).get(PickStackViewModel.class);
+
         setContentView(binding.getRoot());
         setSupportActionBar(binding.toolbar);
 
-        syncManager = new SyncManager(this);
-
-        switchMap(syncManager.hasAccounts(), hasAccounts -> {
+        switchMap(viewModel.hasAccounts(), hasAccounts -> {
             if (hasAccounts) {
-                return syncManager.readAccounts();
+                return viewModel.readAccounts();
             } else {
                 startActivityForResult(new Intent(this, ImportAccountActivity.class), ImportAccountActivity.REQUEST_CODE_IMPORT_ACCOUNT);
                 return null;
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/PushNotificationActivity.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/PushNotificationActivity.java
index a02f5aad3..cdc20ed50 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/PushNotificationActivity.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/PushNotificationActivity.java
@@ -9,8 +9,7 @@ import androidx.annotation.ColorInt;
 import androidx.annotation.NonNull;
 import androidx.annotation.UiThread;
 import androidx.appcompat.app.AppCompatActivity;
-
-import com.nextcloud.android.sso.helper.SingleAccountHelper;
+import androidx.lifecycle.ViewModelProvider;
 
 import it.niedermann.android.util.ColorUtil;
 import it.niedermann.nextcloud.deck.DeckLog;
@@ -18,7 +17,6 @@ import it.niedermann.nextcloud.deck.R;
 import it.niedermann.nextcloud.deck.api.IResponseCallback;
 import it.niedermann.nextcloud.deck.databinding.ActivityPushNotificationBinding;
 import it.niedermann.nextcloud.deck.model.Account;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.card.EditActivity;
 import it.niedermann.nextcloud.deck.ui.exception.ExceptionHandler;
 import it.niedermann.nextcloud.deck.util.ProjectUtil;
@@ -28,6 +26,7 @@ import static it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.Liv
 public class PushNotificationActivity extends AppCompatActivity {
 
     private ActivityPushNotificationBinding binding;
+    private PushNotificationViewModel viewModel;
 
     // Provided by Files app NotificationJob
     private static final String KEY_SUBJECT = "subject";
@@ -47,6 +46,8 @@ public class PushNotificationActivity extends AppCompatActivity {
         }
 
         binding = ActivityPushNotificationBinding.inflate(getLayoutInflater());
+        viewModel = new ViewModelProvider(this).get(PushNotificationViewModel.class);
+
         setContentView(binding.getRoot());
         setSupportActionBar(binding.toolbar);
 
@@ -63,7 +64,6 @@ public class PushNotificationActivity extends AppCompatActivity {
 
         binding.cancel.setOnClickListener((v) -> finish());
 
-        final SyncManager accountReadingSyncManager = new SyncManager(this);
         final String cardRemoteIdString = getIntent().getStringExtra(KEY_CARD_REMOTE_ID);
         final String accountString = getIntent().getStringExtra(KEY_ACCOUNT);
 
@@ -72,18 +72,17 @@ public class PushNotificationActivity extends AppCompatActivity {
             if (cardRemoteIdString != null) {
                 try {
                     final int cardRemoteId = Integer.parseInt(cardRemoteIdString);
-                    observeOnce(accountReadingSyncManager.readAccount(accountString), this, (account -> {
+                    observeOnce(viewModel.readAccount(accountString), this, (account -> {
                         if (account != null) {
-                            SingleAccountHelper.setCurrentAccount(this, account.getName());
-                            final SyncManager syncManager = new SyncManager(this);
+                            viewModel.setAccount(account.getName());
                             DeckLog.verbose("account: " + account);
-                            observeOnce(syncManager.getBoardByRemoteId(account.getId(), ids[0]), PushNotificationActivity.this, (board -> {
+                            observeOnce(viewModel.getBoardByRemoteId(account.getId(), ids[0]), PushNotificationActivity.this, (board -> {
                                 DeckLog.verbose("BoardLocalId " + board);
                                 if (board != null) {
-                                    observeOnce(syncManager.getCardByRemoteID(account.getId(), cardRemoteId), PushNotificationActivity.this, (card -> {
+                                    observeOnce(viewModel.getCardByRemoteID(account.getId(), cardRemoteId), PushNotificationActivity.this, (card -> {
                                         DeckLog.verbose("Card: " + card);
                                         if (card != null) {
-                                            syncManager.synchronizeCard(new IResponseCallback<Boolean>(account) {
+                                            viewModel.synchronizeCard(new IResponseCallback<Boolean>(account) {
                                                 @Override
                                                 public void onResponse(Boolean response) {
                                                     openCardOnSubmit(account, board.getLocalId(), card.getLocalId());
@@ -98,11 +97,11 @@ public class PushNotificationActivity extends AppCompatActivity {
                                         } else {
                                             DeckLog.info("Card is not yet available locally. Synchronize board with localId " + board);
 
-                                            syncManager.synchronizeBoard(new IResponseCallback<Boolean>(account) {
+                                            viewModel.synchronizeBoard(new IResponseCallback<Boolean>(account) {
                                                 @Override
                                                 public void onResponse(Boolean response) {
                                                     runOnUiThread(() -> {
-                                                        observeOnce(syncManager.getCardByRemoteID(account.getId(), cardRemoteId), PushNotificationActivity.this, (card -> {
+                                                        observeOnce(viewModel.getCardByRemoteID(account.getId(), cardRemoteId), PushNotificationActivity.this, (card -> {
                                                             DeckLog.verbose("Card: " + card);
                                                             if (card != null) {
                                                                 openCardOnSubmit(account, board.getLocalId(), card.getLocalId());
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/PushNotificationViewModel.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/PushNotificationViewModel.java
new file mode 100644
index 000000000..d15b412f4
--- /dev/null
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/PushNotificationViewModel.java
@@ -0,0 +1,52 @@
+package it.niedermann.nextcloud.deck.ui;
+
+import android.app.Application;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+
+import com.nextcloud.android.sso.helper.SingleAccountHelper;
+
+import it.niedermann.nextcloud.deck.api.IResponseCallback;
+import it.niedermann.nextcloud.deck.model.Account;
+import it.niedermann.nextcloud.deck.model.Board;
+import it.niedermann.nextcloud.deck.model.Card;
+import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
+
+public class PushNotificationViewModel extends AndroidViewModel {
+
+    private final SyncManager readAccountSyncManager;
+    private SyncManager accountSpecificSyncManager;
+
+    public PushNotificationViewModel(@NonNull Application application) {
+        super(application);
+        this.readAccountSyncManager = new SyncManager(application);
+    }
+
+    public LiveData<Account> readAccount(@Nullable String name) {
+        return readAccountSyncManager.readAccount(name);
+    }
+
+    public void setAccount(@NonNull String accountName) {
+        SingleAccountHelper.setCurrentAccount(getApplication(), accountName);
+        accountSpecificSyncManager = new SyncManager(getApplication());
+    }
+
+    public LiveData<Board> getBoardByRemoteId(long accountId, long remoteId) {
+        return accountSpecificSyncManager.getBoardByRemoteId(accountId, remoteId);
+    }
+
+    public LiveData<Card> getCardByRemoteID(long accountId, long remoteId) {
+        return accountSpecificSyncManager.getCardByRemoteID(accountId, remoteId);
+    }
+
+    public void synchronizeCard(@NonNull IResponseCallback<Boolean> responseCallback, Card card) {
+        accountSpecificSyncManager.synchronizeCard(responseCallback, card);
+    }
+
+    public void synchronizeBoard(@NonNull IResponseCallback<Boolean> responseCallback, long localBoadId) {
+        accountSpecificSyncManager.synchronizeBoard(responseCallback, localBoadId);
+    }
+}
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/accountswitcher/AccountSwitcherDialog.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/accountswitcher/AccountSwitcherDialog.java
index e54923d1e..744498c4a 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/accountswitcher/AccountSwitcherDialog.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/accountswitcher/AccountSwitcherDialog.java
@@ -1,7 +1,6 @@
 package it.niedermann.nextcloud.deck.ui.accountswitcher;
 
 import android.app.Dialog;
-import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
@@ -22,7 +21,6 @@ import it.niedermann.android.util.DimensionUtil;
 import it.niedermann.nextcloud.deck.DeckLog;
 import it.niedermann.nextcloud.deck.R;
 import it.niedermann.nextcloud.deck.databinding.DialogAccountSwitcherBinding;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.MainViewModel;
 import it.niedermann.nextcloud.deck.ui.branding.BrandedDialogFragment;
 import it.niedermann.nextcloud.deck.ui.manageaccounts.ManageAccountsActivity;
@@ -33,21 +31,15 @@ import static it.niedermann.nextcloud.deck.ui.MainActivity.ACTIVITY_MANAGE_ACCOU
 public class AccountSwitcherDialog extends BrandedDialogFragment {
 
     private AccountSwitcherAdapter adapter;
-    private SyncManager syncManager;
     private DialogAccountSwitcherBinding binding;
     private MainViewModel viewModel;
 
-    @Override
-    public void onAttach(@NonNull Context context) {
-        super.onAttach(context);
-        viewModel = new ViewModelProvider(requireActivity()).get(MainViewModel.class);
-        syncManager = new SyncManager(requireActivity());
-    }
-
     @NonNull
     @Override
     public Dialog onCreateDialog(Bundle savedInstanceState) {
         binding = DialogAccountSwitcherBinding.inflate(requireActivity().getLayoutInflater());
+        viewModel = new ViewModelProvider(requireActivity()).get(MainViewModel.class);
+
         binding.accountName.setText(viewModel.getCurrentAccount().getUserName());
         binding.accountHost.setText(Uri.parse(viewModel.getCurrentAccount().getUrl()).getHost());
         binding.check.setSelected(true);
@@ -66,7 +58,7 @@ public class AccountSwitcherDialog extends BrandedDialogFragment {
             dismiss();
         }));
 
-        observeOnce(syncManager.readAccounts(), requireActivity(), (accounts) -> {
+        observeOnce(viewModel.readAccounts(), requireActivity(), (accounts) -> {
             accounts.remove(viewModel.getCurrentAccount());
             adapter.setAccounts(accounts);
         });
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedboards/ArchivedBoardsActvitiy.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedboards/ArchivedBoardsActvitiy.java
index ed55c2411..d6d9cac1e 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedboards/ArchivedBoardsActvitiy.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedboards/ArchivedBoardsActvitiy.java
@@ -33,7 +33,6 @@ public class ArchivedBoardsActvitiy extends BrandedActivity implements DeleteBoa
     private MainViewModel viewModel;
     private ActivityArchivedBinding binding;
     private ArchivedBoardsAdapter adapter;
-    private SyncManager syncManager;
 
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState) {
@@ -58,10 +57,9 @@ public class ArchivedBoardsActvitiy extends BrandedActivity implements DeleteBoa
 
         viewModel = new ViewModelProvider(this).get(MainViewModel.class);
         viewModel.setCurrentAccount(account);
-        syncManager = new SyncManager(this);
 
         adapter = new ArchivedBoardsAdapter(viewModel.isCurrentAccountIsSupportedVersion(), getSupportFragmentManager(), (board) -> {
-            final WrappedLiveData<FullBoard> liveData = syncManager.dearchiveBoard(board);
+            final WrappedLiveData<FullBoard> liveData = viewModel.dearchiveBoard(board);
             observeOnce(liveData, this, (fullBoard) -> {
                 if (liveData.hasError()) {
                     ExceptionDialogFragment.newInstance(liveData.getError(), viewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -70,7 +68,7 @@ public class ArchivedBoardsActvitiy extends BrandedActivity implements DeleteBoa
         });
         binding.recyclerView.setAdapter(adapter);
 
-        syncManager.getBoards(account.getId(), true).observe(this, (boards) -> {
+        viewModel.getBoards(account.getId(), true).observe(this, (boards) -> {
             viewModel.setCurrentAccountHasArchivedBoards(boards != null && boards.size() > 0);
             adapter.setBoards(boards == null ? Collections.emptyList() : boards);
         });
@@ -91,7 +89,7 @@ public class ArchivedBoardsActvitiy extends BrandedActivity implements DeleteBoa
 
     @Override
     public void onBoardDeleted(Board board) {
-        final WrappedLiveData<Void> deleteLiveData = syncManager.deleteBoard(board);
+        final WrappedLiveData<Void> deleteLiveData = viewModel.deleteBoard(board);
         observeOnce(deleteLiveData, this, (next) -> {
             if (deleteLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(deleteLiveData.getError())) {
                 ExceptionDialogFragment.newInstance(deleteLiveData.getError(), viewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -101,7 +99,7 @@ public class ArchivedBoardsActvitiy extends BrandedActivity implements DeleteBoa
 
     @Override
     public void onUpdateBoard(FullBoard fullBoard) {
-        final WrappedLiveData<FullBoard> updateLiveData = syncManager.updateBoard(fullBoard);
+        final WrappedLiveData<FullBoard> updateLiveData = viewModel.updateBoard(fullBoard);
         observeOnce(updateLiveData, this, (next) -> {
             if (updateLiveData.hasError()) {
                 ExceptionDialogFragment.newInstance(updateLiveData.getError(), viewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -111,7 +109,7 @@ public class ArchivedBoardsActvitiy extends BrandedActivity implements DeleteBoa
 
     @Override
     public void onArchive(Board board) {
-        final WrappedLiveData<FullBoard> liveData = syncManager.dearchiveBoard(board);
+        final WrappedLiveData<FullBoard> liveData = viewModel.dearchiveBoard(board);
         observeOnce(liveData, this, (fullBoard) -> {
             if (liveData.hasError()) {
                 ExceptionDialogFragment.newInstance(liveData.getError(), viewModel.getCurrentAccount()).show(getSupportFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedcards/ArchivedCardsActvitiy.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedcards/ArchivedCardsActvitiy.java
index ed2ee7097..b3533528e 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedcards/ArchivedCardsActvitiy.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedcards/ArchivedCardsActvitiy.java
@@ -6,12 +6,15 @@ import android.os.Bundle;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import androidx.lifecycle.ViewModelProvider;
 
 import it.niedermann.nextcloud.deck.databinding.ActivityArchivedBinding;
 import it.niedermann.nextcloud.deck.model.Account;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
+import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.LiveDataHelper;
+import it.niedermann.nextcloud.deck.ui.MainViewModel;
 import it.niedermann.nextcloud.deck.ui.branding.BrandedActivity;
 import it.niedermann.nextcloud.deck.ui.exception.ExceptionHandler;
+import it.niedermann.nextcloud.deck.ui.pickstack.PickStackViewModel;
 
 public class ArchivedCardsActvitiy extends BrandedActivity {
 
@@ -21,7 +24,8 @@ public class ArchivedCardsActvitiy extends BrandedActivity {
 
     private ActivityArchivedBinding binding;
     private ArchivedCardsAdapter adapter;
-    private SyncManager syncManager;
+    private MainViewModel viewModel;
+    private PickStackViewModel pickStackViewModel;
 
     private Account account;
     private long boardId;
@@ -50,16 +54,20 @@ public class ArchivedCardsActvitiy extends BrandedActivity {
         }
 
         binding = ActivityArchivedBinding.inflate(getLayoutInflater());
+        viewModel = new ViewModelProvider(this).get(MainViewModel.class);
+        pickStackViewModel = new ViewModelProvider(this).get(PickStackViewModel.class);
+
         setContentView(binding.getRoot());
         setSupportActionBar(binding.toolbar);
 
-        syncManager = new SyncManager(this);
+        viewModel.setCurrentAccount(account);
+        LiveDataHelper.observeOnce(viewModel.getFullBoardById(account.getId(), boardId), this, (fullBoard) -> {
+            viewModel.setCurrentBoard(fullBoard.getBoard());
 
-        adapter = new ArchivedCardsAdapter(this, getSupportFragmentManager(), account, boardId, false, syncManager, this);
-        binding.recyclerView.setAdapter(adapter);
+            adapter = new ArchivedCardsAdapter(this, getSupportFragmentManager(), viewModel, this);
+            binding.recyclerView.setAdapter(adapter);
 
-        syncManager.getArchivedFullCardsForBoard(account.getId(), boardId).observe(this, (fullCards) -> {
-            adapter.setCardList(fullCards);
+            viewModel.getArchivedFullCardsForBoard(account.getId(), boardId).observe(this, (fullCards) -> adapter.setCardList(fullCards));
         });
 
     }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedcards/ArchivedCardsAdapter.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedcards/ArchivedCardsAdapter.java
index 324d8362c..b5034ebfa 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedcards/ArchivedCardsAdapter.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/archivedcards/ArchivedCardsAdapter.java
@@ -8,10 +8,10 @@ import androidx.fragment.app.FragmentManager;
 import androidx.lifecycle.LifecycleOwner;
 
 import it.niedermann.nextcloud.deck.R;
-import it.niedermann.nextcloud.deck.model.Account;
 import it.niedermann.nextcloud.deck.model.full.FullCard;
 import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.WrappedLiveData;
+import it.niedermann.nextcloud.deck.ui.MainViewModel;
 import it.niedermann.nextcloud.deck.ui.card.AbstractCardViewHolder;
 import it.niedermann.nextcloud.deck.ui.card.CardAdapter;
 import it.niedermann.nextcloud.deck.ui.exception.ExceptionDialogFragment;
@@ -21,39 +21,35 @@ import static it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.Liv
 public class ArchivedCardsAdapter extends CardAdapter {
 
     @SuppressWarnings("WeakerAccess")
-    public ArchivedCardsAdapter(@NonNull Context context, @NonNull FragmentManager fragmentManager, @NonNull Account account, long boardId, boolean hasEditPermission, @NonNull SyncManager syncManager, @NonNull LifecycleOwner lifecycleOwner) {
-        super(context, fragmentManager, account, boardId, 0L, 0L, hasEditPermission, syncManager, lifecycleOwner, null);
+    public ArchivedCardsAdapter(@NonNull Context context, @NonNull FragmentManager fragmentManager, @NonNull MainViewModel viewModel, @NonNull LifecycleOwner lifecycleOwner) {
+        super(context, fragmentManager, 0L, viewModel, lifecycleOwner, null);
     }
 
     @Override
     public void onBindViewHolder(@NonNull AbstractCardViewHolder viewHolder, int position) {
-        viewHolder.bind(cardList.get(position), account, boardRemoteId, hasEditPermission, R.menu.archived_card_menu, this, counterMaxValue, mainColor);
+        viewHolder.bind(cardList.get(position), mainViewModel.getCurrentAccount(), mainViewModel.getCurrentBoardRemoteId(), false, R.menu.archived_card_menu, this, counterMaxValue, mainColor);
     }
 
     @Override
     public boolean onCardOptionsItemSelected(@NonNull MenuItem menuItem, @NonNull FullCard fullCard) {
-        switch (menuItem.getItemId()) {
-            case R.id.action_card_dearchive: {
-                final WrappedLiveData<FullCard> liveData = syncManager.dearchiveCard(fullCard);
-                observeOnce(liveData, lifecycleOwner, (next) -> {
-                    if (liveData.hasError()) {
-                        ExceptionDialogFragment.newInstance(liveData.getError(), account).show(fragmentManager, ExceptionDialogFragment.class.getSimpleName());
-                    }
-                });
-                return true;
-            }
-            case R.id.action_card_delete: {
-                final WrappedLiveData<Void> liveData = syncManager.deleteCard(fullCard.getCard());
-                observeOnce(liveData, lifecycleOwner, (next) -> {
-                    if (liveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(liveData.getError())) {
-                        ExceptionDialogFragment.newInstance(liveData.getError(), account).show(fragmentManager, ExceptionDialogFragment.class.getSimpleName());
-                    }
-                });
-                return true;
-            }
-            default: {
-                return super.onCardOptionsItemSelected(menuItem, fullCard);
-            }
+        int itemId = menuItem.getItemId();
+        if (itemId == R.id.action_card_dearchive) {
+            final WrappedLiveData<FullCard> liveData = mainViewModel.dearchiveCard(fullCard);
+            observeOnce(liveData, lifecycleOwner, (next) -> {
+                if (liveData.hasError()) {
+                    ExceptionDialogFragment.newInstance(liveData.getError(), mainViewModel.getCurrentAccount()).show(fragmentManager, ExceptionDialogFragment.class.getSimpleName());
+                }
+            });
+            return true;
+        } else if (itemId == R.id.action_card_delete) {
+            final WrappedLiveData<Void> liveData = mainViewModel.deleteCard(fullCard.getCard());
+            observeOnce(liveData, lifecycleOwner, (next) -> {
+                if (liveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(liveData.getError())) {
+                    ExceptionDialogFragment.newInstance(liveData.getError(), mainViewModel.getCurrentAccount()).show(fragmentManager, ExceptionDialogFragment.class.getSimpleName());
+                }
+            });
+            return true;
         }
+        return super.onCardOptionsItemSelected(menuItem, fullCard);
     }
 }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/attachments/AttachmentsActivity.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/attachments/AttachmentsActivity.java
index 2eefd0c83..6618f7f72 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/attachments/AttachmentsActivity.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/attachments/AttachmentsActivity.java
@@ -12,6 +12,7 @@ import androidx.appcompat.app.AppCompatActivity;
 import androidx.core.app.SharedElementCallback;
 import androidx.core.content.ContextCompat;
 import androidx.core.graphics.drawable.DrawableCompat;
+import androidx.lifecycle.ViewModelProvider;
 import androidx.recyclerview.widget.RecyclerView;
 import androidx.viewpager2.widget.ViewPager2;
 
@@ -24,7 +25,6 @@ import it.niedermann.nextcloud.deck.R;
 import it.niedermann.nextcloud.deck.databinding.ActivityAttachmentsBinding;
 import it.niedermann.nextcloud.deck.model.Account;
 import it.niedermann.nextcloud.deck.model.Attachment;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.exception.ExceptionHandler;
 import it.niedermann.nextcloud.deck.util.MimeTypeUtil;
 
@@ -35,6 +35,7 @@ public class AttachmentsActivity extends AppCompatActivity {
     private static final String BUNDLE_KEY_CURRENT_ATTACHMENT_LOCAL_ID = "currentAttachmenLocaltId";
 
     private ActivityAttachmentsBinding binding;
+    private AttachmentsViewModel viewModel;
     private ViewPager2.OnPageChangeCallback onPageChangeCallback;
 
     @Override
@@ -43,6 +44,8 @@ public class AttachmentsActivity extends AppCompatActivity {
         Thread.currentThread().setUncaughtExceptionHandler(new ExceptionHandler(this));
 
         binding = ActivityAttachmentsBinding.inflate(getLayoutInflater());
+        viewModel = new ViewModelProvider(this).get(AttachmentsViewModel.class);
+
         setContentView(binding.getRoot());
         supportPostponeEnterTransition();
 
@@ -64,8 +67,7 @@ public class AttachmentsActivity extends AppCompatActivity {
 
         long cardId = args.getLong(BUNDLE_KEY_CARD_ID);
 
-        final SyncManager syncManager = new SyncManager(this);
-        syncManager.getFullCardWithProjectsByLocalId(account.getId(), cardId).observe(this, fullCard -> {
+        viewModel.getFullCardWithProjectsByLocalId(account.getId(), cardId).observe(this, fullCard -> {
             final List<Attachment> attachments = new ArrayList<>();
             for (Attachment a : fullCard.getAttachments()) {
                 if (MimeTypeUtil.isImage(a.getMimetype())) {
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/attachments/AttachmentsViewModel.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/attachments/AttachmentsViewModel.java
new file mode 100644
index 000000000..87a17470c
--- /dev/null
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/attachments/AttachmentsViewModel.java
@@ -0,0 +1,25 @@
+package it.niedermann.nextcloud.deck.ui.attachments;
+
+import android.app.Application;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+
+import it.niedermann.nextcloud.deck.model.full.FullCardWithProjects;
+import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
+
+@SuppressWarnings("WeakerAccess")
+public class AttachmentsViewModel extends AndroidViewModel {
+
+    private final SyncManager syncManager;
+
+    public AttachmentsViewModel(@NonNull Application application) {
+        super(application);
+        this.syncManager = new SyncManager(application);
+    }
+
+    public LiveData<FullCardWithProjects> getFullCardWithProjectsByLocalId(long accountId, long cardLocalId) {
+        return syncManager.getFullCardWithProjectsByLocalId(accountId, cardLocalId);
+    }
+}
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/EditBoardDialogFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/EditBoardDialogFragment.java
index 1ee23abfa..9da836c4c 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/EditBoardDialogFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/EditBoardDialogFragment.java
@@ -14,7 +14,6 @@ import androidx.lifecycle.ViewModelProvider;
 import it.niedermann.nextcloud.deck.R;
 import it.niedermann.nextcloud.deck.databinding.DialogTextColorInputBinding;
 import it.niedermann.nextcloud.deck.model.full.FullBoard;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.MainViewModel;
 import it.niedermann.nextcloud.deck.ui.branding.BrandedAlertDialogBuilder;
 import it.niedermann.nextcloud.deck.ui.branding.BrandedDialogFragment;
@@ -59,7 +58,7 @@ public class EditBoardDialogFragment extends BrandedDialogFragment {
                 this.editBoardListener.onUpdateBoard(fullBoard);
             });
             final MainViewModel viewModel = new ViewModelProvider(requireActivity()).get(MainViewModel.class);
-            new SyncManager(requireActivity()).getFullBoardById(viewModel.getCurrentAccount().getId(), args.getLong(KEY_BOARD_ID)).observe(EditBoardDialogFragment.this, (FullBoard fb) -> {
+            viewModel.getFullBoardById(viewModel.getCurrentAccount().getId(), args.getLong(KEY_BOARD_ID)).observe(EditBoardDialogFragment.this, (FullBoard fb) -> {
                 if (fb.board != null) {
                     this.fullBoard = fb;
                     String title = this.fullBoard.getBoard().getTitle();
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/accesscontrol/AccessControlDialogFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/accesscontrol/AccessControlDialogFragment.java
index e2320ca45..78ccd5333 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/accesscontrol/AccessControlDialogFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/accesscontrol/AccessControlDialogFragment.java
@@ -43,7 +43,6 @@ public class AccessControlDialogFragment extends BrandedDialogFragment implement
     private static final String KEY_BOARD_ID = "board_id";
 
     private long boardId;
-    private SyncManager syncManager;
     private UserAutoCompleteAdapter userAutoCompleteAdapter;
     private AccessControlAdapter adapter;
 
@@ -75,10 +74,9 @@ public class AccessControlDialogFragment extends BrandedDialogFragment implement
         adapter = new AccessControlAdapter(viewModel.getCurrentAccount(), this, requireContext());
         binding.peopleList.setAdapter(adapter);
 
-        syncManager = new SyncManager(requireActivity());
-        syncManager.getFullBoardById(viewModel.getCurrentAccount().getId(), boardId).observe(this, (FullBoard fullBoard) -> {
+        viewModel.getFullBoardById(viewModel.getCurrentAccount().getId(), boardId).observe(this, (FullBoard fullBoard) -> {
             if (fullBoard != null) {
-                syncManager.getAccessControlByLocalBoardId(viewModel.getCurrentAccount().getId(), boardId).observe(this, (List<AccessControl> accessControlList) -> {
+                viewModel.getAccessControlByLocalBoardId(viewModel.getCurrentAccount().getId(), boardId).observe(this, (List<AccessControl> accessControlList) -> {
                     final AccessControl ownerControl = new AccessControl();
                     ownerControl.setLocalId(HEADER_ITEM_LOCAL_ID);
                     ownerControl.setUser(fullBoard.getOwner());
@@ -103,7 +101,7 @@ public class AccessControlDialogFragment extends BrandedDialogFragment implement
 
     @Override
     public void updateAccessControl(AccessControl accessControl) {
-        WrappedLiveData<AccessControl> updateLiveData = syncManager.updateAccessControl(accessControl);
+        WrappedLiveData<AccessControl> updateLiveData = viewModel.updateAccessControl(accessControl);
         observeOnce(updateLiveData, requireActivity(), (next) -> {
             if (updateLiveData.hasError()) {
                 ExceptionDialogFragment.newInstance(updateLiveData.getError(), viewModel.getCurrentAccount()).show(getChildFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
@@ -113,7 +111,7 @@ public class AccessControlDialogFragment extends BrandedDialogFragment implement
 
     @Override
     public void deleteAccessControl(AccessControl ac) {
-        final WrappedLiveData<Void> wrappedDeleteLiveData = syncManager.deleteAccessControl(ac);
+        final WrappedLiveData<Void> wrappedDeleteLiveData = viewModel.deleteAccessControl(ac);
         adapter.remove(ac);
         observeOnce(wrappedDeleteLiveData, this, (ignored) -> {
             if (wrappedDeleteLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(wrappedDeleteLiveData.getError())) {
@@ -134,7 +132,7 @@ public class AccessControlDialogFragment extends BrandedDialogFragment implement
         ac.setType(0L); // https://github.com/nextcloud/deck/blob/master/docs/API.md#post-boardsboardidacl---add-new-acl-rule
         ac.setUserId(user.getLocalId());
         ac.setUser(user);
-        final WrappedLiveData<AccessControl> createLiveData = syncManager.createAccessControl(viewModel.getCurrentAccount().getId(), ac);
+        final WrappedLiveData<AccessControl> createLiveData = viewModel.createAccessControl(viewModel.getCurrentAccount().getId(), ac);
         observeOnce(createLiveData, this, (next) -> {
             if (createLiveData.hasError()) {
                 ExceptionDialogFragment.newInstance(createLiveData.getError(), viewModel.getCurrentAccount()).show(getChildFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/managelabels/ManageLabelsDialogFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/managelabels/ManageLabelsDialogFragment.java
index e06606493..bc0d98ca3 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/managelabels/ManageLabelsDialogFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/board/managelabels/ManageLabelsDialogFragment.java
@@ -38,7 +38,6 @@ public class ManageLabelsDialogFragment extends BrandedDialogFragment implements
     private static final String KEY_BOARD_ID = "board_id";
 
     private long boardId;
-    private SyncManager syncManager;
 
     @Override
     public void onAttach(@NonNull Context context) {
@@ -67,8 +66,7 @@ public class ManageLabelsDialogFragment extends BrandedDialogFragment implements
         colors = getResources().getStringArray(R.array.board_default_colors);
         adapter = new ManageLabelsAdapter(this, requireContext());
         binding.labels.setAdapter(adapter);
-        syncManager = new SyncManager(requireActivity());
-        syncManager.getFullBoardById(viewModel.getCurrentAccount().getId(), boardId).observe(this, (fullBoard) -> {
+        viewModel.getFullBoardById(viewModel.getCurrentAccount().getId(), boardId).observe(this, (fullBoard) -> {
             if (fullBoard == null) {
                 throw new IllegalStateException("FullBoard should not be null");
             }
@@ -82,7 +80,7 @@ public class ManageLabelsDialogFragment extends BrandedDialogFragment implements
             label.setTitle(binding.addLabelTitle.getText().toString());
             label.setColor(colors[new Random().nextInt(colors.length)]);
 
-            WrappedLiveData<Label> createLiveData = syncManager.createLabel(viewModel.getCurrentAccount().getId(), label, boardId);
+            WrappedLiveData<Label> createLiveData = viewModel.createLabel(viewModel.getCurrentAccount().getId(), label, boardId);
             observeOnce(createLiveData, this, (createdLabel) -> {
                 if (createLiveData.hasError()) {
                     final Throwable error = createLiveData.getError();
@@ -126,7 +124,7 @@ public class ManageLabelsDialogFragment extends BrandedDialogFragment implements
 
     @Override
     public void requestDelete(@NonNull Label label) {
-        observeOnce(syncManager.countCardsWithLabel(label.getLocalId()), this, (count) -> {
+        observeOnce(viewModel.countCardsWithLabel(label.getLocalId()), this, (count) -> {
             if (count > 0) {
                 new BrandedDeleteAlertDialogBuilder(requireContext())
                         .setTitle(getString(R.string.delete_something, label.getTitle()))
@@ -141,7 +139,7 @@ public class ManageLabelsDialogFragment extends BrandedDialogFragment implements
     }
 
     private void deleteLabel(@NonNull Label label) {
-        final WrappedLiveData<Void> deleteLiveData = syncManager.deleteLabel(label);
+        final WrappedLiveData<Void> deleteLiveData = viewModel.deleteLabel(label);
         observeOnce(deleteLiveData, this, (v) -> {
             if (deleteLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(deleteLiveData.getError())) {
                 final Throwable error = deleteLiveData.getError();
@@ -159,7 +157,7 @@ public class ManageLabelsDialogFragment extends BrandedDialogFragment implements
 
     @Override
     public void onLabelUpdated(@NonNull Label label) {
-        WrappedLiveData<Label> updateLiveData = syncManager.updateLabel(label);
+        WrappedLiveData<Label> updateLiveData = viewModel.updateLabel(label);
         observeOnce(updateLiveData, this, (updatedLabel) -> {
             if (updateLiveData.hasError()) {
                 final Throwable error = updateLiveData.getError();
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/CardAdapter.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/CardAdapter.java
index ecb06c7a8..87140e544 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/CardAdapter.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/CardAdapter.java
@@ -33,6 +33,7 @@ import it.niedermann.nextcloud.deck.model.Stack;
 import it.niedermann.nextcloud.deck.model.full.FullCard;
 import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.WrappedLiveData;
+import it.niedermann.nextcloud.deck.ui.MainViewModel;
 import it.niedermann.nextcloud.deck.ui.branding.Branded;
 import it.niedermann.nextcloud.deck.ui.exception.ExceptionDialogFragment;
 import it.niedermann.nextcloud.deck.ui.movecard.MoveCardDialogFragment;
@@ -46,16 +47,10 @@ public class CardAdapter extends RecyclerView.Adapter<AbstractCardViewHolder> im
 
     private final boolean compactMode;
     @NonNull
-    protected final SyncManager syncManager;
+    protected final MainViewModel mainViewModel;
     @NonNull
     protected final FragmentManager fragmentManager;
-    @NonNull
-    protected final Account account;
-    @Nullable
-    protected final Long boardRemoteId;
-    private final long boardLocalId;
     private final long stackId;
-    protected final boolean hasEditPermission;
     @NonNull
     private final Context context;
     @Nullable
@@ -69,20 +64,16 @@ public class CardAdapter extends RecyclerView.Adapter<AbstractCardViewHolder> im
     @ColorInt
     protected int mainColor;
     @StringRes
-    private int shareLinkRes;
+    private final int shareLinkRes;
 
-    public CardAdapter(@NonNull Context context, @NonNull FragmentManager fragmentManager, @NonNull Account account, long boardLocalId, @Nullable Long boardRemoteId, long stackId, boolean hasEditPermission, @NonNull SyncManager syncManager, @NonNull LifecycleOwner lifecycleOwner, @Nullable SelectCardListener selectCardListener) {
+    public CardAdapter(@NonNull Context context, @NonNull FragmentManager fragmentManager, long stackId, @NonNull MainViewModel mainViewModel, @NonNull LifecycleOwner lifecycleOwner, @Nullable SelectCardListener selectCardListener) {
         this.context = context;
         this.counterMaxValue = context.getString(R.string.counter_max_value);
         this.fragmentManager = fragmentManager;
         this.lifecycleOwner = lifecycleOwner;
-        this.account = account;
-        this.shareLinkRes = account.getServerDeckVersionAsObject().getShareLinkResource();
-        this.boardLocalId = boardLocalId;
-        this.boardRemoteId = boardRemoteId;
+        this.shareLinkRes = mainViewModel.getCurrentAccount().getServerDeckVersionAsObject().getShareLinkResource();
         this.stackId = stackId;
-        this.hasEditPermission = hasEditPermission;
-        this.syncManager = syncManager;
+        this.mainViewModel = mainViewModel;
         this.selectCardListener = selectCardListener;
         this.mainColor = ContextCompat.getColor(context, R.color.defaultBrand);
         this.compactMode = getDefaultSharedPreferences(context).getBoolean(context.getString(R.string.pref_key_compact), false);
@@ -97,15 +88,12 @@ public class CardAdapter extends RecyclerView.Adapter<AbstractCardViewHolder> im
     @NonNull
     @Override
     public AbstractCardViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {
-        switch (viewType) {
-            case R.layout.item_card_compact:
-                return new CompactCardViewHolder(ItemCardCompactBinding.inflate(LayoutInflater.from(viewGroup.getContext()), viewGroup, false));
-            case R.layout.item_card_default_only_title:
-                return new DefaultCardOnlyTitleViewHolder(ItemCardDefaultOnlyTitleBinding.inflate(LayoutInflater.from(viewGroup.getContext()), viewGroup, false));
-            case R.layout.item_card_default:
-            default:
-                return new DefaultCardViewHolder(ItemCardDefaultBinding.inflate(LayoutInflater.from(viewGroup.getContext()), viewGroup, false));
+        if (viewType == R.layout.item_card_compact) {
+            return new CompactCardViewHolder(ItemCardCompactBinding.inflate(LayoutInflater.from(viewGroup.getContext()), viewGroup, false));
+        } else if (viewType == R.layout.item_card_default_only_title) {
+            return new DefaultCardOnlyTitleViewHolder(ItemCardDefaultOnlyTitleBinding.inflate(LayoutInflater.from(viewGroup.getContext()), viewGroup, false));
         }
+        return new DefaultCardViewHolder(ItemCardDefaultBinding.inflate(LayoutInflater.from(viewGroup.getContext()), viewGroup, false));
     }
 
     @Override
@@ -127,12 +115,12 @@ public class CardAdapter extends RecyclerView.Adapter<AbstractCardViewHolder> im
     @Override
     public void onBindViewHolder(@NonNull AbstractCardViewHolder viewHolder, int position) {
         @NonNull FullCard fullCard = cardList.get(position);
-        viewHolder.bind(fullCard, account, boardRemoteId, hasEditPermission, R.menu.card_menu, this, counterMaxValue, mainColor);
+        viewHolder.bind(fullCard, mainViewModel.getCurrentAccount(), mainViewModel.getCurrentBoardRemoteId(), mainViewModel.currentBoardHasEditPermission(), R.menu.card_menu, this, counterMaxValue, mainColor);
 
         // Only enable details view if there is no one waiting for selecting a card.
         viewHolder.bindCardClickListener((v) -> {
             if (selectCardListener == null) {
-                context.startActivity(EditActivity.createEditCardIntent(context, account, boardLocalId, fullCard.getLocalId()));
+                context.startActivity(EditActivity.createEditCardIntent(context, mainViewModel.getCurrentAccount(), mainViewModel.getCurrentBoardLocalId(), fullCard.getLocalId()));
             } else {
                 selectCardListener.onCardSelected(fullCard);
             }
@@ -194,47 +182,44 @@ public class CardAdapter extends RecyclerView.Adapter<AbstractCardViewHolder> im
 
     @Override
     public boolean onCardOptionsItemSelected(@NonNull MenuItem menuItem, @NonNull FullCard fullCard) {
-        switch (menuItem.getItemId()) {
-            case R.id.share_link: {
-                Intent shareIntent = new Intent()
-                        .setAction(Intent.ACTION_SEND)
-                        .setType(TEXT_PLAIN)
-                        .putExtra(Intent.EXTRA_SUBJECT, fullCard.getCard().getTitle())
-                        .putExtra(Intent.EXTRA_TITLE, fullCard.getCard().getTitle())
-                        .putExtra(Intent.EXTRA_TEXT, account.getUrl() + context.getString(shareLinkRes, boardRemoteId, fullCard.getCard().getId()));
-                context.startActivity(Intent.createChooser(shareIntent, fullCard.getCard().getTitle()));
-            }
-            case R.id.action_card_assign: {
-                new Thread(() -> syncManager.assignUserToCard(syncManager.getUserByUidDirectly(fullCard.getCard().getAccountId(), account.getUserName()), fullCard.getCard())).start();
-                return true;
-            }
-            case R.id.action_card_unassign: {
-                new Thread(() -> syncManager.unassignUserFromCard(syncManager.getUserByUidDirectly(fullCard.getCard().getAccountId(), account.getUserName()), fullCard.getCard())).start();
-                return true;
-            }
-            case R.id.action_card_move: {
-                DeckLog.verbose("[Move card] Launch move dialog for " + Card.class.getSimpleName() + " \"" + fullCard.getCard().getTitle() + "\" (#" + fullCard.getLocalId() + ") from " + Stack.class.getSimpleName() + " #" + +stackId);
-                MoveCardDialogFragment.newInstance(fullCard.getAccountId(), boardLocalId, fullCard.getCard().getTitle(), fullCard.getLocalId()).show(fragmentManager, MoveCardDialogFragment.class.getSimpleName());
-                return true;
-            }
-            case R.id.action_card_archive: {
-                final WrappedLiveData<FullCard> archiveLiveData = syncManager.archiveCard(fullCard);
-                observeOnce(archiveLiveData, lifecycleOwner, (v) -> {
-                    if (archiveLiveData.hasError()) {
-                        ExceptionDialogFragment.newInstance(archiveLiveData.getError(), account).show(fragmentManager, ExceptionDialogFragment.class.getSimpleName());
-                    }
-                });
-                return true;
-            }
-            case R.id.action_card_delete: {
-                final WrappedLiveData<Void> deleteLiveData = syncManager.deleteCard(fullCard.getCard());
-                observeOnce(deleteLiveData, lifecycleOwner, (v) -> {
-                    if (deleteLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(deleteLiveData.getError())) {
-                        ExceptionDialogFragment.newInstance(deleteLiveData.getError(), account).show(fragmentManager, ExceptionDialogFragment.class.getSimpleName());
-                    }
-                });
-                return true;
-            }
+        int itemId = menuItem.getItemId();
+        final Account account = mainViewModel.getCurrentAccount();
+        if (itemId == R.id.share_link) {
+            Intent shareIntent = new Intent()
+                    .setAction(Intent.ACTION_SEND)
+                    .setType(TEXT_PLAIN)
+                    .putExtra(Intent.EXTRA_SUBJECT, fullCard.getCard().getTitle())
+                    .putExtra(Intent.EXTRA_TITLE, fullCard.getCard().getTitle())
+                    .putExtra(Intent.EXTRA_TEXT, account.getUrl() + context.getString(shareLinkRes, mainViewModel.getCurrentBoardRemoteId(), fullCard.getCard().getId()));
+            context.startActivity(Intent.createChooser(shareIntent, fullCard.getCard().getTitle()));
+            new Thread(() -> mainViewModel.assignUserToCard(mainViewModel.getUserByUidDirectly(fullCard.getCard().getAccountId(), account.getUserName()), fullCard.getCard())).start();
+            return true;
+        } else if (itemId == R.id.action_card_assign) {
+            new Thread(() -> mainViewModel.assignUserToCard(mainViewModel.getUserByUidDirectly(fullCard.getCard().getAccountId(), account.getUserName()), fullCard.getCard())).start();
+            return true;
+        } else if (itemId == R.id.action_card_unassign) {
+            new Thread(() -> mainViewModel.unassignUserFromCard(mainViewModel.getUserByUidDirectly(fullCard.getCard().getAccountId(), account.getUserName()), fullCard.getCard())).start();
+            return true;
+        } else if (itemId == R.id.action_card_move) {
+            DeckLog.verbose("[Move card] Launch move dialog for " + Card.class.getSimpleName() + " \"" + fullCard.getCard().getTitle() + "\" (#" + fullCard.getLocalId() + ") from " + Stack.class.getSimpleName() + " #" + +stackId);
+            MoveCardDialogFragment.newInstance(fullCard.getAccountId(), mainViewModel.getCurrentBoardLocalId(), fullCard.getCard().getTitle(), fullCard.getLocalId()).show(fragmentManager, MoveCardDialogFragment.class.getSimpleName());
+            return true;
+        } else if (itemId == R.id.action_card_archive) {
+            final WrappedLiveData<FullCard> archiveLiveData = mainViewModel.archiveCard(fullCard);
+            observeOnce(archiveLiveData, lifecycleOwner, (v) -> {
+                if (archiveLiveData.hasError()) {
+                    ExceptionDialogFragment.newInstance(archiveLiveData.getError(), account).show(fragmentManager, ExceptionDialogFragment.class.getSimpleName());
+                }
+            });
+            return true;
+        } else if (itemId == R.id.action_card_delete) {
+            final WrappedLiveData<Void> deleteLiveData = mainViewModel.deleteCard(fullCard.getCard());
+            observeOnce(deleteLiveData, lifecycleOwner, (v) -> {
+                if (deleteLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(deleteLiveData.getError())) {
+                    ExceptionDialogFragment.newInstance(deleteLiveData.getError(), account).show(fragmentManager, ExceptionDialogFragment.class.getSimpleName());
+                }
+            });
+            return true;
         }
         return true;
     }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/EditActivity.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/EditActivity.java
index fcc9d24e6..2e1ff5e06 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/EditActivity.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/EditActivity.java
@@ -26,7 +26,6 @@ import it.niedermann.nextcloud.deck.R;
 import it.niedermann.nextcloud.deck.databinding.ActivityEditBinding;
 import it.niedermann.nextcloud.deck.model.Account;
 import it.niedermann.nextcloud.deck.model.full.FullCard;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.branding.BrandedActivity;
 import it.niedermann.nextcloud.deck.ui.branding.BrandedAlertDialogBuilder;
 import it.niedermann.nextcloud.deck.ui.exception.ExceptionHandler;
@@ -45,7 +44,6 @@ public class EditActivity extends BrandedActivity {
 
     private ActivityEditBinding binding;
     private EditCardViewModel viewModel;
-    private SyncManager syncManager;
 
     private static final int[] tabTitles = new int[]{
             R.string.card_edit_details,
@@ -116,11 +114,10 @@ public class EditActivity extends BrandedActivity {
             throw new IllegalArgumentException(BUNDLE_KEY_ACCOUNT + " must not be null.");
         }
         viewModel.setAccount(account);
-        syncManager = new SyncManager(this, viewModel.getAccount().getName());
 
         final long boardId = args.getLong(BUNDLE_KEY_BOARD_ID);
 
-        observeOnce(syncManager.getFullBoardById(account.getId(), boardId), EditActivity.this, (fullBoard -> {
+        observeOnce(viewModel.getFullBoardById(account.getId(), boardId), EditActivity.this, (fullBoard -> {
             applyBrand(fullBoard.getBoard().getColor());
             viewModel.setCanEdit(fullBoard.getBoard().isPermissionEdit());
             invalidateOptionsMenu();
@@ -138,7 +135,7 @@ public class EditActivity extends BrandedActivity {
                 setupViewPager();
                 setupTitle();
             } else {
-                observeOnce(syncManager.getFullCardWithProjectsByLocalId(account.getId(), cardId), EditActivity.this, (fullCard) -> {
+                observeOnce(viewModel.getFullCardWithProjectsByLocalId(account.getId(), cardId), EditActivity.this, (fullCard) -> {
                     if (fullCard == null) {
                         new BrandedAlertDialogBuilder(this)
                                 .setTitle(R.string.card_not_found)
@@ -199,9 +196,9 @@ public class EditActivity extends BrandedActivity {
                         .show();
             } else {
                 if (viewModel.isCreateMode()) {
-                    observeOnce(syncManager.createFullCard(viewModel.getAccount().getId(), viewModel.getBoardId(), viewModel.getFullCard().getCard().getStackId(), viewModel.getFullCard()), EditActivity.this, (card) -> runnable.run());
+                    observeOnce(viewModel.createFullCard(viewModel.getAccount().getId(), viewModel.getBoardId(), viewModel.getFullCard().getCard().getStackId(), viewModel.getFullCard()), EditActivity.this, (card) -> runnable.run());
                 } else {
-                    observeOnce(syncManager.updateCard(viewModel.getFullCard()), EditActivity.this, (card) -> runnable.run());
+                    observeOnce(viewModel.updateCard(viewModel.getFullCard()), EditActivity.this, (card) -> runnable.run());
                 }
             }
         }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/EditCardViewModel.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/EditCardViewModel.java
index 62fe6785f..c754d0800 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/EditCardViewModel.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/EditCardViewModel.java
@@ -1,18 +1,32 @@
 package it.niedermann.nextcloud.deck.ui.card;
 
+import android.app.Application;
+
 import androidx.annotation.NonNull;
-import androidx.lifecycle.ViewModel;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
 
+import java.io.File;
 import java.util.ArrayList;
+import java.util.List;
 
 import it.niedermann.nextcloud.deck.DeckLog;
 import it.niedermann.nextcloud.deck.model.Account;
+import it.niedermann.nextcloud.deck.model.Attachment;
+import it.niedermann.nextcloud.deck.model.Board;
 import it.niedermann.nextcloud.deck.model.Card;
+import it.niedermann.nextcloud.deck.model.Label;
+import it.niedermann.nextcloud.deck.model.full.FullBoard;
+import it.niedermann.nextcloud.deck.model.full.FullCard;
 import it.niedermann.nextcloud.deck.model.full.FullCardWithProjects;
+import it.niedermann.nextcloud.deck.model.ocs.Activity;
+import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
+import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.WrappedLiveData;
 
 @SuppressWarnings("WeakerAccess")
-public class EditCardViewModel extends ViewModel {
+public class EditCardViewModel extends AndroidViewModel {
 
+    private SyncManager syncManager;
     private Account account;
     private long boardId;
     private FullCardWithProjects originalCard;
@@ -23,6 +37,11 @@ public class EditCardViewModel extends ViewModel {
     private boolean canEdit = false;
     private boolean createMode = false;
 
+    public EditCardViewModel(@NonNull Application application) {
+        super(application);
+        this.syncManager = new SyncManager(application);
+    }
+
     /**
      * Stores a deep copy of the given fullCard to be able to compare the state at every time in #{@link EditCardViewModel#hasChanges()}
      *
@@ -55,11 +74,12 @@ public class EditCardViewModel extends ViewModel {
 
     public void setAccount(@NonNull Account account) {
         this.account = account;
+        this.syncManager = new SyncManager(getApplication(), account.getName());
         hasCommentsAbility = account.getServerDeckVersionAsObject().supportsComments();
     }
 
     public boolean hasChanges() {
-        if(fullCard == null) {
+        if (fullCard == null) {
             DeckLog.info("Can not check for changes because fullCard is null → assuming no changes have been made yet.");
             return false;
         }
@@ -105,4 +125,44 @@ public class EditCardViewModel extends ViewModel {
     public long getBoardId() {
         return boardId;
     }
+
+    public LiveData<FullBoard> getFullBoardById(Long accountId, Long localId) {
+        return syncManager.getFullBoardById(accountId, localId);
+    }
+
+    public WrappedLiveData<Label> createLabel(long accountId, Label label, long localBoardId) {
+        return syncManager.createLabel(accountId, label, localBoardId);
+    }
+
+    public LiveData<FullCardWithProjects> getFullCardWithProjectsByLocalId(long accountId, long cardLocalId) {
+        return syncManager.getFullCardWithProjectsByLocalId(accountId, cardLocalId);
+    }
+
+    public WrappedLiveData<FullCard> createFullCard(long accountId, long localBoardId, long localStackId, @NonNull FullCard card) {
+        return syncManager.createFullCard(accountId, localBoardId, localStackId, card);
+    }
+
+    public WrappedLiveData<FullCard> updateCard(@NonNull FullCard card) {
+        return syncManager.updateCard(card);
+    }
+
+    public LiveData<List<Activity>> syncActivitiesForCard(@NonNull Card card) {
+        return syncManager.syncActivitiesForCard(card);
+    }
+
+    public WrappedLiveData<Attachment> addAttachmentToCard(long accountId, long localCardId, @NonNull String mimeType, @NonNull File file) {
+        return syncManager.addAttachmentToCard(accountId, localCardId, mimeType, file);
+    }
+
+    public WrappedLiveData<Void> deleteAttachmentOfCard(long accountId, long localCardId, long localAttachmentId) {
+        return syncManager.deleteAttachmentOfCard(accountId, localCardId, localAttachmentId);
+    }
+
+    public LiveData<Card> getCardByRemoteID(long accountId, long remoteId) {
+        return syncManager.getCardByRemoteID(accountId, remoteId);
+    }
+
+    public LiveData<Board> getBoardByRemoteId(long accountId, long remoteId) {
+        return syncManager.getBoardByRemoteId(accountId, remoteId);
+    }
 }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/activities/CardActivityFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/activities/CardActivityFragment.java
index 08d960257..f95eea89f 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/activities/CardActivityFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/activities/CardActivityFragment.java
@@ -8,11 +8,9 @@ import android.view.ViewGroup;
 import androidx.annotation.NonNull;
 import androidx.fragment.app.Fragment;
 import androidx.lifecycle.ViewModelProvider;
-import androidx.recyclerview.widget.RecyclerView;
 
 import it.niedermann.nextcloud.deck.DeckLog;
 import it.niedermann.nextcloud.deck.databinding.FragmentCardEditTabActivitiesBinding;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.card.EditCardViewModel;
 
 public class CardActivityFragment extends Fragment {
@@ -39,17 +37,14 @@ public class CardActivityFragment extends Fragment {
         }
 
         if (!viewModel.isCreateMode()) {
-            final SyncManager syncManager = new SyncManager(requireContext());
-
-            syncManager.syncActivitiesForCard(viewModel.getFullCard().getCard()).observe(getViewLifecycleOwner(), (activities -> {
+            viewModel.syncActivitiesForCard(viewModel.getFullCard().getCard()).observe(getViewLifecycleOwner(), (activities -> {
                 if (activities == null || activities.size() == 0) {
                     binding.emptyContentView.setVisibility(View.VISIBLE);
                     binding.activitiesList.setVisibility(View.GONE);
                 } else {
                     binding.emptyContentView.setVisibility(View.GONE);
                     binding.activitiesList.setVisibility(View.VISIBLE);
-                    RecyclerView.Adapter adapter = new CardActivityAdapter(activities, requireActivity().getMenuInflater());
-                    binding.activitiesList.setAdapter(adapter);
+                    binding.activitiesList.setAdapter(new CardActivityAdapter(activities, requireActivity().getMenuInflater()));
                 }
             }));
         } else {
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/attachments/CardAttachmentsFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/attachments/CardAttachmentsFragment.java
index 81a166cb6..07e8d39dd 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/attachments/CardAttachmentsFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/attachments/CardAttachmentsFragment.java
@@ -104,7 +104,6 @@ public class CardAttachmentsFragment extends BrandedFragment implements Attachme
     @ColorInt
     private int primaryColor;
 
-    private SyncManager syncManager;
     private CardAttachmentAdapter adapter;
 
     private AbstractPickerAdapter<?> pickerAdapter;
@@ -146,7 +145,6 @@ public class CardAttachmentsFragment extends BrandedFragment implements Attachme
             return binding.getRoot();
         }
 
-        syncManager = new SyncManager(requireContext());
         adapter = new CardAttachmentAdapter(
                 getChildFragmentManager(),
                 requireActivity().getMenuInflater(),
@@ -436,7 +434,7 @@ public class CardAttachmentsFragment extends BrandedFragment implements Attachme
                 editViewModel.getFullCard().getAttachments().add(0, a);
                 adapter.addAttachment(a);
                 if (!editViewModel.isCreateMode()) {
-                    WrappedLiveData<Attachment> liveData = syncManager.addAttachmentToCard(editViewModel.getAccount().getId(), editViewModel.getFullCard().getLocalId(), a.getMimetype(), fileToUpload);
+                    WrappedLiveData<Attachment> liveData = editViewModel.addAttachmentToCard(editViewModel.getAccount().getId(), editViewModel.getFullCard().getLocalId(), a.getMimetype(), fileToUpload);
                     observeOnce(liveData, getViewLifecycleOwner(), (next) -> {
                         if (liveData.hasError()) {
                             Throwable t = liveData.getError();
@@ -500,7 +498,7 @@ public class CardAttachmentsFragment extends BrandedFragment implements Attachme
         adapter.removeAttachment(attachment);
         editViewModel.getFullCard().getAttachments().remove(attachment);
         if (!editViewModel.isCreateMode() && attachment.getLocalId() != null) {
-            final WrappedLiveData<Void> deleteLiveData = syncManager.deleteAttachmentOfCard(editViewModel.getAccount().getId(), editViewModel.getFullCard().getLocalId(), attachment.getLocalId());
+            final WrappedLiveData<Void> deleteLiveData = editViewModel.deleteAttachmentOfCard(editViewModel.getAccount().getId(), editViewModel.getFullCard().getLocalId(), attachment.getLocalId());
             observeOnce(deleteLiveData, this, (next) -> {
                 if (deleteLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(deleteLiveData.getError())) {
                     ExceptionDialogFragment.newInstance(deleteLiveData.getError(), editViewModel.getAccount()).show(getChildFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/CardCommentsFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/CardCommentsFragment.java
index 7f90e575a..3fd536aa6 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/CardCommentsFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/CardCommentsFragment.java
@@ -41,7 +41,6 @@ public class CardCommentsFragment extends BrandedFragment implements CommentEdit
     private FragmentCardEditTabCommentsBinding binding;
     private EditCardViewModel mainViewModel;
     private CommentsViewModel commentsViewModel;
-    private SyncManager syncManager;
     private CardCommentsAdapter adapter;
 
     public static Fragment newInstance() {
@@ -71,7 +70,6 @@ public class CardCommentsFragment extends BrandedFragment implements CommentEdit
 
         commentsViewModel = new ViewModelProvider(this).get(CommentsViewModel.class);
 
-        syncManager = new SyncManager(requireActivity());
         adapter = new CardCommentsAdapter(requireContext(), mainViewModel.getAccount(), requireActivity().getMenuInflater(), this, this, getChildFragmentManager());
         binding.comments.setAdapter(adapter);
 
@@ -85,7 +83,7 @@ public class CardCommentsFragment extends BrandedFragment implements CommentEdit
                 setupMentions(mainViewModel.getAccount(), comment.getComment().getMentions(), binding.replyCommentText);
             }
         });
-        syncManager.getFullCommentsForLocalCardId(mainViewModel.getFullCard().getLocalId()).observe(getViewLifecycleOwner(),
+        commentsViewModel.getFullCommentsForLocalCardId(mainViewModel.getFullCard().getLocalId()).observe(getViewLifecycleOwner(),
                 (comments) -> {
                     if (comments != null && comments.size() > 0) {
                         binding.emptyContentView.setVisibility(GONE);
@@ -109,7 +107,7 @@ public class CardCommentsFragment extends BrandedFragment implements CommentEdit
                         comment.setParentId(parent.getId());
                         commentsViewModel.setReplyToComment(null);
                     }
-                    syncManager.addCommentToCard(mainViewModel.getAccount().getId(), mainViewModel.getFullCard().getLocalId(), comment);
+                    commentsViewModel.addCommentToCard(mainViewModel.getAccount().getId(), mainViewModel.getFullCard().getLocalId(), comment);
                 }
                 binding.message.setText(null);
             });
@@ -137,12 +135,12 @@ public class CardCommentsFragment extends BrandedFragment implements CommentEdit
 
     @Override
     public void onCommentEdited(Long id, String comment) {
-        syncManager.updateComment(mainViewModel.getAccount().getId(), mainViewModel.getFullCard().getLocalId(), id, comment);
+        commentsViewModel.updateComment(mainViewModel.getAccount().getId(), mainViewModel.getFullCard().getLocalId(), id, comment);
     }
 
     @Override
     public void onCommentDeleted(Long localId) {
-        final WrappedLiveData<Void> deleteLiveData = syncManager.deleteComment(mainViewModel.getAccount().getId(), mainViewModel.getFullCard().getLocalId(), localId);
+        final WrappedLiveData<Void> deleteLiveData = commentsViewModel.deleteComment(mainViewModel.getAccount().getId(), mainViewModel.getFullCard().getLocalId(), localId);
         observeOnce(deleteLiveData, this, (next) -> {
             if (deleteLiveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(deleteLiveData.getError())) {
                 ExceptionDialogFragment.newInstance(deleteLiveData.getError(), mainViewModel.getAccount()).show(getChildFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/CommentsViewModel.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/CommentsViewModel.java
index f7fd247a9..dada94d5b 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/CommentsViewModel.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/comments/CommentsViewModel.java
@@ -1,15 +1,30 @@
 package it.niedermann.nextcloud.deck.ui.card.comments;
 
+import android.app.Application;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
-import androidx.lifecycle.ViewModel;
 
+import java.util.List;
+
+import it.niedermann.nextcloud.deck.model.ocs.comment.DeckComment;
 import it.niedermann.nextcloud.deck.model.ocs.comment.full.FullDeckComment;
+import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
+import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.WrappedLiveData;
 
 @SuppressWarnings("WeakerAccess")
-public class CommentsViewModel extends ViewModel {
+public class CommentsViewModel extends AndroidViewModel {
 
-    private MutableLiveData<FullDeckComment> replyToComment = new MutableLiveData<>();
+    private final SyncManager syncManager;
+
+    private final MutableLiveData<FullDeckComment> replyToComment = new MutableLiveData<>();
+
+    public CommentsViewModel(@NonNull Application application) {
+        super(application);
+        this.syncManager = new SyncManager(application);
+    }
 
     public void setReplyToComment(FullDeckComment replyToComment) {
         this.replyToComment.postValue(replyToComment);
@@ -18,4 +33,20 @@ public class CommentsViewModel extends ViewModel {
     public LiveData<FullDeckComment> getReplyToComment() {
         return this.replyToComment;
     }
+
+    public LiveData<List<FullDeckComment>> getFullCommentsForLocalCardId(long localCardId) {
+        return syncManager.getFullCommentsForLocalCardId(localCardId);
+    }
+
+    public void addCommentToCard(long accountId, long cardId, @NonNull DeckComment comment) {
+        syncManager.addCommentToCard(accountId, cardId, comment);
+    }
+
+    public void updateComment(long accountId, long localCardId, long localCommentId, String comment) {
+        syncManager.updateComment(accountId, localCardId, localCommentId, comment);
+    }
+
+    public WrappedLiveData<Void> deleteComment(long accountId, long localCardId, long localCommentId) {
+        return syncManager.deleteComment(accountId, localCardId, localCommentId);
+    }
 }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/details/CardDetailsFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/details/CardDetailsFragment.java
index 70689f1f7..2c697de08 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/details/CardDetailsFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/details/CardDetailsFragment.java
@@ -46,7 +46,6 @@ import it.niedermann.nextcloud.deck.R;
 import it.niedermann.nextcloud.deck.databinding.FragmentCardEditTabDetailsBinding;
 import it.niedermann.nextcloud.deck.model.Label;
 import it.niedermann.nextcloud.deck.model.User;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.WrappedLiveData;
 import it.niedermann.nextcloud.deck.ui.branding.BrandedDatePickerDialog;
 import it.niedermann.nextcloud.deck.ui.branding.BrandedFragment;
@@ -69,7 +68,6 @@ public class CardDetailsFragment extends BrandedFragment implements OnDateSetLis
 
     private FragmentCardEditTabDetailsBinding binding;
     private EditCardViewModel viewModel;
-    private SyncManager syncManager;
     private AssigneeAdapter adapter;
     private final DateTimeFormatter dateFormatter = DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM);
     private final DateTimeFormatter timeFormatter = DateTimeFormatter.ofLocalizedTime(FormatStyle.SHORT);
@@ -94,7 +92,6 @@ public class CardDetailsFragment extends BrandedFragment implements OnDateSetLis
                              ViewGroup container,
                              Bundle savedInstanceState) {
         binding = FragmentCardEditTabDetailsBinding.inflate(inflater, container, false);
-
         viewModel = new ViewModelProvider(activity).get(EditCardViewModel.class);
 
         // This might be a zombie fragment with an empty EditCardViewModel after Android killed the activity (but not the fragment instance
@@ -104,10 +101,7 @@ public class CardDetailsFragment extends BrandedFragment implements OnDateSetLis
             return binding.getRoot();
         }
 
-        syncManager = new SyncManager(requireContext());
-
-        @Px
-        final int avatarSize = DimensionUtil.INSTANCE.dpToPx(requireContext(), R.dimen.avatar_size);
+        @Px final int avatarSize = DimensionUtil.INSTANCE.dpToPx(requireContext(), R.dimen.avatar_size);
         final LinearLayout.LayoutParams avatarLayoutParams = new LinearLayout.LayoutParams(avatarSize, avatarSize);
         avatarLayoutParams.setMargins(0, 0, DimensionUtil.INSTANCE.dpToPx(requireContext(), R.dimen.spacer_1x), 0);
 
@@ -239,7 +233,7 @@ public class CardDetailsFragment extends BrandedFragment implements OnDateSetLis
                     newLabel.setBoardId(boardId);
                     newLabel.setTitle(((LabelAutoCompleteAdapter) binding.labels.getAdapter()).getLastFilterText());
                     newLabel.setLocalId(null);
-                    WrappedLiveData<Label> createLabelLiveData = syncManager.createLabel(accountId, newLabel, boardId);
+                    WrappedLiveData<Label> createLabelLiveData = viewModel.createLabel(accountId, newLabel, boardId);
                     observeOnce(createLabelLiveData, CardDetailsFragment.this, createdLabel -> {
                         if (createLabelLiveData.hasError()) {
                             DeckLog.logError(createLabelLiveData.getError());
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourceAdapter.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourceAdapter.java
index b6747a11c..4c95574c3 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourceAdapter.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourceAdapter.java
@@ -11,20 +11,20 @@ import java.util.ArrayList;
 import java.util.List;
 
 import it.niedermann.nextcloud.deck.databinding.ItemProjectResourceBinding;
-import it.niedermann.nextcloud.deck.model.Account;
 import it.niedermann.nextcloud.deck.model.ocs.projects.OcsProjectResource;
+import it.niedermann.nextcloud.deck.ui.card.EditCardViewModel;
 
 public class CardProjectResourceAdapter extends RecyclerView.Adapter<CardProjectResourceViewHolder> {
 
     @NonNull
-    private final Account account;
+    private final EditCardViewModel viewModel;
     @NonNull
     private final List<OcsProjectResource> resources;
     @NonNull
     private final LifecycleOwner owner;
 
-    public CardProjectResourceAdapter(@NonNull Account account, @NonNull List<OcsProjectResource> resources, @NonNull LifecycleOwner owner) {
-        this.account = account;
+    public CardProjectResourceAdapter(@NonNull EditCardViewModel viewModel, @NonNull List<OcsProjectResource> resources, @NonNull LifecycleOwner owner) {
+        this.viewModel = viewModel;
         this.resources = new ArrayList<>(resources.size());
         this.resources.addAll(resources);
         this.owner = owner;
@@ -44,7 +44,7 @@ public class CardProjectResourceAdapter extends RecyclerView.Adapter<CardProject
 
     @Override
     public void onBindViewHolder(@NonNull CardProjectResourceViewHolder holder, int position) {
-        holder.bind(account, resources.get(position), owner);
+        holder.bind(viewModel, resources.get(position), owner);
     }
 
     @Override
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourceViewHolder.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourceViewHolder.java
index d599ad5b5..272945e45 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourceViewHolder.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourceViewHolder.java
@@ -13,8 +13,8 @@ import it.niedermann.nextcloud.deck.R;
 import it.niedermann.nextcloud.deck.databinding.ItemProjectResourceBinding;
 import it.niedermann.nextcloud.deck.model.Account;
 import it.niedermann.nextcloud.deck.model.ocs.projects.OcsProjectResource;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.card.EditActivity;
+import it.niedermann.nextcloud.deck.ui.card.EditCardViewModel;
 import it.niedermann.nextcloud.deck.util.ProjectUtil;
 
 import static android.view.View.GONE;
@@ -30,12 +30,12 @@ public class CardProjectResourceViewHolder extends RecyclerView.ViewHolder {
         this.binding = binding;
     }
 
-    public void bind(@NonNull Account account, @NonNull OcsProjectResource resource, @NonNull LifecycleOwner owner) {
+    public void bind(@NonNull EditCardViewModel viewModel, @NonNull OcsProjectResource resource, @NonNull LifecycleOwner owner) {
+        final Account account = viewModel.getAccount();
         final Resources resources = itemView.getResources();
         binding.name.setText(resource.getName());
         final @Nullable String link = resource.getLink();
         binding.type.setVisibility(VISIBLE);
-        final SyncManager syncManager = new SyncManager(itemView.getContext());
         if (resource.getType() != null) {
             switch (resource.getType()) {
                 case "deck": {
@@ -49,9 +49,9 @@ public class CardProjectResourceViewHolder extends RecyclerView.ViewHolder {
                     try {
                         long[] ids = ProjectUtil.extractBoardIdAndCardIdFromUrl(link);
                         if (ids.length == 2) {
-                            syncManager.getCardByRemoteID(account.getId(), ids[1]).observe(owner, (fullCard) -> {
+                            viewModel.getCardByRemoteID(account.getId(), ids[1]).observe(owner, (fullCard) -> {
                                 if (fullCard != null) {
-                                    syncManager.getBoardByRemoteId(account.getId(), ids[0]).observe(owner, (board) -> {
+                                    viewModel.getBoardByRemoteId(account.getId(), ids[0]).observe(owner, (board) -> {
                                         if (board != null) {
                                             binding.getRoot().setOnClickListener((v) -> itemView.getContext().startActivity(EditActivity.createEditCardIntent(itemView.getContext(), account, board.getLocalId(), fullCard.getLocalId())));
                                         } else {
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourcesDialog.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourcesDialog.java
index 9dc056634..46195b309 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourcesDialog.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/card/projectresources/CardProjectResourcesDialog.java
@@ -62,7 +62,7 @@ public class CardProjectResourcesDialog extends BrandedDialogFragment {
 
     @Override
     public void onActivityCreated(@Nullable Bundle savedInstanceState) {
-        final CardProjectResourceAdapter adapter = new CardProjectResourceAdapter(viewModel.getAccount(), resources, requireActivity());
+        final CardProjectResourceAdapter adapter = new CardProjectResourceAdapter(viewModel, resources, requireActivity());
         binding.getRoot().setAdapter(adapter);
         super.onActivityCreated(savedInstanceState);
     }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterLabelsFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterLabelsFragment.java
index fadf33b88..e7d693185 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterLabelsFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterLabelsFragment.java
@@ -12,7 +12,6 @@ import androidx.lifecycle.ViewModelProvider;
 
 import it.niedermann.nextcloud.deck.databinding.DialogFilterLabelsBinding;
 import it.niedermann.nextcloud.deck.model.Label;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.MainViewModel;
 
 import static it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.LiveDataHelper.observeOnce;
@@ -31,7 +30,7 @@ public class FilterLabelsFragment extends Fragment implements SelectionListener<
 
         filterViewModel = new ViewModelProvider(requireActivity()).get(FilterViewModel.class);
 
-        observeOnce(new SyncManager(requireContext()).findProposalsForLabelsToAssign(mainViewModel.getCurrentAccount().getId(), mainViewModel.getCurrentBoardLocalId()), requireActivity(), (labels) -> {
+        observeOnce(filterViewModel.findProposalsForLabelsToAssign(mainViewModel.getCurrentAccount().getId(), mainViewModel.getCurrentBoardLocalId()), requireActivity(), (labels) -> {
             binding.labels.setNestedScrollingEnabled(false);
             binding.labels.setAdapter(new FilterLabelsAdapter(
                     labels,
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterUserFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterUserFragment.java
index ffd558b65..6ffaec6a6 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterUserFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterUserFragment.java
@@ -14,7 +14,6 @@ import it.niedermann.android.util.DimensionUtil;
 import it.niedermann.nextcloud.deck.R;
 import it.niedermann.nextcloud.deck.databinding.DialogFilterAssigneesBinding;
 import it.niedermann.nextcloud.deck.model.User;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.MainViewModel;
 
 import static it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.LiveDataHelper.observeOnce;
@@ -33,7 +32,7 @@ public class FilterUserFragment extends Fragment implements SelectionListener<Us
 
         filterViewModel = new ViewModelProvider(requireActivity()).get(FilterViewModel.class);
 
-        observeOnce(new SyncManager(requireContext()).findProposalsForUsersToAssign(mainViewModel.getCurrentAccount().getId(), mainViewModel.getCurrentBoardLocalId()), requireActivity(), (users) -> {
+        observeOnce(filterViewModel.findProposalsForUsersToAssign(mainViewModel.getCurrentAccount().getId(), mainViewModel.getCurrentBoardLocalId()), requireActivity(), (users) -> {
             binding.users.setNestedScrollingEnabled(false);
             binding.users.setAdapter(new FilterUserAdapter(
                     DimensionUtil.INSTANCE.dpToPx(requireContext(), R.dimen.avatar_size),
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterViewModel.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterViewModel.java
index 50f287d62..c42a61ebd 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterViewModel.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/filter/FilterViewModel.java
@@ -1,28 +1,40 @@
 package it.niedermann.nextcloud.deck.ui.filter;
 
+import android.app.Application;
+
 import androidx.annotation.IntRange;
 import androidx.annotation.NonNull;
+import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
-import androidx.lifecycle.ViewModel;
+
+import java.util.List;
 
 import it.niedermann.nextcloud.deck.model.Label;
 import it.niedermann.nextcloud.deck.model.User;
 import it.niedermann.nextcloud.deck.model.enums.EDueType;
 import it.niedermann.nextcloud.deck.model.internal.FilterInformation;
+import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 
 import static it.niedermann.nextcloud.deck.model.internal.FilterInformation.hasActiveFilter;
 
 @SuppressWarnings("WeakerAccess")
-public class FilterViewModel extends ViewModel {
+public class FilterViewModel extends AndroidViewModel {
+
+    private final SyncManager syncManager;
 
     @IntRange(from = 0, to = 2)
     private int currentFilterTab = 0;
 
     @NonNull
-    private MutableLiveData<FilterInformation> filterInformationDraft = new MutableLiveData<>(new FilterInformation());
+    private final MutableLiveData<FilterInformation> filterInformationDraft = new MutableLiveData<>(new FilterInformation());
     @NonNull
-    private MutableLiveData<FilterInformation> filterInformation = new MutableLiveData<>();
+    private final MutableLiveData<FilterInformation> filterInformation = new MutableLiveData<>();
+
+    public FilterViewModel(@NonNull Application application) {
+        super(application);
+        this.syncManager = new SyncManager(application);
+    }
 
     public void publishFilterInformationDraft() {
         this.filterInformation.postValue(hasActiveFilter(filterInformationDraft.getValue()) ? filterInformationDraft.getValue() : null);
@@ -98,4 +110,12 @@ public class FilterViewModel extends ViewModel {
     public int getCurrentFilterTab() {
         return this.currentFilterTab;
     }
+
+    public LiveData<List<User>> findProposalsForUsersToAssign(final long accountId, long boardId) {
+        return syncManager.findProposalsForUsersToAssign(accountId, boardId, -1L, -1);
+    }
+
+    public LiveData<List<Label>> findProposalsForLabelsToAssign(final long accountId, final long boardId) {
+        return syncManager.findProposalsForLabelsToAssign(accountId, boardId, -1L);
+    }
 }
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/manageaccounts/ManageAccountsActivity.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/manageaccounts/ManageAccountsActivity.java
index 9d273cdcb..8aa45e39a 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/manageaccounts/ManageAccountsActivity.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/manageaccounts/ManageAccountsActivity.java
@@ -5,15 +5,12 @@ import android.util.Log;
 
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AppCompatActivity;
-
-import com.nextcloud.android.sso.helper.SingleAccountHelper;
+import androidx.lifecycle.ViewModelProvider;
 
 import it.niedermann.nextcloud.deck.databinding.ActivityManageAccountsBinding;
 import it.niedermann.nextcloud.deck.model.Account;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 
 import static it.niedermann.nextcloud.deck.DeckApplication.readCurrentAccountId;
-import static it.niedermann.nextcloud.deck.DeckApplication.saveCurrentAccountId;
 import static it.niedermann.nextcloud.deck.persistence.sync.adapters.db.util.LiveDataHelper.observeOnce;
 
 public class ManageAccountsActivity extends AppCompatActivity {
@@ -21,44 +18,37 @@ public class ManageAccountsActivity extends AppCompatActivity {
     private static final String TAG = ManageAccountsActivity.class.getSimpleName();
 
     private ActivityManageAccountsBinding binding;
+    private ManageAccountsViewModel viewModel;
     private ManageAccountAdapter adapter;
-    private SyncManager syncManager = null;
 
     @Override
     public void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
         binding = ActivityManageAccountsBinding.inflate(getLayoutInflater());
-        setContentView(binding.getRoot());
+        viewModel = new ViewModelProvider(this).get(ManageAccountsViewModel.class);
 
+        setContentView(binding.getRoot());
         setSupportActionBar(binding.toolbar);
 
-        syncManager = new SyncManager(this);
-
-        adapter = new ManageAccountAdapter((account) -> {
-            SingleAccountHelper.setCurrentAccount(getApplicationContext(), account.getName());
-            syncManager = new SyncManager(this);
-            saveCurrentAccountId(this, account.getId());
-        }, (accountPair) -> {
+        adapter = new ManageAccountAdapter((account) -> viewModel.setNewAccount(account), (accountPair) -> {
             if (accountPair.first != null) {
-                syncManager.deleteAccount(accountPair.first.getId());
+                viewModel.deleteAccount(accountPair.first.getId());
             } else {
                 throw new IllegalArgumentException("Could not delete account because given account was null.");
             }
             Account newAccount = accountPair.second;
             if (newAccount != null) {
-                SingleAccountHelper.setCurrentAccount(getApplicationContext(), newAccount.getName());
-                saveCurrentAccountId(this, newAccount.getId());
-                syncManager = new SyncManager(this);
+                viewModel.setNewAccount(newAccount);
             } else {
                 Log.i(TAG, "Got delete account request, but new account is null. Maybe last account has been deleted?");
             }
         });
         binding.accounts.setAdapter(adapter);
 
-        observeOnce(syncManager.readAccount(readCurrentAccountId(this)), this, (account -> {
+        observeOnce(viewModel.readAccount(readCurrentAccountId(this)), this, (account -> {
             adapter.setCurrentAccount(account);
-            syncManager.readAccounts().observe(this, (localAccounts -> {
+            viewModel.readAccounts().observe(this, (localAccounts -> {
                 if (localAccounts.size() == 0) {
                     Log.i(TAG, "No accounts, finishing " + ManageAccountsActivity.class.getSimpleName());
                     setResult(AppCompatActivity.RESULT_FIRST_USER);
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/manageaccounts/ManageAccountsViewModel.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/manageaccounts/ManageAccountsViewModel.java
new file mode 100644
index 000000000..66e9d3850
--- /dev/null
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/manageaccounts/ManageAccountsViewModel.java
@@ -0,0 +1,45 @@
+package it.niedermann.nextcloud.deck.ui.manageaccounts;
+
+import android.app.Application;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+
+import com.nextcloud.android.sso.helper.SingleAccountHelper;
+
+import java.util.List;
+
+import it.niedermann.nextcloud.deck.model.Account;
+import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
+
+import static it.niedermann.nextcloud.deck.DeckApplication.saveCurrentAccountId;
+
+@SuppressWarnings("WeakerAccess")
+public class ManageAccountsViewModel extends AndroidViewModel {
+
+    private SyncManager syncManager;
+
+    public ManageAccountsViewModel(@NonNull Application application) {
+        super(application);
+        this.syncManager = new SyncManager(application);
+    }
+
+    public LiveData<Account> readAccount(long id) {
+        return syncManager.readAccount(id);
+    }
+
+    public LiveData<List<Account>> readAccounts() {
+        return syncManager.readAccounts();
+    }
+
+    public void setNewAccount(@NonNull Account account) {
+        SingleAccountHelper.setCurrentAccount(getApplication(), account.getName());
+        syncManager = new SyncManager(getApplication());
+        saveCurrentAccountId(getApplication(), account.getId());
+    }
+
+    public void deleteAccount(long id) {
+        syncManager.deleteAccount(id);
+    }
+}
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/movecard/MoveCardDialogFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/movecard/MoveCardDialogFragment.java
index b14b60a7a..2b7eb52fe 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/movecard/MoveCardDialogFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/movecard/MoveCardDialogFragment.java
@@ -21,6 +21,7 @@ import it.niedermann.nextcloud.deck.ui.branding.BrandedDialogFragment;
 import it.niedermann.nextcloud.deck.ui.branding.BrandingUtil;
 import it.niedermann.nextcloud.deck.ui.pickstack.PickStackFragment;
 import it.niedermann.nextcloud.deck.ui.pickstack.PickStackListener;
+import it.niedermann.nextcloud.deck.ui.pickstack.PickStackViewModel;
 
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
@@ -37,6 +38,7 @@ public class MoveCardDialogFragment extends BrandedDialogFragment implements Pic
     private Long originCardLocalId;
 
     private DialogMoveCardBinding binding;
+    private PickStackViewModel viewModel;
     private MoveCardListener moveCardListener;
 
     private Account selectedAccount;
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/pickstack/PickStackFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/pickstack/PickStackFragment.java
index 8e0d7179a..d65971cf4 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/pickstack/PickStackFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/pickstack/PickStackFragment.java
@@ -13,6 +13,7 @@ import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.Observer;
+import androidx.lifecycle.ViewModelProvider;
 
 import java.util.List;
 
@@ -20,7 +21,6 @@ import it.niedermann.nextcloud.deck.databinding.FragmentPickStackBinding;
 import it.niedermann.nextcloud.deck.model.Account;
 import it.niedermann.nextcloud.deck.model.Board;
 import it.niedermann.nextcloud.deck.model.Stack;
-import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
 import it.niedermann.nextcloud.deck.ui.ImportAccountActivity;
 import it.niedermann.nextcloud.deck.ui.preparecreate.AccountAdapter;
 import it.niedermann.nextcloud.deck.ui.preparecreate.BoardAdapter;
@@ -35,11 +35,10 @@ import static it.niedermann.nextcloud.deck.DeckApplication.readCurrentStackId;
 public class PickStackFragment extends Fragment {
 
     private FragmentPickStackBinding binding;
+    private PickStackViewModel viewModel;
 
     private static final String KEY_SHOW_BOARDS_WITHOUT_EDIT_PERMISSION = "show_boards_without_edit_permission";
 
-    private SyncManager syncManager;
-
     private PickStackListener pickStackListener;
 
     private boolean showBoardsWithoutEditPermission = false;
@@ -127,6 +126,7 @@ public class PickStackFragment extends Fragment {
         super.onCreate(savedInstanceState);
 
         binding = FragmentPickStackBinding.inflate(getLayoutInflater());
+        viewModel = new ViewModelProvider(requireActivity()).get(PickStackViewModel.class);
 
         accountAdapter = new AccountAdapter(requireContext());
         binding.accountSelect.setAdapter(accountAdapter);
@@ -138,11 +138,9 @@ public class PickStackFragment extends Fragment {
         binding.stackSelect.setAdapter(stackAdapter);
         binding.stackSelect.setEnabled(false);
 
-        syncManager = new SyncManager(requireContext());
-
-        switchMap(syncManager.hasAccounts(), hasAccounts -> {
+        switchMap(viewModel.hasAccounts(), hasAccounts -> {
             if (hasAccounts) {
-                return syncManager.readAccounts();
+                return viewModel.readAccounts();
             } else {
                 startActivityForResult(new Intent(requireActivity(), ImportAccountActivity.class), ImportAccountActivity.REQUEST_CODE_IMPORT_ACCOUNT);
                 return null;
@@ -170,12 +168,12 @@ public class PickStackFragment extends Fragment {
 
         binding.accountSelect.setOnItemSelectedListener((SelectedListener) (parent, view, position, id) -> {
             updateLiveDataSource(boardsLiveData, boardsObserver, showBoardsWithoutEditPermission
-                    ? syncManager.getBoards(parent.getSelectedItemId())
-                    : syncManager.getBoardsWithEditPermission(parent.getSelectedItemId()));
+                    ? viewModel.getBoards(parent.getSelectedItemId())
+                    : viewModel.getBoardsWithEditPermission(parent.getSelectedItemId()));
         });
 
         binding.boardSelect.setOnItemSelectedListener((SelectedListener) (parent, view, position, id) -> {
-            updateLiveDataSource(stacksLiveData, stacksObserver, syncManager.getStacksForBoard(binding.accountSelect.getSelectedItemId(), parent.getSelectedItemId()));
+            updateLiveDataSource(stacksLiveData, stacksObserver, viewModel.getStacksForBoard(binding.accountSelect.getSelectedItemId(), parent.getSelectedItemId()));
         });
 
         binding.stackSelect.setOnItemSelectedListener((SelectedListener) (parent, view, position, id) -> {
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/pickstack/PickStackViewModel.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/pickstack/PickStackViewModel.java
new file mode 100644
index 000000000..cc9fc2259
--- /dev/null
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/pickstack/PickStackViewModel.java
@@ -0,0 +1,45 @@
+package it.niedermann.nextcloud.deck.ui.pickstack;
+
+import android.app.Application;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+
+import java.util.List;
+
+import it.niedermann.nextcloud.deck.model.Account;
+import it.niedermann.nextcloud.deck.model.Board;
+import it.niedermann.nextcloud.deck.model.Stack;
+import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
+
+@SuppressWarnings("WeakerAccess")
+public class PickStackViewModel extends AndroidViewModel {
+
+    private final SyncManager syncManager;
+
+    public PickStackViewModel(@NonNull Application application) {
+        super(application);
+        this.syncManager = new SyncManager(application);
+    }
+
+    public LiveData<Boolean> hasAccounts() {
+        return syncManager.hasAccounts();
+    }
+
+    public LiveData<List<Account>> readAccounts() {
+        return syncManager.readAccounts();
+    }
+
+    public LiveData<List<Board>> getBoards(long accountId) {
+        return syncManager.getBoards(accountId);
+    }
+
+    public LiveData<List<Board>> getBoardsWithEditPermission(long accountId) {
+        return syncManager.getBoardsWithEditPermission(accountId);
+    }
+
+    public LiveData<List<Stack>> getStacksForBoard(long accountId, long localBoardId) {
+        return syncManager.getStacksForBoard(accountId, localBoardId);
+    }
+}
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackAdapter.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackAdapter.java
index 4fe61794a..8fc56759f 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackAdapter.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackAdapter.java
@@ -12,7 +12,7 @@ import it.niedermann.nextcloud.deck.model.Stack;
 
 public class StackAdapter extends FragmentStateAdapter {
     @NonNull
-    private List<Stack> stackList = new ArrayList<>();
+    private final List<Stack> stackList = new ArrayList<>();
 
     public StackAdapter(@NonNull FragmentActivity fragmentActivity) {
         super(fragmentActivity);
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackFragment.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackFragment.java
index 7b0d2f20f..313e6e821 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackFragment.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackFragment.java
@@ -40,7 +40,7 @@ public class StackFragment extends BrandedFragment implements DragAndDropTab<Car
     private static final String KEY_STACK_ID = "stackId";
 
     private FragmentStackBinding binding;
-    private SyncManager syncManager;
+    private MainViewModel mainViewModel;
     private FragmentActivity activity;
     private OnScrollListener onScrollListener;
 
@@ -68,10 +68,10 @@ public class StackFragment extends BrandedFragment implements DragAndDropTab<Car
 
     @Override
     public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        binding = FragmentStackBinding.inflate(inflater, container, false);
         activity = requireActivity();
+        binding = FragmentStackBinding.inflate(inflater, container, false);
+        mainViewModel = new ViewModelProvider(activity).get(MainViewModel.class);
 
-        final MainViewModel mainViewModel = new ViewModelProvider(activity).get(MainViewModel.class);
         final FilterViewModel filterViewModel = new ViewModelProvider(activity).get(FilterViewModel.class);
 
         // This might be a zombie fragment with an empty MainViewModel after Android killed the activity (but not the fragment instance
@@ -81,19 +81,10 @@ public class StackFragment extends BrandedFragment implements DragAndDropTab<Car
             return binding.getRoot();
         }
 
-        syncManager = new SyncManager(activity);
-
-        adapter = new CardAdapter(
-                requireContext(),
-                getChildFragmentManager(),
-                mainViewModel.getCurrentAccount(),
-                mainViewModel.getCurrentBoardLocalId(),
-                mainViewModel.getCurrentBoardRemoteId(),
-                stackId,
-                mainViewModel.currentBoardHasEditPermission(),
-                syncManager,
-                this,
-                (requireActivity() instanceof SelectCardListener) ? (SelectCardListener) requireActivity() : null);
+        adapter = new CardAdapter(requireContext(), getChildFragmentManager(), stackId, mainViewModel, this,
+                (requireActivity() instanceof SelectCardListener)
+                        ? (SelectCardListener) requireActivity()
+                        : null);
         binding.recyclerView.setAdapter(adapter);
 
         if (onScrollListener != null) {
@@ -121,12 +112,12 @@ public class StackFragment extends BrandedFragment implements DragAndDropTab<Car
             }
         });
 
-        cardsLiveData = syncManager.getFullCardsForStack(mainViewModel.getCurrentAccount().getId(), stackId, filterViewModel.getFilterInformation().getValue());
+        cardsLiveData = mainViewModel.getFullCardsForStack(mainViewModel.getCurrentAccount().getId(), stackId, filterViewModel.getFilterInformation().getValue());
         cardsLiveData.observe(getViewLifecycleOwner(), cardsObserver);
 
         filterViewModel.getFilterInformation().observe(getViewLifecycleOwner(), (filterInformation -> {
             cardsLiveData.removeObserver(cardsObserver);
-            cardsLiveData = syncManager.getFullCardsForStack(mainViewModel.getCurrentAccount().getId(), stackId, filterInformation);
+            cardsLiveData = mainViewModel.getFullCardsForStack(mainViewModel.getCurrentAccount().getId(), stackId, filterInformation);
             cardsLiveData.observe(getViewLifecycleOwner(), cardsObserver);
         }));
 
@@ -163,7 +154,7 @@ public class StackFragment extends BrandedFragment implements DragAndDropTab<Car
 
     @Override
     public void move(long originAccountId, long originCardLocalId, long targetAccountId, long targetBoardLocalId, long targetStackLocalId) {
-        WrappedLiveData<Void> liveData = syncManager.moveCard(originAccountId, originCardLocalId, targetAccountId, targetBoardLocalId, targetStackLocalId);
+        final WrappedLiveData<Void> liveData = mainViewModel.moveCard(originAccountId, originCardLocalId, targetAccountId, targetBoardLocalId, targetStackLocalId);
         observeOnce(liveData, requireActivity(), (next) -> {
             if (liveData.hasError() && !SyncManager.ignoreExceptionOnVoidError(liveData.getError())) {
                 ExceptionDialogFragment.newInstance(liveData.getError(), null).show(getChildFragmentManager(), ExceptionDialogFragment.class.getSimpleName());
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/widget/stack/StackWidgetConfigurationActivity.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/widget/stack/StackWidgetConfigurationActivity.java
index 771feabc2..96b5cf672 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/widget/stack/StackWidgetConfigurationActivity.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/widget/stack/StackWidgetConfigurationActivity.java
@@ -5,6 +5,7 @@ import android.content.Intent;
 import android.os.Bundle;
 
 import androidx.appcompat.app.ActionBar;
+import androidx.lifecycle.ViewModelProvider;
 
 import it.niedermann.nextcloud.deck.DeckLog;
 import it.niedermann.nextcloud.deck.R;
@@ -13,10 +14,14 @@ import it.niedermann.nextcloud.deck.ui.PickStackActivity;
 
 public class StackWidgetConfigurationActivity extends PickStackActivity {
     private int appWidgetId;
+    private StackWidgetConfigurationViewModel stackWidgetConfigurationViewModel;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+
+        stackWidgetConfigurationViewModel = new ViewModelProvider(this).get(StackWidgetConfigurationViewModel.class);
+
         final ActionBar actionBar = getSupportActionBar();
         if (actionBar != null) {
             actionBar.setTitle(R.string.add_stack_widget);
@@ -40,9 +45,9 @@ public class StackWidgetConfigurationActivity extends PickStackActivity {
     protected void onSubmit(Account account, long boardId, long stackId) {
         final Bundle extras = new Bundle();
 
-        syncManager.addStackWidget(appWidgetId, account.getId(), stackId, false);
+        stackWidgetConfigurationViewModel.addStackWidget(appWidgetId, account.getId(), stackId, false);
         Intent updateIntent = new Intent(AppWidgetManager.ACTION_APPWIDGET_UPDATE, null,
-                                    getApplicationContext(), StackWidget.class);
+                getApplicationContext(), StackWidget.class);
         extras.putSerializable(StackWidget.ACCOUNT_KEY, account);
         extras.putInt(AppWidgetManager.EXTRA_APPWIDGET_ID, appWidgetId);
 
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/widget/stack/StackWidgetConfigurationViewModel.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/widget/stack/StackWidgetConfigurationViewModel.java
new file mode 100644
index 000000000..cc669accf
--- /dev/null
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/widget/stack/StackWidgetConfigurationViewModel.java
@@ -0,0 +1,23 @@
+package it.niedermann.nextcloud.deck.ui.widget.stack;
+
+import android.app.Application;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.AndroidViewModel;
+
+import it.niedermann.nextcloud.deck.persistence.sync.SyncManager;
+
+@SuppressWarnings("WeakerAccess")
+public class StackWidgetConfigurationViewModel extends AndroidViewModel {
+
+    private final SyncManager syncManager;
+
+    public StackWidgetConfigurationViewModel(@NonNull Application application) {
+        super(application);
+        this.syncManager = new SyncManager(application);
+    }
+
+    public void addStackWidget(int appWidgetId, long accountId, long stackId, boolean darkTheme) {
+        syncManager.addStackWidget(appWidgetId, accountId, stackId, darkTheme);
+    }
+}