redirect from main to setup on zero accounts

app/src/main/AndroidManifest.xml

@@ -94,6 +94,7 @@
         <activity
             android:name="im.conversations.android.ui.activity.MainActivity"
             android:windowSoftInputMode="adjustResize"
+            android:launchMode="singleTask"
             android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

app/src/main/java/im/conversations/android/database/dao/AccountDao.java

@@ -18,6 +18,9 @@ public interface AccountDao {
     @Query("SELECT EXISTS (SELECT id FROM account WHERE address=:address)")
     boolean hasAccount(BareJid address);
 
+    @Query("SELECT NOT EXISTS (SELECT id FROM account)")
+    LiveData<Boolean> hasNoAccounts();
+
     @Insert
     long insert(final AccountEntity account);
 

app/src/main/java/im/conversations/android/repository/AccountRepository.java

@@ -114,6 +114,10 @@ public class AccountRepository extends AbstractRepository {
         return database.accountDao().getAccounts();
     }
 
+    public LiveData<Boolean> hasNoAccounts() {
+        return database.accountDao().hasNoAccounts();
+    }
+
     public static class AccountAlreadyExistsException extends IllegalStateException {
         public AccountAlreadyExistsException(BareJid address) {
             super(String.format("The account %s has already been setup", address));

app/src/main/java/im/conversations/android/ui/activity/MainActivity.java

@@ -1,11 +1,17 @@
 package im.conversations.android.ui.activity;
 
+import android.content.Intent;
 import android.os.Bundle;
 import androidx.databinding.DataBindingUtil;
+import androidx.lifecycle.Observer;
+import androidx.lifecycle.ViewModelProvider;
+
 import im.conversations.android.R;
 import im.conversations.android.databinding.ActivityMainBinding;
 import im.conversations.android.service.ForegroundService;
 import im.conversations.android.ui.Activities;
+import im.conversations.android.ui.model.MainViewModel;
+import im.conversations.android.ui.model.SetupViewModel;
 
 public class MainActivity extends BaseActivity {
 
@@ -15,6 +21,15 @@ public class MainActivity extends BaseActivity {
         ForegroundService.start(this);
         final ActivityMainBinding binding =
                 DataBindingUtil.setContentView(this, R.layout.activity_main);
+        final ViewModelProvider viewModelProvider =
+                new ViewModelProvider(this, getDefaultViewModelProviderFactory());
+        final var mainViewModel = viewModelProvider.get(MainViewModel.class);
+        mainViewModel.hasNoAccounts().observe(this, hasNoAccounts -> {
+            if (Boolean.TRUE.equals(hasNoAccounts)) {
+                startActivity(new Intent(this,SetupActivity.class));
+                finish();
+            }
+        });
         Activities.setStatusAndNavigationBarColors(this, binding.getRoot());
     }
 }

app/src/main/java/im/conversations/android/ui/model/MainViewModel.java

@@ -0,0 +1,26 @@
+package im.conversations.android.ui.model;
+
+import android.app.Application;
+
+import androidx.annotation.NonNull;
+import androidx.lifecycle.AndroidViewModel;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.Transformations;
+
+import im.conversations.android.repository.AccountRepository;
+
+public class MainViewModel extends AndroidViewModel {
+
+    private final AccountRepository accountRepository;
+    private final LiveData<Boolean> hasNoAccounts;
+
+    public MainViewModel(@NonNull Application application) {
+        super(application);
+        this.accountRepository = new AccountRepository(application);
+        this.hasNoAccounts = this.accountRepository.hasNoAccounts();
+    }
+
+    public LiveData<Boolean> hasNoAccounts() {
+        return Transformations.distinctUntilChanged(this.hasNoAccounts);
+    }
+}