Is this a good idea?

app/src/main/java/eu/faircode/email/ActivitySetup.java

@@ -125,6 +125,7 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
     private boolean hasAccount;
     private String password;
     private boolean import_accounts;
+    private boolean import_delete;
     private boolean import_rules;
     private boolean import_contacts;
     private boolean import_answers;
@@ -337,6 +338,7 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
             drawerToggle.setDrawerIndicatorEnabled(savedInstanceState.getBoolean("fair:toggle"));
             password = savedInstanceState.getString("fair:password");
             import_accounts = savedInstanceState.getBoolean("fair:import_accounts");
+            import_delete = savedInstanceState.getBoolean("fair:import_delete");
             import_rules = savedInstanceState.getBoolean("fair:import_rules");
             import_contacts = savedInstanceState.getBoolean("fair:import_contacts");
             import_answers = savedInstanceState.getBoolean("fair:import_answers");
@@ -358,6 +360,7 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
         outState.putBoolean("fair:toggle", drawerToggle.isDrawerIndicatorEnabled());
         outState.putString("fair:password", password);
         outState.putBoolean("fair:import_accounts", import_accounts);
+        outState.putBoolean("fair:import_delete", import_delete);
         outState.putBoolean("fair:import_rules", import_rules);
         outState.putBoolean("fair:import_contacts", import_contacts);
         outState.putBoolean("fair:import_answers", import_answers);
@@ -807,6 +810,7 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
         args.putParcelable("uri", uri);
         args.putString("password", this.password);
         args.putBoolean("import_accounts", this.import_accounts);
+        args.putBoolean("import_delete", this.import_delete);
         args.putBoolean("import_rules", this.import_rules);
         args.putBoolean("import_contacts", this.import_contacts);
         args.putBoolean("import_answers", this.import_answers);
@@ -831,12 +835,14 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
                 Uri uri = args.getParcelable("uri");
                 String password = args.getString("password");
                 boolean import_accounts = args.getBoolean("import_accounts");
+                boolean import_delete = args.getBoolean("import_delete");
                 boolean import_rules = args.getBoolean("import_rules");
                 boolean import_contacts = args.getBoolean("import_contacts");
                 boolean import_answers = args.getBoolean("import_answers");
                 boolean import_settings = args.getBoolean("import_settings");
                 EntityLog.log(context, "Importing " + uri +
                         " accounts=" + import_accounts +
+                        " delete=" + import_delete +
                         " rules=" + import_rules +
                         " contacts=" + import_contacts +
                         " answers=" + import_answers +
@@ -928,6 +934,12 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
                             EntityAccount account = EntityAccount.fromJSON(jaccount);
                             postProgress(context.getString(R.string.title_importing_account, account.name));
 
+                            if (import_delete) {
+                                EntityAccount delete = db.account().getAccount(account.auth_type, account.user);
+                                if (delete != null)
+                                    db.account().deleteAccount(delete.id);
+                            }
+
                             EntityAccount existing = db.account().getAccountByUUID(account.uuid);
                             if (existing != null) {
                                 SpannableStringBuilder ssb = new SpannableStringBuilder();
@@ -1718,6 +1730,7 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
             View dview = LayoutInflater.from(context).inflate(R.layout.dialog_import, null);
             etPassword1 = dview.findViewById(R.id.tilPassword1);
             CheckBox cbAccounts = dview.findViewById(R.id.cbAccounts);
+            CheckBox cbDelete = dview.findViewById(R.id.cbDelete);
             CheckBox cbRules = dview.findViewById(R.id.cbRules);
             CheckBox cbContacts = dview.findViewById(R.id.cbContacts);
             CheckBox cbAnswers = dview.findViewById(R.id.cbAnswers);
@@ -1750,6 +1763,7 @@ public class ActivitySetup extends ActivityBase implements FragmentManager.OnBac
                                 ActivitySetup activity = (ActivitySetup) getActivity();
                                 activity.password = password1;
                                 activity.import_accounts = cbAccounts.isChecked();
+                                activity.import_delete = cbDelete.isChecked();
                                 activity.import_rules = cbRules.isChecked();
                                 activity.import_contacts = cbContacts.isChecked();
                                 activity.import_answers = cbAnswers.isChecked();

app/src/main/java/eu/faircode/email/DaoAccount.java

@@ -147,6 +147,9 @@ public interface DaoAccount {
     @Query("SELECT * FROM account WHERE uuid = :uuid")
     EntityAccount getAccountByUUID(String uuid);
 
+    @Query("SELECT * FROM account WHERE auth_type = :auth_type AND user = :user")
+    EntityAccount getAccount(int auth_type, String user);
+
     @Query("SELECT * FROM account WHERE name = :name")
     EntityAccount getAccount(String name);
 

app/src/main/res/layout/dialog_import.xml

@@ -68,6 +68,17 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@id/cbAccounts" />
 
+        <CheckBox
+            android:id="@+id/cbDelete"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginStart="24dp"
+            android:layout_marginTop="12dp"
+            android:text="@string/title_setup_import_delete"
+            android:visibility="gone"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@id/tvImportHint" />
+
         <CheckBox
             android:id="@+id/cbRules"
             android:layout_width="wrap_content"
@@ -77,7 +88,7 @@
             android:checked="true"
             android:text="@string/title_setup_import_contacts"
             app:layout_constraintStart_toStartOf="parent"
-            app:layout_constraintTop_toBottomOf="@id/tvImportHint" />
+            app:layout_constraintTop_toBottomOf="@id/cbDelete" />
 
         <CheckBox
             android:id="@+id/cbContacts"

app/src/main/res/values/strings.xml

@@ -262,6 +262,7 @@
     <string name="title_setup_password_different">Passwords don\'t match</string>
     <string name="title_setup_password_invalid">Password invalid</string>
     <string name="title_setup_import_accounts">Import accounts and identities</string>
+    <string name="title_setup_import_delete" translatable="false">Delete existing accounts</string>
     <string name="title_setup_import_rules">Import filter rules</string>
     <string name="title_setup_import_contacts">Import local contacts</string>
     <string name="title_setup_import_answers">Import reply templates</string>