prevent using same wallet name as existing (#391)

* Add wallet name validation

lib/src/screens/new_wallet/new_wallet_page.dart

@@ -7,7 +7,7 @@ import 'package:flutter_mobx/flutter_mobx.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:cake_wallet/generated/i18n.dart';
-import 'package:cake_wallet/core/validator.dart';
+import 'package:cake_wallet/core/wallet_name_validator.dart';
 import 'package:cake_wallet/src/widgets/seed_language_selector.dart';
 import 'package:cake_wallet/src/screens/base_page.dart';
 import 'package:cake_wallet/src/widgets/primary_button.dart';
@@ -218,10 +218,21 @@ class _WalletNameFormState extends State<WalletNameForm> {
     if (!_formKey.currentState.validate()) {
       return;
     }
-
-    _walletNewVM.create(
-        options: _walletNewVM.hasLanguageSelector
-            ? _languageSelectorKey.currentState.selected
-            : null);
+    if (_walletNewVM.nameExists(_walletNewVM.name)) {
+      showPopUp<void>(
+          context: context,
+          builder: (_) {
+            return AlertWithOneAction(
+                alertTitle: '',
+                alertContent: S.of(context).wallet_name_exists,
+                buttonText: S.of(context).ok,
+                buttonAction: () => Navigator.of(context).pop());
+          });
+    } else {
+      _walletNewVM.create(
+          options: _walletNewVM.hasLanguageSelector
+              ? _languageSelectorKey.currentState.selected
+              : null);
+    }
   }
 }

lib/src/screens/restore/restore_wallet_from_keys_page.dart

@@ -1,4 +1,4 @@
-import 'package:cake_wallet/core/validator.dart';
+import 'package:cake_wallet/core/wallet_name_validator.dart';
 import 'package:cake_wallet/palette.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/cupertino.dart';

lib/src/screens/restore/restore_wallet_from_seed_details.dart

@@ -3,7 +3,7 @@ import 'package:mobx/mobx.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_mobx/flutter_mobx.dart';
 import 'package:cake_wallet/generated/i18n.dart';
-import 'package:cake_wallet/core/validator.dart';
+import 'package:cake_wallet/core/wallet_name_validator.dart';
 import 'package:cake_wallet/core/execution_state.dart';
 import 'package:cake_wallet/src/screens/base_page.dart';
 import 'package:cake_wallet/src/widgets/blockchain_height_widget.dart';

lib/src/screens/restore/wallet_restore_from_keys_form.dart

@@ -8,7 +8,7 @@ import 'package:cake_wallet/src/widgets/blockchain_height_widget.dart';
 import 'package:cake_wallet/src/widgets/base_text_form_field.dart';
 import 'package:cake_wallet/src/widgets/base_text_form_field.dart';
 import 'package:cake_wallet/generated/i18n.dart';
-import 'package:cake_wallet/core/validator.dart';
+import 'package:cake_wallet/core/wallet_name_validator.dart';
 import 'package:cake_wallet/entities/generate_name.dart';
 
 class WalletRestoreFromKeysFrom extends StatefulWidget {

lib/src/screens/restore/wallet_restore_from_seed_form.dart

@@ -10,7 +10,7 @@ import 'package:cake_wallet/src/widgets/base_text_form_field.dart';
 import 'package:cake_wallet/src/widgets/blockchain_height_widget.dart';
 import 'package:cake_wallet/src/widgets/base_text_form_field.dart';
 import 'package:cake_wallet/generated/i18n.dart';
-import 'package:cake_wallet/core/validator.dart';
+import 'package:cake_wallet/core/wallet_name_validator.dart';
 
 class WalletRestoreFromSeedForm extends StatefulWidget {
   WalletRestoreFromSeedForm(
@@ -41,6 +41,7 @@ class WalletRestoreFromSeedFormState extends State<WalletRestoreFromSeedForm> {
   WalletRestoreFromSeedFormState(this.language)
       : seedWidgetStateKey = GlobalKey<SeedWidgetState>(),
         blockchainHeightKey = GlobalKey<BlockchainHeightState>(),
+        formKey = GlobalKey<FormState>(),
         languageController = TextEditingController(),
         nameTextEditingController = TextEditingController();
 
@@ -48,6 +49,7 @@ class WalletRestoreFromSeedFormState extends State<WalletRestoreFromSeedForm> {
   final GlobalKey<BlockchainHeightState> blockchainHeightKey;
   final TextEditingController languageController;
   final TextEditingController nameTextEditingController;
+  final GlobalKey<FormState> formKey;
   String language;
 
   @override
@@ -61,7 +63,9 @@ class WalletRestoreFromSeedFormState extends State<WalletRestoreFromSeedForm> {
     return Container(
         padding: EdgeInsets.only(left: 24, right: 24),
         child: Column(children: [
-          Stack(
+          Form(
+            key: formKey,
+          child: Stack(
             alignment: Alignment.centerRight,
             children: [
               BaseTextFormField(
@@ -97,7 +101,7 @@ class WalletRestoreFromSeedFormState extends State<WalletRestoreFromSeedForm> {
                 ),
               ),
             ],
-          ),
+          )),
           Container(height: 20),
           SeedWidget(
               key: seedWidgetStateKey,

lib/src/screens/restore/wallet_restore_page.dart

@@ -193,8 +193,7 @@ class WalletRestorePage extends BasePage {
           child: Observer(
             builder: (context) {
               return LoadingPrimaryButton(
-                onPressed: () =>
-                    walletRestoreViewModel.create(options: _credentials()),
+                onPressed: _confirmForm,
                 text: S.of(context).restore_recover,
                 color:
                     Theme.of(context).accentTextTheme.subtitle.decorationColor,
@@ -268,4 +267,45 @@ class WalletRestorePage extends BasePage {
 
     return credentials;
   }
+
+  void _confirmForm() {
+    final formContext = walletRestoreViewModel.mode == WalletRestoreMode.seed
+        ? walletRestoreFromSeedFormKey.currentContext
+        : walletRestoreFromKeysFormKey.currentContext;
+
+    final formKey = walletRestoreViewModel.mode == WalletRestoreMode.seed
+        ? walletRestoreFromSeedFormKey.currentState.formKey
+        : walletRestoreFromKeysFormKey.currentState.formKey;
+
+    final name = walletRestoreViewModel.mode == WalletRestoreMode.seed
+        ? walletRestoreFromSeedFormKey
+        .currentState.nameTextEditingController.value.text
+        : walletRestoreFromKeysFormKey
+        .currentState.nameTextEditingController.value.text;
+
+    if (!formKey.currentState.validate()) {
+      return;
+    }
+
+    if (walletRestoreViewModel.nameExists(name)) {
+      showNameExistsAlert(formContext);
+      return;
+    }
+
+    walletRestoreViewModel.create(options: _credentials());
+  }
+
+  Future<void> showNameExistsAlert(BuildContext context) {
+    return showPopUp<void>(
+        context: context,
+        builder: (_) {
+          return AlertWithOneAction(
+              alertTitle: '',
+              alertContent: S.of(context).wallet_name_exists,
+              buttonText: S.of(context).ok,
+              buttonAction: () => Navigator.of(context).pop());
+        });
+  }
 }
+
+