CW-1103:Token Validation Issues (#2327)

* feat(token_validation): Improve flow for adding new tokens across wallets

This change:
- Implements check to see if a token is already added, preventing duplicates
- Triggers dialog warning if its a duplicate token
- Takes EVM Chains contract adddress case-insensitivity when making checks for potential scams.

* refactor(token_validation): Modify token management flow

This change:
- Removes duplicate token check during token addition in EVMChainWalletBase.
- Introduces a flag to indicate if a token is being edited
- Adjusts token addition validation to bypass checks when editing an existing token.

* Update lib/src/screens/dashboard/edit_token_page.dart

---------

Co-authored-by: Omar Hatem <omarh.ismail1@gmail.com>

lib/ethereum/cw_ethereum.dart

@@ -199,8 +199,16 @@ class CWEthereum extends Ethereum {
   }
 
   @override
-  List<String> getDefaultTokenContractAddresses() =>
-      DefaultEthereumErc20Tokens().initialErc20Tokens.map((e) => e.contractAddress).toList();
+  List<String> getDefaultTokenContractAddresses() {
+    return DefaultEthereumErc20Tokens().initialErc20Tokens.map((e) => e.contractAddress).toList();
+  }
+
+
+  @override
+  bool isTokenAlreadyAdded(WalletBase wallet, String contractAddress) {
+    final ethereumWallet = wallet as EthereumWallet;
+    return ethereumWallet.erc20Currencies.any((element) => element.contractAddress.toLowerCase() == contractAddress.toLowerCase());
+  }
 
   Future<PendingTransaction> createTokenApproval(WalletBase wallet, BigInt amount, String spender,
           CryptoCurrency token, TransactionPriority priority) =>

lib/polygon/cw_polygon.dart

@@ -216,4 +216,10 @@ class CWPolygon extends Polygon {
       .initialPolygonErc20Tokens
       .map((e) => e.contractAddress)
       .toList();
+
+  @override
+  bool isTokenAlreadyAdded(WalletBase wallet, String contractAddress) {
+    final polygonWallet = wallet as PolygonWallet;
+    return polygonWallet.erc20Currencies.any((element) => element.contractAddress.toLowerCase() == contractAddress.toLowerCase());
+  }
 }

lib/solana/cw_solana.dart

@@ -155,4 +155,10 @@ class CWSolana extends Solana {
   List<String> getDefaultTokenContractAddresses() {
     return DefaultSPLTokens().initialSPLTokens.map((e) => e.mintAddress).toList();
   }
+
+  @override
+  bool isTokenAlreadyAdded(WalletBase wallet, String contractAddress) {
+    final solanaWallet = wallet as SolanaWallet;
+    return solanaWallet.splTokenCurrencies.any((element) => element.mintAddress == contractAddress);
+  }
 }

lib/src/screens/dashboard/edit_token_page.dart

@@ -73,6 +73,7 @@ class _EditTokenPageBodyState extends State<EditTokenPageBody> {
 
   bool _showDisclaimer = false;
   bool _disclaimerChecked = false;
+  bool isEditingToken = false;
 
   @override
   void initState() {
@@ -88,6 +89,8 @@ class _EditTokenPageBodyState extends State<EditTokenPageBody> {
       _tokenSymbolController.text = widget.token!.title;
       _tokenDecimalController.text = widget.token!.decimals.toString();
       _tokenIconPathController.text = widget.token?.iconPath ?? '';
+
+      isEditingToken = true;
     }
 
     if (widget.initialContractAddress != null) {
@@ -200,6 +203,25 @@ class _EditTokenPageBodyState extends State<EditTokenPageBody> {
                         onPressed: () async {
                           if (_formKey.currentState!.validate() &&
                               (!_showDisclaimer || _disclaimerChecked)) {
+                            final isTokenAlreadyAdded = isEditingToken
+                                ? false
+                                : await widget.homeSettingsViewModel
+                                    .checkIfTokenIsAlreadyAdded(_contractAddressController.text);
+                            if (isTokenAlreadyAdded) {
+                              showPopUp<void>(
+                                context: context,
+                                builder: (dialogContext) {
+                                  return AlertWithOneAction(
+                                    alertTitle: S.current.warning,
+                                    alertContent: S.of(context).token_already_exists,
+                                    buttonText: S.of(context).ok,
+                                    buttonAction: () => Navigator.of(dialogContext).pop(),
+                                  );
+                                },
+                              );
+                              return;
+                            }
+
                             final isWhitelisted = await widget.homeSettingsViewModel
                                 .checkIfTokenIsWhitelisted(_contractAddressController.text);
 

lib/tron/cw_tron.dart

@@ -138,4 +138,10 @@ class CWTron extends Tron {
   List<String> getDefaultTokenContractAddresses() {
     return DefaultTronTokens().initialTronTokens.map((e) => e.contractAddress).toList();
   }
+
+  @override
+  bool isTokenAlreadyAdded(WalletBase wallet, String contractAddress) {
+    final tronWallet = wallet as TronWallet;
+    return tronWallet.tronTokenCurrencies.any((element) => element.contractAddress == contractAddress);
+  }
 }

lib/view_model/dashboard/home_settings_view_model.dart

@@ -126,6 +126,31 @@ abstract class HomeSettingsViewModelBase with Store {
     }
   }
 
+  @action
+  bool checkIfTokenIsAlreadyAdded(String contractAddress) {
+    if (_balanceViewModel.wallet.type == WalletType.ethereum) {
+      return ethereum!.isTokenAlreadyAdded(_balanceViewModel.wallet, contractAddress);
+    }
+
+    if (_balanceViewModel.wallet.type == WalletType.polygon) {
+      return polygon!.isTokenAlreadyAdded(_balanceViewModel.wallet, contractAddress);
+    }
+
+    if (_balanceViewModel.wallet.type == WalletType.solana) {
+      return solana!.isTokenAlreadyAdded(_balanceViewModel.wallet, contractAddress);
+    }
+
+    if (_balanceViewModel.wallet.type == WalletType.tron) {
+      return tron!.isTokenAlreadyAdded(_balanceViewModel.wallet, contractAddress);
+    }
+
+    if (_balanceViewModel.wallet.type == WalletType.zano) {
+      return zano!.isTokenAlreadyAdded(_balanceViewModel.wallet, contractAddress);
+    }
+
+    return false;
+  }
+
   @action
   Future<void> deleteToken(CryptoCurrency token) async {
     try {
@@ -297,7 +322,7 @@ abstract class HomeSettingsViewModelBase with Store {
     required bool isEthereum,
   }) async {
     final uri = Uri.https(
-       "api.etherscan.io",
+      "api.etherscan.io",
       "/v2/api",
       {
         "chainid": isEthereum ? "1" : "137",

lib/zano/cw_zano.dart

@@ -136,4 +136,10 @@ class CWZano extends Zano {
   Map<String, List<int>> debugCallLength() {
     return api.debugCallLength();
   }
+
+  @override
+  bool isTokenAlreadyAdded(WalletBase wallet, String contractAddress) {
+    final zanoWallet = wallet as ZanoWallet;
+    return zanoWallet.zanoAssets.values.any((element) => element?.assetId == contractAddress);
+  }
 }