hash-wallet/lib/view_model/dashboard/home_settings_view_model.dart

import 'dart:convert';

import 'package:hash_wallet/core/fiat_conversion_service.dart';
import 'package:hash_wallet/entities/fiat_api_mode.dart';
import 'package:hash_wallet/entities/erc20_token_info_moralis.dart';
import 'package:hash_wallet/entities/sort_balance_types.dart';
import 'package:hash_wallet/evm/evm.dart';
import 'package:hash_wallet/reactions/wallet_connect.dart';
import 'package:hash_wallet/store/settings_store.dart';
import 'package:hash_wallet/utils/token_utilities.dart';
import 'package:cw_core/utils/proxy_wrapper.dart';
import 'package:hash_wallet/view_model/dashboard/balance_view_model.dart';
import 'package:cw_core/crypto_currency.dart';
import 'package:cw_core/erc20_token.dart';
import 'package:cw_core/utils/homoglyph_normalizer.dart';
import 'package:cw_core/utils/print_verbose.dart';
import 'package:cw_core/wallet_type.dart';
import 'package:mobx/mobx.dart';
import 'package:hash_wallet/.secrets.g.dart' as secrets;

part 'home_settings_view_model.g.dart';

class HomeSettingsViewModel = HomeSettingsViewModelBase with _$HomeSettingsViewModel;

abstract class HomeSettingsViewModelBase with Store {
  HomeSettingsViewModelBase(this._settingsStore, this._balanceViewModel)
      : tokens = ObservableSet<CryptoCurrency>(),
        isAddingToken = false,
        isDeletingToken = false,
        isValidatingContractAddress = false,
        showCombinedBalance = _balanceViewModel.wallet.walletInfo.showCombinedBalance,
        favoriteToken = _balanceViewModel.wallet.currency {
    _updateTokensList();
  _updateLocalFavoriteToken();


  // React to wallet changes
    reaction((_) => _balanceViewModel.wallet, (_) {
      _updateTokensList();
    });
    reaction((_) {
      final wallet = _balanceViewModel.wallet;
      if (isEVMCompatibleChain(wallet.type)) {
        final selectedChainId = evm!.getSelectedChainId(wallet);
        final erc20Currencies = evm!.getERC20Currencies(wallet);
        return '${wallet.currency.title}_${selectedChainId}_${erc20Currencies.length}';
      }
      return null;
    }, (_) async {
      await Future.delayed(const Duration(milliseconds: 200));
      _updateTokensList();
    });
  }

  final SettingsStore _settingsStore;
  final BalanceViewModel _balanceViewModel;

  final ObservableSet<CryptoCurrency> tokens;

  @computed
  List<CryptoCurrency> get enabledTokens => [_balanceViewModel.wallet.currency, ...tokens.where((item)=>item.enabled).toList()];

  WalletType get walletType => _balanceViewModel.wallet.type;

  @observable
  bool isAddingToken;

  @observable
  bool isDeletingToken;

  @observable
  bool isValidatingContractAddress;

  @observable
  String searchText = '';

  @computed
  SortBalanceBy get sortBalanceBy => _settingsStore.sortBalanceBy;

  @action
  void setSortBalanceBy(SortBalanceBy value) {
    _settingsStore.sortBalanceBy = value;
    _updateTokensList();
  }

  @computed
  bool get pinNativeToken => _settingsStore.pinNativeTokenAtTop;

  @action
  void setPinNativeToken(bool value) => _settingsStore.pinNativeTokenAtTop = value;

  @action
  Future<void> addToken({
    required String contractAddress,
    required CryptoCurrency token,
  }) async {
    try {
      isAddingToken = true;

      if (isEVMCompatibleChain(_balanceViewModel.wallet.type)) {
        final evmToken = Erc20Token(
          name: token.name,
          symbol: token.title,
          decimal: token.decimals,
          contractAddress: contractAddress.toLowerCase(),
          iconPath: token.iconPath,
          isPotentialScam: token.isPotentialScam,
        );
        await evm!.addErc20Token(_balanceViewModel.wallet, evmToken);
      }

      _updateTokensList();
      _updateFiatPrices(token);
    } catch (e) {
      throw e;
    } finally {
      isAddingToken = false;
    }
  }

  @action
  bool checkIfTokenIsAlreadyAdded(String contractAddress) {
    if (isEVMCompatibleChain(_balanceViewModel.wallet.type)) {
      return evm!.isTokenAlreadyAdded(_balanceViewModel.wallet, contractAddress);
    }

    return false;
  }

  @action
  Future<void> deleteToken(CryptoCurrency token) async {
    try {
      isDeletingToken = true;
      if (isEVMCompatibleChain(_balanceViewModel.wallet.type)) {
        await evm!.deleteErc20Token(_balanceViewModel.wallet, token as Erc20Token);
      }

      _updateTokensList();
    } finally {
      isDeletingToken = false;
    }
  }

  Future<bool> checkIfERC20TokenContractAddressIsAPotentialScamAddress(
    String contractAddress,
  ) async {
    try {
      isValidatingContractAddress = true;

      if (!isEVMCompatibleChain(_balanceViewModel.wallet.type)) {
        return false;
      }

      bool isPotentialScamViaMoralis = await _isPotentialScamTokenViaMoralis(
        contractAddress,
        getChainNameBasedOnWalletType(_balanceViewModel.wallet.type),
      );

      bool isUnverifiedContract = await _isContractUnverified(
        contractAddress,
        chainId: evm!.getSelectedChainId(_balanceViewModel.wallet).toString(),
      );

      final showWarningForContractAddress = isPotentialScamViaMoralis || isUnverifiedContract;

      return showWarningForContractAddress;
    } finally {
      isValidatingContractAddress = false;
    }
  }

  bool checkIfTokenIsWhitelisted(String contractAddress) {
    // get the default tokens for each currency type:
    List<String> defaultTokenAddresses = [];
    switch (_balanceViewModel.wallet.type) {
      case WalletType.ethereum:
      case WalletType.polygon:
      case WalletType.base:
      case WalletType.arbitrum:
      case WalletType.bsc:
        defaultTokenAddresses = evm!.getDefaultTokenContractAddresses(_balanceViewModel.wallet);
        break;
      case WalletType.banano:
      case WalletType.monero:
      case WalletType.none:
      case WalletType.bitcoin:
      case WalletType.litecoin:
      case WalletType.nano:
      case WalletType.wownero:
      case WalletType.bitcoinCash:
      case WalletType.dogecoin:
        return false;
    }

    // check if the contractAddress is in the defaultTokenAddresses
    bool isInWhitelist = defaultTokenAddresses
        .any((element) => element.toLowerCase() == contractAddress.toLowerCase());
    return isInWhitelist;
  }

  bool checkIfTokenSymbolMatchesDefaultToken(String symbol) {
    final normalizedSymbol = normalizeHomoglyphs(symbol.trim().toUpperCase());
    if (normalizedSymbol.isEmpty) return false;

    List<String> defaultTokenSymbols = [];
    switch (_balanceViewModel.wallet.type) {
      case WalletType.ethereum:
      case WalletType.polygon:
      case WalletType.base:
      case WalletType.arbitrum:
      case WalletType.bsc:
        defaultTokenSymbols = evm!.getDefaultTokenSymbols(_balanceViewModel.wallet);
        break;
      case WalletType.banano:
      case WalletType.monero:
      case WalletType.none:
      case WalletType.bitcoin:
      case WalletType.litecoin:
      case WalletType.nano:
      case WalletType.wownero:
      case WalletType.bitcoinCash:
      case WalletType.dogecoin:
        return false;
    }

    return defaultTokenSymbols.any((s) => s.toUpperCase() == normalizedSymbol);
  }

  Future<bool> _isPotentialScamTokenViaMoralis(
    String contractAddress,
    String chainName,
  ) async {
    final uri = Uri.https(
      'deep-index.moralis.io',
      '/api/v2.2/erc20/metadata',
      {
        "chain": chainName,
        "addresses": contractAddress,
      },
    );

    try {
      final response = await ProxyWrapper().get(
        clearnetUri: uri,
        headers: {
          "Accept": "application/json",
          "X-API-Key": secrets.moralisApiKey,
        },
      );

      final decodedResponse = jsonDecode(response.body);

      final tokenInfo = Erc20TokenInfoMoralis.fromJson(decodedResponse[0] as Map<String, dynamic>);

      // Based on analysis using Moralis internal metrics
      if (tokenInfo.possibleSpam == true) {
        return true;
      }

      // Tokens whose contract have not been verified are potentially risky tokens.
      // if (tokenInfo.verifiedContract == false) {
      //   return true;
      // }

      // Tokens with a security score less than 40 are potentially risky, requiring caution when dealing with them.
      if (tokenInfo.securityScore != null && tokenInfo.securityScore! < 40) {
        return true;
      }

      // Having a Fully Diluted Valiuation of 0 is a significant red flag that could signify:
      // - An abandoned/unlaunched project
      // - Incorrect/missing token data
      // - Suspicious manipulation of token data

      /// commented out as it's failing a lot of legit tokens
      // if (tokenInfo.fullyDilutedValuation == '0') {
      //   return true;
      // }

      return false;
    } catch (e) {
      printV('Error while checking scam via moralis: ${e.toString()}');
      return true;
    }
  }

  Future<bool> _isContractUnverified(
    String contractAddress, {
    required String chainId,
  }) async {
    final uri = Uri.https(
      "api.etherscan.io",
      "/v2/api",
      {
        "chainid": chainId,
        "module": "contract",
        "action": "getsourcecode",
        "address": contractAddress,
        "apikey": secrets.etherScanApiKey,
      },
    );

    try {
      final response = await ProxyWrapper().get(clearnetUri: uri);

      final decodedResponse = jsonDecode(response.body) as Map<String, dynamic>;

      if (decodedResponse['status'] == '0') {
        printV('${response.body}\n');
        printV('${decodedResponse['result']}\n');
        return true;
      }

      if (decodedResponse['status'] == '1' &&
          decodedResponse['result'][0]['ABI'] == 'Contract source code not verified') {
        printV('Call is valid but contract is not verified');
        return true; // Contract is not verified
      } else {
        printV('Call is valid and contract is verified');
        return false; // Contract is verified
      }
    } catch (e) {
      printV('Error while checking contract verification: ${e.toString()}');
      return true;
    }
  }

  Future<CryptoCurrency?> getToken(String contractAddress) async {
    if (isEVMCompatibleChain(_balanceViewModel.wallet.type)) {
      return await evm!.getErc20Token(_balanceViewModel.wallet, contractAddress);
    }

    return null;
  }

  CryptoCurrency get nativeToken => _balanceViewModel.wallet.currency;

  void _updateFiatPrices(CryptoCurrency token) async {
    if (token.isPotentialScam) return; // don't fetch price data for potential scam tokens
    try {
      _balanceViewModel.fiatConversionStore.prices[token] =
          await FiatConversionService.fetchPrice(
              crypto: token,
              fiat: _settingsStore.fiatCurrency,
              torOnly: _settingsStore.fiatApiMode == FiatApiMode.torOnly);
    } catch (_) {}
  }

  void changeTokenAvailability(CryptoCurrency token, bool value) async {
    token.enabled = value;

    if (isEVMCompatibleChain(_balanceViewModel.wallet.type)) {
      evm!.addErc20Token(_balanceViewModel.wallet, token as Erc20Token);
      if (!value) evm!.removeTokenTransactionsInHistory(_balanceViewModel.wallet, token);
    }

    _refreshTokensList();
  }

  @action
  void _updateTokensList() {
    int _sortFunc(CryptoCurrency e1, CryptoCurrency e2) {
      int index1 = _balanceViewModel.formattedBalances.indexWhere((element) => element.asset == e1);
      int index2 = _balanceViewModel.formattedBalances.indexWhere((element) => element.asset == e2);

      if (e1.enabled && !e2.enabled) {
        return -1;
      } else if (e2.enabled && !e1.enabled) {
        return 1;
      } else if (!e1.enabled && !e2.enabled) {
        // if both are disabled then sort alphabetically
        return e1.name.compareTo(e2.name);
      }

      return index1.compareTo(index2);
    }

    tokens.clear();

    if (isEVMCompatibleChain(_balanceViewModel.wallet.type)) {
      tokens.addAll(evm!
          .getERC20Currencies(_balanceViewModel.wallet)
          .where((element) => _matchesSearchText(element))
          .toList()
        ..sort(_sortFunc));
    }
  }


  // FIXME these two observables cause duplicated state and are needed because mobx. remove them as part of the refactor and replace with proper getters
  @observable
  bool showCombinedBalance;

  @observable
  CryptoCurrency favoriteToken;

  @action
  void setShowCombinedBalance(bool value) {
    _balanceViewModel.wallet.walletInfo.showCombinedBalance = value;
    showCombinedBalance = value;
    _balanceViewModel.wallet.updateBalance();
    _balanceViewModel.wallet.walletInfo.save();
  }

  @action
  Future<void> setFavoriteToken(CryptoCurrency token) async {
    final String? address;

    if(token == _balanceViewModel.wallet.currency) {
      address = null;
    } else {
      address = getTokenAddressBasedOnWallet(token);
    }

    _balanceViewModel.wallet.walletInfo.favoriteTokenAddress = address;
    _balanceViewModel.wallet.walletInfo.save();
    _updateLocalFavoriteToken();
  }

  @action
  Future<void> _updateLocalFavoriteToken() async {
    favoriteToken = await TokenUtilities.findTokenByAddress(
        walletType: _balanceViewModel.wallet.type, address: _balanceViewModel.wallet.walletInfo.favoriteTokenAddress ?? "") ??
        _balanceViewModel.wallet.currency;
  }


  @action
  void _refreshTokensList() {
    final _tokens = Set.of(tokens);
    tokens.clear();
    tokens.addAll(_tokens);
  }

  @action
  void changeSearchText(String text) {
    searchText = text;
    _updateTokensList();
  }

  bool _matchesSearchText(CryptoCurrency asset) {
    final address = getTokenAddressBasedOnWallet(asset);

    // The homes settings would only be displayed for either of Tron, EVM or Solana Wallets.
    if (address == null) return false;

    return searchText.isEmpty ||
        asset.fullName!.toLowerCase().contains(searchText.toLowerCase()) ||
        asset.title.toLowerCase().contains(searchText.toLowerCase()) ||
        address == searchText;
  }

  String? getTokenAddressBasedOnWallet(CryptoCurrency asset) {
    if (isEVMCompatibleChain(_balanceViewModel.wallet.type)) {
      return evm!.getTokenAddress(asset);
    }

    return null;
  }
}