cake_wallet/cw_evm/lib/evm_chain_client.dart

import 'dart:async';
import 'dart:convert';
import 'dart:developer';

import 'package:cw_core/crypto_currency.dart';
import 'package:cw_core/erc20_token.dart';
import 'package:cw_core/node.dart';
import 'package:cw_evm/evm_chain_transaction_model.dart';
import 'package:cw_evm/evm_chain_transaction_priority.dart';
import 'package:cw_evm/evm_erc20_balance.dart';
import 'package:cw_evm/pending_evm_chain_transaction.dart';
import 'package:cw_evm/.secrets.g.dart' as secrets;
import 'package:flutter/foundation.dart';
import 'package:hex/hex.dart' as hex;
import 'package:http/http.dart';
import 'package:web3dart/web3dart.dart';

import 'contract/erc20.dart';

abstract class EVMChainClient {
  final httpClient = Client();
  Web3Client? _client;

  //! To be overridden by all child classes

  int get chainId;

  Future<List<EVMChainTransactionModel>> fetchTransactions(String address,
      {String? contractAddress});

  Future<List<EVMChainTransactionModel>> fetchInternalTransactions(String address);

  Uint8List prepareSignedTransactionForSending(Uint8List signedTransaction);

  //! Common methods across all child classes

  bool connect(Node node) {
    try {
      Uri? rpcUri;
      bool isModifiedNodeUri = false;

      if (node.uriRaw == 'eth.nownodes.io' || node.uriRaw == 'matic.nownodes.io') {
        isModifiedNodeUri = true;
        String nowNodeApiKey = secrets.nowNodesApiKey;

        rpcUri = Uri.https(node.uriRaw, '/$nowNodeApiKey');
      }

      _client =
          Web3Client(isModifiedNodeUri ? rpcUri!.toString() : node.uri.toString(), httpClient);

      return true;
    } catch (e) {
      return false;
    }
  }

  void setListeners(EthereumAddress userAddress, Function() onNewTransaction) async {
    // _client?.pendingTransactions().listen((transactionHash) async {
    //   final transaction = await _client!.getTransactionByHash(transactionHash);
    //
    //   if (transaction.from.hex == userAddress || transaction.to?.hex == userAddress) {
    //     onNewTransaction();
    //   }
    // });
  }

  Future<EtherAmount> getBalance(EthereumAddress address) async {
    try {
      return await _client!.getBalance(address);
    } catch (_) {
      return EtherAmount.zero();
    }
  }

  Future<int> getGasUnitPrice() async {
    try {
      final gasPrice = await _client!.getGasPrice();
    
      return gasPrice.getInWei.toInt();
    } catch (_) {
      return 0;
    }
  }

  Future<int?> getGasBaseFee() async {
    try {
      final blockInfo = await _client!.getBlockInformation(isContainFullObj: false);
      final baseFee = blockInfo.baseFeePerGas;

      return baseFee?.getInWei.toInt();
    } catch (_) {
      return 0;
    }
  }

  Future<int> getEstimatedGasUnitsForTransaction({
    required EthereumAddress toAddress,
    required EthereumAddress senderAddress,
    required EtherAmount value,
    String? contractAddress,
    EtherAmount? gasPrice,
    EtherAmount? maxFeePerGas,
  }) async {
    try {
      if (contractAddress == null) {
        final estimatedGas = await _client!.estimateGas(
          sender: senderAddress,
          to: toAddress,
          value: value,
          // maxFeePerGas: maxFeePerGas,
        );

        return estimatedGas.toInt();
      } else {
        final contract = DeployedContract(
          ethereumContractAbi,
          EthereumAddress.fromHex(contractAddress),
        );

        final transfer = contract.function('transfer');

        // Estimate gas units
        final gasEstimate = await _client!.estimateGas(
          sender: senderAddress,
          to: EthereumAddress.fromHex(contractAddress),
          data: transfer.encodeCall([
            toAddress,
            value.getInWei,
          ]),
        );

        return gasEstimate.toInt();
      }
    } catch (_) {
      return 0;
    }
  }

  Future<PendingEVMChainTransaction> signTransaction({
    required Credentials privateKey,
    required String toAddress,
    required BigInt amount,
    required BigInt gasFee,
    required int estimatedGasUnits,
    required int maxFeePerGas,
    required EVMChainTransactionPriority priority,
    required CryptoCurrency currency,
    required int exponent,
    String? contractAddress,
    String? data,
  }) async {
    assert(currency == CryptoCurrency.eth ||
        currency == CryptoCurrency.maticpoly ||
        contractAddress != null);

    bool isNativeToken = currency == CryptoCurrency.eth || currency == CryptoCurrency.maticpoly;

    final Transaction transaction = createTransaction(
      from: privateKey.address,
      to: EthereumAddress.fromHex(toAddress),
      maxPriorityFeePerGas: EtherAmount.fromInt(EtherUnit.gwei, priority.tip),
      amount: isNativeToken ? EtherAmount.inWei(amount) : EtherAmount.zero(),
      data: data != null ? hexToBytes(data) : null,
      maxGas: estimatedGasUnits,
      maxFeePerGas: EtherAmount.fromInt(EtherUnit.wei, maxFeePerGas),
    );

    Uint8List signedTransaction;

    final Function _sendTransaction;

    if (isNativeToken) {
      signedTransaction = await _client!.signTransaction(privateKey, transaction, chainId: chainId);
    } else {
      final erc20 = ERC20(
        client: _client!,
        address: EthereumAddress.fromHex(contractAddress!),
        chainId: chainId,
      );

      signedTransaction = await erc20.transfer(
        EthereumAddress.fromHex(toAddress),
        amount,
        credentials: privateKey,
        transaction: transaction,
      );
    }

    _sendTransaction = () async => await sendTransaction(signedTransaction);

    return PendingEVMChainTransaction(
      signedTransaction: signedTransaction,
      amount: amount.toString(),
      fee: gasFee,
      sendTransaction: _sendTransaction,
      exponent: exponent,
    );
  }

  Transaction createTransaction({
    required EthereumAddress from,
    required EthereumAddress to,
    required EtherAmount amount,
    EtherAmount? maxPriorityFeePerGas,
    EtherAmount? gasPrice,
    EtherAmount? maxFeePerGas,
    Uint8List? data,
    int? maxGas,
  }) {
    return Transaction(
      from: from,
      to: to,
      maxPriorityFeePerGas: maxPriorityFeePerGas,
      value: amount,
      data: data,
      maxGas: maxGas,
      gasPrice: gasPrice,
      maxFeePerGas: maxFeePerGas,
    );
  }

  Future<String> sendTransaction(Uint8List signedTransaction) async {
    return await _client!.sendRawTransaction(prepareSignedTransactionForSending(signedTransaction));
  }

  Future getTransactionDetails(String transactionHash) async {
    // Wait for the transaction receipt to become available
    TransactionReceipt? receipt;
    while (receipt == null) {
      receipt = await _client!.getTransactionReceipt(transactionHash);
      await Future.delayed(const Duration(seconds: 1));
    }

    // Print the receipt information
    log('Transaction Hash: ${receipt.transactionHash}');
    log('Block Hash: ${receipt.blockHash}');
    log('Block Number: ${receipt.blockNumber}');
    log('Gas Used: ${receipt.gasUsed}');

    /*
      Transaction Hash: [112, 244, 4, 238, 89, 199, 171, 191, 210, 236, 110, 42, 185, 202, 220, 21, 27, 132, 123, 221, 137, 90, 77, 13, 23, 43, 12, 230, 93, 63, 221, 116]
      I/flutter ( 4474): Block Hash: [149, 44, 250, 119, 111, 104, 82, 98, 17, 89, 30, 190, 25, 44, 218, 118, 127, 189, 241, 35, 213, 106, 25, 95, 195, 37, 55, 131, 185, 180, 246, 200]
      I/flutter ( 4474): Block Number: 17120242
      I/flutter ( 4474): Gas Used: 21000
    */

    // Wait for the transaction receipt to become available
    TransactionInformation? transactionInformation;
    while (transactionInformation == null) {
      log("********************************");
      transactionInformation = await _client!.getTransactionByHash(transactionHash);
      await Future.delayed(const Duration(seconds: 1));
    }
    // Print the receipt information
    log('Transaction Hash: ${transactionInformation.hash}');
    log('Block Hash: ${transactionInformation.blockHash}');
    log('Block Number: ${transactionInformation.blockNumber}');
    log('Gas Used: ${transactionInformation.gas}');

    /*
      Transaction Hash: 0x70f404ee59c7abbfd2ec6e2ab9cadc151b847bdd895a4d0d172b0ce65d3fdd74
      I/flutter ( 4474): Block Hash: 0x952cfa776f68526211591ebe192cda767fbdf123d56a195fc3253783b9b4f6c8
      I/flutter ( 4474): Block Number: 17120242
      I/flutter ( 4474): Gas Used: 53000
    */
  }

  Future<EVMChainERC20Balance> fetchERC20Balances(
      EthereumAddress userAddress, String contractAddress) async {
    final erc20 = ERC20(address: EthereumAddress.fromHex(contractAddress), client: _client!);
    final balance = await erc20.balanceOf(userAddress);

    int exponent = (await erc20.decimals()).toInt();

    return EVMChainERC20Balance(balance, exponent: exponent);
  }

  Future<Erc20Token?> getErc20Token(String contractAddress, String chainName) async {
    try {
      final uri = Uri.https(
        'deep-index.moralis.io',
        '/api/v2.2/erc20/metadata',
        {
          "chain": chainName,
          "addresses": contractAddress,
        },
      );

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

      final decodedResponse = jsonDecode(response.body)[0] as Map<String, dynamic>;

      final symbol = (decodedResponse['symbol'] ?? '') as String;
      String filteredSymbol = symbol.replaceFirst(RegExp('^\\\$'), '');

      final name = decodedResponse['name'] ?? '';
      final decimal = decodedResponse['decimals'] ?? '0';
      final iconPath = decodedResponse['logo'] ?? '';

      return Erc20Token(
        name: name,
        symbol: filteredSymbol,
        contractAddress: contractAddress,
        decimal: int.tryParse(decimal) ?? 0,
        iconPath: iconPath,
      );
    } catch (e) {
      try {
        final erc20 = ERC20(address: EthereumAddress.fromHex(contractAddress), client: _client!);
        final name = await erc20.name();
        final symbol = await erc20.symbol();
        final decimal = await erc20.decimals();

        return Erc20Token(
          name: name,
          symbol: symbol,
          contractAddress: contractAddress,
          decimal: decimal.toInt(),
        );
      } catch (_) {}

      return null;
    }
  }

  Uint8List hexToBytes(String hexString) {
    return Uint8List.fromList(
        hex.HEX.decode(hexString.startsWith('0x') ? hexString.substring(2) : hexString));
  }

  void stop() {
    _client?.dispose();
  }

  Web3Client? getWeb3Client() {
    return _client;
  }

// Future<int> _getDecimalPlacesForContract(DeployedContract contract) async {
//     final String abi = await rootBundle.loadString("assets/abi_json/erc20_abi.json");
//     final contractAbi = ContractAbi.fromJson(abi, "ERC20");
//
//     final contract = DeployedContract(
//       contractAbi,
//       EthereumAddress.fromHex(_erc20Currencies[erc20Currency]!),
//     );
//     final decimalsFunction = contract.function('decimals');
//     final decimals = await _client!.call(
//       contract: contract,
//       function: decimalsFunction,
//       params: [],
//     );
//
//     int exponent = int.parse(decimals.first.toString());
//     return exponent;
//   }
}