Add Base network to the chain selector

src/App.jsx

@@ -2,7 +2,8 @@ import { useEffect, useState } from 'react';
 import { NearContext } from './context';
 import { Wallet } from './services/near-wallet';
 import Navbar from './components/Navbar';
-import { EthereumView } from './components/Ethereum/Ethereum';
+import { EthereumView } from './components/EVM/Ethereum';
+import { BaseView } from './components/EVM/Base';
 import { BitcoinView } from './components/Bitcoin';
 import { MPC_CONTRACT } from './services/kdf/mpc';
 
@@ -68,13 +69,17 @@ function App() {
                   onChange={(e) => setChain(e.target.value)}
                 >
                   <option value='eth'> Ξ Ethereum </option>
+                  <option value='base'> Ξ Base </option>
                   <option value='btc'> ₿ BTC </option>
                 </select>
               </div>
 
               {chain === 'eth' && (
                 <EthereumView props={{ setStatus, MPC_CONTRACT }} />
               )}
+              {chain === 'base' && (
+                <BaseView props={{ setStatus, MPC_CONTRACT }} />
+              )}
               {chain === 'btc' && (
                 <BitcoinView props={{ setStatus, MPC_CONTRACT }} />
               )}

src/components/EVM/Base.jsx

@@ -0,0 +1,325 @@
+import { useState, useEffect, useContext, useRef } from "react";
+import PropTypes from "prop-types";
+
+import { NearContext } from "../../context";
+import { useDebounce } from "../../hooks/debounce";
+import { getTransactionHashes } from "../../services/utils";
+import { TransferForm } from "./Transfer";
+import { FunctionCallForm } from "./FunctionCall";
+import { EthereumVM } from "../../services/evm";
+
+const Evm = new EthereumVM("https://base-sepolia.drpc.org");
+
+const contractAddress = "0xCd3b988b216790C598d9AB85Eee189e446CE526D";
+
+const transactions = getTransactionHashes();
+
+export function BaseView({ props: { setStatus, MPC_CONTRACT } }) {
+  const { wallet, signedAccountId } = useContext(NearContext);
+
+  const [loading, setLoading] = useState(false);
+  const [step, setStep] = useState(transactions ? "relay" : "request");
+  const [signedTransaction, setSignedTransaction] = useState(null);
+  const [senderLabel, setSenderLabel] = useState("");
+  const [senderAddress, setSenderAddress] = useState("");
+  const [balance, setBalance] = useState(""); // Add balance state
+  const [action, setAction] = useState("transfer");
+  const [derivation, setDerivation] = useState(
+    sessionStorage.getItem("derivation") || "ethereum-1"
+  );
+  const [reloaded, setReloaded] = useState(transactions.length);
+
+  const [gasPriceInGwei, setGasPriceInGwei] = useState("");
+  const [txCost, setTxCost] = useState("");
+
+  const derivationPath = useDebounce(derivation, 1200);
+  const childRef = useRef();
+
+  useEffect(() => {
+    async function fetchEthereumGasPrice() {
+      try {
+        // Fetch gas price in Wei
+        const gasPriceInWei = await Evm.web3.eth.getGasPrice();
+
+        // Convert gas price from Wei to Gwei
+        const gasPriceInGwei = Evm.web3.utils.fromWei(gasPriceInWei, "gwei");
+
+        // Gas limit for a standard ETH transfer
+        const gasLimit = 21000;
+
+        // Calculate transaction cost in ETH (gwei * gasLimit) / 1e9
+        const txCost = (gasPriceInGwei * gasLimit) / 1000000000;
+
+        // Format both gas price and transaction cost to 7 decimal places
+        const formattedGasPriceInGwei = parseFloat(gasPriceInGwei).toFixed(7);
+        const formattedTxCost = parseFloat(txCost).toFixed(7);
+
+        console.log(
+          `Current Sepolia Gas Price: ${formattedGasPriceInGwei} Gwei`
+        );
+        console.log(`Estimated Transaction Cost: ${formattedTxCost} ETH`);
+
+        setTxCost(formattedTxCost);
+        setGasPriceInGwei(formattedGasPriceInGwei);
+      } catch (error) {
+        console.error("Error fetching gas price:", error);
+      }
+    }
+
+    fetchEthereumGasPrice();
+  }, []);
+
+  // Handle signing transaction when the page is reloaded and senderAddress is set
+  useEffect(() => {
+    if (reloaded && senderAddress) {
+      signTransaction();
+    }
+
+    async function signTransaction() {
+      const { big_r, s, recovery_id } = await wallet.getTransactionResult(
+        transactions[0]
+      );
+      const signedTransaction = await Evm.reconstructSignedTXFromLocalSession(
+        big_r,
+        s,
+        recovery_id,
+        senderAddress
+      );
+
+      setSignedTransaction(signedTransaction);
+      setStatus(
+        "✅ Signed payload ready to be relayed to the Base network"
+      );
+      setStep("relay");
+
+      setReloaded(false);
+      removeUrlParams();
+    }
+  }, [senderAddress, reloaded, wallet, setStatus]);
+
+  // Handle changes to derivation path and query Base address and balance
+  useEffect(() => {
+    resetAddressState();
+    fetchEthereumAddress();
+  }, [derivationPath, signedAccountId]);
+
+  const resetAddressState = () => {
+    setSenderLabel("Waiting for you to stop typing...");
+    setSenderAddress(null);
+    setStatus("");
+    setBalance(""); // Reset balance when derivation path changes
+    setStep("request");
+  };
+
+  const fetchEthereumAddress = async () => {
+    const { address } = await Evm.deriveAddress(
+      signedAccountId,
+      derivationPath
+    );
+    setSenderAddress(address);
+    setSenderLabel(address);
+
+    if (!reloaded) {
+      const balance = await Evm.getBalance(address);
+      setBalance(balance); // Update balance state
+    }
+  };
+
+  async function chainSignature() {
+    setStatus("🏗️ Creating transaction");
+
+    const { transaction } = await childRef.current.createTransaction();
+
+    setStatus(
+      `🕒 Asking ${MPC_CONTRACT} to sign the transaction, this might take a while`
+    );
+    try {
+      // to reconstruct on reload
+      sessionStorage.setItem("derivation", derivationPath);
+
+      const { big_r, s, recovery_id } = await Evm.requestSignatureToMPC({
+        wallet,
+        path: derivationPath,
+        transaction,
+      });
+      const signedTransaction = await Evm.reconstructSignedTransaction(
+        big_r,
+        s,
+        recovery_id,
+        transaction
+      );
+
+      setSignedTransaction(signedTransaction);
+      setStatus(
+        `✅ Signed payload ready to be relayed to the Base network`
+      );
+      setStep("relay");
+    } catch (e) {
+      setStatus(`❌ Error: ${e.message}`);
+      setLoading(false);
+    }
+  }
+
+  async function relayTransaction() {
+    setLoading(true);
+    setStatus(
+      "🔗 Relaying transaction to the Base network... this might take a while"
+    );
+
+    try {
+      const txHash = await Evm.broadcastTX(signedTransaction);
+      setStatus(
+        <>
+          <a href={`https://base-sepolia.blockscout.com/tx/${txHash}`} target="_blank">
+            {" "}
+            ✅ Successful{" "}
+          </a>
+        </>
+      );
+      childRef.current.afterRelay();
+    } catch (e) {
+      setStatus(`❌ Error: ${e.message}`);
+    }
+
+    setStep("request");
+    setLoading(false);
+  }
+
+  const UIChainSignature = async () => {
+    setLoading(true);
+    await chainSignature();
+    setLoading(false);
+  };
+
+  function removeUrlParams() {
+    const url = new URL(window.location.href);
+    url.searchParams.delete("transactionHashes");
+    window.history.replaceState({}, document.title, url);
+  }
+
+  return (
+    <>
+      {/* Form Inputs */}
+      <div className="row mb-0">
+        <label className="col-sm-2 col-form-label"></label>
+        <div className="col-sm-10"></div>
+      </div>
+
+      <div className="input-group input-group-sm my-2 mb-2">
+        <span className="input-group-text bg-primary text-white" id="chain">
+          PATH
+        </span>
+        <input
+          type="text"
+          className="form-control form-control-sm"
+          value={derivation}
+          onChange={(e) => setDerivation(e.target.value)}
+          disabled={loading}
+        />
+      </div>
+
+      {/* ADDRESS & BALANCE */}
+      <div className="card">
+        <div className="row mb-0">
+          <label className="col-sm-2 col-form-label text-end">Address:</label>
+          <div className="col-sm-10 fs-5">
+            <div className="form-text" id="eth-sender">
+              {senderLabel}
+            </div>
+          </div>
+        </div>
+        <div className="row mb-0">
+          <label className="col-sm-2 col-form-label text-end">Balance:</label>
+          <div className="col-sm-10 fs-5">
+            <div className="form-text text-muted ">
+              {balance ? (
+                `${balance} ETH`
+              ) : (
+                <span className="text-warning">Fetching balance...</span>
+              )}
+            </div>
+          </div>
+        </div>
+      </div>
+
+      <div className="input-group input-group-sm my-2 mb-4">
+        <span className="input-group-text bg-info text-white" id="chain">
+          ACTION
+        </span>
+        <select
+          className="form-select"
+          aria-describedby="chain"
+          onChange={(e) => setAction(e.target.value)}
+          disabled={loading}
+        >
+          <option value="transfer">Ξ Transfer</option>
+          <option value="function-call">Ξ Call Counter</option>
+        </select>
+      </div>
+
+      {action === "transfer" ? (
+        <TransferForm ref={childRef} props={{ Evm, senderAddress, loading }} />
+      ) : (
+        <FunctionCallForm
+          ref={childRef}
+          props={{ Evm, contractAddress, senderAddress, loading }}
+        />
+      )}
+
+      <div className="text-center mt-4 d-flex justify-content-center">
+        <div className="table-responsive " style={{ maxWidth: "400px" }}>
+          <table className="table table-hover text-center w-auto">
+            <caption className="caption-top text-center">
+              Sepolia Gas Prices
+            </caption>
+            <thead>
+              <tr className="table-light">
+                <th scope="col">Price</th>
+                <th scope="col">Unit</th>
+              </tr>
+            </thead>
+            <tbody>
+              <tr>
+                <td>{gasPriceInGwei}</td>
+                <td>GWEI</td>
+              </tr>
+              <tr>
+                <td>{txCost}</td>
+                <td>ETH</td>
+              </tr>
+            </tbody>
+          </table>
+        </div>
+      </div>
+
+      {/* Execute Buttons */}
+      <div className="d-grid gap-2">
+        {step === "request" && (
+          <button
+            className="btn btn-outline-success text-center btn-lg"
+            onClick={UIChainSignature}
+            disabled={loading}
+          >
+            Request Signature
+          </button>
+        )}
+        {step === "relay" && (
+          <button
+            className="btn btn-success text-center"
+            onClick={relayTransaction}
+            disabled={loading}
+          >
+            Relay Transaction
+          </button>
+        )}
+      </div>
+    </>
+  );
+}
+
+BaseView.propTypes = {
+  props: PropTypes.shape({
+    setStatus: PropTypes.func.isRequired,
+    MPC_CONTRACT: PropTypes.string.isRequired,
+  }).isRequired,
+};