associate.ts

import secp256k1 from "secp256k1";
import { createPublicClient, createWalletClient, hexToNumber, http, numberToHex, parseSignature, toHex } from "viem";
import { privateKeyToAccount, generatePrivateKey } from "viem/accounts";
import { seiTestnet } from "viem/chains";
import { ADDRESS_PRECOMPILE_ABI, ADDRESS_PRECOMPILE_ADDRESS } from '@sei-js/evm'

// replace pk
const PRIVATE_KEY = "";

const publicClient = createPublicClient({
  chain: seiTestnet,
  transport: http(),
});
const client = createWalletClient({
  chain: seiTestnet,
  transport: http(),
});

interface AssociateRequest {
    r: string;
    s: string;
    v: string;
    custom_message: string;
}

interface AssociateRequestSchema {
    Method: 'sei_associate';
    Parameters: [request: AssociateRequest];
    ReturnType: null;
}

const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

// Associate account using signed message
const associate = async () => {
  const account = privateKeyToAccount(PRIVATE_KEY);
  const newPk = generatePrivateKey();
  const newAccount = privateKeyToAccount(newPk);

  // Sign a message
  const message = "associate"
  const signature = await newAccount.signMessage({ message });
  const parsedSignature = parseSignature(signature);
    
  const messageLength = Buffer.from(message, 'utf8').length;
  const signedMessage = `\x19Ethereum Signed Message:\n${messageLength}${message}`;

  const response = await client.writeContract({
    account,
    address: ADDRESS_PRECOMPILE_ADDRESS,
    abi: ADDRESS_PRECOMPILE_ABI,
    functionName: "associate",
    args: [numberToHex(Number(parsedSignature.v)-27), parsedSignature.r, parsedSignature.s, signedMessage],
    gasPrice: BigInt(100_000_000_000), // 100 GWEI
  });
  console.log(response);

  // Get evm address after association
  await sleep(3000); // Sometimes it fails if you query it immeditely bc RPC nodes are behind
  const evmAddress = await publicClient.readContract({
    address: ADDRESS_PRECOMPILE_ADDRESS,
    abi: ADDRESS_PRECOMPILE_ABI,
    functionName: "getSeiAddr",
    args: [newAccount.address],
  });
  console.log(evmAddress);
};

// Associate account using public key
const associateViaPubkey = async () => {
  const account = privateKeyToAccount(PRIVATE_KEY);
  const newPk = generatePrivateKey();
  const newAccount = privateKeyToAccount(newPk);

  // compress pubkey
  const publicKeyBuffer = Buffer.from(newAccount.publicKey.slice(2), "hex");
  const compressedPubKey = secp256k1.publicKeyConvert(publicKeyBuffer, true);
  // console.log(newAccount.publicKey, toHex(compressedPublicKey));
  const response = await client.writeContract({
    account,
    address: ADDRESS_PRECOMPILE_ADDRESS,
    abi: ADDRESS_PRECOMPILE_ABI,
    functionName: "associatePubKey",
    args: [Buffer.from(compressedPubKey).toString("hex")],
    gasPrice: BigInt(100_000_000_000), // 100 GWEI
  });
  console.log(response);

  // Get evm address after association
  await sleep(3000); // Sometimes it fails if you query it immeditely bc RPC nodes are behind
  const evmAddress = await publicClient.readContract({
    address: ADDRESS_PRECOMPILE_ADDRESS,
    abi: ADDRESS_PRECOMPILE_ABI,
    functionName: "getSeiAddr",
    args: [newAccount.address],
  });
  console.log(evmAddress);
};

// Associate account using a signed message without gas (only allowed if the account already has funds)
const associateGasless = async (signature: `0x${string}`, message: string) => {
    const parsedSignature = parseSignature(signature);

    const messageLength = Buffer.from(message, 'utf8').length;
    const messageToSign = `\x19Ethereum Signed Message:\n${messageLength}${message}`;
    const request: AssociateRequest = {
        r: parsedSignature.r,
        s: parsedSignature.s,
        v: numberToHex(Number(parsedSignature.v)-27),
        custom_message: messageToSign
    };

    const response = await client.request<AssociateRequestSchema>({
        method: 'sei_associate',
        params: [request]
    });
    console.log(response);
}

const main = async () => {
    associate();
    // associateViaPubkey();
    // associateGasless(signature, message);
}

main();