Stake

import {
    createSolanaRpc,
    createSolanaRpcSubscriptions,
    address,
    pipe,
    createTransactionMessage,
    setTransactionMessageFeePayerSigner,
    setTransactionMessageLifetimeUsingBlockhash,
    appendTransactionMessageInstructions,
    signTransactionMessageWithSigners,
    getSignatureFromTransaction,
    assertIsTransactionWithinSizeLimit,
    sendAndConfirmTransactionFactory,
} from "@solana/kit";
import { parseKeypairFile } from "@kamino-finance/klend-sdk/dist/utils/signer";
import { Farms, FarmState } from "@kamino-finance/farms-sdk";
import { getScopePricesFromFarm } from "@kamino-finance/farms-sdk/dist/utils/option";
import Decimal from "decimal.js";

const KEYPAIR_FILE = "/path/to/your/keypair.json";
const RPC_ENDPOINT = "https://api.mainnet-beta.solana.com";
const WS_ENDPOINT = "wss://api.mainnet-beta.solana.com";

const FARM = address("9wSacmF3KBr4HmgncxXeBhDdw4Shi2X9ETAFzWJS6pG6"); // non-delegated farm
const STAKE_MINT = address("3EmfhZ3KUaYdwKZ9CwfGoKRqQqUV1MhSCVL5Ch7szX7e"); // the farm's stake token
const STAKE_AMOUNT = new Decimal(0.02); // amount of shares to stake

const signer = await parseKeypairFile(KEYPAIR_FILE);
const rpc = createSolanaRpc(RPC_ENDPOINT);
const rpcSubscriptions = createSolanaRpcSubscriptions(WS_ENDPOINT);
const farms = new Farms(rpc);

const farmState = await FarmState.fetch(rpc, FARM);
if (!farmState) console.log(`Farm not found: ${FARM}`);

const scopePrices = getScopePricesFromFarm(farmState);
const decimals = farmState.token.decimals.toNumber();
const amountLamports = STAKE_AMOUNT.mul(new Decimal(10).pow(decimals));

const existing = await farms
    .getUserStateKeyForUndelegatedFarm(signer.address, FARM)
    .catch(() => null);

const instructions = [
    ...(existing ? [] : [await farms.createNewUserIx(signer, FARM)]),
    await farms.refreshFarmIx(FARM, scopePrices),
    ...(existing ? [await farms.refreshUserIx(existing.key, FARM, scopePrices)] : []),
    await farms.stakeIx(signer, FARM, amountLamports, STAKE_MINT, scopePrices),
];

const { value: blockhash } = await rpc
    .getLatestBlockhash({ commitment: "finalized" })
    .send();

const transactionMessage = pipe(
    createTransactionMessage({ version: 0 }),
    (m) => setTransactionMessageFeePayerSigner(signer, m),
    (m) => setTransactionMessageLifetimeUsingBlockhash(blockhash, m),
    (m) => appendTransactionMessageInstructions(instructions, m),
);

const signedTransaction = await signTransactionMessageWithSigners(transactionMessage);
assertIsTransactionWithinSizeLimit(signedTransaction);
const signature = getSignatureFromTransaction(signedTransaction);

await sendAndConfirmTransactionFactory({ rpc, rpcSubscriptions })(signedTransaction, {
    commitment: "confirmed",
    skipPreflight: true,
});

console.log("Stake successful! Signature:", signature);