import { PublicKey, TransactionInstruction } from "@solana/web3.js";
import { idlAddress } from "@project-serum/anchor/dist/cjs/idl";

export async function createIdlUpgradeInstruction(
  programId: PublicKey,
  bufferAddress: PublicKey,
  upgradeAuthority: PublicKey
) {
  const prefix = Buffer.from("0a69e9a778bcf440", "hex");
  const ixn = Buffer.from("03", "hex");
  const data = Buffer.concat([prefix.reverse(), ixn]);
  const idlAddr = await idlAddress(programId);

  const keys = [
    {
      pubkey: bufferAddress,
      isWritable: true,
      isSigner: false,
    },
    {
      pubkey: idlAddr,
      isWritable: true,
      isSigner: false,
    },
    {
      pubkey: upgradeAuthority,
      isWritable: true,
      isSigner: true,
    },
  ];

  return new TransactionInstruction({
    keys,
    programId,
    data,
  });
}