import {
  createAssociatedTokenAccountInstruction,
  getAssociatedTokenAddress
} from '@solana/spl-token';
import type { Connection, PublicKey, Transaction } from '@solana/web3.js';

/**
 * Utility function for adding a find or init associated token account instruction to a transaction
 * Useful when using associated token accounts so you can be sure they are created before hand
 * @param transaction
 * @param connection
 * @param mint
 * @param owner
 * @param payer
 * @param allowOwnerOffCurve
 * @returns The associated token account ID that was found or will be created. This also adds the relevent instruction to create it to the transaction if not found
 */
export async function withFindOrInitAssociatedTokenAccount(
  transaction: Transaction,
  connection: Connection,
  mint: PublicKey,
  owner: PublicKey,
  payer: PublicKey,
  allowOwnerOffCurve?: boolean
): Promise<PublicKey> {
  const associatedToken = await getAssociatedTokenAddress(
    mint,
    owner,
    allowOwnerOffCurve
  );
  const account = await connection.getAccountInfo(associatedToken);
  if (!account) {
    transaction.add(
      createAssociatedTokenAccountInstruction(
        payer,
        associatedToken,
        owner,
        mint
      )
    );
  }
  return associatedToken;
}