import { AccountInfo, Connection, PublicKey } from "@solana/web3.js";
import {
  u64,
  AccountLayout,
  TOKEN_PROGRAM_ID,
  AccountInfo as TokenAccountInfo,
} from "@solana/spl-token";
import { truthy } from "./truthy";

export const deserializeAccount = (data: Buffer) => {
  const accountInfo = AccountLayout.decode(data);
  accountInfo.mint = new PublicKey(accountInfo.mint);
  accountInfo.owner = new PublicKey(accountInfo.owner);
  accountInfo.amount = u64.fromBuffer(accountInfo.amount);

  if (accountInfo.delegateOption === 0) {
    accountInfo.delegate = null;
    accountInfo.delegatedAmount = new u64(0);
  } else {
    accountInfo.delegate = new PublicKey(accountInfo.delegate);
    accountInfo.delegatedAmount = u64.fromBuffer(accountInfo.delegatedAmount);
  }

  accountInfo.isInitialized = accountInfo.state !== 0;
  accountInfo.isFrozen = accountInfo.state === 2;

  if (accountInfo.isNativeOption === 1) {
    accountInfo.rentExemptReserve = u64.fromBuffer(accountInfo.isNative);
    accountInfo.isNative = true;
  } else {
    accountInfo.rentExemptReserve = null;
    accountInfo.isNative = false;
  }

  if (accountInfo.closeAuthorityOption === 0) {
    accountInfo.closeAuthority = null;
  } else {
    accountInfo.closeAuthority = new PublicKey(accountInfo.closeAuthority);
  }

  return accountInfo;
};

export interface TokenAccount {
  pubkey: PublicKey;
  account: AccountInfo<Buffer>;
  info: TokenAccountInfo;
}

export const TokenAccountParser = (
  pubKey: PublicKey,
  info: AccountInfo<Buffer>
): TokenAccount | undefined => {
  // Sometimes a wrapped sol account gets closed, goes to 0 length,
  // triggers an update over wss which triggers this guy to get called
  // since your UI already logged that pubkey as a token account. Check for length.
  if (info.data.length > 0) {
    const buffer = Buffer.from(info.data);
    const data = deserializeAccount(buffer);

    const details = {
      pubkey: pubKey,
      account: {
        ...info,
      },
      info: data,
    } as TokenAccount;

    return details;
  }
};

export const getWalletTokenAccounts = async (
  connection: Connection,
  owner?: PublicKey
): Promise<TokenAccount[]> => {
  if (!owner) {
    return [];
  }

  // user accounts are updated via ws subscription
  const accounts = await connection.getTokenAccountsByOwner(owner, {
    programId: TOKEN_PROGRAM_ID,
  });

  const tokenAccounts = accounts.value
    .map((info) => TokenAccountParser(info.pubkey, info.account))
    .filter(truthy)
    .filter((t) => t.info.amount.gt(new u64(0)));

  return tokenAccounts;
};