Capture a Partial Amount

function capture(
    bytes32 orderId,
    address payer,
    uint256 actualAmount,
    uint256 authorizedMaximum,
    uint256 permitDeadline,
    uint8 v,
    bytes32 r,
    bytes32 s
) external {
    if (msg.sender != merchant) revert NotMerchant();
    if (captured[orderId]) revert OrderAlreadyCaptured(orderId);
    if (actualAmount > authorizedMaximum) revert AmountExceedsMaximum();
    captured[orderId] = true;

    token.permit(payer, address(this), authorizedMaximum, permitDeadline, v, r, s);
    require(token.transferFrom(payer, merchant, actualAmount), "transfer failed");
    emit PaymentCaptured(orderId, payer, actualAmount, authorizedMaximum);
}

export async function authorizeVariablePayment(
  checkout: Address,
  orderId: string,
  maximum: string,
): Promise<VariablePayment> {
  const { account: payer, publicClient: browserClient, walletClient } = await browserClients();
  const [name, version, nonce] = await Promise.all([
    browserClient.readContract({ address: USDC, abi: usdcAbi, functionName: "name" }),
    browserClient.readContract({ address: USDC, abi: usdcAbi, functionName: "version" }),
    browserClient.readContract({ address: USDC, abi: usdcAbi, functionName: "nonces", args: [payer] }),
  ]);
  const value = parseUnits(maximum, 6);
  const deadline = BigInt(Math.floor(Date.now() / 1000) + 15 * 60);
  const signature = await walletClient.signTypedData({
    account: payer,
    domain: { name, version, chainId: baseSepolia.id, verifyingContract: USDC },
    types: permitTypes,
    primaryType: "Permit",
    message: { owner: payer, spender: checkout, value, nonce, deadline },
  });
  return { orderId: stringToHex(orderId, { size: 32 }), payer, maximum: value, deadline, signature };
}

export async function captureVariablePayment(
  checkout: Address,
  payment: VariablePayment,
  actual: string,
) {
  const actualAmount = parseUnits(actual, 6);
  if (actualAmount > payment.maximum) throw new Error("Actual amount exceeds the signed maximum");
  const { v, r, s } = parseSignature(payment.signature);
  const simulation = await publicClient.simulateContract({
    account,
    address: checkout,
    abi: checkoutAbi,
    functionName: "capture",
    args: [payment.orderId, payment.payer, actualAmount, payment.maximum, payment.deadline, Number(v), r, s],
  });
  const hash = await merchantWallet.writeContract(simulation.request);
  return publicClient.waitForTransactionReceipt({ hash, confirmations: 2 });
}