interface Order {
  sellToken: string;
  buyToken: string;
  receiver: string;
  sellAmount: BigNumberish;
  buyAmount: BigNumberish;
  validTo: number | Date;
  appData: string;
  feeAmount: BigNumberish;
  kind: OrderKind;
  partiallyFillable: boolean;
  sellTokenBalance?: OrderBalance;
  buyTokenBalance?: OrderBalance;
}

const sellOrder: Order = {
  sellToken: WETH,
  buyToken: DAI,
  sellAmount: ethers.utils.parseEther("1.0"),   // Exact
  buyAmount: ethers.utils.parseEther("2000"),    // Minimum
  kind: OrderKind.SELL,
  // ...
};

const buyOrder: Order = {
  sellToken: WETH,
  buyToken: DAI,
  sellAmount: ethers.utils.parseEther("1.1"),    // Maximum
  buyAmount: ethers.utils.parseEther("2000"),     // Exact
  kind: OrderKind.BUY,
  // ...
};

import { normalizeOrder } from "@cowprotocol/contracts";

const normalized = normalizeOrder(order);

import { hashOrder, domain } from "@cowprotocol/contracts";

const settlementDomain = domain(1, "0x9008D19f58AAbD9eD0D60971565AA8510560ab41");
const hash = hashOrder(settlementDomain, order);

import { computeOrderUid } from "@cowprotocol/contracts";

const uid = computeOrderUid(settlementDomain, order, ownerAddress);

import { extractOrderUidParams } from "@cowprotocol/contracts";

const { orderDigest, owner, validTo } = extractOrderUidParams(uid);

// Special address for purchasing native ETH (use only in buyToken field)
const BUY_ETH_ADDRESS = "0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE";

// Order UID length in bytes
const ORDER_UID_LENGTH = 56;