const encoder = new SettlementEncoder(domain: TypedDataDomain);

encoder.encodeTrade(
  order: Order,
  signature: Signature,
  execution?: TradeExecution
): void;

await encoder.signEncodeTrade(
  order: Order,
  signer: Signer,
  scheme: SigningScheme,
  execution?: TradeExecution
): Promise<void>;

encoder.encodeInteraction(
  interaction: InteractionLike,
  stage?: InteractionStage
): void;

encoder.encodedSettlement(
  prices: Record<string, BigNumberish>
): EncodedSettlement;

encoder.clearingPrices(
  prices: Record<string, BigNumberish>
): BigNumberish[];

const registry = new TokenRegistry();
const index = registry.index(tokenAddress);

enum InteractionStage {
  PRE = 0,   // Before trading (e.g., permit approvals)
  INTRA = 1, // During token swaps (e.g., AMM operations)
  POST = 2,  // After settlement completion
}

interface TradeExecution {
  executedAmount: BigNumberish;
}

type EncodedSettlement = [
  string[],              // tokens
  BigNumberish[],        // clearingPrices
  Trade[],               // trades
  Interaction[][],       // [pre, intra, post] interactions
];

import {
  domain,
  SettlementEncoder,
  SigningScheme,
  InteractionStage,
  Order,
  OrderKind,
} from "@cowprotocol/contracts";
import { ethers } from "ethers";

const settlementDomain = domain(1, "0x9008D19f58AAbD9eD0D60971565AA8510560ab41");
const encoder = new SettlementEncoder(settlementDomain);

const order: Order = {
  sellToken: WETH,
  buyToken: DAI,
  sellAmount: ethers.utils.parseEther("1"),
  buyAmount: ethers.utils.parseEther("2000"),
  validTo: Math.floor(Date.now() / 1000) + 3600,
  appData: ethers.constants.HashZero,
  feeAmount: ethers.utils.parseEther("0.01"),
  kind: OrderKind.SELL,
  partiallyFillable: false,
  receiver: ethers.constants.AddressZero,
};

await encoder.signEncodeTrade(order, wallet, SigningScheme.EIP712);

const settlement = encoder.encodedSettlement({
  [WETH]: ethers.utils.parseEther("2000"),
  [DAI]: ethers.utils.parseEther("1"),
});