WIP: Integrate withdrawals with OrangeKit and tBTC SDK

This branch expects two dependencies changes that are not yet merged:
- @keep-network/tbtc-v2.ts: keep-network/tbtc-v2#814
- @orangekit/sdk: thesis/orangekit#83

sdk/src/acre.ts

@@ -1,11 +1,7 @@
 import { OrangeKitSdk } from "@orangekit/sdk"
 import { getDefaultProvider } from "ethers"
 import { AcreContracts } from "./lib/contracts"
-import {
-  EthereumAddress,
-  EthereumNetwork,
-  getEthereumContracts,
-} from "./lib/ethereum"
+import { EthereumNetwork, getEthereumContracts } from "./lib/ethereum"
 import Account from "./modules/account"
 import Tbtc from "./modules/tbtc"
 import { VoidSigner } from "./lib/utils"
@@ -71,14 +67,12 @@ class Acre {
     )
 
     const accountBitcoinAddress = await bitcoinProvider.getAddress()
-    const accountEthereumAddress = EthereumAddress.from(
-      await orangeKit.predictAddress(accountBitcoinAddress),
+    const accountEthereumAddress = await orangeKit.predictAddress(
+      accountBitcoinAddress,
     )
+    const accountPublicKey = await bitcoinProvider.getPublicKey()
 
-    const signer = new VoidSigner(
-      accountEthereumAddress.identifierHex,
-      ethersProvider,
-    )
+    const signer = new VoidSigner(accountEthereumAddress, ethersProvider)
 
     const contracts = getEthereumContracts(signer, ethereumNetwork)
 
@@ -88,15 +82,18 @@ class Acre {
       tbtcApiUrl,
       contracts.bitcoinDepositor,
     )
+
     const subgraph = new AcreSubgraphApi(
       // TODO: Set correct url based on the network
       "https://api.studio.thegraph.com/query/73600/acre/version/latest",
     )
 
-    const account = new Account(contracts, tbtc, subgraph, {
+    const account = new Account(contracts, tbtc, subgraph, orangeKit, {
       bitcoinAddress: accountBitcoinAddress,
       ethereumAddress: accountEthereumAddress,
+      publicKey: accountPublicKey,
     })
+
     const protocol = new Protocol(contracts)
 
     return new Acre(

sdk/src/lib/contracts/stbtc.ts

@@ -1,6 +1,11 @@
 import { ChainIdentifier } from "./chain-identifier"
 
 export interface StBTC {
+  /**
+   * @returns The chain-specific identifier of this contract.
+   */
+  getAddress(): ChainIdentifier
+
   /**
    * @param identifier The generic chain identifier.
    * @returns Value of the basis for calculating final BTC balance.
@@ -20,4 +25,16 @@ export interface StBTC {
    * @returns Deposit fee.
    */
   calculateDepositFee(amount: bigint): Promise<bigint>
+
+  /**
+   * Calculates the amount of tBTC that will be redeemed for the given amount
+   * of stBTC shares.
+   * @param amount Amount of stBTC shares to redeem.
+   */
+  previewRedeem(amount: bigint): Promise<bigint>
+
+  encodeRedeemToBitcoinFunctionData(
+    stbtcAmount: bigint,
+    tbtcRedemptionData: string,
+  ): string
 }

sdk/src/lib/ethereum/stbtc.ts

@@ -18,11 +18,17 @@ class EthereumStBTC
 {
   readonly #BASIS_POINT_SCALE = BigInt(1e4)
 
+  readonly #bitcoinRedeemerContractAddress: string
+
   #cache: {
     entryFeeBasisPoints?: bigint
   } = { entryFeeBasisPoints: undefined }
 
-  constructor(config: EthersContractConfig, network: EthereumNetwork) {
+  constructor(
+    config: EthersContractConfig,
+    network: EthereumNetwork,
+    bitcoinRedeemerContractAddress: string,
+  ) {
     let artifact: EthersContractDeployment
 
     switch (network) {
@@ -35,6 +41,15 @@ class EthereumStBTC
     }
 
     super(config, artifact)
+
+    this.#bitcoinRedeemerContractAddress = bitcoinRedeemerContractAddress
+  }
+
+  /**
+   * @see {StBTC#previewRedeem}
+   */
+  previewRedeem(sharesAmount: bigint): Promise<bigint> {
+    return this.instance.previewRedeem(sharesAmount)
   }
 
   /**
@@ -54,11 +69,11 @@ class EthereumStBTC
   /**
    * @see {StBTC#calculateDepositFee}
    */
-  async calculateDepositFee(amount: bigint): Promise<bigint> {
+  async calculateDepositFee(tbtcAmount: bigint): Promise<bigint> {
     const entryFeeBasisPoints = await this.#getEntryFeeBasisPoints()
 
     return (
-      (amount * entryFeeBasisPoints) /
+      (tbtcAmount * entryFeeBasisPoints) /
       (entryFeeBasisPoints + this.#BASIS_POINT_SCALE)
     )
   }
@@ -72,6 +87,17 @@ class EthereumStBTC
 
     return this.#cache.entryFeeBasisPoints
   }
+
+  encodeRedeemToBitcoinFunctionData(
+    sharesAmount: bigint,
+    tbtcRedemptionData: string,
+  ): string {
+    return this.instance.interface.encodeFunctionData("approveAndCall", [
+      this.#bitcoinRedeemerContractAddress,
+      sharesAmount,
+      tbtcRedemptionData,
+    ])
+  }
 }
 
 // eslint-disable-next-line import/prefer-default-export

sdk/src/modules/account.ts

@@ -1,14 +1,15 @@
-import { AcreContracts, ChainIdentifier } from "../lib/contracts"
+import { OrangeKitSdk } from "@orangekit/sdk"
+import { AcreContracts } from "../lib/contracts"
 import StakeInitialization from "./staking"
 import { toSatoshi } from "../lib/utils"
 import Tbtc from "./tbtc"
 import AcreSubgraphApi from "../lib/api/AcreSubgraphApi"
 import { DepositStatus } from "../lib/api/TbtcApi"
-
-export { DepositReceipt } from "./tbtc"
+import WithdrawalService from "./withdrawal-service"
+import { EthereumAddress } from "../lib/ethereum"
 
 /**
- * Represents the deposit data.
+ * Represents the deposit data
  */
 export type Deposit = {
   /**
@@ -56,19 +57,32 @@ export default class Account {
 
   readonly #bitcoinAddress: string
 
-  readonly #ethereumAddress: ChainIdentifier
+  readonly #ethereumAddress: EthereumAddress
+
+  readonly #withdrawalService: WithdrawalService
 
   constructor(
     contracts: AcreContracts,
     tbtc: Tbtc,
     acreSubgraphApi: AcreSubgraphApi,
-    account: { bitcoinAddress: string; ethereumAddress: ChainIdentifier },
+    orangeKit: OrangeKitSdk,
+    accountData: {
+      bitcoinAddress: string
+      ethereumAddress: string
+      publicKey: string
+    },
   ) {
     this.#contracts = contracts
     this.#tbtc = tbtc
     this.#acreSubgraphApi = acreSubgraphApi
-    this.#bitcoinAddress = account.bitcoinAddress
-    this.#ethereumAddress = account.ethereumAddress
+    this.#bitcoinAddress = accountData.bitcoinAddress
+    this.#ethereumAddress = EthereumAddress.from(accountData.ethereumAddress)
+    this.#withdrawalService = new WithdrawalService(
+      contracts,
+      tbtc,
+      orangeKit,
+      accountData,
+    )
   }
 
   /**
@@ -102,6 +116,23 @@ export default class Account {
     return new StakeInitialization(tbtcDeposit)
   }
 
+  /**
+   * Initializes the withdrawal process.
+   * @param referral Data used for referral program.
+
+   * @returns Object represents the deposit process.
+   */
+  async initializeWithdrawal(
+    sharesAmount: bigint,
+    bitcoinSignMessageFn: (message: string) => Promise<string>,
+  ) {
+    return this.#withdrawalService.initiateWithdrawal(
+      this.#bitcoinAddress,
+      sharesAmount,
+      bitcoinSignMessageFn,
+    )
+  }
+
   /**
    * @returns Value of the basis for calculating final BTC balance in 1e18
    *          precision.

sdk/src/modules/tbtc/Tbtc.ts

@@ -1,4 +1,9 @@
-import { ChainIdentifier, TBTC as TbtcSdk } from "@keep-network/tbtc-v2.ts"
+import {
+  ChainIdentifier,
+  TBTC as TbtcSdk,
+  RedeemerProxy as TbtcRedeemerProxy,
+  EthereumAddress,
+} from "@keep-network/tbtc-v2.ts"
 
 import { ethers } from "ethers"
 import TbtcApi, { DepositStatus } from "../../lib/api/TbtcApi"
@@ -145,4 +150,32 @@ export default class Tbtc {
       timestamp: deposit.createdAt,
     }))
   }
+
+  async initiateRedemption(
+    redeemerAddress: string,
+    destinationBitcoinAddress: string,
+    tbtcAmount: bigint,
+    handleRedemptionRequestFn: (redemptionData: string) => Promise<string>,
+  ): Promise<string> {
+    const tbtcRedeemer: TbtcRedeemerProxy = {
+      redeemerAddress(): ChainIdentifier {
+        return EthereumAddress.from(redeemerAddress)
+      },
+      async requestRedemption(redemptionData: Hex): Promise<Hex> {
+        const txHash = await handleRedemptionRequestFn(
+          redemptionData.toPrefixedString(),
+        )
+        return Hex.from(txHash)
+      },
+    }
+
+    const { targetChainTxHash } =
+      await this.#tbtcSdk.redemptions.requestRedemptionWithProxy(
+        destinationBitcoinAddress,
+        tbtcAmount,
+        tbtcRedeemer,
+      )
+
+    return targetChainTxHash.toPrefixedString()
+  }
 }

sdk/src/modules/withdrawal-service.ts

@@ -0,0 +1,75 @@
+import { OrangeKitSdk } from "@orangekit/sdk"
+
+import { AcreContracts } from "../lib/contracts"
+
+import Tbtc from "./tbtc"
+
+export default class WithdrawalService {
+  readonly #contracts: AcreContracts
+
+  readonly #tbtc: Tbtc
+
+  #orangeKitSdk: OrangeKitSdk
+
+  #account: {
+    bitcoinAddress: string
+    ethereumAddress: string
+    publicKey: string
+  }
+
+  constructor(
+    contracts: AcreContracts,
+    tbtc: Tbtc,
+    orangeKitSdk: OrangeKitSdk,
+    account: {
+      bitcoinAddress: string
+      ethereumAddress: string
+      publicKey: string
+    },
+  ) {
+    this.#contracts = contracts
+    this.#tbtc = tbtc
+    this.#orangeKitSdk = orangeKitSdk
+    this.#account = account
+  }
+
+  async initiateWithdrawal(
+    destinationBitcoinAddress: string,
+    sharesAmount: bigint,
+    bitcoinSignMessageFn: (message: string) => Promise<string>,
+  ): Promise<string> {
+    // Estimate the amount of tBTC released after redeeming stBTC tokens.
+    // The value is required by the tBTC SDK to determine the tBTC Wallet from
+    // which the Bitcoin will be bridged to the depositor's Bitcoin address.
+    const tbtcAmount = await this.#contracts.stBTC.previewRedeem(sharesAmount)
+
+    const requestRedemptionWithOrangeKit = async (
+      tbtcRedemptionData: string,
+    ) => {
+      const safeTxData =
+        this.#contracts.stBTC.encodeRedeemToBitcoinFunctionData(
+          sharesAmount,
+          tbtcRedemptionData,
+        )
+
+      const transactionHash = await this.#orangeKitSdk.sendTransaction(
+        this.#contracts.stBTC.getAddress(),
+        "0x0",
+        safeTxData,
+        this.#account.bitcoinAddress,
+        this.#account.publicKey,
+        bitcoinSignMessageFn,
+      )
+
+      // TODO: CHANGE RESULT
+      return transactionHash
+    }
+
+    return this.#tbtc.initiateRedemption(
+      this.#account.ethereumAddress,
+      destinationBitcoinAddress,
+      tbtcAmount,
+      requestRedemptionWithOrangeKit,
+    )
+  }
+}