@atomiqlabs/sdk/src/swaps/escrow_swaps/frombtc/onchain/FromBTCSwap.ts

atomiq labs SDK for cross-chain swaps between smart chains and bitcoin

import {IFromBTCSelfInitSwap} from "../IFromBTCSelfInitSwap";
import {SwapType} from "../../../../enums/SwapType";
import {FromBTCDefinition, FromBTCWrapper} from "./FromBTCWrapper";
import {
    BtcTxWithBlockheight,
    ChainType,
    isAbstractSigner,
    SwapCommitState,
    SwapCommitStateType,
    SwapData
} from "@atomiqlabs/base";
import {Buffer} from "buffer";
import {
    extendAbortController,
    getTxoHash, toBigInt
} from "../../../../utils/Utils";
import {
    fromOutputScript, getSenderAddress, getVoutIndex,
    parsePsbtTransaction,
    toOutputScript,
} from "../../../../utils/BitcoinUtils";
import {IBitcoinWallet, isIBitcoinWallet} from "../../../../bitcoin/wallet/IBitcoinWallet";
import {IBTCWalletSwap} from "../../../IBTCWalletSwap";
import {Transaction} from "@scure/btc-signer";
import {SingleAddressBitcoinWallet} from "../../../../bitcoin/wallet/SingleAddressBitcoinWallet";
import {
    MinimalBitcoinWalletInterface,
    MinimalBitcoinWalletInterfaceWithSigner
} from "../../../../types/wallets/MinimalBitcoinWalletInterface";
import {IClaimableSwap} from "../../../IClaimableSwap";
import {IEscrowSelfInitSwapInit, isIEscrowSelfInitSwapInit} from "../../IEscrowSelfInitSwap";
import {IAddressSwap} from "../../../IAddressSwap";
import {TokenAmount, toTokenAmount} from "../../../../types/TokenAmount";
import {BitcoinTokens, BtcToken, SCToken} from "../../../../types/Token";
import {getLogger, LoggerType} from "../../../../utils/Logger";
import {timeoutPromise} from "../../../../utils/TimeoutUtils";
import {toBitcoinWallet} from "../../../../utils/BitcoinWalletUtils";
import {
    SwapExecutionActionSendToAddress,
    SwapExecutionActionSignPSBT,
    SwapExecutionActionSignSmartChainTx,
    SwapExecutionActionWait
} from "../../../../types/SwapExecutionAction";
import {
    SwapExecutionStepPayment,
    SwapExecutionStepSettlement,
    SwapExecutionStepSetup
} from "../../../../types/SwapExecutionStep";
import {SwapStateInfo} from "../../../../types/SwapStateInfo";

/**
 * State enum for legacy escrow based Bitcoin -> Smart chain swaps.
 *
 * @category Swaps/Legacy/Bitcoin → Smart chain
 */
export enum FromBTCSwapState {
    /**
     * Bitcoin swap address has expired and the intermediary (LP) has already refunded
     *  its funds. No BTC should be sent anymore!
     */
    FAILED = -4,
    /**
     * Bitcoin swap address has expired, user should not send any BTC anymore! Though
     *  the intermediary (LP) hasn't refunded yet. So if there is a transaction already
     *  in-flight the swap might still succeed.
     */
    EXPIRED = -3,
    /**
     * Swap has expired for good and there is no way how it can be executed anymore
     */
    QUOTE_EXPIRED = -2,
    /**
     * A swap is almost expired, and it should be presented to the user as expired, though
     *  there is still a chance that it will be processed
     */
    QUOTE_SOFT_EXPIRED = -1,
    /**
     * Swap quote was created, use the {@link FromBTCSwap.commit} or {@link FromBTCSwap.txsCommit} functions
     *  to initiate it by creating the swap escrow on the destination smart chain
     */
    PR_CREATED = 0,
    /**
     * Swap escrow was initiated (committed) on the destination chain, user can send the BTC to the
     *  swap address with the {@link FromBTCSwap.getFundedPsbt}, {@link FromBTCSwap.getAddress} or
     *  {@link FromBTCSwap.getHyperlink} functions.
     */
    CLAIM_COMMITED = 1,
    /**
     * Input bitcoin transaction was confirmed, wait for automatic settlement by the watchtowers
     *  using the {@link FromBTCSwap.waitTillClaimed} function or settle manually using the {@link FromBTCSwap.claim}
     *  or {@link FromBTCSwap.txsClaim} function.
     */
    BTC_TX_CONFIRMED = 2,
    /**
     * Swap successfully settled and funds received on the destination chain
     */
    CLAIM_CLAIMED = 3
}

const FromBTCSwapStateDescription = {
    [FromBTCSwapState.FAILED]: "Bitcoin swap address has expired and the intermediary (LP) has already refunded its funds. No BTC should be sent anymore!",
    [FromBTCSwapState.EXPIRED]: "Bitcoin swap address has expired, user should not send any BTC anymore! Though the intermediary (LP) hasn't refunded yet. So if there is a transaction already in-flight the swap might still succeed.",
    [FromBTCSwapState.QUOTE_EXPIRED]: "Swap has expired for good and there is no way how it can be executed anymore",
    [FromBTCSwapState.QUOTE_SOFT_EXPIRED]: "The swap is expired, though there is still a chance that it will be processed",
    [FromBTCSwapState.PR_CREATED]: "Swap quote was created, initiate it by creating the swap escrow on the destination smart chain",
    [FromBTCSwapState.CLAIM_COMMITED]: "Swap escrow was initiated (committed) on the destination chain, user can send the BTC to the Bitcoin swap address.",
    [FromBTCSwapState.BTC_TX_CONFIRMED]: "Input bitcoin transaction was confirmed, wait for automatic settlement by the watchtower or settle manually.",
    [FromBTCSwapState.CLAIM_CLAIMED]: "Swap successfully settled and funds received on the destination chain"
};

export type FromBTCSwapInit<T extends SwapData> = IEscrowSelfInitSwapInit<T> & {
    data: T;
    address?: string;
    amount?: bigint;
    requiredConfirmations?: number;
};

export function isFromBTCSwapInit<T extends SwapData>(obj: any): obj is FromBTCSwapInit<T> {
    return typeof(obj.data) === "object" &&
        (obj.address==null || typeof(obj.address) === "string") &&
        (obj.amount==null || typeof(obj.amount) === "bigint") &&
        (obj.requiredConfirmations==null || typeof(obj.requiredConfirmations) === "number") &&
        isIEscrowSelfInitSwapInit<T>(obj);
}

/**
 * Legacy escrow (PrTLC) based swap for Bitcoin -> Smart chains, requires manual initiation
 *  of the swap escrow on the destination chain.
 *
 * @category Swaps/Legacy/Bitcoin → Smart chain
 */
export class FromBTCSwap<T extends ChainType = ChainType>
    extends IFromBTCSelfInitSwap<T, FromBTCDefinition<T>, FromBTCSwapState>
    implements IBTCWalletSwap, IClaimableSwap<T, FromBTCDefinition<T>, FromBTCSwapState>, IAddressSwap {

    protected readonly TYPE: SwapType.FROM_BTC = SwapType.FROM_BTC;
    /**
     * @internal
     */
    protected readonly swapStateName = (state: number) => FromBTCSwapState[state];
    /**
     * @internal
     */
    protected readonly swapStateDescription = FromBTCSwapStateDescription;
    /**
     * @internal
     */
    protected readonly logger: LoggerType;
    /**
     * @internal
     */
    protected readonly inputToken: BtcToken<false> = BitcoinTokens.BTC;
    /**
     * @internal
     */
    protected readonly feeRate!: string;

    /**
     * @internal
     */
    readonly _data!: T["Data"];

    private address?: string;
    private amount?: bigint;
    private requiredConfirmations?: number;

    private senderAddress?: string;
    private txId?: string;
    private vout?: number;

    private btcTxConfirmedAt?: number;

    constructor(wrapper: FromBTCWrapper<T>, init: FromBTCSwapInit<T["Data"]>);
    constructor(wrapper: FromBTCWrapper<T>, obj: any);
    constructor(wrapper: FromBTCWrapper<T>, initOrObject: FromBTCSwapInit<T["Data"]> | any) {
        if(isFromBTCSwapInit(initOrObject) && initOrObject.url!=null) initOrObject.url += "/frombtc";
        super(wrapper, initOrObject);
        if(isFromBTCSwapInit(initOrObject)) {
            this._state = FromBTCSwapState.PR_CREATED;
            this._data = initOrObject.data;
            this.feeRate = initOrObject.feeRate;
            this.address = initOrObject.address;
            this.amount = initOrObject.amount;
            this.requiredConfirmations = initOrObject.requiredConfirmations;
        } else {
            this.address = initOrObject.address;
            this.amount = toBigInt(initOrObject.amount);
            this.senderAddress = initOrObject.senderAddress;
            this.txId = initOrObject.txId;
            this.vout = initOrObject.vout;
            this.requiredConfirmations = initOrObject.requiredConfirmations ?? this._data.getConfirmationsHint();
            this.btcTxConfirmedAt = initOrObject.btcTxConfirmedAt;
        }
        this.tryRecomputeSwapPrice();
        this.logger = getLogger("FromBTC("+this.getIdentifierHashString()+"): ");
    }

    /**
     * @inheritDoc
     * @internal
     */
    protected getSwapData(): T["Data"] {
        return this._data;
    }

    /**
     * @inheritDoc
     * @internal
     */
    protected upgradeVersion() {
        if(this.version == null) {
            switch(this._state) {
                case -2:
                    this._state = FromBTCSwapState.FAILED
                    break;
                case -1:
                    this._state = FromBTCSwapState.QUOTE_EXPIRED
                    break;
                case 0:
                    this._state = FromBTCSwapState.PR_CREATED
                    break;
                case 1:
                    this._state = FromBTCSwapState.CLAIM_COMMITED
                    break;
                case 2:
                    this._state = FromBTCSwapState.BTC_TX_CONFIRMED
                    break;
                case 3:
                    this._state = FromBTCSwapState.CLAIM_CLAIMED
                    break;
            }
            this.version = 1;
        }
    }


    //////////////////////////////
    //// Getters & utils

    /**
     * Returns bitcoin address where the on-chain BTC should be sent to
     */
    getAddress(): string {
        if(this._state===FromBTCSwapState.PR_CREATED) throw new Error("Cannot get bitcoin address of non-initiated swaps! Initiate swap first with commit() or txsCommit().");
        return this.address ?? "";
    }

    /**
     * Unsafe bitcoin hyperlink getter, returns the address even before the swap is committed!
     *
     * @private
     */
    private _getHyperlink(): string {
        return this.address==null || this.amount==null ? "" : "bitcoin:"+this.address+"?amount="+encodeURIComponent((Number(this.amount) / 100000000).toString(10));
    }

    /**
     * @inheritDoc
     */
    getHyperlink(): string {
        if(this._state===FromBTCSwapState.PR_CREATED) throw new Error("Cannot get bitcoin address of non-initiated swaps! Initiate swap first with commit() or txsCommit().");
        return this._getHyperlink();
    }

    /**
     * @inheritDoc
     */
    getInputAddress(): string | null {
        return this.senderAddress ?? null;
    }

    /**
     * @inheritDoc
     */
    getInputTxId(): string | null {
        return this.txId ?? null;
    }

    private async _setSubmittedBitcoinTx(txId: string, psbt?: Transaction): Promise<void> {
        let changed = false;
        if(this.txId!==txId) {
            this.txId = txId;
            changed = true;
        }

        const submittedVout = this.address==null || this.amount==null || psbt==null
            ? undefined
            : getVoutIndex(psbt, this.wrapper._options.bitcoinNetwork, this.address, this.amount);
        if(submittedVout!=null && this.vout!==submittedVout) {
            this.vout = submittedVout;
            changed = true;
        }

        const submittedSenderAddress = psbt==null
            ? undefined
            : getSenderAddress(psbt, this.wrapper._options.bitcoinNetwork);
        if(submittedSenderAddress!=null && this.senderAddress!==submittedSenderAddress) {
            this.senderAddress = submittedSenderAddress;
            changed = true;
        }

        if(changed) await this._saveAndEmit();
    }

    /**
     * Returns timeout time (in UNIX milliseconds) when the on-chain address will expire and no funds should be sent
     *  to that address anymore
     */
    getTimeoutTime(): number {
        return Number(this.wrapper._getOnchainSendTimeout(this._data, this.requiredConfirmations ?? 6)) * 1000;
    }

    /**
     * @inheritDoc
     */
    requiresAction(): boolean {
        return this.isClaimable() || (this._state===FromBTCSwapState.CLAIM_COMMITED && this.getTimeoutTime()>Date.now() && this.txId==null);
    }

    /**
     * @inheritDoc
     */
    isFinished(): boolean {
        return this._state===FromBTCSwapState.CLAIM_CLAIMED || this._state===FromBTCSwapState.QUOTE_EXPIRED || this._state===FromBTCSwapState.FAILED;
    }

    /**
     * @inheritDoc
     */
    isClaimable(): boolean {
        return this._state===FromBTCSwapState.BTC_TX_CONFIRMED;
    }

    /**
     * @inheritDoc
     */
    isSuccessful(): boolean {
        return this._state===FromBTCSwapState.CLAIM_CLAIMED;
    }

    /**
     * @inheritDoc
     */
    isFailed(): boolean {
        return this._state===FromBTCSwapState.FAILED || this._state===FromBTCSwapState.EXPIRED;
    }

    /**
     * @inheritDoc
     */
    isInProgress(): boolean {
        return this._state===FromBTCSwapState.CLAIM_COMMITED ||
            this._state===FromBTCSwapState.BTC_TX_CONFIRMED;
    }

    /**
     * @inheritDoc
     */
    isQuoteExpired(): boolean {
        return this._state===FromBTCSwapState.QUOTE_EXPIRED;
    }

    /**
     * @inheritDoc
     */
    isQuoteSoftExpired(): boolean {
        return this._state===FromBTCSwapState.QUOTE_EXPIRED || this._state===FromBTCSwapState.QUOTE_SOFT_EXPIRED;
    }

    /**
     * @inheritDoc
     * @internal
     */
    protected canCommit(skipQuoteExpiryChecks?: boolean): boolean {
        if(this._state!==FromBTCSwapState.PR_CREATED && (!skipQuoteExpiryChecks || this._state!==FromBTCSwapState.QUOTE_SOFT_EXPIRED)) return false;
        if(this.requiredConfirmations==null) return false;
        const expiry = this.wrapper._getOnchainSendTimeout(this._data, this.requiredConfirmations);
        const currentTimestamp = BigInt(Math.floor(Date.now()/1000));

        return (expiry - currentTimestamp) >= this.wrapper._options.minSendWindow;
    }


    //////////////////////////////
    //// Amounts & fees

    /**
     * @inheritDoc
     */
    getInputToken(): BtcToken<false> {
        return BitcoinTokens.BTC;
    }

    /**
     * @inheritDoc
     */
    getInput(): TokenAmount<BtcToken<false>> {
        return toTokenAmount(this.amount ?? null, this.inputToken, this.wrapper._prices);
    }

    /**
     * Returns claimer bounty, acting as a reward for watchtowers to claim the swap automatically,
     *  this amount is pre-funded by the user on the destination chain when the swap escrow
     *  is initiated. For total pre-funded deposit amount see {@link getTotalDeposit}.
     */
    getClaimerBounty(): TokenAmount<SCToken<T["ChainId"]>, true> {
        return toTokenAmount(this._data.getClaimerBounty(), this.wrapper._tokens[this._data.getDepositToken()], this.wrapper._prices);
    }


    //////////////////////////////
    //// Bitcoin tx

    /**
     * If the required number of confirmations is not known, this function tries to infer it by looping through
     *  possible confirmation targets and comparing the claim hashes
     *
     * @param btcTx Bitcoin transaction
     * @param vout Output index of the desired output in the bitcoin transaction
     *
     * @private
     */
    private inferRequiredConfirmationsCount(btcTx: Omit<BtcTxWithBlockheight, "hex" | "raw">, vout: number): number | undefined {
        const txOut = btcTx.outs[vout];
        for(let i=1;i<=20;i++) {
            const computedClaimHash = this._contract.getHashForOnchain(
                Buffer.from(txOut.scriptPubKey.hex, "hex"),
                BigInt(txOut.value),
                i
            );
            if(computedClaimHash.toString("hex")===this._data.getClaimHash()) {
                return i;
            }
        }
    }

    /**
     * @inheritDoc
     */
    getRequiredConfirmationsCount(): number {
        return this.requiredConfirmations ?? NaN;
    }

    /**
     * Checks whether a bitcoin payment was already made, returns the payment or `null` when no payment has been made.
     *
     * @internal
     */
    protected async getBitcoinPayment(): Promise<{
        txId: string,
        vout: number,
        confirmations: number,
        targetConfirmations: number,
        inputAddresses?: string[]
    } | null> {
        const txoHashHint = this._data.getTxoHashHint();
        if(txoHashHint==null) throw new Error("Swap data doesn't include the txo hash hint! Cannot check bitcoin transaction!");
        if(this.address==null) throw new Error("Cannot check bitcoin payment, because the address is not known! This can happen after a swap is recovered.");

        const result = await this.wrapper._btcRpc.checkAddressTxos(this.address, Buffer.from(txoHashHint, "hex"));
        if(result==null) return null;

        if(this.requiredConfirmations==null) {
            this.requiredConfirmations = this.inferRequiredConfirmationsCount(result.tx, result.vout);
        }

        return {
            inputAddresses: result.tx.inputAddresses,
            txId: result.tx.txid,
            vout: result.vout,
            confirmations: result.tx.confirmations ?? 0,
            targetConfirmations: this.getRequiredConfirmationsCount()
        }
    }

    /**
     * Used to set the txId of the bitcoin payment from the on-chain events listener
     *
     * @param txId Transaction ID that settled the swap on the smart chain
     *
     * @internal
     */
    async _setBitcoinTxId(txId: string) {
        if(this.txId!==txId || this.address==null || this.vout==null || this.senderAddress==null || this.amount==null) {
            const btcTx = await this.wrapper._btcRpc.getTransaction(txId);
            if(btcTx==null) return;

            const txoHashHint = this._data.getTxoHashHint();
            if(txoHashHint!=null) {
                const expectedTxoHash = Buffer.from(txoHashHint, "hex");
                const vout = btcTx.outs.findIndex(out => getTxoHash(out.scriptPubKey.hex, out.value).equals(expectedTxoHash));
                if(vout!==-1) {
                    this.vout = vout;
                    //If amount or address are not known, parse them from the bitcoin tx
                    // this can happen if the swap is recovered from on-chain data and
                    // hence doesn't contain the address and amount data
                    if(this.amount==null) this.amount = BigInt(btcTx.outs[vout].value);
                    if(this.address==null) try {
                        this.address = fromOutputScript(this.wrapper._options.bitcoinNetwork, btcTx.outs[vout].scriptPubKey.hex);
                    } catch (e: any) {
                        this.logger.warn("_setBitcoinTxId(): Failed to parse address from output script: ", e);
                    }
                    if(this.requiredConfirmations==null) {
                        this.requiredConfirmations = this.inferRequiredConfirmationsCount(btcTx, vout);
                    }
                }
            }

            if(btcTx.inputAddresses!=null) {
                this.senderAddress = btcTx.inputAddresses[0];
            }
        }

        this.txId = txId;
    }

    /**
     * @inheritDoc
     *
     * @throws {Error} if in invalid state (must be {@link FromBTCSwapState.CLAIM_COMMITED})
     */
    async waitForBitcoinTransaction(
        updateCallback?: (txId?: string, confirmations?: number, targetConfirmations?: number, txEtaMs?: number) => void,
        checkIntervalSeconds?: number,
        abortSignal?: AbortSignal
    ): Promise<string> {
        if(this._state!==FromBTCSwapState.CLAIM_COMMITED && this._state!==FromBTCSwapState.EXPIRED) throw new Error("Must be in COMMITED state!");
        const txoHashHint = this._data.getTxoHashHint();
        if(txoHashHint==null) throw new Error("Swap data doesn't include the txo hash hint! Cannot check bitcoin transaction!");
        if(this.address==null) throw new Error("Cannot check bitcoin payment, because the address is not known! This can happen after a swap is recovered.");

        let abortedDueToEnoughConfirmationsResult: {
            tx: Omit<BtcTxWithBlockheight, "hex" | "raw">, vout: number
        } | undefined;
        const abortController = extendAbortController(abortSignal);

        const result = await this.wrapper._btcRpc.waitForAddressTxo(
            this.address,
            Buffer.from(txoHashHint, "hex"),
            this.requiredConfirmations ?? 6, //In case confirmation count is not known, we use a conservative estimate
            (btcTx?: Omit<BtcTxWithBlockheight, "hex" | "raw">, vout?: number, txEtaMs?: number) => {
                let requiredConfirmations = this.requiredConfirmations;

                if(btcTx!=null && vout!=null && requiredConfirmations==null) {
                    requiredConfirmations = this.inferRequiredConfirmationsCount(btcTx, vout);
                }

                if(btcTx!=null && (
                    btcTx.txid!==this.txId ||
                    this.vout==null ||
                    this.senderAddress==null ||
                    (this.requiredConfirmations==null && requiredConfirmations!=null)
                )) {
                    this.txId = btcTx.txid;
                    this.vout = vout;
                    this.requiredConfirmations = requiredConfirmations;
                    if(btcTx.inputAddresses!=null) this.senderAddress = btcTx.inputAddresses[0];
                    this._saveAndEmit().catch(e => {
                        this.logger.error("waitForBitcoinTransaction(): Failed to save swap from within waitForAddressTxo callback:", e)
                    });
                }

                //Abort the loop as soon as the transaction gets enough confirmations, this is required in case
                // we pass a default 6 confirmations to the fn, but then are able to infer the actual confirmation
                // target from the prior block
                if(btcTx?.confirmations!=null && requiredConfirmations!=null && requiredConfirmations<=btcTx.confirmations && vout!=null) {
                    abortedDueToEnoughConfirmationsResult = {
                        tx: btcTx,
                        vout
                    };
                    abortController.abort();
                    return;
                }

                if(updateCallback!=null) updateCallback(btcTx?.txid, btcTx==null ? undefined : (btcTx?.confirmations ?? 0), requiredConfirmations ?? NaN, txEtaMs);
            },
            abortController.signal,
            checkIntervalSeconds
        ).catch(e => {
            //We catch the case when the loop was aborted due to the transaction getting enough confirmations
            if(abortedDueToEnoughConfirmationsResult!=null) return abortedDueToEnoughConfirmationsResult;
            throw e;
        });

        if(abortSignal!=null) abortSignal.throwIfAborted();

        this.txId = result.tx.txid;
        this.vout = result.vout;
        if(result.tx.inputAddresses!=null) this.senderAddress = result.tx.inputAddresses[0];

        if(
            (this._state as FromBTCSwapState)!==FromBTCSwapState.CLAIM_CLAIMED &&
            (this._state as FromBTCSwapState)!==FromBTCSwapState.FAILED
        ) {
            this.btcTxConfirmedAt ??= Date.now();
            this._state = FromBTCSwapState.BTC_TX_CONFIRMED;
        }

        await this._saveAndEmit();

        return result.tx.txid;
    }

    /**
     * Private getter of the funded PSBT that doesn't check current state
     *
     * @param _bitcoinWallet Bitcoin wallet to fund the PSBT with
     * @param feeRate Optional bitcoin fee rate in sats/vB
     * @param additionalOutputs Optional additional outputs that should also be included in the generated PSBT
     *
     * @private
     */
    private async _getFundedPsbt(
        _bitcoinWallet: IBitcoinWallet | MinimalBitcoinWalletInterface,
        feeRate?: number,
        additionalOutputs?: ({amount: bigint, outputScript: Uint8Array} | {amount: bigint, address: string})[]
    ): Promise<{psbt: Transaction, psbtHex: string, psbtBase64: string, signInputs: number[], feeRate: number}> {
        if(this.address==null) throw new Error("Cannot create funded PSBT, because the address is not known! This can happen after a swap is recovered.");

        let bitcoinWallet: IBitcoinWallet;
        if(isIBitcoinWallet(_bitcoinWallet)) {
            bitcoinWallet = _bitcoinWallet;
        } else {
            bitcoinWallet = new SingleAddressBitcoinWallet(this.wrapper._btcRpc, this.wrapper._options.bitcoinNetwork, _bitcoinWallet);
        }
        //TODO: Maybe re-introduce fee rate check here if passed from the user
        if(feeRate==null) {
            feeRate = await bitcoinWallet.getFeeRate();
        }

        const basePsbt = new Transaction({
            allowUnknownOutputs: true,
            allowLegacyWitnessUtxo: true
        });
        basePsbt.addOutput({
            amount: this.amount,
            script: toOutputScript(this.wrapper._options.bitcoinNetwork, this.address)
        });
        if(additionalOutputs!=null) additionalOutputs.forEach(output => {
            basePsbt.addOutput({
                amount: output.amount,
                script: (output as {outputScript: Uint8Array}).outputScript ?? toOutputScript(this.wrapper._options.bitcoinNetwork, (output as {address: string}).address)
            });
        });

        const psbt = await bitcoinWallet.fundPsbt(basePsbt, feeRate);
        //Sign every input
        const signInputs: number[] = [];
        for(let i=0;i<psbt.inputsLength;i++) {
            signInputs.push(i);
        }
        const serializedPsbt = Buffer.from(psbt.toPSBT());
        return {
            psbt,
            psbtHex: serializedPsbt.toString("hex"),
            psbtBase64: serializedPsbt.toString("base64"),
            signInputs,
            feeRate
        };
    }

    /**
     * @inheritDoc
     */
    getFundedPsbt(
        _bitcoinWallet: IBitcoinWallet | MinimalBitcoinWalletInterface,
        feeRate?: number,
        additionalOutputs?: ({amount: bigint, outputScript: Uint8Array} | {amount: bigint, address: string})[]
    ) {
        if(this._state!==FromBTCSwapState.CLAIM_COMMITED)
            throw new Error("Swap not committed yet, please initiate the swap first with commit() call!");
        if(this.txId!=null)
            throw new Error("Bitcoin transaction already submitted for this swap!");
        return this._getFundedPsbt(_bitcoinWallet, feeRate, additionalOutputs);
    }

    /**
     * @inheritDoc
     *
     * @throws {Error} if the swap is in invalid state (not in {@link FromBTCSwapState.CLAIM_COMMITED}), or if
     *  the swap bitcoin address already expired.
     */
    async submitPsbt(_psbt: Transaction | string): Promise<string> {
        const psbt = parsePsbtTransaction(_psbt);
        if(this._state!==FromBTCSwapState.CLAIM_COMMITED)
            throw new Error("Swap not committed yet, please initiate the swap first with commit() call!");
        if(this.txId!=null)
            throw new Error("Bitcoin transaction already submitted for this swap!");

        //Ensure not expired
        if(this.getTimeoutTime()<Date.now()) {
            throw new Error("Swap address expired!");
        }

        const output0 = psbt.getOutput(0);
        if(this.amount!=null && output0.amount!==this.amount)
            throw new Error("PSBT output amount invalid, expected: "+this.amount+" got: "+output0.amount);
        if(this.address!=null) {
            const expectedOutputScript = toOutputScript(this.wrapper._options.bitcoinNetwork, this.address);
            if(output0.script==null || !expectedOutputScript.equals(output0.script))
                throw new Error("PSBT output script invalid!");
        }

        if(!psbt.isFinal) psbt.finalize();

        const txId = await this.wrapper._btcRpc.sendRawTransaction(Buffer.from(psbt.toBytes(true, true)).toString("hex"));
        await this._setSubmittedBitcoinTx(txId, psbt);
        return txId;
    }

    /**
     * @inheritDoc
     */
    async estimateBitcoinFee(_bitcoinWallet: IBitcoinWallet | MinimalBitcoinWalletInterface, feeRate?: number): Promise<TokenAmount<BtcToken<false>, true> | null> {
        if(this.address==null || this.amount==null) return null;
        const bitcoinWallet: IBitcoinWallet = toBitcoinWallet(_bitcoinWallet, this.wrapper._btcRpc, this.wrapper._options.bitcoinNetwork);
        const txFee = await bitcoinWallet.getTransactionFee(this.address, this.amount, feeRate);
        if(txFee==null) return null;
        return toTokenAmount(BigInt(txFee), BitcoinTokens.BTC, this.wrapper._prices);
    }

    /**
     * @inheritDoc
     */
    async sendBitcoinTransaction(wallet: IBitcoinWallet | MinimalBitcoinWalletInterfaceWithSigner, feeRate?: number): Promise<string> {
        if(this.address==null || this.amount==null) throw new Error("Cannot send bitcoin transaction, because the address is not known! This can happen after a swap is recovered.");

        if(this._state!==FromBTCSwapState.CLAIM_COMMITED)
            throw new Error("Swap not committed yet, please initiate the swap first with commit() call!");
        if(this.txId!=null)
            throw new Error("Bitcoin transaction already submitted for this swap!");

        //Ensure not expired
        if(this.getTimeoutTime()<Date.now()) {
            throw new Error("Swap address expired!");
        }

        if(isIBitcoinWallet(wallet)) {
            const txId = await wallet.sendTransaction(this.address, this.amount, feeRate);
            await this._setSubmittedBitcoinTx(txId);
            return txId;
        } else {
            const {psbt, psbtHex, psbtBase64, signInputs} = await this.getFundedPsbt(wallet, feeRate);
            const signedPsbt = await wallet.signPsbt({
                psbt, psbtHex, psbtBase64
            }, signInputs);
            return await this.submitPsbt(signedPsbt);
        }
    }


    //////////////////////////////
    //// Execution

    /**
     * Executes the swap with the provided bitcoin wallet,
     *
     * @param dstSigner Signer on the destination network, needs to have the same address as the one specified when
     *  quote was created, this is required for legacy swaps because the destination wallet needs to actively open
     *  a bitcoin swap address to which the BTC is then sent, this means that the address also needs to have enough
     *  native tokens to pay for gas on the destination network
     * @param wallet Bitcoin wallet to use to sign the bitcoin transaction, can also be null - then the execution waits
     *  till a transaction is received from an external wallet
     * @param callbacks Callbacks to track the progress of the swap
     * @param options Optional options for the swap like feeRate, AbortSignal, and timeouts/intervals
     *
     * @returns {boolean} Whether a swap was settled automatically by swap watchtowers or requires manual claim by the
     *  user, in case `false` is returned the user should call `swap.claim()` to settle the swap on the destination manually
     */
    async execute(
        dstSigner: T["Signer"] | T["NativeSigner"],
        wallet?: IBitcoinWallet | MinimalBitcoinWalletInterfaceWithSigner | null | undefined,
        callbacks?: {
            onDestinationCommitSent?: (destinationCommitTxId: string) => void,
            onSourceTransactionSent?: (sourceTxId: string) => void,
            onSourceTransactionConfirmationStatus?: (sourceTxId?: string, confirmations?: number, targetConfirations?: number, etaMs?: number) => void,
            onSourceTransactionConfirmed?: (sourceTxId: string) => void,
            onSwapSettled?: (destinationTxId: string) => void
        },
        options?: {
            feeRate?: number,
            abortSignal?: AbortSignal,
            btcTxCheckIntervalSeconds?: number,
            maxWaitTillAutomaticSettlementSeconds?: number
        }
    ): Promise<boolean> {
        if(this._state===FromBTCSwapState.FAILED) throw new Error("Swap failed!");
        if(this._state===FromBTCSwapState.EXPIRED) throw new Error("Swap address expired!");
        if(this._state===FromBTCSwapState.QUOTE_EXPIRED || this._state===FromBTCSwapState.QUOTE_SOFT_EXPIRED) throw new Error("Swap quote expired!");
        if(this._state===FromBTCSwapState.CLAIM_CLAIMED) throw new Error("Swap already settled!");

        if(this._state===FromBTCSwapState.PR_CREATED) {
            await this.commit(dstSigner, options?.abortSignal, undefined, callbacks?.onDestinationCommitSent);
        }
        if(this._state===FromBTCSwapState.CLAIM_COMMITED) {
            if(wallet!=null) {
                const bitcoinPaymentSent = await this.getBitcoinPayment();

                if(bitcoinPaymentSent==null && this.txId==null) {
                    //Send btc tx
                    const txId = await this.sendBitcoinTransaction(wallet, options?.feeRate);
                    if(callbacks?.onSourceTransactionSent!=null) callbacks.onSourceTransactionSent(txId);
                }
            }

            const txId = await this.waitForBitcoinTransaction(callbacks?.onSourceTransactionConfirmationStatus, options?.btcTxCheckIntervalSeconds, options?.abortSignal);
            if (callbacks?.onSourceTransactionConfirmed != null) callbacks.onSourceTransactionConfirmed(txId);
        }

        // @ts-ignore
        if(this._state===FromBTCSwapState.CLAIM_CLAIMED) return true;

        if(this._state===FromBTCSwapState.BTC_TX_CONFIRMED) {
            const success = await this.waitTillClaimed(options?.maxWaitTillAutomaticSettlementSeconds ?? 60, options?.abortSignal);
            if(success && callbacks?.onSwapSettled!=null) callbacks.onSwapSettled(this.getOutputTxId()!);
            return success;
        }

        throw new Error("Invalid state reached!");
    }

    /**
     * @internal
     */
    protected async _getExecutionStatus(options?: {
        maxWaitTillAutomaticSettlementSeconds?: number
    }) {
        const state = this._state;
        const now = Date.now();
        const timeoutTime = this.getTimeoutTime();

        let confirmations: {
            current: number,
            target: number,
            etaSeconds: number
        } | undefined;
        let bitcoinTxId: string | undefined;

        let destinationSetupStatus: SwapExecutionStepSetup<T["ChainId"]>["status"] = "awaiting";
        let bitcoinPaymentStatus: SwapExecutionStepPayment<"BITCOIN">["status"] = "inactive";
        let destinationSettlementStatus: SwapExecutionStepSettlement<T["ChainId"], "awaiting_automatic" | "awaiting_manual">["status"] = "inactive";
        let buildCurrentAction: (actionOptions?: {
            bitcoinFeeRate?: number,
            bitcoinWallet?: MinimalBitcoinWalletInterface,
            skipChecks?: boolean,
            manualSettlementSmartChainSigner?: string | T["Signer"] | T["NativeSigner"],
        }) => Promise<
            SwapExecutionActionSendToAddress<false> |
            SwapExecutionActionSignPSBT<"FUNDED_PSBT"> |
            SwapExecutionActionWait<"BITCOIN_CONFS" | "SETTLEMENT"> |
            SwapExecutionActionSignSmartChainTx<T> |
            undefined
        > = async () => undefined;

        switch(state) {
            case FromBTCSwapState.PR_CREATED: {
                const quoteValid = await this._verifyQuoteValid();
                destinationSetupStatus = quoteValid && timeoutTime>=now ? "awaiting" : "soft_expired";
                if(quoteValid && timeoutTime>=now) {
                    buildCurrentAction = this._buildInitSmartChainTxAction.bind(this);
                }
                break;
            }
            case FromBTCSwapState.QUOTE_SOFT_EXPIRED:
                destinationSetupStatus = "soft_expired";
                break;
            case FromBTCSwapState.QUOTE_EXPIRED:
                destinationSetupStatus = "expired";
                break;
            case FromBTCSwapState.CLAIM_COMMITED:
            case FromBTCSwapState.EXPIRED:
            case FromBTCSwapState.FAILED:
                const bitcoinPayment = this.address==null ? null : await this.getBitcoinPayment();
                bitcoinTxId = bitcoinPayment?.txId;
                let bitcoinConfirmationDelay: number | undefined;
                if(bitcoinPayment!=null && bitcoinPayment.confirmations < bitcoinPayment.targetConfirmations) {
                    const tx = await this.wrapper._btcRpc.getTransaction(bitcoinPayment.txId);
                    const result = tx==null
                        ? null
                        : await this.wrapper._btcRpc.getConfirmationDelay(tx, bitcoinPayment.targetConfirmations);
                    bitcoinConfirmationDelay = result ?? -1;
                }

                destinationSetupStatus = "completed";
                if(bitcoinPayment==null) {
                    if(this.txId!=null) {
                        bitcoinPaymentStatus = state===FromBTCSwapState.FAILED ? "expired" : "received";
                        if(state!==FromBTCSwapState.FAILED) {
                            buildCurrentAction = this._buildWaitBitcoinConfirmationsAction.bind(this, -1, "Wait for bitcoin transaction to be picked up by the RPC and confirmed.");
                        }
                    } else {
                        bitcoinPaymentStatus = "awaiting";
                        if(state===FromBTCSwapState.EXPIRED) bitcoinPaymentStatus = "soft_expired";
                        if(state===FromBTCSwapState.FAILED) bitcoinPaymentStatus = "expired";
                        if(
                            state===FromBTCSwapState.CLAIM_COMMITED && timeoutTime>=now &&
                            this.address!=null && this.amount!=null
                        ) {
                            buildCurrentAction = this._buildSendToAddressOrSignPsbtAction.bind(this);
                        }
                    }
                } else if(bitcoinPayment.confirmations >= bitcoinPayment.targetConfirmations) {
                    bitcoinPaymentStatus = "confirmed";
                    if(state!==FromBTCSwapState.FAILED) {
                        buildCurrentAction = this._buildWaitBitcoinConfirmationsAction.bind(this, bitcoinConfirmationDelay ?? -1, undefined);
                    }
                } else {
                    bitcoinPaymentStatus = "received";
                    confirmations = {
                        current: bitcoinPayment.confirmations,
                        target: bitcoinPayment.targetConfirmations,
                        etaSeconds: bitcoinConfirmationDelay ?? -1
                    };
                    if(state!==FromBTCSwapState.FAILED) {
                        buildCurrentAction = this._buildWaitBitcoinConfirmationsAction.bind(this, bitcoinConfirmationDelay ?? -1, undefined);
                    }
                }
                destinationSettlementStatus = state===FromBTCSwapState.FAILED ? "expired" : "inactive";
                break;
            case FromBTCSwapState.BTC_TX_CONFIRMED:
                destinationSetupStatus = "completed";
                bitcoinPaymentStatus = "confirmed";
                if(
                    this.btcTxConfirmedAt==null ||
                    options?.maxWaitTillAutomaticSettlementSeconds===0 ||
                    (now - this.btcTxConfirmedAt) > (options?.maxWaitTillAutomaticSettlementSeconds ?? 60)*1000
                ) {
                    destinationSettlementStatus = "awaiting_manual";
                    buildCurrentAction = this._buildClaimSmartChainTxAction.bind(this);
                } else {
                    destinationSettlementStatus = "awaiting_automatic";
                    buildCurrentAction = this._buildWaitSettlementAction.bind(this, options?.maxWaitTillAutomaticSettlementSeconds);
                }
                break;
            case FromBTCSwapState.CLAIM_CLAIMED:
                destinationSetupStatus = "completed";
                bitcoinPaymentStatus = "confirmed";
                destinationSettlementStatus = "settled";
                break;
        }

        if(bitcoinPaymentStatus==="confirmed") {
            const requiredConfirmations = this.getRequiredConfirmationsCount();
            if(!Number.isNaN(requiredConfirmations)) {
                confirmations = {
                    current: requiredConfirmations,
                    target: requiredConfirmations,
                    etaSeconds: 0
                };
            }
        }

        return {
            steps: [
                {
                    type: "Setup",
                    side: "destination",
                    chain: this.chainIdentifier,
                    title: "Open Bitcoin swap address",
                    description: `Create the escrow on the ${this.chainIdentifier} side to open the Bitcoin swap address`,
                    status: destinationSetupStatus,
                    setupTxId: this._commitTxId
                },
                {
                    type: "Payment",
                    side: "source",
                    chain: "BITCOIN",
                    title: "Bitcoin payment",
                    description: "Send Bitcoin to the swap address and wait for the transaction to confirm",
                    status: bitcoinPaymentStatus,
                    confirmations,
                    initTxId: this.txId ?? bitcoinTxId,
                    settleTxId: this.txId
                },
                {
                    type: "Settlement",
                    side: "destination",
                    chain: this.chainIdentifier,
                    title: "Destination settlement",
                    description: `Wait for automatic settlement on the ${this.chainIdentifier} side, or settle manually if it takes too long`,
                    status: destinationSettlementStatus,
                    initTxId: this._commitTxId,
                    settleTxId: this._claimTxId
                }
            ] as [
                SwapExecutionStepSetup<T["ChainId"]>,
                SwapExecutionStepPayment<"BITCOIN">,
                SwapExecutionStepSettlement<T["ChainId"], "awaiting_automatic" | "awaiting_manual">
            ],
            buildCurrentAction,
            state
        };
    }

    /**
     * @inheritDoc
     * @internal
     */
    async _submitExecutionTransactions(txs: (T["SignedTXType"] | Transaction | string)[], abortSignal?: AbortSignal, requiredStates?: FromBTCSwapState[], idempotent?: boolean): Promise<string[]> {
        if(txs.length===0) throw new Error("Need to submit at least 1 transaction in the array, submitted empty array of transactions!");

        if(idempotent) {
            // Handle idempotent calls
            let idempotencyTriggered = false;
            const txIds: string[] = [];
            for(let tx of txs) {
                let parsedTx: T["SignedTXType"] | Transaction | undefined;
                if(typeof(tx)==="string") {
                    try {
                        parsedTx = await this.wrapper._chain.deserializeSignedTx(tx);
                    } catch (e) {}
                    try {
                        parsedTx = parsePsbtTransaction(tx);
                    } catch (e) {}
                } else {
                    parsedTx = tx;
                }

                if(parsedTx==null) {
                    this.logger.debug("_submitExecutionTransactions(): Failed to parse provided execution transaction: ", tx);
                    continue;
                }

                if(parsedTx instanceof Transaction) {
                    // Bitcoin tx
                    const btcTx = await this.wrapper._btcRpc.parseTransaction(Buffer.from(parsedTx.toBytes(true)).toString("hex"));
                    if(btcTx.txid===this.txId) idempotencyTriggered = true;
                    txIds.push(btcTx.txid);
                } else {
                    // SC tx
                    if(this.wrapper._chain.getTxId!=null) {
                        const txId = await this.wrapper._chain.getTxId(parsedTx);
                        if(this._commitTxId===txId || this._claimTxId===txId) idempotencyTriggered = true;
                        txIds.push(txId);
                    }
                }
            }
            if(idempotencyTriggered) return txIds;
        }

        if(requiredStates!=null && !requiredStates.includes(this._state)) throw new Error("Swap state has changed before transactions were submitted!");

        if(this._state===FromBTCSwapState.CLAIM_COMMITED) {
            let psbt: string | Transaction;
            if(txs.length!==1) throw new Error("Need to submit exactly 1 signed PSBT!");
            if(typeof(txs[0])!=="string" && !(txs[0] instanceof Transaction))
                throw new Error("Must submit a valid PSBT as hex/base64 string or `@scure/btc-signer` Transaction object!");
            psbt = txs[0];
            return [await this.submitPsbt(psbt)];
        }

        if(this._state===FromBTCSwapState.PR_CREATED || this._state===FromBTCSwapState.QUOTE_SOFT_EXPIRED) {
            if(!await this._verifyQuoteValid()) throw new Error("Quote is already expired!");
            if(this.getTimeoutTime()<Date.now()) throw new Error("Swap address already expired or close to expiry!");

            const parsedTxs: T["SignedTXType"][] = [];
            for(let tx of txs) {
                parsedTxs.push(typeof(tx)==="string" ? await this.wrapper._chain.deserializeSignedTx(tx) : tx);
            }
            const txIds = await this.wrapper._chain.sendSignedAndConfirm(parsedTxs, true, abortSignal, false);
            await this.waitTillCommited(abortSignal);
            return txIds;
        }

        if(this._state===FromBTCSwapState.BTC_TX_CONFIRMED) {
            const parsedTxs: T["SignedTXType"][] = [];
            for(let tx of txs) {
                parsedTxs.push(typeof(tx)==="string" ? await this.wrapper._chain.deserializeSignedTx(tx) : tx);
            }
            const txIds = await this.wrapper._chain.sendSignedAndConfirm(parsedTxs, true, abortSignal, false);
            await this.waitTillClaimed(undefined, abortSignal);
            return txIds;
        }

        throw new Error("Invalid swap state for transaction submission!");
    }

    /**
     * @internal
     */
    private async _buildSendToAddressOrSignPsbtAction(actionOptions?: {
        bitcoinFeeRate?: number,
        bitcoinWallet?: MinimalBitcoinWalletInterface,
    }): Promise<
        SwapExecutionActionSendToAddress<false> |
        SwapExecutionActionSignPSBT<"FUNDED_PSBT">
    > {
        if(this.address==null) throw new Error("Bitcoin swap address not known!");
        if(this.amount==null) throw new Error("Bitcoin swap amount not known!");

        if(actionOptions?.bitcoinWallet==null) {
            return {
                type: "SendToAddress",
                name: "Deposit on Bitcoin",
                description: "Send funds to the bitcoin swap address",
                chain: "BITCOIN",
                txs: [{
                    type: "BITCOIN_ADDRESS",
                    address: this.address,
                    hyperlink: this._getHyperlink(),
                    amount: toTokenAmount(this.amount, BitcoinTokens.BTC, this.wrapper._prices)
                }],
                waitForTransactions: async (
                    maxWaitTimeSeconds?: number, pollIntervalSeconds?: number, abortSignal?: AbortSignal
                ) => {
                    let btcTxId: string | undefined;
                    const abortController = extendAbortController(
                        abortSignal, maxWaitTimeSeconds, "Timed out waiting for bitcoin transaction"
                    );

                    try {
                        return await this.waitForBitcoinTransaction(
                            (txId) => {
                                btcTxId = txId;
                                abortController.abort();
                            },
                            pollIntervalSeconds,
                            abortController.signal
                        );
                    } catch (e) {
                        if(btcTxId!=null) return btcTxId;
                        throw e;
                    }
                }
            } as SwapExecutionActionSendToAddress<false>;
        }

        return {
            type: "SignPSBT",
            name: "Deposit on Bitcoin",
            description: "Send funds to the bitcoin swap address",
            chain: "BITCOIN",
            txs: [{
                ...await this.getFundedPsbt(actionOptions.bitcoinWallet, actionOptions?.bitcoinFeeRate),
                type: "FUNDED_PSBT"
            }],
            submitPsbt: async (signedPsbt: string | Transaction | (string | Transaction)[], idempotent?: boolean) => {
                return this._submitExecutionTransactions(
                    Array.isArray(signedPsbt) ? signedPsbt : [signedPsbt],