@atomiqlabs/sdk/src/swaps/trusted/ln/LnForGasWrapper.ts

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

import {LnForGasSwap, LnForGasSwapInit, LnForGasSwapState} from "./LnForGasSwap";
import {ISwapWrapper, SwapTypeDefinition} from "../../ISwapWrapper";
import {decode as bolt11Decode} from "@atomiqlabs/bolt11";
import {IntermediaryError} from "../../../errors/IntermediaryError";
import {ChainType} from "@atomiqlabs/base";
import {Intermediary} from "../../../intermediaries/Intermediary";
import {SwapType} from "../../../enums/SwapType";

export type LnForGasSwapTypeDefinition<T extends ChainType> = SwapTypeDefinition<T, LnForGasWrapper<T>, LnForGasSwap<T>>;

/**
 * Trusted swap for Bitcoin Lightning -> Smart chains, to be used for minor amounts to get gas tokens on
 *  the destination chain, which is only needed for Solana, which still uses legacy swaps
 *
 * @category Swaps/Trusted Gas Swaps
 */
export class LnForGasWrapper<T extends ChainType> extends ISwapWrapper<T, LnForGasSwapTypeDefinition<T>> {
    public TYPE: SwapType.TRUSTED_FROM_BTCLN = SwapType.TRUSTED_FROM_BTCLN;
    /**
     * @internal
     */
    public readonly _swapDeserializer = LnForGasSwap;

    /**
     * @internal
     */
    readonly _pendingSwapStates = [LnForGasSwapState.PR_CREATED];
    /**
     * @internal
     */
    protected readonly tickSwapState = undefined;
    /**
     * @internal
     */
    protected processEvent = undefined;

    /**
     * Returns a newly created trusted Lightning network -> Smart chain swap, receiving
     *  the specified amount of native token on the destination chain.
     *
     * @param recipient Address of the recipient on the smart chain destination chain
     * @param amount Amount of native token to receive in base units
     * @param lpOrUrl Intermediary (LP) to use for the swap
     */
    async create(recipient: string, amount: bigint, lpOrUrl: Intermediary | string): Promise<LnForGasSwap<T>> {
        if(!this.isInitialized) throw new Error("Not initialized, call init() first!");

        const lpUrl = typeof(lpOrUrl)==="string" ? lpOrUrl : lpOrUrl.url;

        const token = this._chain.getNativeCurrencyAddress();

        const resp = await this._lpApi.initTrustedFromBTCLN(this.chainIdentifier, lpUrl, {
            address: recipient,
            amount,
            token
        }, this._options.getRequestTimeout);

        const decodedPr = bolt11Decode(resp.pr);
        if(decodedPr.millisatoshis==null) throw new Error("Invalid payment request returned, no msat amount value!");
        if(decodedPr.timeExpireDate==null) throw new Error("Invalid payment request returned, no time expire date!");
        const amountIn = (BigInt(decodedPr.millisatoshis) + 999n) / 1000n;

        if(resp.total!==amount) throw new IntermediaryError("Invalid total returned");

        const pricingInfo = await this.verifyReturnedPrice(
            typeof(lpOrUrl)==="string" || lpOrUrl.services[SwapType.TRUSTED_FROM_BTCLN]==null ?
                {swapFeePPM: 10000, swapBaseFee: 10} :
                lpOrUrl.services[SwapType.TRUSTED_FROM_BTCLN],
            false, amountIn,
            amount, token, {swapFeeBtc: resp.swapFeeSats}
        );

        const quoteInit: LnForGasSwapInit = {
            pr: resp.pr,
            outputAmount: resp.total,
            recipient,
            pricingInfo,
            url: lpUrl,
            expiry: decodedPr.timeExpireDate*1000,
            swapFee: resp.swapFee,
            swapFeeBtc: resp.swapFeeSats,
            token,
            exactIn: false,
            contractVersion: "v1"
        };
        const quote = new LnForGasSwap(this, quoteInit);
        return quote;
    }

}