feat(offer): add offer transaction fee

package.json

@@ -7,7 +7,7 @@
     "build": "tsc",
     "start": "DEBUG=sado-* ts-node-dev ./src/main.ts",
     "clean": "rm -rf dist",
-    "lint": "eslint --ext .ts src"
+    "lint": "eslint --fix --ext .ts src"
   },
   "dependencies": {
     "@fastify/cors": "^8.2.1",

src/Entities/Offer.ts

@@ -5,9 +5,10 @@ import { Network } from "../Libraries/Network";
 import { PriceList } from "../Libraries/PriceList";
 import { getAddressVoutValue } from "../Libraries/Transaction";
 import { IPFSLookupFailed } from "../Orderbook/Exceptions/GeneralExceptions";
-import { getAskingPrice } from "../Orderbook/Utilities";
+import { getAskingPrice, utils } from "../Orderbook/Utilities";
 import { validator } from "../Orderbook/Validator";
 import { ipfs } from "../Services/IPFS";
+import { Lookup } from "../Services/Lookup";
 import { db } from "../Services/Mongo";
 import { IPFSOffer, IPFSOrder } from "./IPFS";
 import { Inscription, Ordinal, Transaction, Vout } from "./Transaction";
@@ -59,6 +60,11 @@ export class Offer {
    */
   readonly time: OfferTime;
 
+  /**
+   * Estimated fee in satoshis for the offer transaction.
+   */
+  readonly fee?: number;
+
   /**
    * Vout containing the ordinals and inscription array.
    */
@@ -83,6 +89,7 @@ export class Offer {
     this.offer = document.offer;
     this.value = document.value;
     this.time = document.time;
+    this.fee = document.fee;
     this.vout = document.vout;
     this.proof = document.proof;
     this.rejection = document.rejection;
@@ -94,7 +101,7 @@ export class Offer {
   |--------------------------------------------------------------------------------
   */
 
-  static async insert(tx: Transaction): Promise<Offer | undefined> {
+  static async insert(tx: Transaction, lookup: Lookup): Promise<Offer | undefined> {
     const offer = await ipfs.getOffer(tx.cid);
     if ("error" in offer) {
       await collection.insertOne(makeRejectedOffer(tx, new IPFSLookupFailed(tx.txid, offer.error, offer.data)));
@@ -105,7 +112,8 @@ export class Offer {
       await collection.insertOne(makeRejectedOffer(tx, new IPFSLookupFailed(tx.txid, order.error, order.data), offer));
       return;
     }
-    const result = await collection.insertOne(makePendingOffer(tx, order, offer));
+    const fee = await getTransactioFee(offer.offer, lookup);
+    const result = await collection.insertOne(makePendingOffer(tx, order, offer, fee));
     if (result.acknowledged === true) {
       return this.findById(result.insertedId);
     }
@@ -198,6 +206,7 @@ export class Offer {
       },
       ago: moment(this.tx.blocktime).fromNow(), // [TODO] Deprecate in favor of `time.ago`.
       value: new PriceList(this.value),
+      fee: new PriceList(this.fee),
       order: {
         ...this.order,
         price: new PriceList(getAskingPrice(this.order)),
@@ -231,7 +240,7 @@ export class Offer {
  |--------------------------------------------------------------------------------
  */
 
-function makePendingOffer(tx: Transaction, order: IPFSOrder, offer: IPFSOffer): OfferDocument {
+function makePendingOffer(tx: Transaction, order: IPFSOrder, offer: IPFSOffer, fee?: number): OfferDocument {
   return {
     status: "pending",
     address: tx.from,
@@ -243,6 +252,7 @@ function makePendingOffer(tx: Transaction, order: IPFSOrder, offer: IPFSOffer):
       block: tx.blocktime,
       offer: offer.ts,
     },
+    fee,
     tx,
   };
 }
@@ -263,6 +273,14 @@ function makeRejectedOffer(tx: Transaction, rejection: any, offer?: IPFSOffer):
   };
 }
 
+async function getTransactioFee(offer: string, lookup: Lookup): Promise<number | undefined> {
+  const psbt = utils.psbt.decode(offer);
+  if (psbt === undefined) {
+    return undefined;
+  }
+  return utils.psbt.getFee(psbt, lookup);
+}
+
 /*
  |--------------------------------------------------------------------------------
  | Document
@@ -278,6 +296,7 @@ type OfferDocument = {
   offer: IPFSOffer;
   value?: number;
   time: OfferTime;
+  fee?: number;
   vout?: Vout;
   proof?: string;
   rejection?: any;

src/Libraries/Bitcoin.ts

@@ -5,6 +5,17 @@ import { dexPrices } from "../Services/DexPrices";
  */
 export const BTC_TO_SAT = 100_000_000;
 
+/**
+ * Convert provided BTC to satoshis.
+ *
+ * @param btc - BTC to convert.
+ *
+ * @returns Satoshi value.
+ */
+export function btcToSat(btc: number): number {
+  return btc * BTC_TO_SAT;
+}
+
 /**
  * Convert provided satoshis to BTC.
  *

src/Orderbook/Resolver.ts

@@ -18,17 +18,23 @@ export async function resolveOrderbookTransactions(address: string, network: Net
   // ### Add Transactions
   // For any non-processed transactions in the address, add them to the database.
 
+  const result: (Order | Offer)[] = [];
+
   const nextTxs = await addOrderbookTransactions(sadoTxs, address, network);
-  const result = await Promise.all(
-    nextTxs.map((tx) => {
-      if (tx.type === "order") {
-        return Order.insert(tx);
+  for (const tx of nextTxs) {
+    if (tx.type === "order") {
+      const order = await Order.insert(tx);
+      if (order !== undefined) {
+        result.push(order);
       }
-      if (tx.type === "offer") {
-        return Offer.insert(tx);
+    }
+    if (tx.type === "offer") {
+      const offer = await Offer.insert(tx, lookup);
+      if (offer !== undefined) {
+        result.push(offer);
       }
-    })
-  );
+    }
+  }
 
   // ### Resolve Pending
   // Run through pending orders and offers, checking of changes and transitioning

src/Orderbook/Utilities/PSBT.ts

@@ -0,0 +1,61 @@
+import * as btc from "bitcoinjs-lib";
+
+import { btcToSat } from "../../Libraries/Bitcoin";
+import { Lookup } from "../../Services/Lookup";
+
+export const psbt = {
+  decode,
+  getFee,
+};
+
+/**
+ * Attempt to retrieve a PSBT from the offer string. We try both hex and base64
+ * formats as we don't know which one the user will provide.
+ *
+ * @param offer - Encoded offer transaction.
+ *
+ * @returns The PSBT or undefined if it could not be parsed.
+ */
+function decode(offer: string): btc.Psbt | undefined {
+  try {
+    return btc.Psbt.fromHex(offer);
+  } catch (err) {
+    // TODO: Add better check in case the error is not about failure to
+    //       parse the hex.
+    // not a PSBT hex offer
+  }
+  try {
+    return btc.Psbt.fromBase64(offer);
+  } catch (err) {
+    // TODO: Add better check in case the error is not about failure to
+    //       parse the base64.
+    // not a PSBT base64 offer
+  }
+}
+
+/**
+ * Calculate the fee for given PSBT by looking up the input transactions and
+ * subtracting the output values.
+ *
+ * @param psbt   - The PSBT to calculate the fee for.
+ * @param lookup - The lookup service to use to retrieve the input transactions.
+ *
+ * @returns The fee in satoshis.
+ */
+async function getFee(psbt: btc.Psbt, lookup: Lookup): Promise<number> {
+  let inputSum = 0;
+  for (const input of psbt.txInputs) {
+    const hash = input.hash.reverse().toString("hex");
+    const tx = await lookup.getTransaction(hash);
+    if (tx !== undefined) {
+      inputSum += btcToSat(tx.vout[input.index].value);
+    }
+  }
+
+  let outputSum = 0;
+  for (const output of psbt.txOutputs) {
+    outputSum += output.value;
+  }
+
+  return inputSum - outputSum;
+}

src/Orderbook/Utilities.ts → src/Orderbook/Utilities/index.ts

@@ -1,9 +1,14 @@
-import { IPFSOffer, IPFSOrder } from "../Entities/IPFS";
-import { Transaction } from "../Entities/Transaction";
-import { BTC_TO_SAT } from "../Libraries/Bitcoin";
-import { PriceList } from "../Libraries/PriceList";
-import { parseLocation } from "../Libraries/Transaction";
-import { Lookup } from "../Services/Lookup";
+import { IPFSOffer, IPFSOrder } from "../../Entities/IPFS";
+import { Transaction } from "../../Entities/Transaction";
+import { BTC_TO_SAT } from "../../Libraries/Bitcoin";
+import { PriceList } from "../../Libraries/PriceList";
+import { parseLocation } from "../../Libraries/Transaction";
+import { Lookup } from "../../Services/Lookup";
+import { psbt } from "./PSBT";
+
+export const utils = {
+  psbt,
+};
 
 /**
  * Get order item from a vout scriptPubKey utf8 string.

src/Orderbook/Validator/Offer/Format/PSBT.ts

@@ -3,6 +3,7 @@ import * as btc from "bitcoinjs-lib";
 import { IPFSOffer, IPFSOrder } from "../../../../Entities/IPFS";
 import { parseLocation } from "../../../../Libraries/Transaction";
 import { OfferValidationFailed } from "../../../Exceptions/OfferException";
+import { utils } from "../../../Utilities";
 
 /**
  * Attempt to validate the offer string as a PSBT. If the offer is not a PSBT
@@ -16,39 +17,14 @@ import { OfferValidationFailed } from "../../../Exceptions/OfferException";
  * @returns `true` if the offer is a valid PSBT, `false` otherwise.
  */
 export function validatePSBT({ offer }: IPFSOffer, { location }: IPFSOrder): boolean {
-  const psbt = getPsbt(offer);
+  const psbt = utils.psbt.decode(offer);
   if (psbt === undefined) {
     return false;
   }
   validateOrderInput(psbt, location);
   return true;
 }
 
-/**
- * Attempt to retrieve a PSBT from the offer string. We try both hex and base64
- * formats as we don't know which one the user will provide.
- *
- * @param offer - Encoded offer transaction.
- *
- * @returns The PSBT or undefined if it could not be parsed.
- */
-function getPsbt(offer: string): btc.Psbt | undefined {
-  try {
-    return btc.Psbt.fromHex(offer);
-  } catch (err) {
-    // TODO: Add better check in case the error is not about failure to
-    //       parse the hex.
-    // not a PSBT hex offer
-  }
-  try {
-    return btc.Psbt.fromBase64(offer);
-  } catch (err) {
-    // TODO: Add better check in case the error is not about failure to
-    //       parse the base64.
-    // not a PSBT base64 offer
-  }
-}
-
 // ### ORDER INPUTS
 
 function validateOrderInput(psbt: btc.Psbt, location: string): void {

src/Services/Lookup.ts

@@ -2,7 +2,14 @@ import debug from "debug";
 import fetch, { RequestInit } from "node-fetch";
 
 import { config } from "../Config";
-import { getTransaction, Inscription, Ordinal, ScriptPubKey, Transaction } from "../Entities/Transaction";
+import {
+  addTransaction,
+  getTransaction,
+  Inscription,
+  Ordinal,
+  ScriptPubKey,
+  Transaction,
+} from "../Entities/Transaction";
 import { DEFAULT_NETWORK, Network } from "../Libraries/Network";
 
 const log = debug("sado-lookup");
@@ -60,6 +67,7 @@ export class Lookup {
     }
     const tx = (await getTransaction(txid, this.network)) ?? (await get("/transaction", { txid }, this.network));
     if (tx !== undefined) {
+      await addTransaction(tx, this.network);
       this.transactions.set(txid, tx);
     }
     return tx;