fixup! feat(input-selection): added new greedy input selector

packages/input-selection/package.json

@@ -68,6 +68,7 @@
   "dependencies": {
     "@cardano-sdk/core": "workspace:~",
     "@cardano-sdk/util": "workspace:~",
+    "bignumber.js": "^9.1.1",
     "lodash": "^4.17.21",
     "ts-custom-error": "^3.2.0"
   },

packages/input-selection/src/GreedySelection/GreedyInputSelector.ts

@@ -1,17 +1,19 @@
+import { AssetId } from '@cardano-sdk/core/dist/cjs/Cardano';
 import { Cardano } from '@cardano-sdk/core';
 import { InputSelectionError, InputSelectionFailure } from '../InputSelectionError';
 import { InputSelectionParameters, InputSelector, SelectionConstraints, SelectionResult } from '../types';
 import {
+  getAssetAddition,
   getAssetDifference,
   getAssetQuantities,
   getCoinQuantity,
   hasNegativeAssetValue,
-  isValidValue,
   sortByCoins,
+  splitChange,
   toValues
 } from '../util';
 
-type AdjustedOutputs = { outputs: Set<Cardano.TxOut>; fee: bigint; change: Set<Cardano.Value> };
+type AdjustedOutputs = { fee: bigint; change: Array<Cardano.TxOut> };
 
 interface GreedySelectorProps {
   getChangeAddresses: () => Promise<Map<Cardano.PaymentAddress, number>>;
@@ -25,38 +27,32 @@ interface GreedySelectorProps {
  * @param constraints The selection constraints.
  * @param inputs The inputs of the transaction.
  * @param outputs The outputs of the transaction.
+ * @param changeOutputs The list of change outputs.
  * @param currentFee The current computed fee for this selection.
- * @param change Change value if any.
  */
 const adjustOutputsForFee = async (
   constraints: SelectionConstraints,
   inputs: Set<Cardano.Utxo>,
   outputs: Set<Cardano.TxOut>,
-  currentFee: bigint,
-  change?: Cardano.Value
+  changeOutputs: Array<Cardano.TxOut>,
+  currentFee: bigint
 ): Promise<AdjustedOutputs> => {
-  let result = { change: new Set<Cardano.Value>(), fee: currentFee, outputs };
-  // const changeBundles = new Set<Cardano.Value>();
-  // const changeBundlesByAddress = new Map<Cardano.PaymentAddress, Set<Cardano.Value>>();
-
-  // if (change) changeBundles.add(change);
-
-  // Compute the fee. If the current fee is less than the newly computed fee, deduct the difference from the output with
-  // the highest coin value and try again. If the coin value falls below the minimum coin quantity, deduct from the next
-  // highest coin value output instead. If we run out of outputs to deduct the fee from, throw.
-  // Calculate fee with change outputs that include fee.
-  // It will cover the fee of final selection,
-  // where fee is excluded from change bundles
+  let result = { change: [...changeOutputs], fee: currentFee };
+
+  // Compute the fee. If the current fee is less than the newly computed fee, deduct the difference from the change output
+  // with the highest coin value and try again. If the coin value falls below the minimum coin quantity, deduct from the
+  // next highest coin value output instead. If we run out of outputs to deduct the fee from, throw.
+  const totalOutputs = new Set([...outputs, ...changeOutputs]);
   const fee = await constraints.computeMinimumCost({
     change: [],
     fee: currentFee,
     inputs,
-    outputs
+    outputs: totalOutputs
   });
 
   if (currentFee < fee) {
     const feeDifference = fee - currentFee;
-    const updatedOutputs = [...outputs];
+    const updatedOutputs = [...changeOutputs];
 
     updatedOutputs.sort(sortByCoins);
 
@@ -73,7 +69,7 @@ const adjustOutputsForFee = async (
 
     if (!feeAccountedFor) throw new InputSelectionError(InputSelectionFailure.UtxoBalanceInsufficient);
 
-    result = await adjustOutputsForFee(constraints, inputs, new Set(updatedOutputs), fee, change);
+    result = await adjustOutputsForFee(constraints, inputs, outputs, updatedOutputs, fee);
   }
 
   return result;
@@ -93,63 +89,53 @@ const adjustOutputsForFee = async (
  * the user has too many native assets.
  */
 export class GreedyInputSelector implements InputSelector {
-  getChangeAddresses: GreedySelectorProps;
+  #props: GreedySelectorProps;
 
   constructor(props: GreedySelectorProps) {
-    this.getChangeAddresses = props;
+    this.#props = props;
   }
 
   async select(params: InputSelectionParameters): Promise<SelectionResult> {
-    const { utxo: inputs, outputs, constraints } = params;
+    const { utxo: inputs, outputs, constraints, implicitValue } = params;
     const utxoValues = toValues([...inputs]);
     const outputsValues = toValues([...outputs]);
     const totalLovelaceInUtxoSet = getCoinQuantity(utxoValues);
     const totalLovelaceInOutputSet = getCoinQuantity(outputsValues);
     const totalAssetsInUtxoSet = getAssetQuantities(utxoValues);
     const totalAssetsInOutputSet = getAssetQuantities(utxoValues);
-    // const changeBundlesByAddress = new Map<Cardano.PaymentAddress, Set<Cardano.Value>>();
-
-    if (totalLovelaceInUtxoSet === totalLovelaceInOutputSet && totalAssetsInUtxoSet === totalAssetsInOutputSet) {
-      // The wallet is trying to spend the whole balance, we just need to account for the fee and return the modified selection.
-      const adjustedOutputs = await adjustOutputsForFee(constraints, inputs, outputs, 0n);
-
-      return {
-        remainingUTxO: new Set<Cardano.Utxo>(),
-        selection: {
-          change: [],
-          fee: adjustedOutputs.fee,
-          inputs,
-          outputs: adjustedOutputs.outputs
-        }
-      };
-    }
-
-    // The wallet did not spend all the balance, so we must add the remaining as change.
-    const changeLovelace = totalLovelaceInOutputSet - totalLovelaceInUtxoSet;
-    const changeAssets = getAssetDifference(totalAssetsInOutputSet, totalAssetsInUtxoSet);
-
-    // If the wallet tries to spend more than we can cover with the current UTXO set throw.
+    const implicitCoinInput = implicitValue?.coin?.input || 0n;
+    const implicitCoinOutput = implicitValue?.coin?.deposit || 0n;
+    const implicitAssetInput = implicitValue?.mint || new Map<AssetId, bigint>();
+    const totalLovelaceInput = totalLovelaceInUtxoSet + implicitCoinInput;
+    const totalLovelaceOutput = totalLovelaceInOutputSet + implicitCoinOutput;
+    const totalAssetsInput = getAssetAddition(totalAssetsInUtxoSet, implicitAssetInput);
+
+    // Calculate the difference between the given outputs and the UTXO set. This will let us know
+    // how much we need to return as change.
+    const changeLovelace = totalLovelaceOutput - totalLovelaceInput;
+    const changeAssets = getAssetDifference(totalAssetsInOutputSet, totalAssetsInput);
+
+    // If the wallet tries to spend more than we can cover with the current UTXO set + implicit value throw.
     if (changeLovelace <= 0n || hasNegativeAssetValue(changeAssets))
       throw new InputSelectionError(InputSelectionFailure.UtxoBalanceInsufficient);
 
-    const change = {
-      assets: changeAssets.size === 0 ? undefined : changeAssets,
-      coins: changeLovelace
-    };
-
-    // If not enough balance remaining to create a valid change output throw.
-    if (!isValidValue(change, constraints.computeMinimumCoinQuantity, constraints.tokenBundleSizeExceedsLimit))
-      throw new InputSelectionError(InputSelectionFailure.UtxoBalanceInsufficient);
-
-    const adjustedOutputs = await adjustOutputsForFee(constraints, inputs, outputs, 0n, change);
+    // Split the remaining amount to be returned as change proportionally between the given addresses.
+    const changeOutputs = await splitChange(
+      this.#props.getChangeAddresses,
+      changeLovelace,
+      changeAssets,
+      constraints.computeMinimumCoinQuantity,
+      constraints.tokenBundleSizeExceedsLimit
+    );
 
+    const adjustedChangeOutputs = await adjustOutputsForFee(constraints, inputs, outputs, changeOutputs, 0n);
     return {
       remainingUTxO: new Set<Cardano.Utxo>(),
       selection: {
-        change: [],
-        fee: adjustedOutputs.fee,
+        change: adjustedChangeOutputs.change,
+        fee: adjustedChangeOutputs.fee,
         inputs,
-        outputs: adjustedOutputs.outputs
+        outputs
       }
     };
   }