Merge pull request #54 from curvefi/feat/add-future-leverage-for-remove-and-add-collateral

feat: add future leverage for add and remove collateral

Author: fedorovdg

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@curvefi/llamalend-api",
-  "version": "1.0.40",
+  "version": "1.0.41",
   "description": "JavaScript library for Curve Lending",
   "main": "lib/index.js",
   "author": "Macket",

src/lendMarkets/LendMarketTemplate.ts

@@ -21,6 +21,7 @@ import {
     _getUsdRate,
     DIGas,
     smartNumber,
+    calculateFutureLeverage,
 } from "../utils.js";
 import {IDict, TGas, TAmount, IReward, IQuoteOdos, IOneWayMarket, IPartialFrac} from "../interfaces.js";
 import { _getExpectedOdos, _getQuoteOdos, _assembleTxOdos, _getUserCollateral, _getUserCollateralForce, _getMarketsData } from "../external-api.js";
@@ -1747,6 +1748,18 @@ export class LendMarketTemplate {
         return await this._addCollateral(collateral, address, false) as string;
     }
 
+    public async addCollateralFutureLeverage(collateral: number | string, userAddress = ''): Promise<string> {
+        userAddress = _getAddress.call(this.llamalend, userAddress);
+        const [userCollateral, {collateral: currentCollateral}] = await Promise.all([
+            _getUserCollateral(this.llamalend.constants.NETWORK_NAME, this.addresses.controller, userAddress),
+            this.userState(userAddress),
+        ]);
+
+        const total_deposit_from_user = userCollateral.total_deposit_from_user_precise;
+
+        return calculateFutureLeverage(currentCollateral, total_deposit_from_user, collateral, 'add');
+    }
+
     // ---------------- REMOVE COLLATERAL ----------------
 
     public async maxRemovable(): Promise<string> {
@@ -1813,6 +1826,18 @@ export class LendMarketTemplate {
         return await this._removeCollateral(collateral, false) as string;
     }
 
+    public async removeCollateralFutureLeverage(collateral: number | string, userAddress = ''): Promise<string> {
+        userAddress = _getAddress.call(this.llamalend, userAddress);
+        const [userCollateral, {collateral: currentCollateral}] = await Promise.all([
+            _getUserCollateral(this.llamalend.constants.NETWORK_NAME, this.addresses.controller, userAddress),
+            this.userState(userAddress),
+        ]);
+
+        const total_deposit_from_user = userCollateral.total_deposit_from_user_precise;
+
+        return calculateFutureLeverage(currentCollateral, total_deposit_from_user, collateral, 'remove');
+    }
+
     // ---------------- REPAY ----------------
 
     private async _repayBands(debt: number | string, address: string): Promise<[bigint, bigint]> {

src/mintMarkets/MintMarketTemplate.ts

@@ -19,6 +19,7 @@ import {
     MAX_ACTIVE_BAND,
     _mulBy1_3,
     DIGas,
+    calculateFutureLeverage,
 } from "../utils.js";
 import {IDict, ILlamma, TGas} from "../interfaces.js";
 import {_getUserCollateralCrvUsd, _getUserCollateralCrvUsdFull} from "../external-api.js";
@@ -1001,6 +1002,19 @@ export class MintMarketTemplate {
         return await this._addCollateral(collateral, address, false) as string;
     }
 
+    public async addCollateralFutureLeverage(collateral: number | string, userAddress = ''): Promise<string> {
+        this._checkLeverageForStats();
+        userAddress = _getAddress.call(this.llamalend, userAddress);
+        const [userCollateral, {collateral: currentCollateral}] = await Promise.all([
+            _getUserCollateralCrvUsdFull(this.llamalend.constants.NETWORK_NAME, this.controller, userAddress),
+            this.userState(userAddress),
+        ]);
+
+        const total_deposit_from_user = userCollateral.total_deposit_from_user_precise ?? userCollateral.total_deposit_precise;
+
+        return calculateFutureLeverage(currentCollateral, total_deposit_from_user, collateral, 'add');
+    }
+
     // ---------------- REMOVE COLLATERAL ----------------
 
     public async maxRemovable(): Promise<string> {
@@ -1069,6 +1083,19 @@ export class MintMarketTemplate {
         return await this._removeCollateral(collateral, false) as string;
     }
 
+    public async removeCollateralFutureLeverage(collateral: number | string, userAddress = ''): Promise<string> {
+        this._checkLeverageForStats();
+        userAddress = _getAddress.call(this.llamalend, userAddress);
+        const [userCollateral, {collateral: currentCollateral}] = await Promise.all([
+            _getUserCollateralCrvUsdFull(this.llamalend.constants.NETWORK_NAME, this.controller, userAddress),
+            this.userState(userAddress),
+        ]);
+
+        const total_deposit_from_user = userCollateral.total_deposit_from_user_precise ?? userCollateral.total_deposit_precise;
+
+        return calculateFutureLeverage(currentCollateral, total_deposit_from_user, collateral, 'remove');
+    }
+
     // ---------------- REPAY ----------------
 
     private async _repayBands(debt: number | string, address: string): Promise<[bigint, bigint]> {

src/utils.ts

@@ -498,4 +498,21 @@ export const getLsdApy = memoize(async(name: 'wstETH' | 'sfrxETH'): Promise<{
 {
     promise: true,
     maxAge: 60 * 1000, // 1m
-});
+});
+
+export const calculateFutureLeverage = (
+    currentCollateral: number | string,
+    totalDepositFromUser: number | string,
+    collateral: number | string,
+    operation: 'add' | 'remove'
+): string => {
+    const collateralBN = BN(collateral);
+    const currentCollateralBN = BN(currentCollateral);
+    const totalDepositBN = BN(totalDepositFromUser);
+
+    if (operation === 'add') {
+        return currentCollateralBN.plus(collateralBN).div(totalDepositBN.plus(collateralBN)).toString();
+    } else {
+        return currentCollateralBN.minus(collateralBN).div(totalDepositBN.minus(collateralBN)).toString();
+    }
+};