support for staking apr in lending pool info (#81)

* support for staking apr in lending pool info

* refactor

* remove examples

.changeset/eighty-poets-exercise.md

@@ -0,0 +1,5 @@
+---
+"@folks-finance/algorand-sdk": patch
+---
+
+support for staking apr in lending pool info

src/lend/amm.ts

@@ -1,4 +1,4 @@
-import { compoundEveryHour, ONE_16_DP } from "../math-lib";
+import { compoundEveryHour, ONE_12_DP, ONE_16_DP } from "../math-lib";
 import {
   getAccountApplicationLocalState,
   getApplicationGlobalState,
@@ -7,6 +7,8 @@ import {
 } from "../utils";
 
 import type {
+  AssetsAdditionalInterest,
+  LendingPool,
   PactLendingPool,
   PactLendingPoolInfo,
   PoolManagerInfo,
@@ -22,12 +24,14 @@ import type { Algodv2, Indexer } from "algosdk";
  * @param client - Algorand client to query
  * @param lendingPool - Pact lending pool to query about
  * @param poolManagerInfo - pool manager info which is returned by retrievePoolManagerInfo function
+ * @param additionalInterests - optional additional interest to consider
  * @returns Promise<LendingPoolInfo> lending pool info
  */
 async function retrievePactLendingPoolInfo(
   client: Algodv2 | Indexer,
   lendingPool: PactLendingPool,
   poolManagerInfo: PoolManagerInfo,
+  additionalInterests?: AssetsAdditionalInterest,
 ): Promise<PactLendingPoolInfo> {
   const { currentRound, globalState: state } = await getApplicationGlobalState(client, lendingPool.lpPoolAppId);
   if (state === undefined) throw Error("Could not find lending pool");
@@ -43,23 +47,18 @@ async function retrievePactLendingPoolInfo(
   const swapFeeInterestRate = BigInt(Math.round(Number(pactPoolData?.["apr_7d"] || 0) * 1e16));
   const tvlUsd = Number(pactPoolData?.["tvl_usd"] || 0);
 
-  // lending pool deposit interest
-  const pool0 = poolManagerInfo.pools[lendingPool.pool0AppId];
-  const pool1 = poolManagerInfo.pools[lendingPool.pool1AppId];
-  if (pool0 === undefined || pool1 === undefined) throw Error("Could not find deposit pool");
+  // lending pool deposit interest and additional interest
+  const commonLendingPoolInterest = getDepositAndAdditionalInterest(lendingPool, poolManagerInfo, additionalInterests);
 
   return {
+    ...commonLendingPoolInterest,
     currentRound,
     fAsset0Supply: fa0s,
     fAsset1Supply: fa1s,
     liquidityTokenCirculatingSupply: ltcs,
     fee: config[2],
     swapFeeInterestRate,
     swapFeeInterestYield: compoundEveryHour(swapFeeInterestRate, ONE_16_DP),
-    asset0DepositInterestRate: pool0.depositInterestRate / BigInt(2),
-    asset0DepositInterestYield: pool0.depositInterestYield / BigInt(2),
-    asset1DepositInterestRate: pool1.depositInterestRate / BigInt(2),
-    asset1DepositInterestYield: pool1.depositInterestYield / BigInt(2),
     tvlUsd,
   };
 }
@@ -72,13 +71,15 @@ async function retrievePactLendingPoolInfo(
  * @param tinymanAppId - Tinyman application id where lending pool belongs to
  * @param lendingPool - Pact lending pool to query about
  * @param poolManagerInfo - pool manager info which is returned by retrievePoolManagerInfo function
+ * @param additionalInterests - optional additional interest to consider
  * @returns Promise<LendingPoolInfo> lending pool info
  */
 async function retrieveTinymanLendingPoolInfo(
   client: Algodv2 | Indexer,
   tinymanAppId: number,
   lendingPool: TinymanLendingPool,
   poolManagerInfo: PoolManagerInfo,
+  additionalInterests?: AssetsAdditionalInterest,
 ): Promise<TinymanLendingPoolInfo> {
   const { currentRound, localState: state } = await getAccountApplicationLocalState(
     client,
@@ -103,26 +104,61 @@ async function retrieveTinymanLendingPoolInfo(
   );
   const tvlUsd = Number(tmPoolData?.["liquidity_in_usd"] || 0);
 
-  // lending pool deposit interest
-  const pool0 = poolManagerInfo.pools[lendingPool.pool0AppId];
-  const pool1 = poolManagerInfo.pools[lendingPool.pool1AppId];
-  if (pool0 === undefined || pool1 === undefined) throw Error("Could not find deposit pool");
+  // lending pool deposit interest and additional interest
+  const commonLendingPoolInterest = getDepositAndAdditionalInterest(lendingPool, poolManagerInfo, additionalInterests);
 
   return {
+    ...commonLendingPoolInterest,
     currentRound,
     fAsset0Supply: fa0s,
     fAsset1Supply: fa1s,
     liquidityTokenCirculatingSupply: ltcs,
     fee,
     swapFeeInterestRate,
     swapFeeInterestYield,
-    asset0DepositInterestRate: pool0.depositInterestRate / BigInt(2),
-    asset0DepositInterestYield: pool0.depositInterestYield / BigInt(2),
-    asset1DepositInterestRate: pool1.depositInterestRate / BigInt(2),
-    asset1DepositInterestYield: pool1.depositInterestYield / BigInt(2),
     farmInterestYield,
     tvlUsd,
   };
 }
 
+function getDepositAndAdditionalInterest(
+  lendingPool: LendingPool,
+  poolManagerInfo: PoolManagerInfo,
+  additionalInterests?: AssetsAdditionalInterest,
+) {
+  const { asset0Id, asset1Id, pool0AppId, pool1AppId } = lendingPool;
+
+  // lending pool deposit interest
+  const pool0 = poolManagerInfo.pools[pool0AppId];
+  const pool1 = poolManagerInfo.pools[pool1AppId];
+  if (pool0 === undefined || pool1 === undefined) throw Error("Could not find deposit pool");
+  const asset0DepositInterestRate = pool0.depositInterestRate / BigInt(2);
+  const asset0DepositInterestYield = pool0.depositInterestYield / BigInt(2);
+  const asset1DepositInterestRate = pool1.depositInterestRate / BigInt(2);
+  const asset1DepositInterestYield = pool1.depositInterestYield / BigInt(2);
+
+  // add additional interests if specified
+  let additionalInterestRate;
+  let additionalInterestYield;
+  if (additionalInterests) {
+    for (const assetId of [asset0Id, asset1Id]) {
+      if (additionalInterests[assetId]) {
+        const { rateBps, yieldBps } = additionalInterests[assetId];
+        // multiply by 1e12 to standardise at 16 d.p.
+        additionalInterestRate = (additionalInterestRate || BigInt(0)) + (rateBps * ONE_12_DP) / BigInt(2);
+        additionalInterestYield = (additionalInterestYield || BigInt(0)) + (yieldBps * ONE_12_DP) / BigInt(2);
+      }
+    }
+  }
+
+  return {
+    asset0DepositInterestRate,
+    asset0DepositInterestYield,
+    asset1DepositInterestRate,
+    asset1DepositInterestYield,
+    additionalInterestRate,
+    additionalInterestYield,
+  };
+}
+
 export { retrievePactLendingPoolInfo, retrieveTinymanLendingPoolInfo };

src/lend/types.ts

@@ -52,6 +52,8 @@ interface BaseLendingPoolInfo {
   asset0DepositInterestYield: bigint; // approximation 16 d.p.
   asset1DepositInterestRate: bigint; // 16 d.p.
   asset1DepositInterestYield: bigint; // approximation 16 d.p.
+  additionalInterestRate?: bigint; // 16 d.p.
+  additionalInterestYield?: bigint; // approximation 16 d.p.
   tvlUsd: number;
 }
 

tsconfig.json

@@ -19,5 +19,5 @@
     "declarationDir": "dist/types",
     "sourceMap": true
   },
-  "include": ["src/**/*", "examples/**/*"]
+  "include": ["src/**/*"]
 }