feat(exactly): ✨ return deposit rates

Co-authored-by: itofarina <[email protected]>

src/apps/exactly/ethereum/exactly.deposit.token-fetcher.ts

@@ -1,5 +1,7 @@
+import { type BigNumber, constants } from 'ethers';
+
 import { PositionTemplate } from '~app-toolkit/decorators/position-template.decorator';
-import type { GetTokenPropsParams } from '~position/template/app-token.template.types';
+import type { GetDataPropsParams, GetTokenPropsParams } from '~position/template/app-token.template.types';
 
 import type { ExactlyMarketDefinition } from '../common/exactly.definitions-resolver';
 import { type ExactlyMarketProps, ExactlyTokenFetcher } from '../common/exactly.token-fetcher';
@@ -16,4 +18,28 @@ export class EthereumExactlyDepositFetcher extends ExactlyTokenFetcher {
   getTotalAssets({ definition }: GetTokenPropsParams<Market, ExactlyMarketProps, ExactlyMarketDefinition>) {
     return definition.totalFloatingDepositAssets;
   }
+
+  async getApr({
+    definition: { blockNumber, timestamp, totalFloatingDepositShares, totalFloatingDepositAssets },
+    multicall: { contract: multicall },
+    contract: market,
+  }: GetDataPropsParams<Market, ExactlyMarketProps, ExactlyMarketDefinition>) {
+    const [, [[, totalSupplyData], [, totalAssetsData], [, tsData]]] = await multicall.callStatic.aggregate(
+      [
+        { target: market.address, callData: market.interface.encodeFunctionData('totalSupply') },
+        { target: market.address, callData: market.interface.encodeFunctionData('totalAssets') },
+        { target: multicall.address, callData: multicall.interface.encodeFunctionData('getCurrentBlockTimestamp') },
+      ],
+      true,
+      { blockTag: blockNumber - 123 },
+    );
+    const [prevTotalSupply] = market.interface.decodeFunctionResult('totalSupply', totalSupplyData) as [BigNumber];
+    const [prevTotalAssets] = market.interface.decodeFunctionResult('totalAssets', totalAssetsData) as [BigNumber];
+    const [prevTimestamp] = multicall.interface.decodeFunctionResult('getCurrentBlockTimestamp', tsData) as [BigNumber];
+
+    const shareValue = totalFloatingDepositAssets.mul(constants.WeiPerEther).div(totalFloatingDepositShares);
+    const prevShareValue = prevTotalAssets.mul(constants.WeiPerEther).div(prevTotalSupply);
+    const proportion = shareValue.mul(constants.WeiPerEther).div(prevShareValue);
+    return (Number(proportion) / 1e16 - 100) * (31_536_000 / (timestamp - prevTimestamp.toNumber()));
+  }
 }