Curve oracle factory (#1179)

contracts/facade/factories/CurveOracleFactory.sol

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: BlueOak-1.0.0
+pragma solidity 0.8.19;
+
+import { divuu } from "../../libraries/Fixed.sol";
+
+// weird circular inheritance preventing us from using proper IRToken, not worth figuring out
+interface IMinimalRToken {
+    function basketsNeeded() external view returns (uint192);
+
+    function totalSupply() external view returns (uint256);
+}
+
+contract CurveOracle {
+    address public immutable rToken;
+
+    constructor(address _rToken) {
+        rToken = _rToken;
+    }
+
+    function exchangeRate() external view returns (uint256) {
+        return
+            divuu(
+                uint256(IMinimalRToken(rToken).basketsNeeded()),
+                IMinimalRToken(rToken).totalSupply()
+            );
+    }
+}
+
+/**
+ * @title CurveOracleFactory
+ * @notice An immutable factory for Curve oracles
+ */
+contract CurveOracleFactory {
+    error CurveOracleAlreadyDeployed();
+
+    event CurveOracleDeployed(address indexed rToken, address indexed curveOracle);
+
+    mapping(address => CurveOracle) public curveOracles;
+
+    function deployCurveOracle(address rToken) external returns (address) {
+        if (address(curveOracles[rToken]) != address(0)) revert CurveOracleAlreadyDeployed();
+        CurveOracle curveOracle = new CurveOracle(rToken);
+        curveOracle.exchangeRate(); // ensure it works
+        curveOracles[rToken] = curveOracle;
+        emit CurveOracleDeployed(address(rToken), address(curveOracle));
+        return address(curveOracle);
+    }
+}

tasks/deployment/create-curve-oracle-factory.ts

@@ -0,0 +1,56 @@
+import { getChainId } from '../../common/blockchain-utils'
+import { task, types } from 'hardhat/config'
+import { CurveOracleFactory } from '../../typechain'
+
+task('create-curve-oracle-factory', 'Deploys a CurveOracleFactory')
+  .addOptionalParam('noOutput', 'Suppress output', false, types.boolean)
+  .setAction(async (params, hre) => {
+    const [wallet] = await hre.ethers.getSigners()
+
+    const chainId = await getChainId(hre)
+
+    if (!params.noOutput) {
+      console.log(
+        `Deploying CurveOracleFactory to ${hre.network.name} (${chainId}) with burner account ${wallet.address}`
+      )
+    }
+
+    const CurveOracleFactoryFactory = await hre.ethers.getContractFactory('CurveOracleFactory')
+    const curveOracleFactory = <CurveOracleFactory>(
+      await CurveOracleFactoryFactory.connect(wallet).deploy()
+    )
+    await curveOracleFactory.deployed()
+
+    if (!params.noOutput) {
+      console.log(
+        `Deployed CurveOracleFactory to ${hre.network.name} (${chainId}): ${curveOracleFactory.address}`
+      )
+    }
+
+    // Uncomment to verify
+    if (!params.noOutput) {
+      console.log('sleeping 30s')
+    }
+
+    // Sleep to ensure API is in sync with chain
+    await new Promise((r) => setTimeout(r, 30000)) // 30s
+
+    if (!params.noOutput) {
+      console.log('verifying')
+    }
+
+    /** ******************** Verify CurveOracleFactory ****************************************/
+    console.time('Verifying CurveOracleFactory')
+    await hre.run('verify:verify', {
+      address: curveOracleFactory.address,
+      constructorArguments: [],
+      contract: 'contracts/facade/factories/CurveOracleFactory.sol:CurveOracleFactory',
+    })
+    console.timeEnd('Verifying CurveOracleFactory')
+
+    if (!params.noOutput) {
+      console.log('verified')
+    }
+
+    return { curveOracleFactory: curveOracleFactory.address }
+  })

tasks/index.ts

@@ -16,6 +16,7 @@ import './deployment/mock/deploy-mock-aave'
 import './deployment/mock/deploy-mock-wbtc'
 import './deployment/mock/deploy-mock-easyauction'
 import './deployment/create-deployer-registry'
+import './deployment/create-curve-oracle-factory'
 import './deployment/deploy-facade-monitor'
 import './deployment/empty-wallet'
 import './deployment/cancel-tx'