chore: add AssetValueCalculator

Co-authored-by: Sebastian Siemssen <[email protected]>

contracts/persistent/off-chain/README.md

@@ -0,0 +1,8 @@
+# Contracts primarily for off-chain consumption
+
+This directory contains data aggregation contracts that are primarily intended to be consumed off-chain.
+
+Prior to using any of these contracts for on-chain purposes, confirm that:
+
+1. it has been audited
+2. the logic is suitable for on-chain use (gas, state changes, etc)

contracts/release/off-chain/AssetValueCalculator.sol

@@ -0,0 +1,78 @@
+// SPDX-License-Identifier: GPL-3.0
+
+/*
+    This file is part of the Enzyme Protocol.
+
+    (c) Enzyme Council <[email protected]>
+
+    For the full license information, please view the LICENSE
+    file that was distributed with this source code.
+*/
+
+pragma solidity 0.6.12;
+
+import "@openzeppelin/contracts/math/SafeMath.sol";
+import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import "../infrastructure/value-interpreter/ValueInterpreter.sol";
+
+/// @title AssetValueCalculator Contract
+/// @author Enzyme Council <[email protected]>
+/// @notice A peripheral contract for calculating asset values
+/// @dev These are convenience functions intended for off-chain consumption,
+/// some of which involve potentially expensive state transitions
+contract AssetValueCalculator {
+    using SafeMath for uint256;
+
+    address private immutable VALUE_INTERPRETER;
+
+    constructor(address _valueInterpreter) public {
+        VALUE_INTERPRETER = _valueInterpreter;
+    }
+
+    // EXTERNAL FUNCTIONS
+
+    /// @notice Calculates the value of a given amount of one asset in terms of another asset
+    /// @param _baseAsset The asset from which to convert
+    /// @param _quoteAsset The asset to which to convert
+    /// @return timestamp_ The current block timestamp
+    /// @return value_ The equivalent quantity in the _quoteAsset
+    function calcNormalizedAssetValue(address _baseAsset, address _quoteAsset)
+        external
+        returns (
+            uint256 timestamp_,
+            uint256 value_,
+            bool valueIsValid_
+        )
+    {
+        timestamp_ = block.timestamp;
+        uint256 amount = 10**uint256(ERC20(_baseAsset).decimals());
+
+        try
+            ValueInterpreter(getValueInterpreter()).calcCanonicalAssetValue(
+                _baseAsset,
+                amount,
+                _quoteAsset
+            )
+        returns (uint256 value, bool isValid) {
+            if (isValid) {
+                value_ = value;
+                valueIsValid_ = true;
+            }
+        } catch {}
+
+        uint256 decimals = ERC20(_quoteAsset).decimals();
+        value_ = value_.mul(10**18).div(10**decimals);
+
+        return (timestamp_, value_, valueIsValid_);
+    }
+
+    ///////////////////
+    // STATE GETTERS //
+    ///////////////////
+
+    /// @notice Gets the `VALUE_INTERPRETER` variable
+    /// @return valueInterpreter_ The `VALUE_INTERPRETER` variable value
+    function getValueInterpreter() public view returns (address valueInterpreter_) {
+        return VALUE_INTERPRETER;
+    }
+}

contracts/release/off-chain/README.md

@@ -0,0 +1,8 @@
+# Contracts primarily for off-chain consumption
+
+This directory contains data aggregation contracts that are primarily intended to be consumed off-chain.
+
+Prior to using any of these contracts for on-chain purposes, confirm that:
+
+1. it has been audited
+2. the logic is suitable for on-chain use (gas, state changes, etc)

deploy/scripts/release/off-chain/AssetValueCalculator.ts

@@ -0,0 +1,21 @@
+import { AssetValueCalculatorArgs } from '@enzymefinance/protocol';
+import { DeployFunction } from 'hardhat-deploy/types';
+
+const fn: DeployFunction = async function (hre) {
+  const { deploy, get } = hre.deployments;
+  const deployer = (await hre.ethers.getSigners())[0];
+
+  const valueInterpreter = await get('ValueInterpreter');
+
+  await deploy('AssetValueCalculator', {
+    args: [valueInterpreter.address] as AssetValueCalculatorArgs,
+    from: deployer.address,
+    log: true,
+    skipIfAlreadyDeployed: true,
+  });
+};
+
+fn.tags = ['Release', 'OffChain', 'AssetValueCalculator'];
+fn.dependencies = ['ValueInterpreter'];
+
+export default fn;

packages/protocol/src/contracts.ts

@@ -88,6 +88,9 @@ export * from './codegen/AuthUserExecutedSharesRequestorProxy';
 export * from './codegen/FundActionsWrapper';
 export * from './codegen/FundValueCalculator';
 
+// Off-chain
+export * from './codegen/AssetValueCalculator';
+
 // Test contracts
 export * from './codegen/TestPeggedDerivativesPriceFeed';
 export * from './codegen/TestSinglePeggedDerivativePriceFeed';