Add ERC: DeFi Protocol Solvency Proof Mechanism

assets/erc-7893/LICENSE.md

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+# MIT License
+
+Copyright (c) 2025 Sean Luis
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

assets/erc-7893/SolvencyProof.sol

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+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import "./ISolvencyProof.sol";
+import "@openzeppelin/contracts/access/Ownable.sol";
+import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
+
+/**
+ * @title SolvencyProof
+ * @author Sean Luis (@SeanLuis) <[email protected]>
+ * @notice Implementation of DeFi Protocol Solvency Proof Standard (EIP-DRAFT)
+ * @dev This contract implements ISolvencyProof interface for tracking and verifying protocol solvency
+ *      It includes asset/liability tracking, solvency ratio calculations, and historical metrics
+ */
+contract SolvencyProof is ISolvencyProof, Ownable, ReentrancyGuard {
+    // === Constants ===
+    /// @notice Base multiplier for ratio calculations (100% = 10000)
+    uint256 private constant RATIO_DECIMALS = 10000;
+
+    /// @notice Minimum solvency ratio required (105%)
+    uint256 private constant MIN_SOLVENCY_RATIO = 10500;
+
+    /// @notice Critical threshold for emergency measures (102%)
+    uint256 private constant CRITICAL_RATIO = 10200;
+
+    // === State Variables ===
+    /// @notice Current state of protocol assets
+    ProtocolAssets private currentAssets;
+
+    /// @notice Current state of protocol liabilities
+    ProtocolLiabilities private currentLiabilities;
+
+    /// @notice Mapping of authorized price oracles
+    /// @dev address => isAuthorized
+    mapping(address => bool) public assetOracles;
+
+    /**
+     * @notice Structure for storing historical solvency metrics
+     * @dev Used to track protocol's financial health over time
+     * @param timestamp Time when metrics were recorded
+     * @param solvencyRatio Calculated solvency ratio at that time
+     * @param assets Snapshot of protocol assets
+     * @param liabilities Snapshot of protocol liabilities
+     */
+    struct HistoricalMetric {
+        uint256 timestamp;
+        uint256 solvencyRatio;
+        ProtocolAssets assets;
+        ProtocolLiabilities liabilities;
+    }
+
+    /// @notice Array storing historical solvency metrics
+    HistoricalMetric[] private metricsHistory;
+
+    // === Events ===
+    /// @notice Emitted when an oracle's authorization status changes
+    /// @param oracle Address of the oracle
+    /// @param authorized New authorization status
+    event OracleUpdated(address indexed oracle, bool authorized);
+
+    /**
+     * @notice Contract constructor
+     * @dev Initializes Ownable with msg.sender as owner
+     */
+    constructor() Ownable(msg.sender) {}
+
+    /**
+     * @notice Restricts function access to authorized oracles
+     * @dev Throws if called by non-authorized address
+     */
+    modifier onlyOracle() {
+        require(assetOracles[msg.sender], "Not authorized oracle");
+        _;
+    }
+
+    // === External Functions ===
+    /// @inheritdoc ISolvencyProof
+    function getProtocolAssets() external view returns (ProtocolAssets memory) {
+        return currentAssets;
+    }
+
+    /// @inheritdoc ISolvencyProof
+    function getProtocolLiabilities() external view returns (ProtocolLiabilities memory) {
+        return currentLiabilities;
+    }
+
+    /// @inheritdoc ISolvencyProof
+    function getSolvencyRatio() external view returns (uint256) {
+        return _calculateSolvencyRatio();
+    }
+
+    /// @inheritdoc ISolvencyProof
+    function verifySolvency() external view returns (bool isSolvent, uint256 healthFactor) {
+        uint256 ratio = _calculateSolvencyRatio();
+        return (ratio >= MIN_SOLVENCY_RATIO, ratio);
+    }
+
+    /// @inheritdoc ISolvencyProof
+    function getSolvencyHistory(uint256 startTime, uint256 endTime) 
+        external 
+        view 
+        returns (
+            uint256[] memory timestamps,
+            uint256[] memory ratios,
+            ProtocolAssets[] memory assets,
+            ProtocolLiabilities[] memory liabilities
+        )
+    {
+        uint256 count = 0;
+        for (uint256 i = 0; i < metricsHistory.length; i++) {
+            if (metricsHistory[i].timestamp >= startTime && 
+                metricsHistory[i].timestamp <= endTime) {
+                count++;
+            }
+        }
+
+        timestamps = new uint256[](count);
+        ratios = new uint256[](count);
+        assets = new ProtocolAssets[](count);
+        liabilities = new ProtocolLiabilities[](count);
+        uint256 index = 0;
+
+        for (uint256 i = 0; i < metricsHistory.length && index < count; i++) {
+            if (metricsHistory[i].timestamp >= startTime && 
+                metricsHistory[i].timestamp <= endTime) {
+                timestamps[index] = metricsHistory[i].timestamp;
+                ratios[index] = metricsHistory[i].solvencyRatio;
+                assets[index] = metricsHistory[i].assets;
+                liabilities[index] = metricsHistory[i].liabilities;
+                index++;
+            }
+        }
+
+        return (timestamps, ratios, assets, liabilities);
+    }
+
+    /// @inheritdoc ISolvencyProof
+    function updateAssets(
+        address[] calldata tokens,
+        uint256[] calldata amounts,
+        uint256[] calldata values
+    ) external onlyOracle nonReentrant {
+        require(tokens.length == amounts.length && amounts.length == values.length, 
+                "Array lengths mismatch");
+
+        currentAssets = ProtocolAssets({
+            tokens: tokens,
+            amounts: amounts,
+            values: values,
+            timestamp: block.timestamp
+        });
+
+        _updateMetrics();
+    }
+
+    /// @inheritdoc ISolvencyProof
+    function updateLiabilities(
+        address[] calldata tokens,
+        uint256[] calldata amounts,
+        uint256[] calldata values
+    ) external onlyOracle nonReentrant {
+        require(tokens.length == amounts.length && amounts.length == values.length, 
+                "Array lengths mismatch");
+
+        currentLiabilities = ProtocolLiabilities({
+            tokens: tokens,
+            amounts: amounts,
+            values: values,
+            timestamp: block.timestamp
+        });
+
+        _updateMetrics();
+    }
+
+    /**
+     * @notice Updates oracle authorization status
+     * @dev Only callable by contract owner
+     * @param oracle Address of the oracle to update
+     * @param authorized New authorization status
+     */
+    function setOracle(address oracle, bool authorized) external onlyOwner {
+        require(oracle != address(0), "Invalid oracle address");
+        assetOracles[oracle] = authorized;
+        emit OracleUpdated(oracle, authorized);
+    }
+
+    // === Internal Functions ===
+    /**
+     * @notice Calculates current solvency ratio
+     * @dev Ratio = (Total Assets / Total Liabilities) × RATIO_DECIMALS
+     * @return Current solvency ratio with RATIO_DECIMALS precision
+     */
+    function _calculateSolvencyRatio() internal view returns (uint256) {
+        uint256 totalAssets = _sumArray(currentAssets.values);
+        uint256 totalLiabilities = _sumArray(currentLiabilities.values);
+
+        if (totalLiabilities == 0) {
+            return totalAssets > 0 ? RATIO_DECIMALS * 2 : RATIO_DECIMALS;
+        }
+
+        return (totalAssets * RATIO_DECIMALS) / totalLiabilities;
+    }
+
+    /**
+     * @notice Updates protocol metrics and emits relevant events
+     * @dev Called after asset or liability updates
+     */
+    function _updateMetrics() internal {
+        uint256 totalAssets = _sumArray(currentAssets.values);
+        uint256 totalLiabilities = _sumArray(currentLiabilities.values);
+        uint256 ratio = _calculateSolvencyRatio();
+
+        // Debug log
+        emit SolvencyMetricsUpdated(
+            totalAssets,
+            totalLiabilities,
+            ratio,
+            block.timestamp
+        );
+
+        metricsHistory.push(HistoricalMetric({
+            timestamp: block.timestamp,
+            solvencyRatio: ratio,
+            assets: currentAssets,
+            liabilities: currentLiabilities
+        }));
+
+        // Update alerts based on actual ratio
+        if (ratio < CRITICAL_RATIO) {
+            emit RiskAlert("CRITICAL", ratio, totalAssets, totalLiabilities);
+        } else if (ratio < MIN_SOLVENCY_RATIO) {
+            emit RiskAlert("HIGH_RISK", ratio, totalAssets, totalLiabilities);
+        }
+    }
+
+    /**
+     * @notice Sums all values in an array
+     * @param array Array of uint256 values to sum
+     * @return sum Total sum of array values
+     */
+    function _sumArray(uint256[] memory array) internal pure returns (uint256) {
+        uint256 sum = 0;
+        for (uint256 i = 0; i < array.length; i++) {
+            sum += array[i];
+        }
+        return sum;
+    }
+}