feat: add dia oracle adaptor

src/adapter/dia/DIAOracleV2Adapter.sol

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.0;
+
+import {BaseAdapter, Errors, IPriceOracle} from "../BaseAdapter.sol";
+import {IDIAOracleV2} from "./IDIAOracleV2.sol";
+import {ScaleUtils, Scale} from "../../lib/ScaleUtils.sol";
+
+/// @title DIAOracleV2Adapter
+/// @notice PriceOracle adapter for DIA Oracle V2 price feeds.
+contract DIAOracleV2Adapter is BaseAdapter {
+    /// @inheritdoc IPriceOracle
+    string public constant name = "DIAOracleV2Adapter";
+    /// @notice The minimum permitted value for `maxStaleness`.
+    uint256 internal constant MAX_STALENESS_LOWER_BOUND = 1 minutes;
+    /// @notice The maximum permitted value for `maxStaleness`.
+    uint256 internal constant MAX_STALENESS_UPPER_BOUND = 72 hours;
+    /// @notice The address of the base asset corresponding to the feed.
+    address public immutable base;
+    /// @notice The address of the quote asset corresponding to the feed.
+    address public immutable quote;
+    /// @notice The address of the DIA Oracle V2 contract.
+    address public immutable oracle;
+    /// @notice The key used to fetch the price from DIA Oracle.
+    string public feedKey;
+    /// @notice The maximum allowed age of the price.
+    /// @dev Reverts if block.timestamp - updatedAt > maxStaleness.
+    uint256 public immutable maxStaleness;
+    /// @notice The scale factors used for decimal conversions.
+    Scale internal immutable scale;
+
+    /// @notice Deploy a DIAOracleV2Adapter.
+    /// @param _base The address of the base asset corresponding to the feed.
+    /// @param _quote The address of the quote asset corresponding to the feed.
+    /// @param _oracle The address of the DIA Oracle V2 contract.
+    /// @param _feedKey The key used to fetch the price from DIA Oracle (e.g., "ETH/USD").
+    /// @param _maxStaleness The maximum allowed age of the price.
+    /// @param _feedDecimals The number of decimals in the DIA price feed.
+    constructor(
+        address _base,
+        address _quote,
+        address _oracle,
+        string memory _feedKey,
+        uint256 _maxStaleness,
+        uint8 _feedDecimals
+    ) {
+        if (_maxStaleness < MAX_STALENESS_LOWER_BOUND || _maxStaleness > MAX_STALENESS_UPPER_BOUND) {
+            revert Errors.PriceOracle_InvalidConfiguration();
+        }
+
+        base = _base;
+        quote = _quote;
+        oracle = _oracle;
+        feedKey = _feedKey;
+        maxStaleness = _maxStaleness;
+
+        // The scale factor is used to correctly convert decimals.
+        uint8 baseDecimals = _getDecimals(base);
+        uint8 quoteDecimals = _getDecimals(quote);
+
+        // Validate decimals to prevent overflow (same check as in ScaleUtils)
+        if (quoteDecimals > 38 || _feedDecimals + baseDecimals > 38) {
+            revert Errors.PriceOracle_InvalidConfiguration();
+        }
+
+        scale = ScaleUtils.calcScale(baseDecimals, quoteDecimals, _feedDecimals);
+    }
+
+    /// @notice Get the quote from the DIA Oracle V2 feed.
+    /// @param inAmount The amount of `base` to convert.
+    /// @param _base The token that is being priced.
+    /// @param _quote The token that is the unit of account.
+    /// @return The converted amount using the DIA Oracle feed.
+    function _getQuote(uint256 inAmount, address _base, address _quote) internal view override returns (uint256) {
+        bool inverse = ScaleUtils.getDirectionOrRevert(_base, base, _quote, quote);
+
+        (uint128 value, uint128 timestamp) = IDIAOracleV2(oracle).getValue(feedKey);
+
+        if (value == 0) revert Errors.PriceOracle_InvalidAnswer();
+
+        uint256 staleness = block.timestamp - timestamp;
+        if (staleness > maxStaleness) revert Errors.PriceOracle_TooStale(staleness, maxStaleness);
+
+        uint256 price = uint256(value);
+        return ScaleUtils.calcOutAmount(inAmount, price, scale, inverse);
+    }
+}

src/adapter/dia/IDIAOracleV2.sol

@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+pragma solidity ^0.8.0;
+
+interface IDIAOracleV2 {
+    function getValue(string memory key) external view returns (uint128 value, uint128 timestamp);
+}