feat(libraries): add oracle helper for twap consumers

src/libraries/OracleLibrary.sol

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.36;
+
+import {IFluxClPool} from "../interfaces/IFluxClPool.sol";
+import {TickMath} from "./TickMath.sol";
+import {FullMath} from "./FullMath.sol";
+
+/// @title Time weighted average tick and price quotes derived from pool observations.
+library OracleLibrary {
+    function consult(address pool, uint32 secondsAgo) internal view returns (int24 arithmeticMeanTick) {
+        require(secondsAgo != 0, "OracleLibrary: PERIOD");
+
+        uint32[] memory secondsAgos = new uint32[](2);
+        secondsAgos[0] = secondsAgo;
+        secondsAgos[1] = 0;
+
+        (int56[] memory tickCumulatives,) = IFluxClPool(pool).observe(secondsAgos);
+        int56 tickCumulativesDelta = tickCumulatives[1] - tickCumulatives[0];
+
+        arithmeticMeanTick = int24(tickCumulativesDelta / int56(uint56(secondsAgo)));
+        if (tickCumulativesDelta < 0 && (tickCumulativesDelta % int56(uint56(secondsAgo)) != 0)) {
+            arithmeticMeanTick--;
+        }
+    }
+
+    function getQuoteAtTick(int24 tick, uint128 baseAmount, address baseToken, address quoteToken)
+        internal
+        pure
+        returns (uint256 quoteAmount)
+    {
+        uint160 sqrtRatioX96 = TickMath.getSqrtRatioAtTick(tick);
+
+        if (sqrtRatioX96 <= type(uint128).max) {
+            uint256 ratioX192 = uint256(sqrtRatioX96) * sqrtRatioX96;
+            quoteAmount = baseToken < quoteToken
+                ? FullMath.mulDiv(ratioX192, baseAmount, 1 << 192)
+                : FullMath.mulDiv(1 << 192, baseAmount, ratioX192);
+        } else {
+            uint256 ratioX128 = FullMath.mulDiv(sqrtRatioX96, sqrtRatioX96, 1 << 64);
+            quoteAmount = baseToken < quoteToken
+                ? FullMath.mulDiv(ratioX128, baseAmount, 1 << 128)
+                : FullMath.mulDiv(1 << 128, baseAmount, ratioX128);
+        }
+    }
+}