feat: conditional swap using merkle proof

src/constants/BitMask.sol

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+uint256 constant MASK_1_BIT = 0x1;
+uint256 constant MASK_8_BITS = 0xff;
+uint256 constant MASK_24_BITS = 0xffffff;
+uint256 constant MASK_127_BITS = 0x7fffffffffffffffffffffffffffffff;
+uint256 constant MASK_128_BITS = 0xffffffffffffffffffffffffffffffff;
+uint160 constant MASK_160_BITS = 0x00ffffffffffffffffffffffffffffffffffffffff;
+
+uint256 constant MASK_BYTES_4 = 0xffffffff00000000000000000000000000000000000000000000000000000000;

src/hooks/swap/KSConditionalSwapHook.sol

@@ -2,18 +2,28 @@
 pragma solidity ^0.8.0;
 
 import {IKSSmartIntentHook} from '../../interfaces/hooks/IKSSmartIntentHook.sol';
+import {PackedU128} from '../../types/PackedU128.sol';
 import {BaseStatefulHook} from '../base/BaseStatefulHook.sol';
+import {CalldataDecoder} from 'ks-common-sc/src/libraries/calldata/CalldataDecoder.sol';
 import {TokenHelper} from 'ks-common-sc/src/libraries/token/TokenHelper.sol';
+import {MerkleProof} from 'openzeppelin-contracts/contracts/utils/cryptography/MerkleProof.sol';
 
 import {ActionData} from '../../types/ActionData.sol';
 import {IntentData} from '../../types/IntentData.sol';
 
 contract KSConditionalSwapHook is BaseStatefulHook {
   using TokenHelper for address;
+  using CalldataDecoder for bytes;
 
-  error InvalidTokenIn(address tokenIn, address actualTokenIn);
   error AmountInMismatch(uint256 amountIn, uint256 actualAmountIn);
-  error InvalidSwap();
+  error InvalidProof();
+  error InvalidTime(uint256 timestamp, uint256 min, uint256 maxT);
+  error InvalidAmountIn(uint256 amountIn, uint256 minAmountIn, uint256 maxAmountIn);
+  error InvalidFees(
+    uint256 srcFeePercent, uint256 dstFeePercent, uint256 maxSrcFee, uint256 maxDstFee
+  );
+  error InvalidPrice(uint256 price, uint256 minPrice, uint256 maxPrice);
+  error InvalidSwapLimit(uint256 swapCount, uint256 limit);
 
   uint256 public constant DENOMINATOR = 1e18;
   uint256 public constant PRECISION = 1_000_000;
@@ -26,9 +36,7 @@ contract KSConditionalSwapHook is BaseStatefulHook {
    * @param recipient The recipient of the destination token
    */
   struct SwapHookData {
-    SwapCondition[][] swapConditions;
-    address[] srcTokens;
-    address[] dstTokens;
+    bytes32 root;
     address recipient;
   }
 
@@ -42,16 +50,16 @@ contract KSConditionalSwapHook is BaseStatefulHook {
    */
   struct SwapCondition {
     uint8 swapLimit;
-    uint256 timeLimits;
-    uint256 amountInLimits;
-    uint256 maxFees;
-    uint256 priceLimits;
+    PackedU128 timeLimits;
+    PackedU128 amountInLimits;
+    PackedU128 maxFees;
+    PackedU128 priceLimits;
   }
 
   struct SwapValidationData {
-    SwapCondition[] swapConditions;
+    SwapCondition swapCondition;
     bytes32 intentHash;
-    uint256 intentIndex;
+    uint256 leafIndex;
     address tokenIn;
     address tokenOut;
     uint256 amountIn;
@@ -64,14 +72,12 @@ contract KSConditionalSwapHook is BaseStatefulHook {
 
   /**
    * @notice Tracks swap execution counts for each condition to enforce swap limits
-   * @dev Maps intentHash -> intentIndex -> packedIndexes -> packedCounts
+   * @dev Maps intentHash -> packedIndexes -> packedCounts
    *      Each uint256 stores up to 32 uint8 swap counts (8 bits each), indexed by swapIndexes / 32
    *      Individual counts are extracted using bit shifts based on swapIndexes % 32
    */
-  mapping(
-    bytes32 intentHash
-      => mapping(uint256 intentIndex => mapping(uint256 swapIndexes => uint256 swapCount))
-  ) public swapRecord;
+  mapping(bytes32 intentHash => mapping(uint256 swapIndexes => uint256 swapCount)) public
+    swapRecord;
 
   constructor(address[] memory initialRouters) BaseStatefulHook(initialRouters) {}
 
@@ -81,7 +87,6 @@ contract KSConditionalSwapHook is BaseStatefulHook {
     _;
   }
 
-  /// @inheritdoc IKSSmartIntentHook
   function beforeExecution(
     bytes32 intentHash,
     IntentData calldata intentData,
@@ -94,25 +99,28 @@ contract KSConditionalSwapHook is BaseStatefulHook {
     returns (uint256[] memory fees, bytes memory beforeExecutionData)
   {
     SwapHookData calldata swapHookData = _decodeHookData(intentData.coreData.hookIntentData);
-    (uint256 index, uint256 intentSrcFee, uint256 intentDstFee) =
-      _decodeAndValidateHookActionData(actionData.hookActionData, swapHookData);
+    (
+      bytes32[] calldata proof,
+      SwapCondition calldata condition,
+      uint256 leafIndex,
+      address tokenOut,
+      uint256 intentSrcFee,
+      uint256 intentDstFee
+    ) = _decodeHookActionData(actionData.hookActionData);
 
     address tokenIn = intentData.tokenData.erc20Data[actionData.erc20Ids[0]].token;
-    address tokenOut = swapHookData.dstTokens[index];
-    uint256 amountIn = actionData.erc20Amounts[0];
 
-    require(
-      tokenIn == swapHookData.srcTokens[index],
-      InvalidTokenIn(tokenIn, swapHookData.srcTokens[index])
-    );
+    bytes32 leaf = keccak256(abi.encode(leafIndex, tokenIn, tokenOut, condition));
+    require(MerkleProof.verifyCalldata(proof, swapHookData.root, leaf), InvalidProof());
 
+    uint256 amountIn = actionData.erc20Amounts[0];
     fees = new uint256[](1);
     fees[0] = (amountIn * intentSrcFee) / PRECISION;
     beforeExecutionData = abi.encode(
       SwapValidationData({
-        swapConditions: swapHookData.swapConditions[index],
+        swapCondition: condition,
         intentHash: intentHash,
-        intentIndex: index,
+        leafIndex: leafIndex,
         tokenIn: tokenIn,
         tokenOut: tokenOut,
         amountIn: amountIn,
@@ -129,7 +137,6 @@ contract KSConditionalSwapHook is BaseStatefulHook {
     return (fees, beforeExecutionData);
   }
 
-  /// @inheritdoc IKSSmartIntentHook
   function afterExecution(
     bytes32,
     IntentData calldata intentData,
@@ -162,8 +169,9 @@ contract KSConditionalSwapHook is BaseStatefulHook {
     uint256 price = (amountOut * DENOMINATOR) / amountIn;
 
     _validateSwapCondition(
-      validationData.swapConditions,
-      swapRecord[validationData.intentHash][validationData.intentIndex],
+      validationData.swapCondition,
+      validationData.leafIndex,
+      swapRecord[validationData.intentHash],
       price,
       amountIn,
       validationData.srcFeePercent,
@@ -191,60 +199,60 @@ contract KSConditionalSwapHook is BaseStatefulHook {
   /**
    * @notice Gets the number of times a specific swap condition has been executed
    * @param intentHash The hash of the intent
-   * @param intentIndex The index of the specific intent
    * @param conditionIndex The index of the swap condition to check
    * @return The number of times this condition has been executed
    */
-  function getSwapExecutionCount(bytes32 intentHash, uint256 intentIndex, uint256 conditionIndex)
+  function getSwapExecutionCount(bytes32 intentHash, uint256 conditionIndex)
     public
     view
     returns (uint256)
   {
-    uint256 packedValue = swapRecord[intentHash][intentIndex][conditionIndex / 32];
+    uint256 packedValue = swapRecord[intentHash][conditionIndex / 32];
     uint256 bytePosition = conditionIndex % 32;
 
     return uint8(packedValue >> (bytePosition * 8));
   }
 
   function _validateSwapCondition(
-    SwapCondition[] calldata swapCondition,
+    SwapCondition calldata condition,
+    uint256 index,
     mapping(uint256 swapIndexes => uint256 swapCounts) storage record,
     uint256 price,
     uint256 amountIn,
     uint256 srcFeePercent,
     uint256 dstFeePercent
   ) internal {
-    for (uint256 i; i < swapCondition.length; ++i) {
-      SwapCondition calldata condition = swapCondition[i];
-
-      if (
-        block.timestamp < condition.timeLimits >> 128
-          || block.timestamp > uint128(condition.timeLimits)
-      ) {
-        continue;
-      }
-
-      if (
-        amountIn < condition.amountInLimits >> 128 || amountIn > uint128(condition.amountInLimits)
-      ) {
-        continue;
-      }
-
-      if (srcFeePercent > condition.maxFees >> 128 || dstFeePercent > uint128(condition.maxFees)) {
-        continue;
-      }
-
-      if (price < condition.priceLimits >> 128 || price > uint128(condition.priceLimits)) {
-        continue;
-      }
-
-      if (!_increaseByOne(record, uint8(i), condition.swapLimit)) {
-        continue;
-      }
-      return;
+    if (
+      block.timestamp < condition.timeLimits.value0()
+        || block.timestamp > condition.timeLimits.value1()
+    ) {
+      revert InvalidTime(
+        block.timestamp, condition.timeLimits.value0(), condition.timeLimits.value1()
+      );
+    }
+
+    if (
+      amountIn < condition.amountInLimits.value0() || amountIn > condition.amountInLimits.value1()
+    ) {
+      revert InvalidAmountIn(
+        amountIn, condition.amountInLimits.value0(), condition.amountInLimits.value1()
+      );
+    }
+
+    if (srcFeePercent > condition.maxFees.value0() || dstFeePercent > condition.maxFees.value1()) {
+      revert InvalidFees(
+        srcFeePercent, dstFeePercent, condition.maxFees.value0(), condition.maxFees.value1()
+      );
+    }
+
+    if (price < condition.priceLimits.value0() || price > condition.priceLimits.value1()) {
+      revert InvalidPrice(price, condition.priceLimits.value0(), condition.priceLimits.value1());
     }
 
-    revert InvalidSwap();
+    (bool success, uint8 swapCount) = _increaseByOne(record, uint8(index), condition.swapLimit);
+    if (!success) {
+      revert InvalidSwapLimit(swapCount, condition.swapLimit);
+    }
   }
 
   /**
@@ -259,21 +267,21 @@ contract KSConditionalSwapHook is BaseStatefulHook {
     mapping(uint256 packedIndexes => uint256 packedValues) storage record,
     uint8 index,
     uint8 limit
-  ) internal returns (bool) {
+  ) internal returns (bool, uint8) {
     uint256 packedValue = record[index / 32];
     uint256 bytePosition = index % 32;
 
     uint8 swapCount = uint8(packedValue >> (bytePosition * 8)) + 1;
 
     if (swapCount > limit) {
-      return false;
+      return (false, swapCount);
     }
 
     packedValue += 1 << (bytePosition * 8);
 
     record[index / 32] = packedValue;
 
-    return true;
+    return (true, swapCount);
   }
 
   function _getRecipientBalance(address tokenOut, address recipient, uint256 feePercent)
@@ -287,42 +295,46 @@ contract KSConditionalSwapHook is BaseStatefulHook {
     return tokenOut.balanceOf(recipient);
   }
 
-  // @dev: equivalent to abi.decode(data, (SwapCondition))
-  function _decodeSwapCondition(bytes calldata data)
-    internal
-    pure
-    returns (SwapCondition calldata swapCondition)
-  {
-    assembly ('memory-safe') {
-      swapCondition := data.offset
-    }
-  }
-
   // @dev: equivalent to abi.decode(data, (SwapHookData))
   function _decodeHookData(bytes calldata data)
     internal
     pure
     returns (SwapHookData calldata hookData)
   {
     assembly ('memory-safe') {
-      hookData := add(data.offset, calldataload(data.offset))
+      hookData := data.offset
     }
   }
 
   // @dev: equivalent to abi.decode(data, (uint256, uint256, uint256, uint256))
-  function _decodeAndValidateHookActionData(bytes calldata data, SwapHookData calldata swapHookData)
+  function _decodeHookActionData(bytes calldata data)
     internal
-    view
-    returns (uint256 index, uint256 intentSrcFee, uint256 intentDstFee)
+    pure
+    returns (
+      bytes32[] calldata proof,
+      SwapCondition calldata condition,
+      uint256 leafIndex,
+      address tokenOut,
+      uint256 intentSrcFee,
+      uint256 intentDstFee
+    )
   {
-    uint256 packedFees;
+    PackedU128 packedFees;
+    assembly ('memory-safe') {
+      leafIndex := calldataload(add(data.offset, 0x20))
+      tokenOut := calldataload(add(data.offset, 0x40))
+      packedFees := calldataload(add(data.offset, 0x60))
+      condition := add(data.offset, 0x80)
+    }
+
+    (uint256 length, uint256 offset) = data.decodeLengthOffset(0);
     assembly ('memory-safe') {
-      index := calldataload(data.offset)
-      packedFees := calldataload(add(data.offset, 0x20))
+      proof.length := length
+      proof.offset := offset
     }
 
-    intentSrcFee = packedFees >> 128;
-    intentDstFee = uint128(packedFees);
+    intentSrcFee = packedFees.value0();
+    intentDstFee = packedFees.value1();
   }
 
   // @dev: equivalent to abi.decode(data, (SwapValidationData))
@@ -332,7 +344,7 @@ contract KSConditionalSwapHook is BaseStatefulHook {
     returns (SwapValidationData calldata validationData)
   {
     assembly ('memory-safe') {
-      validationData := add(data.offset, calldataload(data.offset))
+      validationData := data.offset
     }
   }
 }