WIP BalancerV2SwapAdapter getLimits

evm/src/balancer-v2/BalancerV2SwapAdapter.sol

@@ -1,19 +1,67 @@
 // SPDX-License-Identifier: AGPL-3.0-or-later
 pragma solidity ^0.8.13;
 
-import {IERC20, ISwapAdapter} from "interfaces/ISwapAdapter.sol";
+import {IERC20, ISwapAdapter} from "src/interfaces/ISwapAdapter.sol";
 
-contract BalancerV2SwapAdapter is ISwapAdapter {
+interface IVault {
+    function getPoolTokens(bytes32 poolId)
+        external
+        view
+        returns (
+            IERC20[] memory tokens,
+            uint256[] memory balances,
+            uint256 lastChangeBlock
+        );
 
-    constructor() {
+    function swap(
+        SingleSwap memory singleSwap,
+        FundManagement memory funds,
+        uint256 limit,
+        uint256 deadline
+    ) external payable returns (uint256);
+
+    function queryBatchSwap(
+        SwapKind kind,
+        BatchSwapStep[] memory swaps,
+        IAsset[] memory assets,
+        FundManagement memory funds
+    ) external returns (int256[] memory assetDeltas);
+
+    struct SingleSwap {
+        bytes32 poolId;
+        SwapKind kind;
+        IAsset assetIn;
+        IAsset assetOut;
+        uint256 amount;
+        bytes userData;
     }
 
-    function getPairReserves(
-        bytes32 pairId,
-        IERC20 sellToken,
-        IERC20 buyToken
-    ) internal view returns (uint112 r0, uint112 r1) {
-        revert NotImplemented("BalancerV2SwapAdapter.getPairReserves");
+    struct BatchSwapStep {
+        bytes32 poolId;
+        uint256 assetInIndex;
+        uint256 assetOutIndex;
+        uint256 amount;
+        bytes userData;
+    }
+
+    struct FundManagement {
+        address sender;
+        bool fromInternalBalance;
+        address payable recipient;
+        bool toInternalBalance;
+    }
+
+    enum SwapKind { GIVEN_IN, GIVEN_OUT }
+}
+
+interface IAsset is IERC20 {
+}
+
+contract BalancerV2SwapAdapter is ISwapAdapter {
+    IVault immutable vault;
+
+    constructor(address vault_) {
+        vault = IVault(vault_);
     }
 
     function price(
@@ -49,7 +97,7 @@ contract BalancerV2SwapAdapter is ISwapAdapter {
         override
         returns (uint256[] memory limits)
     {
-        revert NotImplemented("BalancerV2SwapAdapter.getLimits");
+        (, limits, ) = vault.getPoolTokens(pairId);
     }
 
     function getCapabilities(bytes32, IERC20, IERC20)
@@ -73,6 +121,7 @@ contract BalancerV2SwapAdapter is ISwapAdapter {
         revert NotImplemented("BalancerV2SwapAdapter.getTokens");
     }
 
+    /// @dev Balancer V2 does not support listing pools.
     function getPoolIds(uint256 offset, uint256 limit)
         external
         view