Add AgentExecuteCommand back for compatibility

contracts/src/AgentExecutor.sol

@@ -2,7 +2,7 @@
 // SPDX-FileCopyrightText: 2023 Snowfork <[email protected]>
 pragma solidity 0.8.23;
 
-import {ParaID} from "./Types.sol";
+import {AgentExecuteCommand, ParaID} from "./Types.sol";
 import {SubstrateTypes} from "./SubstrateTypes.sol";
 
 import {IERC20} from "./interfaces/IERC20.sol";
@@ -16,6 +16,17 @@ contract AgentExecutor {
     using SafeTokenTransfer for IERC20;
     using SafeNativeTransfer for address payable;
 
+    /// @dev Execute a message which originated from the Polkadot side of the bridge. In other terms,
+    /// the `data` parameter is constructed by the BridgeHub parachain.
+    ///
+    function execute(bytes memory data) external {
+        (AgentExecuteCommand command, bytes memory params) = abi.decode(data, (AgentExecuteCommand, bytes));
+        if (command == AgentExecuteCommand.TransferToken) {
+            (address token, address recipient, uint128 amount) = abi.decode(params, (address, address, uint128));
+            _transferToken(token, recipient, amount);
+        }
+    }
+
     /// @dev Transfer ether to `recipient`. Unlike `_transferToken` This logic is not nested within `execute`,
     /// as the gateway needs to control an agent's ether balance directly.
     ///
@@ -24,10 +35,15 @@ contract AgentExecutor {
     }
 
     /// @dev Transfer ERC20 to `recipient`. Only callable via `execute`.
-    function transferToken(address token, address recipient, uint128 amount) external {
+    function _transferToken(address token, address recipient, uint128 amount) internal {
         IERC20(token).safeTransfer(recipient, amount);
     }
 
+    /// @dev Transfer ERC20 to `recipient`. Only callable via `execute`.
+    function transferToken(address token, address recipient, uint128 amount) external {
+        _transferToken(token, recipient, amount);
+    }
+
     /// @dev Mint ERC20 token to `recipient`.
     function mintToken(address token, address recipient, uint256 amount) external {
         ERC20(token).mint(recipient, amount);

contracts/src/Gateway.sol

@@ -18,7 +18,8 @@ import {
     MultiAddress,
     Ticket,
     Costs,
-    TokenInfo
+    TokenInfo,
+    AgentExecuteCommand
 } from "./Types.sol";
 import {IGateway} from "./interfaces/IGateway.sol";
 import {IInitializable} from "./interfaces/IInitializable.sol";
@@ -30,6 +31,7 @@ import {Math} from "./utils/Math.sol";
 import {ScaleCodec} from "./utils/ScaleCodec.sol";
 
 import {
+    AgentExecuteParams,
     UpgradeParams,
     CreateAgentParams,
     CreateChannelParams,
@@ -85,6 +87,7 @@ contract Gateway is IGateway, IInitializable {
     error ChannelAlreadyCreated();
     error ChannelDoesNotExist();
     error InvalidChannelUpdate();
+    error AgentExecutionFailed(bytes returndata);
     error InvalidAgentExecutionPayload();
     error InvalidCodeHash();
     error InvalidConstructorParams();
@@ -169,8 +172,8 @@ contract Gateway is IGateway, IInitializable {
         bool success = true;
 
         // Dispatch message to a handler
-        if (message.command == Command.TransferToken) {
-            try Gateway(this).transferToken{gas: maxDispatchGas}(message.params) {}
+        if (message.command == Command.AgentExecute) {
+            try Gateway(this).agentExecute{gas: maxDispatchGas}(message.params) {}
             catch {
                 success = false;
             }
@@ -214,6 +217,11 @@ contract Gateway is IGateway, IInitializable {
             catch {
                 success = false;
             }
+        } else if (message.command == Command.TransferToken) {
+            try Gateway(this).transferToken{gas: maxDispatchGas}(message.params) {}
+            catch {
+                success = false;
+            }
         } else if (message.command == Command.RegisterForeignToken) {
             try Gateway(this).registerForeignToken{gas: maxDispatchGas}(message.params) {}
             catch {
@@ -277,6 +285,24 @@ contract Gateway is IGateway, IInitializable {
      * Handlers
      */
 
+    // Execute code within an agent
+    function agentExecute(bytes calldata data) external onlySelf {
+        AgentExecuteParams memory params = abi.decode(data, (AgentExecuteParams));
+
+        address agent = _ensureAgent(params.agentID);
+
+        if (params.payload.length == 0) {
+            revert InvalidAgentExecutionPayload();
+        }
+
+        bytes memory call = abi.encodeCall(AgentExecutor.execute, params.payload);
+
+        (bool success, bytes memory returndata) = Agent(payable(agent)).invoke(AGENT_EXECUTOR, call);
+        if (!success) {
+            revert AgentExecutionFailed(returndata);
+        }
+    }
+
     /// @dev Create an agent for a consensus system on Polkadot
     function createAgent(bytes calldata data) external onlySelf {
         CoreStorage.Layout storage $ = CoreStorage.layout();

contracts/src/Params.sol

@@ -5,6 +5,12 @@ pragma solidity 0.8.23;
 import {ChannelID, OperatingMode} from "./Types.sol";
 import {UD60x18} from "prb/math/src/UD60x18.sol";
 
+// Payload for AgentExecute
+struct AgentExecuteParams {
+    bytes32 agentID;
+    bytes payload;
+}
+
 // Payload for CreateAgent
 struct CreateAgentParams {
     /// @dev The agent ID of the consensus system

contracts/src/Types.sol

@@ -76,7 +76,7 @@ enum OperatingMode {
 
 /// @dev Messages from Polkadot take the form of these commands.
 enum Command {
-    TransferToken,
+    AgentExecute,
     Upgrade,
     CreateAgent,
     CreateChannel,
@@ -85,10 +85,16 @@ enum Command {
     TransferNativeFromAgent,
     SetTokenTransferFees,
     SetPricingParameters,
+    TransferToken,
     RegisterForeignToken,
     MintForeignToken
 }
 
+enum AgentExecuteCommand {
+    TransferToken,
+    MintToken
+}
+
 /// @dev Application-level costs for a message
 struct Costs {
     /// @dev Costs in foreign currency

contracts/test/Gateway.t.sol

@@ -27,6 +27,7 @@ import {ERC20Lib} from "../src/ERC20Lib.sol";
 import {
     UpgradeParams,
     CreateAgentParams,
+    AgentExecuteParams,
     CreateChannelParams,
     UpdateChannelParams,
     SetOperatingModeParams,
@@ -39,6 +40,7 @@ import {
 } from "../src/Params.sol";
 
 import {
+    AgentExecuteCommand,
     InboundMessage,
     OperatingMode,
     ParaID,
@@ -1033,4 +1035,16 @@ contract GatewayTest is Test {
 
         IGateway(address(gateway)).sendToken{value: 0.1 ether}(address(dotToken), destPara, recipientAddress32, 1, 1);
     }
+
+    function testLegacyAgentExecutionForCompatibility() public {
+        token.transfer(address(assetHubAgent), 200);
+
+        AgentExecuteParams memory params = AgentExecuteParams({
+            agentID: assetHubAgentID,
+            payload: abi.encode(AgentExecuteCommand.TransferToken, abi.encode(address(token), address(account2), 10))
+        });
+
+        bytes memory encodedParams = abi.encode(params);
+        GatewayMock(address(gateway)).agentExecutePublic(encodedParams);
+    }
 }

contracts/test/mocks/GatewayMock.sol

@@ -19,6 +19,10 @@ contract GatewayMock is Gateway {
         uint8 foreignTokenDecimals
     ) Gateway(beefyClient, agentExecutor, bridgeHubParaID, bridgeHubHubAgentID, foreignTokenDecimals) {}
 
+    function agentExecutePublic(bytes calldata params) external {
+        this.agentExecute(params);
+    }
+
     function createAgentPublic(bytes calldata params) external {
         this.createAgent(params);
     }