Add BaseHook contract

src/BaseHook.sol

@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import {AgoraGovernor} from "src/AgoraGovernor.sol";
+import {Hooks} from "src/libraries/Hooks.sol";
+import {IHooks} from "src/interfaces/IHooks.sol";
+
+/// @title Base Hook
+/// @notice Base Hook contract
+/// @custom:security-contact [email protected]
+/// Inspired by https://github.com/Uniswap/v4-periphery/blob/main/src/base/hooks/BaseHook.sol[Uniswap v4 implementation of hooks].
+abstract contract BaseHook is IHooks {
+    error AlreadyInit();
+    error InvalidGovernor();
+    error HookNotImplemented();
+
+    AgoraGovernor public immutable governor;
+
+    constructor(address payable _governor) {
+        if (address(governor) != address(0)) revert AlreadyInit();
+        if (_governor == address(0)) revert InvalidGovernor();
+
+        governor = AgoraGovernor(_governor);
+        validateHookAddress(this);
+    }
+
+    /// @notice Returns a struct of permissions to signal which hook functions are to be implemented
+    /// @dev Used at deployment to validate the address correctly represents the expected permissions
+    function getHookPermissions() public pure virtual returns (Hooks.Permissions memory);
+
+    /// @notice Validates the deployed hook address agrees with the expected permissions of the hook
+    /// @dev this function is virtual so that we can override it during testing,
+    /// which allows us to deploy an implementation to any address
+    /// and then etch the bytecode into the correct address
+    function validateHookAddress(BaseHook _this) internal pure virtual {
+        Hooks.validateHookPermissions(_this, getHookPermissions());
+    }
+
+    /// @inheritdoc IHooks
+    function beforeInitialize(address) external virtual returns (bytes4) {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function afterInitialize(address) external virtual returns (bytes4) {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function beforeQuorumCalculation(address, uint256) external view virtual returns (bytes4, uint256) {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function afterQuorumCalculation(address, uint256) external view virtual returns (bytes4, uint256) {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function beforeVote(address, uint256, address, uint8, string memory, bytes memory)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function afterVote(address, uint256, uint256, address, uint8, string memory, bytes memory)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function beforePropose(address, address[] memory, uint256[] memory, bytes[] memory, string memory)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function afterPropose(address, uint256, address[] memory, uint256[] memory, bytes[] memory, string memory)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function beforeCancel(address, address[] memory, uint256[] memory, bytes[] memory, bytes32)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function afterCancel(address, uint256, address[] memory, uint256[] memory, bytes[] memory, bytes32)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+
+    /// @notice The hook called before a proposal is queued
+    function beforeQueue(address, address[] memory, uint256[] memory, bytes[] memory, bytes32)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function afterQueue(address, uint256, address[] memory, uint256[] memory, bytes[] memory, bytes32)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function beforeExecute(address, address[] memory, uint256[] memory, bytes[] memory, bytes32)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+
+    /// @inheritdoc IHooks
+    function afterExecute(address, uint256, address[] memory, uint256[] memory, bytes[] memory, bytes32)
+        external
+        virtual
+        returns (bytes4, uint256)
+    {
+        revert HookNotImplemented();
+    }
+}