feat: implement the governance smart-contract

packages/zevm-app-contracts/contracts/xp-nft/ZetaXPGov.sol

@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: MIT
+// Compatible with OpenZeppelin Contracts ^5.0.0
+pragma solidity ^0.8.20;
+
+import "@openzeppelin/contracts/governance/Governor.sol";
+import "@openzeppelin/contracts/governance/extensions/GovernorSettings.sol";
+import "@openzeppelin/contracts/governance/extensions/GovernorCountingSimple.sol";
+import "@openzeppelin/contracts/governance/extensions/GovernorTimelockControl.sol";
+import "@openzeppelin/contracts/interfaces/IERC6372.sol";
+
+import "./xpNFT_V2.sol";
+
+contract ZetaXPGov is Governor, GovernorSettings, GovernorCountingSimple, GovernorTimelockControl {
+    bytes32 public tagValidToVote;
+    ZetaXP_V2 public xpNFT;
+    uint256 public quorumPercentage; // New state to store the quorum percentage
+
+    constructor(
+        ZetaXP_V2 _xpNFT,
+        TimelockController _timelock,
+        uint256 _quorumPercentage // Set the quorum percentage (e.g., 4%)
+    )
+        Governor("ZetaXPGov")
+        GovernorSettings(7200 /* 1 day */, 50400 /* 1 week */, 0)
+        GovernorTimelockControl(_timelock)
+    {
+        xpNFT = _xpNFT;
+        quorumPercentage = _quorumPercentage;
+    }
+
+    function setTagValidToVote(bytes32 _tag) external onlyGovernance {
+        tagValidToVote = _tag;
+    }
+
+    // Override the _getVotes function to apply custom weight based on NFT levels
+    function _getVotes(
+        address account,
+        uint256 blockNumber,
+        bytes memory params
+    ) internal view override returns (uint256) {
+        uint256 tokenId = xpNFT.tokenByUserTag(account, tagValidToVote);
+        uint256 level = xpNFT.getLevel(tokenId);
+
+        // Assign voting weight based on NFT level
+        if (level == 1) {
+            return 1; // Rosegold
+        } else if (level == 2) {
+            return 2; // Black
+        } else if (level == 3) {
+            return 3; // Green
+        } else {
+            return 0; // Silver cannot vote
+        }
+    }
+
+    // Manually implement the quorum function to define quorum based on the total percentage of votes
+    function quorum(uint256 blockNumber) public view override returns (uint256) {
+        uint256 totalSupply = xpNFT.totalSupply(); // Total number of NFTs in circulation
+        return (totalSupply * quorumPercentage) / 100; // Quorum calculation based on the percentage
+    }
+
+    // Override the _execute function to resolve the conflict
+    function _execute(
+        uint256 proposalId,
+        address[] memory targets,
+        uint256[] memory values,
+        bytes[] memory calldatas,
+        bytes32 descriptionHash
+    ) internal override(Governor, GovernorTimelockControl) {
+        super._execute(proposalId, targets, values, calldatas, descriptionHash);
+    }
+
+    // Override the supportsInterface function to resolve the conflict
+    function supportsInterface(
+        bytes4 interfaceId
+    ) public view override(Governor, GovernorTimelockControl) returns (bool) {
+        return super.supportsInterface(interfaceId);
+    }
+
+    // Implementation of clock and CLOCK_MODE functions to comply with IERC6372
+    function clock() public view override returns (uint48) {
+        return uint48(block.timestamp);
+    }
+
+    function CLOCK_MODE() public view override returns (string memory) {
+        return "mode=timestamp";
+    }
+
+    // The rest of the functions required to be overridden by Solidity
+
+    function votingDelay() public view override(IGovernor, GovernorSettings) returns (uint256) {
+        return super.votingDelay();
+    }
+
+    function votingPeriod() public view override(IGovernor, GovernorSettings) returns (uint256) {
+        return super.votingPeriod();
+    }
+
+    function state(uint256 proposalId) public view override(Governor, GovernorTimelockControl) returns (ProposalState) {
+        return super.state(proposalId);
+    }
+
+    function proposalThreshold() public view override(Governor, GovernorSettings) returns (uint256) {
+        return super.proposalThreshold();
+    }
+
+    function _cancel(
+        address[] memory targets,
+        uint256[] memory values,
+        bytes[] memory calldatas,
+        bytes32 descriptionHash
+    ) internal override(Governor, GovernorTimelockControl) returns (uint256) {
+        return super._cancel(targets, values, calldatas, descriptionHash);
+    }
+
+    function _executor() internal view override(Governor, GovernorTimelockControl) returns (address) {
+        return super._executor();
+    }
+}

packages/zevm-app-contracts/contracts/xp-nft/xpNFT.sol

@@ -8,7 +8,7 @@
 import {SignatureChecker} from "@openzeppelin/contracts/utils/cryptography/SignatureChecker.sol";
 
 contract ZetaXP is ERC721Upgradeable, Ownable2StepUpgradeable, EIP712Upgradeable {
-    bytes32 private constant MINTORUPDATE_TYPEHASH =
+    bytes32 internal constant MINTORUPDATE_TYPEHASH =
         keccak256("MintOrUpdateNFT(address to,uint256 signatureExpiration,uint256 sigTimestamp,bytes32 tag)");
 
     struct UpdateData {
@@ -28,7 +28,7 @@
     address public signerAddress;
 
     // Counter for the next token ID
-    uint256 private _currentTokenId;
+    uint256 internal _currentTokenId;
 
     // Event for New Mint
     event NFTMinted(address indexed sender, uint256 indexed tokenId, bytes32 tag);
@@ -97,25 +97,25 @@
         return super.supportsInterface(interfaceId);
     }
 
-    function _verify(uint256 tokenId, UpdateData memory updateData) private view {
+    function _verify(uint256 tokenId, UpdateData memory updateData) internal view {
         bytes32 structHash = keccak256(
             abi.encode(
                 MINTORUPDATE_TYPEHASH,
                 updateData.to,
                 updateData.signatureExpiration,
                 updateData.sigTimestamp,
                 updateData.tag
             )
         );
         bytes32 constructedHash = _hashTypedDataV4(structHash);
 
         if (!SignatureChecker.isValidSignatureNow(signerAddress, constructedHash, updateData.signature)) {
             revert InvalidSigner();
         }
 
         if (block.timestamp > updateData.signatureExpiration) revert SignatureExpired();
         if (updateData.sigTimestamp <= lastUpdateTimestampByTokenId[tokenId]) revert OutdatedSignature();
     }
 
     function _updateNFT(uint256 tokenId, UpdateData memory updateData) internal {
         _verify(tokenId, updateData);

packages/zevm-app-contracts/contracts/xp-nft/xpNFT_V2.sol

@@ -4,7 +4,7 @@
 import "./xpNFT.sol";
 
 contract ZetaXP_V2 is ZetaXP {
-    bytes32 private constant SETLEVEL_TYPEHASH =
+    bytes32 internal constant SETLEVEL_TYPEHASH =
         keccak256("SetLevel(uint256 tokenId,uint256 signatureExpiration,uint256 sigTimestamp,uint256 level)");
 
     struct SetLevelData {
@@ -16,25 +16,31 @@
     }
 
     mapping(uint256 => uint256) public levelByTokenId;
+
+    // Event for Level Set
     event LevelSet(address indexed sender, uint256 indexed tokenId, uint256 level);
 
     function version() public pure override returns (string memory) {
         return "2.0.0";
     }
 
-    function _verifySetLevelSignature(SetLevelData memory data) private view {
+    function _verifyUpdateNFTSignature(uint256 tokenId, UpdateData memory updateData) internal view {
+        _verify(tokenId, updateData);
+    }
+
+    function _verifySetLevelSignature(SetLevelData memory data) internal view {
         bytes32 structHash = keccak256(
             abi.encode(SETLEVEL_TYPEHASH, data.tokenId, data.signatureExpiration, data.sigTimestamp, data.level)
         );
         bytes32 constructedHash = _hashTypedDataV4(structHash);
 
         if (!SignatureChecker.isValidSignatureNow(signerAddress, constructedHash, data.signature)) {
             revert InvalidSigner();
         }
 
         if (block.timestamp > data.signatureExpiration) revert SignatureExpired();
         if (data.sigTimestamp <= lastUpdateTimestampByTokenId[data.tokenId]) revert OutdatedSignature();
     }
 
     function setLevel(SetLevelData memory data) external {
         _verifySetLevelSignature(data);
@@ -47,4 +53,8 @@
     function getLevel(uint256 tokenId) external view returns (uint256) {
         return levelByTokenId[tokenId];
     }
+
+    function totalSupply() external view returns (uint256) {
+        return _currentTokenId - 1;
+    }
 }