smom-dbis-138/contracts/registry/handlers/CommodityHandler.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "../interfaces/IAssetTypeHandler.sol";

/**
 * @title CommodityHandler
 * @notice Handler for commodity-backed tokens (gold, oil, etc.) with certificate validation
 */
contract CommodityHandler is IAssetTypeHandler {
    // Certificate registry for commodity authenticity
    mapping(address => mapping(bytes32 => bool)) public validCertificates;
    
    // Custodian registry
    mapping(address => address) public custodians;
    
    function validateAsset(address token) external view override returns (bool) {
        if (token.code.length == 0) return false;
        
        // Verify custodian is registered
        return custodians[token] != address(0);
    }

    function getRequiredCompliance() external pure override returns (UniversalAssetRegistry.ComplianceLevel) {
        return UniversalAssetRegistry.ComplianceLevel.KYC;
    }

    function getDefaultLimits() external pure override returns (uint256 min, uint256 max) {
        return (1e15, 1000000e18); // 0.001 to 1M units
    }

    function preTransferHook(address, address, uint256 amount) external pure override {
        require(amount > 0, "Invalid amount");
        // Certificate validation would happen here in production
    }

    function postTransferHook(address, address, uint256) external pure override {
        // Post-transfer custodian notification if needed
    }
    
    // Admin functions
    function registerCustodian(address token, address custodian) external {
        custodians[token] = custodian;
    }
    
    function registerCertificate(address token, bytes32 certificateHash) external {
        validCertificates[token][certificateHash] = true;
    }
}