// SPDX-License-Identifier: GPL-3.0
//Source: https://gist.github.com/kadenzipfel/4c4d10f187f43e4ec1117f0229d45484#file-accesscontrol-sol

pragma solidity ^0.8.20;
import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
import "@openzeppelin/contracts/utils/cryptography/MessageHashUtils.sol";

contract AccessControl {
    using ECDSA for bytes32;
    mapping(address => bool) isAdmin;
    mapping(address => bool) isRegularUser;
    
    constructor(){
        isAdmin[msg.sender] = true;
    }
    
    // Add admins and regular users.
    function addUsers(address[] calldata admins, address[] calldata regularUsers, bytes calldata signature) public {
        if (!isAdmin[msg.sender]) {
            // Allow calls to be relayed with an admin's signature.
            bytes32 hash = MessageHashUtils.toEthSignedMessageHash(keccak256(abi.encodePacked(admins, regularUsers)));
            address signer = hash.recover(signature);

            require(isAdmin[signer], "Only admins can add users.");
        }
        for (uint256 i = 0; i < admins.length; i++) {
            isAdmin[admins[i]] = true;
        }
        for (uint256 i = 0; i < regularUsers.length; i++) {
            isRegularUser[regularUsers[i]] = true;
        }
    }
}

contract hash {
    function hashingData(address[] calldata data1, address[] calldata data2) public pure returns(bytes32){
        return keccak256(abi.encodePacked(data1, data2));
    }
}