A simple Ens name verification smart contract: Web3bridge Assignment

gistfile1.txt

@Uche

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract ensdomain {
    mapping(address => bytes) public addressToBytesName;
    mapping(bytes => address) public bytesNameToAddress;
    
    string[] public nameList;

    uint256 public totalRegAddress = 0;

    event resgisterAlert(address, string);
    event nameChange(address, string);

    function register(address _address, string memory _name) public {
        bytes memory _empty;
        bytes memory callerName = addressToBytesName[_address];
        require(
            keccak256(abi.encodePacked(callerName)) ==
                keccak256(abi.encodePacked(_empty)),
            "This address has an existing name"
        );
        require(
            bytesNameToAddress[bytes(_name)] == address(0),
            "This name is Taken"
        );
        addressToBytesName[_address] = bytes(_name);
        bytesNameToAddress[bytes(_name)] = _address;
        nameList.push(_name);
        totalRegAddress += 1;
        emit resgisterAlert(_address, _name);
    }

    function getOwner(string memory _name) public view returns (address) {
        return (bytesNameToAddress[bytes(_name)]);
    }

    function getNameFromAddress(address _address)
        public
        view
        returns (string memory)
    {
        return string(addressToBytesName[_address]);
    }

    function changeName(string memory _newName) public {
        bytes memory callerName = addressToBytesName[msg.sender];
        bytes memory _empty;
        require(
            keccak256(abi.encodePacked(callerName)) !=
                keccak256(abi.encodePacked(_empty)),
            "You dont have any name assigned to you"
        );
        delete (addressToBytesName[msg.sender]);
        delete (bytesNameToAddress[callerName]);
        totalRegAddress -= 1;
        register(msg.sender, _newName);
        emit nameChange(msg.sender, _newName);
    }
    
     function allNames() public view returns(string[] memory){
        return nameList;
    }
}