Scalable
Sybil Resistance

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.13;

// Specify the path to IGetterLogic.sol or use the npm package
import "@violetprotocol/erc721extendable/contracts/extensions/base/IGetterLogic.sol"

contract CounterForHumansOnly {
    // Stored address of the Humanbound Token contract
    address public hbtContract;
    uint256 public counter;
    
    // Expects the HBT contract address to be passed during deployment
    constructor(address hbtContract_) {
        hbtContract = hbtContract_;
    }
    
    modifier onlyHBTOwners {
        // Verify HBT ownership
        require(IGetterLogic(hbtContract).balanceOf(msg.sender) > 0, "Unauthorized: Ownership of a Humanbound Token is required");
        _;
    }
    
    // Function to increment the counter: this will revert when
    // called with an address that doesn't own an HBT
    function gatedIncrement() public onlyHBTOwners {
        counter += 1;
    }
}