// SPDX-License-Identifier: MIT

pragma solidity 0.8.19;

import "@ethereum-attestation-service/eas-contracts/contracts/IEAS.sol";
import "@ethereum-attestation-service/eas-contracts/contracts/resolver/SchemaResolver.sol";
import "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

/// @title AttesterAllowlistResolver
/// @notice This contract allows an owner to manage an allowlist of attesters
contract AttesterAllowlistResolver is SchemaResolver, Ownable {

    using EnumerableSet for EnumerableSet.AddressSet;

    EnumerableSet.AddressSet private _allowlist;

    event AddedToAllowlist(address indexed addedBy, address indexed attester);
    event RemovedFromAllowlist(address indexed removedBy, address indexed attester);
    
    constructor(IEAS eas, address initialOwner) SchemaResolver(eas) Ownable(initialOwner) {
    }

    function onAttest(Attestation calldata attestation, uint256 /*value*/) internal view override returns (bool) {
        return _allowlist.contains(attestation.attester);
    }

    function onRevoke(Attestation calldata /*attestation*/, uint256 /*value*/) internal pure override returns (bool) {
        return true;
    }

    function addToAllowlist(address attester) public {
        _allowlist.add(attester);
        emit AddedToAllowlist(msg.sender, attester);
    }

    function removeFromAllowlist(address attester) public {
        _allowlist.remove(attester);
        emit RemovedFromAllowlist(msg.sender, attester);
    }

    function lengthAllowlist() public view returns (uint256) {
        return _allowlist.length();
    }

    function isPresentAllowlist(address attester) public view returns (bool) {
        return _allowlist.contains(attester);
    }

}