// SPDX-License-Identifier: MIT
pragma solidity 0.8.19;

contract ClaimHistory {
  mapping(address user=> mapping(uint256 index => uint256 val)) private claimedBitMap;

  function isClaimed(address user, uint256 index) public view returns (bool) {
    uint256 claimedWordIndex = index / 256;
    uint256 claimedBitIndex = index % 256;
    uint256 claimedWord = claimedBitMap[user][claimedWordIndex];
    uint256 mask = (1 << claimedBitIndex);
    return claimedWord & mask == mask;
  }

  function setClaimed(address user, uint256 index) internal {
    uint256 claimedWordIndex = index / 256;
    uint256 claimedBitIndex = index % 256;
    claimedBitMap[user][claimedWordIndex] = claimedBitMap[user][claimedWordIndex] | (1 << claimedBitIndex);
  }
  
}