pragma solidity ^0.4.19;

import "./playerhelper.sol";

contract PlayerChallenge is PlayerHelper {
  uint randNonce = 0;
  uint victoryProbability = 70;

  function randMod(uint _modulus) internal returns(uint) {
    randNonce++;
    return uint(keccak256(now, msg.sender, randNonce)) % _modulus;
  }

  function challenge(uint _footballerId, uint _targetId) external onlyOwnerOf(_footballerId) {
    Footballer storage myPlayer = players[_footballerId];
    Footballer storage opponentPlayer = players[_targetId];
    uint rand = randMod(100);

    if (rand <= victoryProbability) {
      myPlayer.winCount = myPlayer.winCount.add(1);
      myPlayer.level = myPlayer.level.add(1);
      opponentPlayer.lossCount = opponentPlayer.lossCount.add(1);
      clone(_footballerId, opponentPlayer.dna, "footballer");
    } // start here
  }
}