Lottery.sol

Lottery.sol

pragma solidity ^0.4.17;

contract Lottery {
    address public manager;
    address[] public players;
    
    constructor() public {
        manager = msg.sender;                
    }
    
    function enter() public payable {
        require(msg.value > .01 ether);
        players.push(msg.sender);
        
    }
    
    function pickWinner() public {
        require(msg.sender == manager);
        uint256 index = random() % players.length;
        players[index].transfer(address(this).balance);
        players = new address[](0);
    }
    
    /* 
    * Not really random at all but it's simple.
    * We have reasonable idea of what difficulty, now and players is
    * We can know the value ahead of time if we tried very hard
    * Vulnerable for attack, but it works as a demo
    */
    function random() private view returns (uint256) {
        return uint(keccak256(abi.encodePacked(block.difficulty, now, players)));
    }
    
    // function debugGetBalance() public view returns (uint256) {
    //     return address(this).balance;
    // }
}