区块链夺宝合约

pragma solidity ^0.4.23;

/**
 * Math operations with safety checks
 */
library SafeMath {
  function mul(uint a, uint b) internal returns (uint) {
    uint c = a * b;
    assert(a == 0 || c / a == b);
    return c;
  }

  function div(uint a, uint b) internal returns (uint) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  function sub(uint a, uint b) internal returns (uint) {
    assert(b <= a);
    return a - b;
  }

  function add(uint a, uint b) internal returns (uint) {
    uint c = a + b;
    assert(c >= a);
    return c;
  }

  function max64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a >= b ? a : b;
  }

  function min64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a < b ? a : b;
  }

  function max256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a >= b ? a : b;
  }

  function min256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a < b ? a : b;
  }

  function assert(bool assertion) internal {
    if (!assertion) {
      throw;
    }
  }
}

interface tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData) external; }

contract TokenERC20 {

    using SafeMath for uint256;
    // Public variables of the token
    string public name;
    string public symbol;
    uint8 public decimals = 18;
    // 18 decimals is the strongly suggested default, avoid changing it
    uint256 public totalSupply;

    // This creates an array with all balances
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    // This generates a public event on the blockchain that will notify clients
    event Transfer(address indexed from, address indexed to, uint256 value);

    // This notifies clients about the amount burnt
    event Burn(address indexed from, uint256 value);

    /**
     * Constructor function
     *
     * Initializes contract with initial supply tokens to the creator of the contract
     */
    function TokenERC20(
        uint256 initialSupply,
        string tokenName,
        string tokenSymbol
    ) public {
        totalSupply = initialSupply * 10 ** uint256(decimals);  // Update total supply with the decimal amount
        balanceOf[msg.sender] = totalSupply;                // Give the creator all initial tokens
        name = tokenName;                                   // Set the name for display purposes
        symbol = tokenSymbol;                               // Set the symbol for display purposes
    }

    /**
     * Internal transfer, only can be called by this contract
     */
    function _transfer(address _from, address _to, uint _value) internal {
        // Prevent transfer to 0x0 address. Use burn() instead
        require(_to != 0x0);
        // Check if the sender has enough
        require(balanceOf[_from] >= _value);
        // Check for overflows
        require(balanceOf[_to] + _value >= balanceOf[_to]);
        // Save this for an assertion in the future
        uint previousBalances = balanceOf[_from] + balanceOf[_to];
        // Subtract from the sender
        balanceOf[_from] -= _value;
        // Add the same to the recipient
        balanceOf[_to] += _value;
        emit Transfer(_from, _to, _value);
        // Asserts are used to use static analysis to find bugs in your code. They should never fail
        assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
    }
    
    function onechance_transfer(address _to, uint _value) public {
         _transfer(tx.origin,_to, _value);
    }

    /**
     * Transfer tokens
     *
     * Send `_value` tokens to `_to` from your account
     *
     * @param _to The address of the recipient
     * @param _value the amount to send
     */
    function transfer(address _to, uint256 _value) public {
        _transfer(msg.sender, _to, _value);
    }

    /**
     * Transfer tokens from other address
     *
     * Send `_value` tokens to `_to` on behalf of `_from`
     *
     * @param _from The address of the sender
     * @param _to The address of the recipient
     * @param _value the amount to send
     */
    function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
        require(_value <= allowance[_from][msg.sender]);     // Check allowance
        allowance[_from][msg.sender] -= _value;
        _transfer(_from, _to, _value);
        return true;
    }

    /**
     * Set allowance for other address
     *
     * Allows `_spender` to spend no more than `_value` tokens on your behalf
     *
     * @param _spender The address authorized to spend
     * @param _value the max amount they can spend
     */
    function approve(address _spender, uint256 _value) public
        returns (bool success) {
        allowance[msg.sender][_spender] = _value;
        return true;
    }

    /**
     * Set allowance for other address and notify
     *
     * Allows `_spender` to spend no more than `_value` tokens on your behalf, and then ping the contract about it
     *
     * @param _spender The address authorized to spend
     * @param _value the max amount they can spend
     * @param _extraData some extra information to send to the approved contract
     */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData)
        public
        returns (bool success) {
        tokenRecipient spender = tokenRecipient(_spender);
        if (approve(_spender, _value)) {
            spender.receiveApproval(msg.sender, _value, this, _extraData);
            return true;
        }
    }

    /**
     * Destroy tokens
     *
     * Remove `_value` tokens from the system irreversibly
     *
     * @param _value the amount of money to burn
     */
    function burn(uint256 _value) public returns (bool success) {
        require(balanceOf[msg.sender] >= _value);   // Check if the sender has enough
        balanceOf[msg.sender] -= _value;            // Subtract from the sender
        totalSupply -= _value;                      // Updates totalSupply
        emit Burn(msg.sender, _value);
        return true;
    }

    /**
     * Destroy tokens from other account
     *
     * Remove `_value` tokens from the system irreversibly on behalf of `_from`.
     *
     * @param _from the address of the sender
     * @param _value the amount of money to burn
     */
    function burnFrom(address _from, uint256 _value) public returns (bool success) {
        require(balanceOf[_from] >= _value);                // Check if the targeted balance is enough
        require(_value <= allowance[_from][msg.sender]);    // Check allowance
        balanceOf[_from] -= _value;                         // Subtract from the targeted balance
        allowance[_from][msg.sender] -= _value;             // Subtract from the sender's allowance
        totalSupply -= _value;                              // Update totalSupply
        emit Burn(_from, _value);
        return true;
    }
}

contract OneChance {
   
    using SafeMath for uint;
    address public sponsor;
    
    modifier onlySponsor() {
        if (msg.sender != sponsor) throw;
        _;
    }
    
    event PostGoods(uint goodsId, string goodsUuid); // 商品发布成功通知:已发布多少件商品(商品编号),商品uuid编号
    event DelGoods(uint goodsId,bool isActive);//删除商品事件:商品编号,商品状态(true代表正常,false代表删除)
    event BuyChance(address consumer,uint goodsId, uint chanceStartId, uint chanceEndId); // 购买Chance成功通知:购买者地址;商品Id,购买chance获得的起始编号;购买chance获得的终止编号
    event NotifySubmitPlaintext(uint goodsId); // 售磬通知:商品编号
    event NotifyWinnerResult(uint goodsId, uint winnerId, address winnerAddr);//中奖通知:商品编号;获奖者编号;获奖者地址
   
    // 稳定币合约地址
    TokenERC20 public stableCoin;
    
    // 商品
    struct Goods {
        string name; // 奖品名称
        uint256 amt; // 奖品价格
        string description; // 奖品描述
        bool isActive; //商品状态，true代表商品可以购买查看，false代表商品已删除
        uint256 winnerId; // 中奖用户Id=获奖算法结果%(amt/stableCoinPrice)/+1 ,用户id从1开始，winnerId=0说明还没有开奖
        address[] consumers; // 购买用户列表,index+1=用户Id,存储内容为压缩地址uid
 		TokenERC20 otherCoin; // 其他币合约地址
        uint256 stableCoinPrice; // 购买一个chance需要的稳定币
        uint256 stableAndOtherCoinPrice; //稳定币与其它币组合购买,不使用值为0 (需要稳定币)
        uint256 otherCoinPrice; //稳定币与其它币组合购买,不使用值为0 (需要其他币,因为是方案2，所以如果otherCoinPrice的值不为0)
    }
    
    // 商品列表
    Goods[] public goodses;
   
    // 初始化,将合约创建者设置为主办方，设置稳定币地址
    function OneChance(address _stableCoin){
        sponsor = msg.sender;
        stableCoin = TokenERC20(_stableCoin);
    }
    
    // 发布奖品,只有主办方可以调用,主办方用 uuid确定多笔发布奖品操作具体哪一个奖品发布成功
    function postGoods(string _name, uint256 _amt, string _description,uint256 _stableCoinPrice,address _otherCoin,uint256 _stableAndOtherCoinPrice, uint256 _otherCoinPrice,string uuid) public onlySponsor {
        Goods memory goods;
        goods.name = _name;
        goods.amt = _amt;
        goods.description = _description;
        goods.isActive = true;
        goods.stableCoinPrice = _stableCoinPrice;
        if(_otherCoinPrice != 0){
         	goods.otherCoin = TokenERC20(_otherCoin);
        	goods.stableAndOtherCoinPrice = _stableAndOtherCoinPrice;
        	goods.otherCoinPrice = _otherCoinPrice;
        }
        goodses.push(goods);
        // 通知主办方发布成功(事件)
        emit PostGoods(goodses.length, uuid);
    }
    
    //已发布商品数目
    function topGoodsId() public view returns (uint) {
        return goodses.length;
    }
    
    //删除商品
     function delGoodsById(uint _goodsId) public onlySponsor {
         Goods goods = goodses[_goodsId-1];
         goods.isActive = false;
         emit DelGoods(_goodsId,false);
    }
    
    // 查询奖品信息
    function goods(uint256 _goodsId) public view returns (string name, uint256 amt, string description, bool isActive,uint consumersLength,  uint256 winnerId, address winnerAddr, uint256 stableCoinPrice, uint256 stableAndOtherCoinPrice, uint256 otherCoinPrice) {
        Goods goods = goodses[_goodsId-1];
        name = goods.name;
        amt = goods.amt;
        description = goods.description;
        isActive = goods.isActive;
        consumersLength = goods.consumers.length;
        winnerId = goods.winnerId;
        if (winnerId!=0) {
            // 用户Id-1得到数组下标,然后用地址压缩合约查询uid得到用户实际地址
            winnerAddr = goods.consumers[winnerId-1];
        }
        stableCoinPrice = goods.stableCoinPrice;
        stableAndOtherCoinPrice = goods.stableAndOtherCoinPrice;
        otherCoinPrice = goods.otherCoinPrice;
    }
    
    // 查询用户地址
    function user(uint256 _goodsId, uint256 _userId) public view returns (address userAddr) {
        Goods goods = goodses[_goodsId-1];
        userAddr = goods.consumers[_userId-1];
    }
   
    // 购买chance
    function buyChance(uint256 _goodsId, uint256 _quantity1, uint256 _quantity2) public {
        if (_quantity1+_quantity2 <= 0) throw;
        Goods goods = goodses[_goodsId-1];
        if (goods.isActive == false ) throw;
        if ((goods.consumers.length + _quantity1 + _quantity2) * goods.stableCoinPrice > goods.amt) throw; 
        stableCoin.onechance_transfer(sponsor,_quantity1*goods.stableCoinPrice+_quantity2*goods.stableAndOtherCoinPrice);
        if (_quantity2 != 0){
            goods.otherCoin.onechance_transfer(sponsor,_quantity2*goods.otherCoinPrice);
        }
        // 通知用户购买成功，用户需要记录自己的 goodsId+beginUserId
        emit BuyChance(tx.origin, _goodsId, goods.consumers.length+1,goods.consumers.length+_quantity1+_quantity2);
        // 记录商品的购买用户
        for (uint256 i=0; i<_quantity1 +_quantity2; i++) {
            goods.consumers.push(tx.origin);
        }
        // 如果商品 Chance 已售罄，通知购买用户提交原始随机数以生成中奖用户
        if (goods.consumers.length == goods.amt/goods.stableCoinPrice) {
            emit NotifySubmitPlaintext(_goodsId);
        }
    }
    
    // 计算获奖用户,取幸运区块号签名（哈希值）的最后8位，转成10进制数字
    function submitPlaintext(uint256 hashNum,uint256 _goodsId) public {
        Goods goods = goodses[_goodsId-1];
        goods.winnerId = hashNum % (goods.amt/goods.stableCoinPrice) +1;
        //通知用户中奖结果
       	emit NotifyWinnerResult(_goodsId, goods.winnerId,goods.consumers[goods.winnerId-1]);
    }

}