contract RRDSToken is StandardToken, SafeMath {
    
    // metadata
    string  public constant name = "Renrendianshang";
    string  public constant symbol = "RRDS";
    uint256 public constant decimals = 18;
    string  public version = "1.0";

    // contracts
    address public ethFundDeposit;          // ETH存放地址
    address public newContractAddr;         // token更新地址

    // crowdsale parameters
    bool    public isFunding;                // 状态切换到true
    uint256 public fundingStartBlock;
    uint256 public fundingStopBlock;

    uint256 public currentSupply;           // 正在售卖中的tokens数量
    uint256 public tokenRaised = 0;         // 总的售卖数量token
    uint256 public tokenMigrated = 0;     // 总的已经交易的 token
    uint256 public tokenExchangeRate = 300;             // 代币兑换比例 N代币 兑换 1 ETH

    // events
    event AllocateToken(address indexed _to, uint256 _value);   // allocate token for private sale;
    event IssueToken(address indexed _to, uint256 _value);      // issue token for public sale;
    event IncreaseSupply(uint256 _value);
    event DecreaseSupply(uint256 _value);
    event Migrate(address indexed _to, uint256 _value);

    // 转换
    function formatDecimals(uint256 _value) internal pure returns (uint256 ) {
        return _value * 10 ** decimals;
    }

    // constructor
    constructor(
        address _ethFundDeposit,
        uint256 _currentSupply) public
    {
        ethFundDeposit = _ethFundDeposit;

        isFunding = false;                           //通过控制预CrowdS ale状态
        fundingStartBlock = 0;
        fundingStopBlock = 0;

        currentSupply = formatDecimals(_currentSupply);
        totalSupply = formatDecimals(100000000);
        balances[msg.sender] = totalSupply;
        require(currentSupply <= totalSupply);
    }

    modifier isOwner()  { require(msg.sender == ethFundDeposit); _; }

    ///  设置token汇率
    function setTokenExchangeRate(uint256 _tokenExchangeRate) isOwner external {
        require(_tokenExchangeRate != 0);
        require(_tokenExchangeRate != tokenExchangeRate);

        tokenExchangeRate = _tokenExchangeRate;
    }

    ///增发代币
    function increaseSupply (uint256 _value) isOwner external {
        uint256 value = formatDecimals(_value);
        require(value + currentSupply <= totalSupply);
        currentSupply = safeAdd(currentSupply, value);
        emit IncreaseSupply(value);
    }

    ///减少代币
    function decreaseSupply (uint256 _value) isOwner external {
        uint256 value = formatDecimals(_value);
        require(value + tokenRaised <= currentSupply);

        currentSupply = safeSubtract(currentSupply, value);
        emit DecreaseSupply(value);
    }

    ///开启
    function startFunding (uint256 _fundingStartBlock, uint256 _fundingStopBlock) isOwner external {
        require(!isFunding);
        require(_fundingStartBlock < _fundingStopBlock);
        require(block.number < _fundingStartBlock);

        fundingStartBlock = _fundingStartBlock;
        fundingStopBlock = _fundingStopBlock;
        isFunding = true;
    }

    ///关闭
    function stopFunding() isOwner external {
        require(isFunding);
        isFunding = false;
    }

    ///set a new contract for recieve the tokens (for update contract)
    function setMigrateContract(address _newContractAddr) isOwner external {
        require(_newContractAddr != newContractAddr);
        newContractAddr = _newContractAddr;
    }

    ///set a new owner.
    function changeOwner(address _newFundDeposit) isOwner() external {
        require(_newFundDeposit != address(0x0));
        ethFundDeposit = _newFundDeposit;
    }

    ///sends the tokens to new contract
    function migrate() external {
        require(!isFunding);
        require(newContractAddr != address(0x0));

        uint256 tokens = balances[msg.sender];
        require(tokens != 0);

        balances[msg.sender] = 0;
        tokenMigrated = safeAdd(tokenMigrated, tokens);

        IMigrationContract newContract = IMigrationContract(newContractAddr);
        require(newContract.migrate(msg.sender, tokens));

        emit Migrate(msg.sender, tokens);               // log it
    }

    /// 转账ETH 到团队
    function transferETH() isOwner external {
        require(address(this).balance != 0);
        require(ethFundDeposit.send(address(this).balance));
    }

    ///  将token分配到预处理地址。
    function allocateToken (address _addr, uint256 _eth) isOwner external {
        require(_eth != 0);
        require(_addr != address(0x0));

        uint256 tokens = safeMult(formatDecimals(_eth), tokenExchangeRate);
        require(tokens + tokenRaised <= currentSupply);

        tokenRaised = safeAdd(tokenRaised, tokens);
        balances[_addr] += tokens;

        emit AllocateToken(_addr, tokens);  // 记录token日志
    }

    /// 购买token
    function () public payable {
        require(isFunding);
        require(msg.value != 0);

        require(block.number >= fundingStartBlock);
        require(block.number <= fundingStopBlock);

        uint256 tokens = safeMult(msg.value, tokenExchangeRate);
        require(tokens + tokenRaised <= currentSupply);

        tokenRaised = safeAdd(tokenRaised, tokens);
        balances[msg.sender] += tokens;

        emit IssueToken(msg.sender, tokens);  //记录日志
    }
}
function decreaseSupply (uint256 _value) isOwner external {
        uint256 value = formatDecimals(_value);
        require(value + tokenRaised <= currentSupply);

        currentSupply = safeSubtract(currentSupply, value);
        emit DecreaseSupply(value);
    }
///减少代币