liquid-funding/contracts/SwapProxy.sol

109 lines
4.2 KiB
Solidity

pragma solidity ^0.4.18;
import "./LiquidPledging.sol";
import "./common/SafeToken.sol";
import "./common/Pausable.sol";
import "./IKyberSwap.sol";
contract SwapProxy is Pausable, SafeToken {
address public ETH;
address public vault;
uint public maxSlippage;
KyberNetworkProxy public kyberProxy;
LiquidPledging public liquidPledging;
/**
* @param _liquidPledging LiquidPledging contract address
* @param _kyberProxy Kyber Network Proxy address
* @param _ETH Kyber ETH address
* @param _vault address that receives swap fees
* @param _maxSlippage most slippage as a percentage
*/
function SwapProxy(address _liquidPledging, address _kyberProxy, address _ETH, address _vault, uint _maxSlippage) public {
require(_maxSlippage < 100);
if (_vault == address(0)){
_vault = address(this);
}
liquidPledging = LiquidPledging(_liquidPledging);
kyberProxy = KyberNetworkProxy(_kyberProxy);
ETH = _ETH;
vault = _vault;
maxSlippage = _maxSlippage;
}
/**
* @notice Gets the conversion rate for the destToken given the srcQty.
* @param srcToken source token contract address
* @param srcQty amount of source tokens
* @param destToken destination token contract address
* @return exchange rate
*/
function getConversionRates(address srcToken, uint srcQty, address destToken) public view returns (uint exchangeRate)
{
if(srcToken == address(0)){
srcToken = ETH;
}
uint minConversionRate;
uint slippageRate;
(minConversionRate, slippageRate) = kyberProxy.getExpectedRate(srcToken, destToken, srcQty);
require(minConversionRate > 0);
return slippageRate;
}
/**
* @notice Funds a project in desired token using ETH
* @dev Requires a msg.value
* @param idReceiver receiver of donation
* @param token token to convert from ETH
*/
function fundWithETH(uint64 idReceiver, address token) public payable whenNotPaused {
require(msg.value > 0);
uint expectedRate;
uint slippageRate;
(expectedRate, slippageRate) = kyberProxy.getExpectedRate(ETH, token, msg.value);
require(expectedRate > 0);
uint slippagePercent = 100 - ((slippageRate * 100) / expectedRate);
require(slippagePercent <= maxSlippage);
uint maxDestinationAmount = (slippageRate / (10**18)) * msg.value;
uint amount = kyberProxy.trade.value(msg.value)(ETH, msg.value, token, address(this), maxDestinationAmount, slippageRate, vault);
require(amount > 0);
require(EIP20Interface(token).approve(address(liquidPledging), amount));
liquidPledging.addGiverAndDonate(idReceiver, token, amount);
}
/**
* @notice Funds a project in desired token using an ERC20 Token
* @param idReceiver receiver of donation
* @param token token to convert from
* @param amount being sent
* @param receiverToken token being converted to
*/
function fundWithToken(uint64 idReceiver, address token, uint amount, address receiverToken) public whenNotPaused {
Error err = doTransferIn(token, msg.sender, amount);
require(err == Error.NO_ERROR);
uint expectedRate;
uint slippageRate;
(expectedRate, slippageRate) = kyberProxy.getExpectedRate(token, receiverToken, amount);
require(expectedRate > 0);
uint slippagePercent = (slippageRate * 100) / expectedRate;
require(slippagePercent <= maxSlippage);
require(EIP20Interface(token).approve(address(kyberProxy), 0));
require(EIP20Interface(token).approve(address(kyberProxy), amount));
uint maxDestinationAmount = (slippageRate / (10**18)) * amount;
uint receiverAmount = kyberProxy.trade(token, amount, receiverToken, address(this), maxDestinationAmount, slippageRate, vault);
require(receiverAmount > 0);
require(EIP20Interface(token).approve(address(liquidPledging), receiverAmount));
liquidPledging.addGiverAndDonate(idReceiver, receiverToken, receiverAmount);
}
function transferOut(address asset, address to, uint amount) public onlyOwner {
Error err = doTransferOut(asset, to, amount);
require(err == Error.NO_ERROR);
}
function() payable external {}
}