pragma solidity >=0.0; import "../Events/Event.sol"; import "../Markets/StandardMarketFactory.sol"; import "../Utils/Math.sol"; /// @title Campaign contract - Allows to crowdfund a market /// @author Stefan George - contract Campaign { using Math for *; /* * Events */ event CampaignFunding(address indexed sender, uint funding); event CampaignRefund(address indexed sender, uint refund); event MarketCreation(Market indexed market); event MarketClosing(); event FeeWithdrawal(address indexed receiver, uint fees); /* * Constants */ uint24 public constant FEE_RANGE = 1000000; // 100% /* * Storage */ Event public eventContract; MarketFactory public marketFactory; MarketMaker public marketMaker; Market public market; uint24 public fee; uint public funding; uint public deadline; uint public finalBalance; mapping (address => uint) public contributions; Stages public stage; enum Stages { AuctionStarted, AuctionSuccessful, AuctionFailed, MarketCreated, MarketClosed } /* * Modifiers */ modifier atStage(Stages _stage) { // Contract has to be in given stage require(stage == _stage); _; } modifier timedTransitions() { if (stage == Stages.AuctionStarted && deadline < now) stage = Stages.AuctionFailed; _; } /* * Public functions */ /// @dev Constructor validates and sets campaign properties /// @param _eventContract Event contract /// @param _marketFactory Market factory contract /// @param _marketMaker Market maker contract /// @param _fee Market fee /// @param _funding Initial funding for market /// @param _deadline Campaign deadline constructor( Event _eventContract, MarketFactory _marketFactory, MarketMaker _marketMaker, uint24 _fee, uint _funding, uint _deadline ) public { // Validate input require( address(_eventContract) != address(0) && address(_marketFactory) != address(0) && address(_marketMaker) != address(0) && _fee < FEE_RANGE && _funding > 0 && now < _deadline); eventContract = _eventContract; marketFactory = _marketFactory; marketMaker = _marketMaker; fee = _fee; funding = _funding; deadline = _deadline; } /// @dev Allows to contribute to required market funding /// @param amount Amount of collateral tokens function fund(uint amount) public timedTransitions atStage(Stages.AuctionStarted) { uint raisedAmount = eventContract.collateralToken().balanceOf(address(this)); uint maxAmount = funding.sub(raisedAmount); if (maxAmount < amount) amount = maxAmount; // Collect collateral tokens require(eventContract.collateralToken().transferFrom(msg.sender, address(this), amount)); contributions[msg.sender] = contributions[msg.sender].add(amount); if (amount == maxAmount) stage = Stages.AuctionSuccessful; emit CampaignFunding(msg.sender, amount); } /// @dev Withdraws refund amount /// @return Refund amount function refund() public timedTransitions atStage(Stages.AuctionFailed) returns (uint refundAmount) { refundAmount = contributions[msg.sender]; contributions[msg.sender] = 0; // Refund collateral tokens require(eventContract.collateralToken().transfer(msg.sender, refundAmount)); emit CampaignRefund(msg.sender, refundAmount); } /// @dev Allows to create market after successful funding /// @return Market address function createMarket() public timedTransitions atStage(Stages.AuctionSuccessful) returns (Market) { market = marketFactory.createMarket(eventContract, marketMaker, fee); require(eventContract.collateralToken().approve(address(market), funding)); market.fund(funding); stage = Stages.MarketCreated; emit MarketCreation(market); return market; } /// @dev Allows to withdraw fees from market contract to campaign contract /// @return Fee amount function closeMarket() public atStage(Stages.MarketCreated) { // Winning outcome should be set require(eventContract.isOutcomeSet()); market.close(); market.withdrawFees(); eventContract.redeemWinnings(); finalBalance = eventContract.collateralToken().balanceOf(address(this)); stage = Stages.MarketClosed; emit MarketClosing(); } /// @dev Allows to withdraw fees from campaign contract to contributor /// @return Fee amount function withdrawFees() public atStage(Stages.MarketClosed) returns (uint fees) { fees = finalBalance.mul(contributions[msg.sender]) / funding; contributions[msg.sender] = 0; // Send fee share to contributor require(eventContract.collateralToken().transfer(msg.sender, fees)); emit FeeWithdrawal(msg.sender, fees); } }