mirror of https://github.com/embarklabs/embark.git
68 lines
2.1 KiB
Solidity
68 lines
2.1 KiB
Solidity
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pragma solidity >=0.5.0 <0.6.0;
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import "./Stakable.sol";
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import "./Medianizer.sol";
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/**
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* @title USDStakable
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* @dev Staking contract that is integrated with MakerDAO's medianizer to obtain stake prices in USD, with initial price being always ~1USD
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*/
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contract USDStakable is Stakable {
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Medianizer public medianizer;
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uint public basePrice;
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/**
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* @param _burnAddress Address where the slashed stakes are going to be sent
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* @param _medianizer Medianizer contract address
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*/
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constructor(address payable _burnAddress, address _medianizer) internal Stakable(_burnAddress) {
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burnAddress = _burnAddress;
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basePrice = 1 ether; // 1 usd
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medianizer = Medianizer(_medianizer);
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}
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event BasePriceChanged(address sender, uint prevPrice, uint newPrice);
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/**
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* @dev Changes the base price
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* @param _basePrice New burn address
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*/
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function setBasePrice(uint _basePrice) external onlyOwner {
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emit BasePriceChanged(msg.sender, basePrice, _basePrice);
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basePrice = _basePrice;
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}
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event MedianizerChanged(address sender, address _oldAddress, address _newAddress);
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/**
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* @dev Changes the medianizer address
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* @param _medianizer New medianizer address
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*/
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function setMedianizer(address _medianizer) external onlyOwner {
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emit MedianizerChanged(msg.sender, address(medianizer), _medianizer);
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medianizer = Medianizer(_medianizer);
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}
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/**
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* @notice Get amount to stake for the next offer
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* @param _owner Address for which the stake amount will be calculated
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* @return Amount to stake in wei
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*/
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function getAmountToStake(address _owner) public view returns(uint) {
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uint stakeCnt = stakeCounter[_owner] + 1;
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uint mweiPrice = basePrice * 1000000;
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uint daiPrice = uint256(medianizer.read());
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uint oneUsdEth = (mweiPrice / daiPrice) * 1 szabo;
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uint amountToStake = oneUsdEth * (stakeCnt * stakeCnt) / 17; // y = basePrice * x^2/17
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if (amountToStake < oneUsdEth) {
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return oneUsdEth;
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}
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return amountToStake;
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}
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}
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