pragma solidity 0.6.12; import "@openzeppelin/contracts/token/ERC20/IERC20.sol"; import "@openzeppelin/contracts/math/SafeMath.sol"; import "@openzeppelin/contracts/access/Ownable.sol"; import "@openzeppelin/contracts/utils/ReentrancyGuard.sol"; import "./DioneToken.sol"; // DioneStaking is the main contract for Dione oracle network Proof-of-Stake mechanism // // Note that it's ownable and the owner has power over changing miner rewards and minimum DIONE stake // The ownership of the contract would be transfered to 24 hours Timelock contract DioneStaking is Ownable, ReentrancyGuard { using SafeMath for uint256; // MinerInfo contains total DIONEs staked by miner, how much tasks been already computed // and timestamp of first deposit struct MinerInfo { uint256 amount; // How many DIONE tokens was staked by the miner. uint256 firstStakeBlock; // First block for miner DIONE tokens reward. uint256 lastRewardBlock; // Last block for miner DIONE tokens reward } DioneToken public dione; // Aggregator contract address. address public aggregatorAddr; // Miner rewards in DIONE tokens. uint256 public minerReward; // The block number when DIONE mining starts. uint256 public startBlock; // Minimum amount of staked DIONE tokens required to start mining uint256 public minimumStake; // Total amount of DIONE tokens staked uint256 private _totalStake; // Info of each miner that stakes DIONE tokens. mapping (address => MinerInfo) public minerInfo; event Stake(address indexed miner, uint256 amount); event Withdraw(address indexed miner, uint256 amount); event Mine(address indexed miner, uint256 blockNumber); constructor( DioneToken _dione, address _aggregatorAddr, uint256 _minerReward, uint256 _startBlock, uint256 _minimumStake ) public { dione = _dione; aggregatorAddr = _aggregatorAddr; minerReward = _minerReward; startBlock = _startBlock; minimumStake = _minimumStake; } // Mine new dione oracle task, only can be executed by aggregator contract function mine(address _minerAddr) public nonReentrant { require(msg.sender == aggregatorAddr, "not aggregator contract"); MinerInfo storage miner = minerInfo[_minerAddr]; require(miner.amount >= minimumStake); dione.mint(_minerAddr, minerReward); miner.lastRewardBlock = block.number; emit Mine(_minerAddr, block.number); } // Mine new dione oracle task and stake miner reward, only can be executed by aggregator contract function mineAndStake(address _minerAddr) public nonReentrant { require(msg.sender == aggregatorAddr, "not aggregator contract"); MinerInfo storage miner = minerInfo[_minerAddr]; require(miner.amount >= minimumStake); dione.mint(address(this), minerReward); _totalStake = _totalStake.add(minerReward); miner.amount = miner.amount.add(minerReward); miner.lastRewardBlock = block.number; emit Mine(_minerAddr, block.number); } // Deposit DIONE tokens to mine on dione network function stake(uint256 _amount) public nonReentrant { require(_amount > 0, "Cannot stake 0"); MinerInfo storage miner = minerInfo[msg.sender]; _totalStake = _totalStake.add(_amount); miner.amount = miner.amount.add(_amount); dione.transferFrom(address(msg.sender), address(this), _amount); if (miner.firstStakeBlock == 0 && miner.amount >= minimumStake) { miner.firstStakeBlock = block.number > startBlock ? block.number : startBlock; } emit Stake(msg.sender, _amount); } // Withdraw DIONE tokens from DioneStaking function withdraw(uint256 _amount) public nonReentrant { MinerInfo storage miner = minerInfo[msg.sender]; require(miner.amount >= _amount, "withdraw: not enough tokens"); if(_amount > 0) { _totalStake = _totalStake.sub(_amount); miner.amount = miner.amount.sub(_amount); dione.transfer(address(msg.sender), _amount); } emit Withdraw(msg.sender, _amount); } // Returns total amount of DIONE tokens in PoS mining function totalStake() external view returns (uint256) { return _totalStake; } function minerStake(address _minerAddr) external view returns (uint256) { MinerInfo storage miner = minerInfo[_minerAddr]; return miner.amount; } // Update miner reward in DIONE tokens, only can be executed by owner of the contract function setMinerReward(uint256 _minerReward) public onlyOwner { require(_minerReward > 0, "!minerReward-0"); minerReward = _minerReward; } // Update minimum stake in DIONE tokens for miners, only can be executed by owner of the contract function setMinimumStake(uint256 _minimumStake) public onlyOwner { require(_minimumStake > 0, "!minerReward-0"); minimumStake = _minimumStake; } }