DODO starter first edition

contracts/DODOStarter/impl/FairFunding.sol

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+/*
+
+    Copyright 2020 DODO ZOO.
+    SPDX-License-Identifier: Apache-2.0
+
+*/
+
+pragma solidity 0.6.9;
+pragma experimental ABIEncoderV2;
+
+import {InitializableOwnable} from "../../lib/InitializableOwnable.sol";
+import {ReentrancyGuard} from "../../lib/ReentrancyGuard.sol";
+import {IQuota} from "../../DODOFee/UserQuota.sol";
+import {SafeMath} from "../../lib/SafeMath.sol";
+import {DecimalMath} from "../../lib/DecimalMath.sol";
+import {IERC20} from "../../intf/IERC20.sol";
+import {SafeERC20} from "../../lib/SafeERC20.sol";
+
+contract FairFunding is InitializableOwnable, ReentrancyGuard {
+    using SafeMath for uint256;
+    using SafeERC20 for IERC20;
+
+    // ============ Token & Balance ============
+
+    uint256 public _FUNDS_RESERVE_;
+    address public _FUNDS_ADDRESS_;
+    address public _TOKEN_ADDRESS_;
+    uint256 public _TOTAL_TOKEN_AMOUNT_;
+
+    // ============ Fair Mode ============
+
+    uint256 public _START_TIME_;
+    uint256 public _BIDDING_DURATION_;
+    uint256 public _COOLING_DURATION_;
+
+    address _QUOTA_;
+    mapping(address => uint256) _FUNDS_DEPOSITED_;
+    mapping(address => bool) _FUNDS_CLAIMED_;
+    uint256 public _TOTAL_RAISED_FUNDS_;
+    uint256 public _USED_FUND_RATIO_;
+    uint256 public _FINAL_PRICE_;
+
+    // ============ Parameters ============
+
+    uint256 public _LOWER_LIMIT_PRICE_;
+    uint256 public _UPPER_LIMIT_PRICE_;
+
+    // ============ View Functions ============
+
+    function getCurrentPrice() public view returns (uint256) {
+        return getPrice(_TOTAL_RAISED_FUNDS_);
+    }
+
+    function getPrice(uint256 fundAmount) public view returns (uint256 price) {
+        price = DecimalMath.divFloor(fundAmount, _TOTAL_TOKEN_AMOUNT_);
+        if (price < _LOWER_LIMIT_PRICE_) {
+            price = _LOWER_LIMIT_PRICE_;
+        }
+        if (price > _UPPER_LIMIT_PRICE_) {
+            price = _UPPER_LIMIT_PRICE_;
+        }
+    }
+
+    function getUserTokenAllocation(address user) public view returns (uint256) {
+        if (_FINAL_PRICE_ == 0) {
+            return 0;
+        } else {
+            return
+                DecimalMath.divFloor(
+                    DecimalMath.mulFloor(_FUNDS_DEPOSITED_[user], _USED_FUND_RATIO_),
+                    _FINAL_PRICE_
+                );
+        }
+    }
+
+    function getUserFundsUnused(address user) public view returns (uint256) {
+        return
+            DecimalMath.mulFloor(_FUNDS_DEPOSITED_[user], DecimalMath.ONE.sub(_USED_FUND_RATIO_));
+    }
+
+    function getUserFundsUsed(address user) public view returns (uint256) {
+        return DecimalMath.mulFloor(_FUNDS_DEPOSITED_[user], _USED_FUND_RATIO_);
+    }
+
+    // ============ Settle Functions ============
+
+    function settle() public {
+        require(_FINAL_PRICE_ == 0 && isFundingEnd(), "CAN_NOT_SETTLE");
+        _FINAL_PRICE_ = getCurrentPrice();
+        _USED_FUND_RATIO_ = DecimalMath.divFloor(
+            DecimalMath.mulFloor(_TOTAL_TOKEN_AMOUNT_, _FINAL_PRICE_),
+            _TOTAL_RAISED_FUNDS_
+        );
+        if (_USED_FUND_RATIO_ > DecimalMath.ONE) {
+            _USED_FUND_RATIO_ = DecimalMath.ONE;
+        }
+    }
+
+    // ============ Funding Functions ============
+
+    function depositToken(uint256 amount) external preventReentrant onlyOwner {
+        require(block.timestamp < _START_TIME_, "FUNDING_ALREADY_STARTED");
+        IERC20(_TOKEN_ADDRESS_).safeTransferFrom(msg.sender, address(this), amount);
+        _TOTAL_TOKEN_AMOUNT_ = _TOTAL_TOKEN_AMOUNT_.add(amount);
+    }
+
+    function depositFunds(address to) external preventReentrant {
+        require(isDepositOpen(), "DEPOSIT_NOT_OPEN");
+        // input fund check
+        uint256 inputFund = IERC20(_FUNDS_ADDRESS_).balanceOf(address(this)).sub(_FUNDS_RESERVE_);
+        _FUNDS_RESERVE_ = _FUNDS_RESERVE_.add(inputFund);
+
+        if (_QUOTA_ != address(0)) {
+            require(
+                inputFund.add(_FUNDS_DEPOSITED_[to]) <= uint256(IQuota(_QUOTA_).getUserQuota(to)),
+                "QUOTA_EXCEED"
+            );
+        }
+
+        _FUNDS_DEPOSITED_[to] = _FUNDS_DEPOSITED_[to].add(inputFund);
+        _TOTAL_RAISED_FUNDS_ = _TOTAL_RAISED_FUNDS_.add(inputFund);
+    }
+
+    function withdrawFunds(address to, uint256 amount) external preventReentrant {
+        if (!isSettled()) {
+            require(_FUNDS_DEPOSITED_[msg.sender] >= amount, "WITHDRAW_TOO_MUCH");
+            _FUNDS_DEPOSITED_[msg.sender] = _FUNDS_DEPOSITED_[msg.sender].sub(amount);
+            _TOTAL_RAISED_FUNDS_ = _TOTAL_RAISED_FUNDS_.sub(amount);
+            IERC20(_FUNDS_ADDRESS_).safeTransfer(to, amount);
+        } else {
+            require(!_FUNDS_CLAIMED_[msg.sender], "ALREADY_CLAIMED");
+            _FUNDS_CLAIMED_[msg.sender] = true;
+            IERC20(_FUNDS_ADDRESS_).safeTransfer(to, getUserFundsUnused(msg.sender));
+        }
+    }
+
+    function withdrawUnallocatedToken(address to) external preventReentrant onlyOwner {
+        require(_FINAL_PRICE_ == _LOWER_LIMIT_PRICE_, "NO_TOKEN_LEFT");
+        uint256 allocatedToken = DecimalMath.divCeil(_TOTAL_RAISED_FUNDS_, _FINAL_PRICE_);
+        IERC20(_TOKEN_ADDRESS_).safeTransfer(to, _TOTAL_TOKEN_AMOUNT_.sub(allocatedToken));
+        _TOTAL_TOKEN_AMOUNT_ = allocatedToken;
+    }
+
+    // ============ Timeline Control Functions ============
+
+    function isDepositOpen() public returns (bool) {
+        return
+            block.timestamp >= _START_TIME_ &&
+            block.timestamp < _START_TIME_.add(_BIDDING_DURATION_);
+    }
+
+    function isFundingEnd() public returns (bool) {
+        return block.timestamp > _START_TIME_.add(_BIDDING_DURATION_).add(_COOLING_DURATION_);
+    }
+
+    function isSettled() public returns (bool) {
+        return _FINAL_PRICE_ != 0;
+    }
+}