Separate dmc <-> gwt exchange to upgradeable contracts

contracts/exchange.sol

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "@openzeppelin/contracts-upgradeable/proxy/utils/Initializable.sol";
+import "@openzeppelin/contracts-upgradeable/proxy/utils/UUPSUpgradeable.sol";
+import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
+
+import "./dmc.sol";
+import "./gwt.sol";
+
+contract Exchange is Initializable, UUPSUpgradeable, OwnableUpgradeable {
+ DMCToken dmcToken;
+ GWTToken gwtToken;
+
+ function initialize(address _dmcToken, address _gwtToken) public initializer {
+ __ExchangeUpgradable_init(_dmcToken, _gwtToken);
+ }
+
+ function __ExchangeUpgradable_init(address _dmcToken, address _gwtToken) internal onlyInitializing {
+ __UUPSUpgradeable_init();
+ __Ownable_init(msg.sender);
+ dmcToken = DMCToken(_dmcToken);
+ gwtToken = GWTToken(_gwtToken);
+ }
+
+ function _authorizeUpgrade(address newImplementation) internal virtual override onlyOwner {
+
+ }
+
+ function gwtRate() public pure returns(uint256) {
+ // 1 : 210
+ return 210;
+ }
+
+ function exchangeGWT(uint256 amount) public {
+ uint256 gwtAmount = amount * gwtRate();
+ dmcToken.transferFrom(msg.sender, address(this), amount);
+ gwtToken.mint(msg.sender, gwtAmount);
+ }
+
+ function exchangeDMC(uint256 amount) public {
+ uint256 dmcAmount = amount / gwtRate();
+ gwtToken.burnFrom(msg.sender, amount);
+ dmcToken.transfer(msg.sender, dmcAmount);
+ }
+}

contracts/gwt.sol

@@ -1,21 +1,41 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
-import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+import "@openzeppelin/contracts/token/ERC20/extensions/ERC20Burnable.sol";
 import "@openzeppelin/contracts/access/Ownable.sol";
 import "./dmc.sol";
 
-contract GWTToken is ERC20, Ownable {
- DMCToken dmcToken;
+contract GWTToken is ERC20Burnable, Ownable {
  mapping (address => bool) allow_transfer;
+ mapping (address => bool) allow_minter;
 
- // 这种兑换币，是不是需要设定一个最大上限？
- constructor(address _dmcToken) ERC20("Gb storage per Week Token", "GWT") Ownable(msg.sender) {
- dmcToken = DMCToken(_dmcToken);
+ constructor() ERC20("Gb storage per Week Token", "GWT") Ownable(msg.sender) {
  // enable mint and burn
  allow_transfer[address(0)] = true;
  }
 
+ modifier onlyMinter() {
+ require(allow_minter[msg.sender], "mint not allowed");
+ _;
+ }
+
+ modifier canTransfer(address sender, address to) {
+ require(allow_transfer[sender] || allow_transfer[to], "transfer not allowed");
+ _;
+ }
+
+ function enableMinter(address[] calldata addresses) public onlyOwner {
+ for (uint i = 0; i < addresses.length; i++) {
+ allow_minter[addresses[i]] = true;
+ }
+ }
+
+ function disableMinter(address[] calldata addresses) public onlyOwner {
+ for (uint i = 0; i < addresses.length; i++) {
+ allow_minter[addresses[i]] = false;
+ }
+ }
+
  function enableTransfer(address[] calldata addresses) public onlyOwner {
  for (uint i = 0; i < addresses.length; i++) {
  allow_transfer[addresses[i]] = true;
@@ -28,35 +48,11 @@ contract GWTToken is ERC20, Ownable {
  }
  }
 
- function _calcGWTAmount(uint256 dmc_amount) internal pure returns(uint256) {
- // 1 : 210
- return dmc_amount * 210;
- }
-
- function _calcDMCAmount(uint256 gwt_amount) internal pure returns(uint256) {
- // 210 : 1
- return gwt_amount / 210;
+ function mint(address to, uint256 amount) public onlyMinter {
+ _mint(to, amount);
  }
 
- function _update(address sender, address to, uint256 amount) internal override {
- require(allow_transfer[sender] || allow_transfer[to], "transfer not allowed");
+ function _update(address sender, address to, uint256 amount) internal override canTransfer(sender, to) {
  super._update(sender, to, amount);
  }
-
-
- //REVIEW 把兑换合约独立出去，GWT合约只需要认兑换合约（而不是认DMC合约）就可以。
- // 兑换合约是可升级逻辑的。
- function exchange(uint256 amount) public { 
- uint256 gwtAmount = _calcGWTAmount(amount);
-
- dmcToken.transferFrom(msg.sender, address(this), amount);
- _mint(msg.sender, gwtAmount);
- }
-
- function burn(uint256 amount) public {
- uint256 dmcAmount = _calcDMCAmount(amount);
-
- dmcToken.transfer(msg.sender, dmcAmount);
- _burn(msg.sender, amount);
- }
 }