app/src/providers/PlayerProvider.tsx

@@ -100,7 +100,7 @@ const PlayerProvider = ({ children }: { children: ReactNode }) => {
       abi,
       address: contractAddress,
       functionName: 'register',
-      value: parseEther("0.00005"),
+      value: parseEther("0.0005"),
     })
   }, [writeContract])
 

src/Constants.sol

@@ -5,4 +5,6 @@ contract Constants {
     //base addresses
     address public constant DAO_TOKEN = 0x11dC980faf34A1D082Ae8A6a883db3A950a3c6E8;
     address public constant POOL = 0x27004f6d0c1bB7979367D32Ba9d6DF6d61A18926;
+    address public constant WETH9 = 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2;
+    address public constant SWAP_ROUTER_02 = 0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45;
 }

src/RaidGeld.sol

@@ -3,28 +3,39 @@ pragma solidity ^0.8.13;
 
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 import "@openzeppelin/contracts/access/Ownable.sol";
+import '@uniswap/v3-periphery/contracts/interfaces/ISwapRouter.sol';
+import '@uniswap/v3-periphery/contracts/libraries/TransferHelper.sol';
 import {RaidGeldUtils} from "../src/RaidGeldUtils.sol";
 import {Army, Player, Raider} from "../src/RaidGeldStructs.sol";
 
 contract RaidGeld is ERC20, Ownable {
+
     uint256 public constant MANTISSA = 1e4;
-
-    uint256 public constant BUY_IN_AMOUNT = 0.00005 ether;
+    uint256 public constant BUY_IN_AMOUNT = 0.0005 ether;
     uint256 public immutable BUY_IN_DAO_TOKEN_AMOUNT;
-
     uint256 public constant INITIAL_GELD = 50 * MANTISSA;
-
     mapping(address => Player) private players;
     mapping(address => Army) private armies;
 
+    // WETH
+    IERC20 private constant weth = IERC20(Constants.WETH);
+    // RGCVII token
     ERC20 public daoToken;
+    // RGCVII pool
     address public pool;
+    // Uniswap
+    ISwapRouter02 private constant router = ISwapRouter02(Constants.SWAP_ROUTER_02);
 
     // Modifier for functions that should only be available to registered players
     modifier onlyPlayer() {
         require(players[msg.sender].created_at != 0, "Not an initiated player");
         _;
     }
+    // Modifier for functions that should only be available to non initialized players
+    modifier newPlayer() {
+        require(players[msg.sender].created_at == 0, "Whoops, player already exists :)");
+        _;
+    }
 
     constructor(address _daoToken, address _pool) ERC20("Raid Geld", "GELD") Ownable(msg.sender) {
         daoToken = ERC20(_daoToken);
@@ -32,27 +43,14 @@ contract RaidGeld is ERC20, Ownable {
         BUY_IN_DAO_TOKEN_AMOUNT = 50 * 10 ** daoToken.decimals();
     }
 
-    // This effectively registers the user
-    function register() external payable {
-        require(players[msg.sender].created_at == 0, "Whoops, player already exists :)");
-        if (msg.value != 0) {
-            require(msg.value == BUY_IN_AMOUNT, "Incorrect buy in amount");
-        } else {
-            //@notice this is not safe for arbitrary tokens, which may not follow the interface eg. USDT
-            //@notice but should be fine for the DAO token
-            require(
-                daoToken.transferFrom(msg.sender, address(this), BUY_IN_DAO_TOKEN_AMOUNT),
-                "Failed to transfer DAO tokens"
-            );
-        }
-
+    function init_player(address player) private {
         // Mint some starting tokens to the player
-        _mint(msg.sender, INITIAL_GELD);
+        _mint(player, INITIAL_GELD);
 
         // Set initial states
-        players[msg.sender] =
+        players[player] =
             Player({total_minted: INITIAL_GELD, created_at: block.timestamp, last_raided_at: block.timestamp});
-        armies[msg.sender] = Army({
+        armies[player] = Army({
             moloch_denier: Raider({level: 0}),
             apprentice: Raider({level: 0}),
             anointed: Raider({level: 0}),
@@ -61,6 +59,36 @@ contract RaidGeld is ERC20, Ownable {
         });
     }
 
+    // New player want to register with ETH
+    function register_eth() external payable newPlayer {
+        require(weth.transferFrom(msg.sender, address(this), BUY_IN_AMOUNT), "Make sure to send exactly 0.0005 eth");
+        weth.approve(address(router), amountIn);
+        ISwapRouter02.ExactInputSingleParams memory params = ISwapRouter02
+            .ExactInputSingleParams({
+            tokenIn: WETH,
+            tokenOut: DAI,
+            fee: 3000,
+            recipient: msg.sender,
+            amountIn: amountIn,
+            amountOutMinimum: amountOutMin,
+            sqrtPriceLimitX96: 0
+        });
+        router.exactInputSingle(params);
+        init_player();
+    }
+
+    // New player wants to register with dao
+    function register_dao() external payable newPlayer {
+        //@notice this is not safe for arbitrary tokens, which may not follow the interface eg. USDT
+        //@notice but should be fine for the DAO token
+        require(
+            daoToken.transferFrom(msg.sender, address(this), BUY_IN_DAO_TOKEN_AMOUNT),
+            "Failed to transfer DAO tokens"
+        );
+        // Init player
+        init_player(msg.sender);
+    }
+
     // Override for default number of decimals
     function decimals() public view virtual override returns (uint8) {
         return 4;

test/RaidGeld.t.sol

@@ -31,12 +31,12 @@ contract raid_geldTest is Test, Constants {
     }
 
     function registerPlayer() private {
-        raid_geld.register{value: raid_geld.BUY_IN_AMOUNT()}();
+        raid_geld.register_eth{value: raid_geld.BUY_IN_AMOUNT()}();
     }
 
     function registerPlayerWithDaoToken() private {
         raid_geld.daoToken().approve(address(raid_geld), raid_geld.BUY_IN_DAO_TOKEN_AMOUNT());
-        raid_geld.register();
+        raid_geld.register_dao();
     }
 
     function test_00_no_fallback() public {