Added SimpleTreasury contract (#21)

* Added SimpleTreasury contract

* Typo

* Added deployed contract address

Author: gabrielfior

README.md

@@ -10,6 +10,7 @@ Repository holding the contracts made by Gnosis Labs team.
 | OmenAgentResultMapping  | Maps prediction results to markets on Omen 2.0        | [0xbe1F6944496923683ca849fc0cC93fD10523cB83](https://gnosisscan.io/address/0x260E1077dEA98e738324A6cEfB0EE9A272eD471a#code) | [omen-agentresultmapping](https://thegraph.com/studio/subgraph/omen-agentresultmapping/)     |
 | Agent NFT               | Agent NFTs that control mechs for NFT game            | [0x0D7C0Bd4169D090038c6F41CFd066958fe7619D0](https://gnosisscan.io/address/0x0D7C0Bd4169D090038c6F41CFd066958fe7619D0#code) |  |
 | Agent communication contract               | Simple contract storing message queue for each agent            | [0xd422e0059ed819e8d792af936da206878188e34f](https://gnosisscan.io/address/0xd422e0059ed819e8d792af936da206878188e34f#code) |  |
+| Simple Treasury contract               | Contract for storing the NFT agent game treasury | [0x624ad0db52e6b18afb4d36b8e79d0c2a74f3fc8a](https://gnosisscan.io/address/0x624ad0db52e6b18afb4d36b8e79d0c2a74f3fc8a#code) |  |
 
 ## Set up contracts development
 

src/NFT/SimpleTreasury.sol

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
+import "@openzeppelin/contracts/access/Ownable.sol";
+
+contract SimpleTreasury is Ownable {
+    IERC721 public nftContract;
+    uint256 public requiredNFTBalance = 3;
+
+    function setRequiredNFTBalance(uint256 _newBalance) external onlyOwner {
+        requiredNFTBalance = _newBalance;
+    }
+
+    event WithdrawnByNFTHolder(address indexed holder, uint256 amount);
+
+    constructor(address _nftContract) Ownable(msg.sender) {
+        require(_nftContract != address(0), "Invalid NFT contract address");
+        nftContract = IERC721(_nftContract);
+    }
+
+    // Function to receive xDAI
+    receive() external payable {}
+
+    // Withdraw function that checks NFT balance
+    function withdraw() external {
+        uint256 nftBalance = nftContract.balanceOf(msg.sender);
+        require(nftBalance >= requiredNFTBalance, "Insufficient NFT balance");
+
+        uint256 balance = address(this).balance;
+        require(balance > 0, "No funds to withdraw");
+
+        (bool success,) = payable(msg.sender).call{value: balance}("");
+        require(success, "Transfer failed");
+
+        emit WithdrawnByNFTHolder(msg.sender, balance);
+    }
+}

test/SimpleTreasury.t.sol

@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "forge-std/Test.sol";
+import "../src/NFT/SimpleTreasury.sol";
+import "./mocks/MockNFT.sol";
+
+contract SimpleTreasuryTest is Test {
+    SimpleTreasury public treasury;
+    MockNFT public nft;
+
+    address public owner;
+    address public user;
+    uint256 public constant INITIAL_BALANCE = 10 ether;
+
+    function setUp() public {
+        owner = makeAddr("owner");
+        user = makeAddr("user");
+
+        vm.startPrank(owner);
+        nft = new MockNFT();
+        treasury = new SimpleTreasury(address(nft));
+        vm.stopPrank();
+
+        // Fund treasury
+        vm.deal(address(treasury), INITIAL_BALANCE);
+    }
+
+    function test_WithdrawWithSufficientNFTs() public {
+        // Mint 3 NFTs to user
+        vm.startPrank(owner);
+        for (uint256 i = 0; i < treasury.requiredNFTBalance(); ++i) {
+            nft.mint(user);
+        }
+        vm.stopPrank();
+
+        // Try to withdraw as user
+        vm.prank(user);
+        uint256 userBalanceBefore = user.balance;
+        treasury.withdraw();
+
+        assertEq(user.balance - userBalanceBefore, INITIAL_BALANCE, "User should receive all treasury balance");
+        assertEq(address(treasury).balance, 0, "Treasury should be empty");
+    }
+
+    function test_WithdrawWithInsufficientNFTs() public {
+        // Mint only 2 NFTs to user
+        vm.startPrank(owner);
+        nft.mint(user);
+        nft.mint(user);
+        vm.stopPrank();
+
+        // Try to withdraw as user
+        vm.prank(user);
+        vm.expectRevert("Insufficient NFT balance");
+        treasury.withdraw();
+    }
+
+    function test_SetRequiredNFTBalance() public {
+        uint256 newRequiredBalance = 5;
+
+        vm.prank(owner);
+        treasury.setRequiredNFTBalance(newRequiredBalance);
+
+        assertEq(treasury.requiredNFTBalance(), newRequiredBalance, "Required NFT balance should be updated");
+    }
+
+    function test_SetRequiredNFTBalanceNotOwner() public {
+        vm.prank(user);
+        vm.expectRevert(abi.encodeWithSelector(Ownable.OwnableUnauthorizedAccount.selector, address(user)));
+        treasury.setRequiredNFTBalance(5);
+    }
+
+    function test_ReceiveEther() public {
+        uint256 amount = 1 ether;
+        vm.deal(user, amount);
+
+        vm.prank(user);
+        (bool success,) = address(treasury).call{value: amount}("");
+
+        assertTrue(success, "Should accept ether");
+        assertEq(address(treasury).balance, INITIAL_BALANCE + amount, "Treasury balance should increase");
+    }
+}

test/mocks/MockNFT.sol

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
+
+contract MockNFT is ERC721 {
+    uint256 private _tokenIdCounter;
+
+    constructor() ERC721("MockNFT", "MNFT") {}
+
+    function mint(address to) external returns (uint256) {
+        uint256 tokenId = _tokenIdCounter++;
+        _mint(to, tokenId);
+        return tokenId;
+    }
+}