feat: enable one time payments with single address

src/contracts/Grateful.sol

@@ -5,6 +5,8 @@
 import {Ownable2Step} from "@openzeppelin/contracts/access/Ownable2Step.sol";
 
 import {OneTime} from "contracts/OneTime.sol";
+
+import {console} from "forge-std/console.sol";
 import {IERC20} from "forge-std/interfaces/IERC20.sol";
 import {IGrateful} from "interfaces/IGrateful.sol";
 
@@ -13,7 +15,7 @@
 
 /**
  * @title Grateful Contract
  * @notice Allows payments in whitelisted tokens with optional yield via AAVE, including payment splitting functionality.
  */
 contract Grateful is IGrateful, Ownable2Step {
   using Bytes32AddressLib for bytes32;
@@ -61,6 +63,17 @@
     _;
   }
 
+  modifier onlyWhenTokensWhitelisted(
+    address[] memory _tokens
+  ) {
+    for (uint256 i = 0; i < _tokens.length; i++) {
+      if (!tokensWhitelisted[_tokens[i]]) {
+        revert Grateful_TokenNotWhitelisted();
+      }
+    }
+    _;
+  }
+
   /*//////////////////////////////////////////////////////////////
                               CONSTRUCTOR
     //////////////////////////////////////////////////////////////*/
@@ -107,7 +120,7 @@
     //////////////////////////////////////////////////////////////*/
 
   /// @inheritdoc IGrateful
   function addToken(
     address _token
   ) external onlyOwner {
     tokensWhitelisted[_token] = true;
@@ -276,19 +289,19 @@
   /// @inheritdoc IGrateful
   function createOneTimePayment(
     address _merchant,
-    address _token,
+    address[] memory _tokens,
     uint256 _amount,
     uint256 _salt,
     uint256 _paymentId,
     address precomputed,
     address[] calldata _recipients,
     uint256[] calldata _percentages
-  ) external onlyWhenTokenWhitelisted(_token) returns (OneTime oneTime) {
+  ) external onlyWhenTokensWhitelisted(_tokens) returns (OneTime oneTime) {
     oneTimePayments[precomputed] = true;
     oneTime = new OneTime{salt: bytes32(_salt)}(
-      IGrateful(address(this)), IERC20(_token), _merchant, _amount, _paymentId, _recipients, _percentages
+      IGrateful(address(this)), _tokens, _merchant, _amount, _paymentId, _recipients, _percentages
     );
-    emit OneTimePaymentCreated(_merchant, _token, _amount);
+    emit OneTimePaymentCreated(_merchant, _tokens, _amount);
   }
 
   /// @inheritdoc IGrateful
@@ -309,7 +322,7 @@
   /// @inheritdoc IGrateful
   function computeOneTimeAddress(
     address _merchant,
-    address _token,
+    address[] memory _tokens,
     uint256 _amount,
     uint256 _salt,
     uint256 _paymentId,
@@ -318,7 +331,7 @@
   ) external view returns (OneTime oneTime) {
     bytes memory bytecode = abi.encodePacked(
       type(OneTime).creationCode,
-      abi.encode(address(this), _token, _merchant, _amount, _paymentId, _recipients, _percentages)
+      abi.encode(address(this), _tokens, _merchant, _amount, _paymentId, _recipients, _percentages)
     );
     bytes32 bytecodeHash = keccak256(bytecode);
     bytes32 addressHash = keccak256(abi.encodePacked(bytes1(0xff), address(this), bytes32(_salt), bytecodeHash));
@@ -329,38 +342,49 @@
   /// @inheritdoc IGrateful
   function createOneTimePayment(
     address _merchant,
-    address _token,
+    address[] memory _tokens,
     uint256 _amount,
     uint256 _salt,
     uint256 _paymentId,
     address precomputed
-  ) external onlyWhenTokenWhitelisted(_token) returns (OneTime oneTime) {
+  ) external onlyWhenTokensWhitelisted(_tokens) returns (OneTime oneTime) {
     oneTimePayments[precomputed] = true;
     oneTime = new OneTime{salt: bytes32(_salt)}(
-      IGrateful(address(this)), IERC20(_token), _merchant, _amount, _paymentId, new address[](0), new uint256[](0)
+      IGrateful(address(this)), _tokens, _merchant, _amount, _paymentId, new address[](0), new uint256[](0)
     );
-    emit OneTimePaymentCreated(_merchant, _token, _amount);
+    emit OneTimePaymentCreated(_merchant, _tokens, _amount);
   }
 
   /// @inheritdoc IGrateful
-  function receiveOneTimePayment(address _merchant, address _token, uint256 _paymentId, uint256 _amount) external {
+  function receiveOneTimePayment(
+    address _merchant,
+    IERC20[] memory _tokens,
+    uint256 _paymentId,
+    uint256 _amount
+  ) external {
     if (!oneTimePayments[msg.sender]) {
       revert Grateful_OneTimeNotFound();
     }
-    _processPayment(msg.sender, _merchant, _token, _amount, _paymentId, 0, new address[](0), new uint256[](0));
+    for (uint256 i = 0; i < _tokens.length; i++) {
+      if (_tokens[i].balanceOf(msg.sender) >= _amount) {
+        _processPayment(
+          msg.sender, _merchant, address(_tokens[i]), _amount, _paymentId, 0, new address[](0), new uint256[](0)
+        );
+      }
+    }
   }
 
   /// @inheritdoc IGrateful
   function computeOneTimeAddress(
     address _merchant,
-    address _token,
+    address[] memory _tokens,
     uint256 _amount,
     uint256 _salt,
     uint256 _paymentId
   ) external view returns (OneTime oneTime) {
     bytes memory bytecode = abi.encodePacked(
       type(OneTime).creationCode,
-      abi.encode(address(this), _token, _merchant, _amount, _paymentId, new address[](0), new uint256[](0))
+      abi.encode(address(this), _tokens, _merchant, _amount, _paymentId, new address[](0), new uint256[](0))
     );
     bytes32 bytecodeHash = keccak256(bytecode);
     bytes32 addressHash = keccak256(abi.encodePacked(bytes1(0xff), address(this), bytes32(_salt), bytecodeHash));
@@ -455,7 +479,7 @@
             revert Grateful_VaultNotSet();
           }
           uint256 _shares = vault.deposit(recipientShare, address(this));
           shares[recipient][_token] += _shares;
         } else {
           // Transfer tokens to recipient
           if (!IERC20(_token).transfer(recipient, recipientShare)) {
@@ -471,7 +495,7 @@
           revert Grateful_VaultNotSet();
         }
         uint256 _shares = vault.deposit(amountWithFee, address(this));
         shares[_merchant][_token] += _shares;
       } else {
         // Transfer tokens to merchant
         if (!IERC20(_token).transfer(_merchant, amountWithFee)) {

src/contracts/OneTime.sol

@@ -1,20 +1,26 @@
 // SPDX-License-Identifier: MIT
 pragma solidity 0.8.26;
 
+import {console} from "forge-std/console.sol";
 import {IERC20} from "forge-std/interfaces/IERC20.sol";
 import {IGrateful} from "interfaces/IGrateful.sol";
 
 contract OneTime {
   constructor(
     IGrateful _grateful,
-    IERC20 _token,
+    address[] memory _tokens,
     address _merchant,
     uint256 _amount,
     uint256 _paymentId,
     address[] memory _recipients,
     uint256[] memory _percentages
   ) {
-    _token.approve(address(_grateful), _amount);
-    _grateful.receiveOneTimePayment(_merchant, address(_token), _paymentId, _amount, _recipients, _percentages);
+    for (uint256 i = 0; i < _tokens.length; i++) {
+      IERC20 token = IERC20(_tokens[i]);
+      if (token.balanceOf(address(this)) >= _amount) {
+        token.approve(address(_grateful), _amount);
+        _grateful.receiveOneTimePayment(_merchant, address(token), _paymentId, _amount, _recipients, _percentages);
+      }
+    }
   }
 }

src/interfaces/IGrateful.sol

@@ -2,6 +2,8 @@
 pragma solidity 0.8.26;
 
 import {OneTime} from "contracts/OneTime.sol";
+
+import {IERC20} from "forge-std/interfaces/IERC20.sol";
 import {AaveV3ERC4626, IPool} from "yield-daddy/aave-v3/AaveV3ERC4626.sol";
 
 /**
@@ -62,10 +64,10 @@
   /**
    * @notice Emitted when a one-time payment is created.
    * @param merchant Address of the merchant.
-   * @param token Address of the token.
+   * @param tokens Address of the token.
    * @param amount Amount of the token.
    */
-  event OneTimePaymentCreated(address indexed merchant, address indexed token, uint256 amount);
+  event OneTimePaymentCreated(address indexed merchant, address[] indexed tokens, uint256 amount);
 
   event SubscriptionCreated(
     uint256 indexed subscriptionId,
@@ -169,7 +171,7 @@
    * @notice Adds a token to the whitelist.
    * @param _token Address of the token to be added.
    */
   function addToken(
     address _token
   ) external;
 
@@ -264,7 +266,7 @@
   /**
    * @notice Creates a one-time payment.
    * @param _merchant Address of the merchant.
-   * @param _token Address of the token.
+   * @param _tokens Address of the token.
    * @param _amount Amount of the token.
    * @param _salt Salt used for address computation.
    * @param _paymentId ID of the payment.
@@ -273,7 +275,7 @@
    */
   function createOneTimePayment(
     address _merchant,
-    address _token,
+    address[] memory _tokens,
     uint256 _amount,
     uint256 _salt,
     uint256 _paymentId,
@@ -285,7 +287,7 @@
   /**
    * @notice Creates a one-time payment without recipients and percentages.
    * @param _merchant Address of the merchant.
-   * @param _token Address of the token.
+   * @param _tokens Address of the token.
    * @param _amount Amount of the token.
    * @param _salt Salt used for address computation.
    * @param _paymentId ID of the payment.
@@ -294,7 +296,7 @@
    */
   function createOneTimePayment(
     address _merchant,
-    address _token,
+    address[] memory _tokens,
     uint256 _amount,
     uint256 _salt,
     uint256 _paymentId,
@@ -322,16 +324,21 @@
   /**
    * @notice Receives a one-time payment without recipients and percentages.
    * @param _merchant Address of the merchant.
-   * @param _token Address of the token.
+   * @param _tokens Address of the token.
    * @param _paymentId ID of the payment.
    * @param _amount Amount of the token.
    */
-  function receiveOneTimePayment(address _merchant, address _token, uint256 _paymentId, uint256 _amount) external;
+  function receiveOneTimePayment(
+    address _merchant,
+    IERC20[] memory _tokens,
+    uint256 _paymentId,
+    uint256 _amount
+  ) external;
 
   /**
    * @notice Computes the address of a one-time payment contract.
    * @param _merchant Address of the merchant.
-   * @param _token Address of the token.
+   * @param _tokens Address of the token.
    * @param _amount Amount of the token.
    * @param _salt Salt used for address computation.
    * @param _paymentId ID of the payment.
@@ -341,7 +348,7 @@
    */
   function computeOneTimeAddress(
     address _merchant,
-    address _token,
+    address[] memory _tokens,
     uint256 _amount,
     uint256 _salt,
     uint256 _paymentId,
@@ -352,15 +359,15 @@
   /**
    * @notice Computes the address of a one-time payment contract without recipients and percentages.
    * @param _merchant Address of the merchant.
-   * @param _token Address of the token.
+   * @param _tokens Address of the token.
    * @param _amount Amount of the token.
    * @param _salt Salt used for address computation.
    * @param _paymentId ID of the payment.
    * @return oneTime Address of the computed OneTime contract.
    */
   function computeOneTimeAddress(
     address _merchant,
-    address _token,
+    address[] memory _tokens,
     uint256 _amount,
     uint256 _salt,
     uint256 _paymentId

test/integration/Grateful.t.sol

@@ -131,26 +131,29 @@ contract IntegrationGreeter is IntegrationBase {
     uint256 paymentId = _grateful.calculateId(_usdcWhale, _merchant, address(_usdc), _amount);
 
     // 2. Precompute address
-    address precomputed = address(_grateful.computeOneTimeAddress(_merchant, address(_usdc), _amount, 4, paymentId));
+    address precomputed = address(_grateful.computeOneTimeAddress(_merchant, _tokens, _amount, 4, paymentId));
 
     // 3. Once the payment address is precomputed, the client sends the payment
     vm.prank(_usdcWhale);
     _usdc.transfer(precomputed, _amount); // Only tx sent by the client, doesn't need contract interaction
 
     // 4. Merchant calls api to make one time payment to his address
     vm.prank(_gratefulAutomation);
-    _grateful.createOneTimePayment(_merchant, address(_usdc), _amount, 4, paymentId, precomputed);
+    _grateful.createOneTimePayment(_merchant, _tokens, _amount, 4, paymentId, precomputed);
 
     // Merchant receives the payment
     assertEq(_usdc.balanceOf(_merchant), _grateful.applyFee(_amount));
   }
 
   function test_OneTimePaymentYieldingFunds() public {
+    address[] memory _tokens2 = new address[](1);
+    _tokens2[0] = _tokens[0];
+
     // 1. Calculate payment id
     uint256 paymentId = _grateful.calculateId(_usdcWhale, _merchant, address(_usdc), _amount);
 
     // 2. Precompute address
-    address precomputed = address(_grateful.computeOneTimeAddress(_merchant, address(_usdc), _amount, 4, paymentId));
+    address precomputed = address(_grateful.computeOneTimeAddress(_merchant, _tokens, _amount, 4, paymentId));
 
     // 3. Once the payment address is precomputed, the client sends the payment
     vm.prank(_usdcWhale);
@@ -162,7 +165,7 @@ contract IntegrationGreeter is IntegrationBase {
 
     // 5. Grateful automation calls api to make one time payment to his address
     vm.prank(_gratefulAutomation);
-    _grateful.createOneTimePayment(_merchant, address(_usdc), _amount, 4, paymentId, precomputed);
+    _grateful.createOneTimePayment(_merchant, _tokens, _amount, 4, paymentId, precomputed);
     // 6. Advance time
     vm.warp(block.timestamp + 1 days);
 
@@ -225,19 +228,16 @@ contract IntegrationGreeter is IntegrationBase {
     uint256 paymentId = _grateful.calculateId(_usdcWhale, _merchant, address(_usdc), _amount);
 
     // 3. Precompute address
-    address precomputed = address(
-      _grateful.computeOneTimeAddress(_merchant, address(_usdc), _amount, 4, paymentId, recipients, percentages)
-    );
+    address precomputed =
+      address(_grateful.computeOneTimeAddress(_merchant, _tokens, _amount, 4, paymentId, recipients, percentages));
 
     // 4. Once the payment address is precomputed, the client sends the payment
     vm.prank(_usdcWhale);
     _usdc.transfer(precomputed, _amount);
 
     // 5. Merchant calls api to make one time payment to his address
     vm.prank(_gratefulAutomation);
-    _grateful.createOneTimePayment(
-      _merchant, address(_usdc), _amount, 4, paymentId, precomputed, recipients, percentages
-    );
+    _grateful.createOneTimePayment(_merchant, _tokens, _amount, 4, paymentId, precomputed, recipients, percentages);
 
     // 6. Calculate expected amounts after fee
     uint256 amountAfterFee = _grateful.applyFee(_amount);

test/integration/IntegrationBase.sol

@@ -21,6 +21,7 @@ contract IntegrationBase is Test {
   address internal _usdcWhale = 0x555d73f2002A457211d690313f942B065eAD1FFF;
   address[] internal _tokens;
   IERC20 internal _usdc = IERC20(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48);
+  IERC20 internal _usdt = IERC20(0x6B175474E89094C44Da98b954EedeAC495271d0F);
   address internal _aUsdc = 0x98C23E9d8f34FEFb1B7BD6a91B7FF122F4e16F5c;
   address internal _rewardsController = 0x8164Cc65827dcFe994AB23944CBC90e0aa80bFcb;
   IPool internal _aavePool = IPool(0x87870Bca3F3fD6335C3F4ce8392D69350B4fA4E2);
@@ -34,8 +35,9 @@ contract IntegrationBase is Test {
     vm.startPrank(_owner);
     vm.createSelectFork(vm.rpcUrl("mainnet"), _FORK_BLOCK);
     vm.label(address(_vault), "Vault");
-    _tokens = new address[](1);
+    _tokens = new address[](2);
     _tokens[0] = address(_usdc);
+    _tokens[1] = address(_usdt);
     _grateful = new Grateful(_tokens, _aavePool, _fee);
     _vault = new AaveV3Vault(
       ERC20(address(_usdc)),