feat(payment): add relay payment contract (#41)

contracts/payment/PaymentConfigRegistry.sol

@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+import "@openzeppelin/contracts/utils/cryptography/ECDSA.sol";
+import "@openzeppelin/contracts-upgradeable/access/OwnableUpgradeable.sol";
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
+import "../AccessRegistry.sol";
+
+bytes32 constant PAYMENT_ADMIN_ROLE = keccak256("PAYMENT_ADMIN_ROLE");
+
+contract PaymentConfigRegistry is OwnableUpgradeable {
+    using ECDSA for bytes;
+    using ECDSA for bytes32;
+
+    error InvalidSignature();
+    error Forbidden();
+    error CannotWithdraw();
+
+    address public accessRegistry;
+    address public authorizedSigner;
+    uint256 public feePPM;
+    uint256[20] __gap;
+
+    event FeeCollected(string eventId, address token, uint256 amount);
+
+    function initialize(
+        address registry,
+        address signer,
+        uint256 ppm
+    ) public initializer {
+        accessRegistry = registry;
+        authorizedSigner = signer;
+        feePPM = ppm;
+    }
+
+    function setAccessRegistry(address registry) external onlyOwner {
+        accessRegistry = registry;
+    }
+
+    function setAuthorizedSigner(address signer) external onlyAdmin {
+        authorizedSigner = signer;
+    }
+
+    function setFeePPM(uint256 ppm) external onlyAdmin {
+        feePPM = ppm;
+    }
+
+    function withdraw(
+        address token,
+        uint256 amount,
+        address payable destination
+    ) external onlyAdmin {
+        bool success;
+
+        if (token == address(0)) {
+            (success, ) = destination.call{value: amount}("");
+        } else {
+            success = IERC20(token).transfer(destination, amount);
+        }
+
+        if (!success) revert CannotWithdraw();
+    }
+
+    function notifyFee(
+        string calldata eventId,
+        address token,
+        uint256 amount
+    ) external {
+        emit FeeCollected(eventId, token, amount);
+    }
+
+    function assertSignature(
+        bytes32[] calldata data,
+        bytes calldata signature
+    ) public view {
+        address actualSigner = abi
+            .encode(data)
+            .toEthSignedMessageHash()
+            .recover(signature);
+
+        if (actualSigner != authorizedSigner) {
+            revert InvalidSignature();
+        }
+    }
+
+    receive() external payable {}
+
+    fallback() external payable {}
+
+    modifier onlyAdmin() {
+        if (
+            !AccessRegistry(accessRegistry).hasRole(
+                PAYMENT_ADMIN_ROLE,
+                _msgSender()
+            )
+        ) {
+            revert Forbidden();
+        }
+        _;
+    }
+}