rating agency v2 distributor (#504)

Co-authored-by: Hal Hyatt <[email protected]>

contracts/truefi/distributors/RatingAgencyV2Distributor.sol

@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.6.10;
+
+import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+import {SafeMath} from "@openzeppelin/contracts/math/SafeMath.sol";
+
+import {Ownable} from "../common/UpgradeableOwnable.sol";
+import {IArbitraryDistributor} from "../interface/IArbitraryDistributor.sol";
+
+/**
+ * @title ArbitraryTrueDistributor
+ * @notice Distribute TRU to a smart contract
+ * @dev Allows for arbitrary claiming of TRU by a farm contract
+ *
+ * Contracts are registered to receive distributions. Once registered,
+ * a farm contract can claim TRU from the distributor.
+ * - Owner can withdraw funds in case distribution need to be re-allocated
+ */
+contract RatingAgencyV2Distributor is IArbitraryDistributor, Ownable {
+    using SafeMath for uint256;
+
+    // ================ WARNING ==================
+    // ===== THIS CONTRACT IS INITIALIZABLE ======
+    // === STORAGE VARIABLES ARE DECLARED BELOW ==
+    // REMOVAL OR REORDER OF VARIABLES WILL RESULT
+    // ========= IN STORAGE CORRUPTION ===========
+
+    IERC20 public trustToken;
+    address public override beneficiary;
+    uint256 public override amount;
+    uint256 public override remaining;
+    mapping(address => bool) public beneficiaries;
+
+    // ======= STORAGE DECLARATION END ============
+
+    event Distributed(uint256 amount);
+    event BeneficiaryStatusChanged(address beneficiary, bool status);
+
+    /**
+     * @dev Initialize distributor
+     * @param _beneficiary Address for distribution
+     * @param _trustToken TRU address
+     * @param _amount Amount to distribute
+     */
+    function initialize(
+        address _beneficiary,
+        IERC20 _trustToken,
+        uint256 _amount
+    ) public initializer {
+        Ownable.initialize();
+        trustToken = _trustToken;
+        beneficiary = _beneficiary;
+        amount = 500000000000000; // 5M
+        remaining = 30000000000000000; // 300M
+    }
+
+    /**
+     * @dev Only beneficiary can receive TRU
+     */
+    modifier onlyBeneficiary {
+        // prettier-ignore
+        require(msg.sender == beneficiary || beneficiaries[msg.sender],
+            "ArbitraryDistributor: Only beneficiary can receive tokens");
+        _;
+    }
+
+    function setBeneficiaryStatus(address _beneficiary, bool _status) public {
+        beneficiaries[_beneficiary] = _status;
+        emit BeneficiaryStatusChanged(_beneficiary, _status);
+    }
+
+    /**
+     * @dev Distribute arbitrary number of tokens
+     * @param _amount Amount of TRU to distribute
+     */
+    function distribute(uint256 _amount) public override onlyBeneficiary {
+        remaining = remaining.sub(_amount);
+        require(trustToken.transfer(msg.sender, _amount));
+
+        emit Distributed(_amount);
+    }
+
+    /**
+     * @dev Withdraw funds (for instance if owner decides to create a new distribution) and end distribution cycle
+     */
+    function empty() public override onlyOwner {
+        remaining = 0;
+        require(trustToken.transfer(msg.sender, trustToken.balanceOf(address(this))));
+    }
+}