Add global discount

contracts/src/v0.8/llo-feeds/v0.4.0/DestinationFeeManager.sol

@@ -25,6 +25,9 @@ contract DestinationFeeManager is IDestinationFeeManager, IDestinationVerifierFe
   /// @notice list of subscribers and their discounts subscriberDiscounts[subscriber][feedId][token]
   mapping(address => mapping(bytes32 => mapping(address => uint256))) public s_subscriberDiscounts;
 
+  /// @notice map of global discounts
+  mapping(address => mapping(address => uint256)) public s_globalDiscounts;
+
   /// @notice keep track of any subsidised link that is owed to the reward manager.
   mapping(bytes32 => uint256) public s_linkDeficit;
 
@@ -289,9 +292,14 @@ contract DestinationFeeManager is IDestinationFeeManager, IDestinationVerifierFe
       revert ExpiredReport();
     }
 
-    //get the discount being applied
+    //check if feed discount has been applied
     uint256 discount = s_subscriberDiscounts[subscriber][feedId][quoteAddress];
 
+    if (discount == 0) {
+      //check if a global discount has been applied
+      discount = s_globalDiscounts[subscriber][quoteAddress];
+    }
+
     //the reward is always set in LINK
     reward.assetAddress = i_linkAddress;
     reward.amount = Math.ceilDiv(linkQuantity * (PERCENTAGE_SCALAR - discount), PERCENTAGE_SCALAR);
@@ -345,6 +353,21 @@ contract DestinationFeeManager is IDestinationFeeManager, IDestinationVerifierFe
     emit SubscriberDiscountUpdated(subscriber, feedId, token, discount);
   }
 
+  function updateSubscriberGlobalDiscount(
+    address subscriber,
+    address token,
+    uint64 discount
+  ) external onlyOwner {
+    //make sure the discount is not greater than the total discount that can be applied
+    if (discount > PERCENTAGE_SCALAR) revert InvalidDiscount();
+    //make sure the token is either LINK or native
+    if (token != i_linkAddress && token != i_nativeAddress) revert InvalidAddress();
+
+    s_globalDiscounts[subscriber][token] = discount;
+
+    emit SubscriberDiscountUpdated(subscriber, bytes32(0), token, discount);
+  }
+
   /// @inheritdoc IDestinationFeeManager
   function withdraw(address assetAddress, address recipient, uint192 quantity) external onlyOwner {
     //address 0 is used to withdraw native in the context of withdrawing

contracts/src/v0.8/llo-feeds/v0.4.0/interfaces/IDestinationFeeManager.sol

@@ -33,6 +33,14 @@ interface IDestinationFeeManager is IERC165 {
    */
   function updateSubscriberDiscount(address subscriber, bytes32 feedId, address token, uint64 discount) external;
 
+  /**
+   * @notice Adds a subscriber to the fee manager
+   * @param subscriber address of the subscriber
+   * @param token token to apply the discount to
+   * @param discount discount to be applied to the fee
+   */
+  function updateSubscriberGlobalDiscount(address subscriber, address token, uint64 discount) external;
+
   /**
    * @notice Withdraws any native or LINK rewards to the owner address
    * @param assetAddress address of the asset to withdraw

contracts/src/v0.8/llo-feeds/v0.4.0/test/fee-manager/BaseDestinationFeeManager.t.sol

@@ -147,6 +147,18 @@ contract BaseDestinationFeeManagerTest is Test {
     changePrank(originalAddr);
   }
 
+  function setSubscriberGlobalDiscount(address subscriber, address token, uint256 discount, address sender) public {
+    //record the current address and switch to the recipient
+    address originalAddr = msg.sender;
+    changePrank(sender);
+
+    //set the discount
+    feeManager.updateSubscriberGlobalDiscount(subscriber, token, uint64(discount));
+
+    //change back to the original address
+    changePrank(originalAddr);
+  }
+
   function setNativeSurcharge(uint256 surcharge, address sender) public {
     //record the current address and switch to the recipient
     address originalAddr = msg.sender;

contracts/src/v0.8/llo-feeds/v0.4.0/test/fee-manager/DestinationFeeManager.getFeeAndReward.t.sol

@@ -603,4 +603,118 @@ contract DestinationFeeManagerProcessFeeTest is BaseDestinationFeeManagerTest {
     //fee should be half the default
     assertEq(discount, FEE_SCALAR / 2);
   }
+
+  function test_GlobalDiscountWithNative() public {
+    //set the global discount to 50%
+    setSubscriberGlobalDiscount(USER, address(native), FEE_SCALAR / 2, ADMIN);
+
+    //get the discount applied
+    uint256 discount = getAppliedDiscount(getV3Report(DEFAULT_FEED_1_V3), getNativeQuote(), USER);
+
+    //fee should be half the default
+    assertEq(discount, FEE_SCALAR / 2);
+  }
+
+  function test_GlobalDiscountWithLink() public {
+    //set the global discount to 50%
+    setSubscriberGlobalDiscount(USER, address(link), FEE_SCALAR / 2, ADMIN);
+
+    //get the discount applied
+    uint256 discount = getAppliedDiscount(getV3Report(DEFAULT_FEED_1_V3), getLinkQuote(), USER);
+
+    //fee should be half the default
+    assertEq(discount, FEE_SCALAR / 2);
+  }
+
+  function test_GlobalDiscountWithNativeAndLink() public {
+    //set the global discount to 50%
+    setSubscriberGlobalDiscount(USER, address(native), FEE_SCALAR / 2, ADMIN);
+    setSubscriberGlobalDiscount(USER, address(link), FEE_SCALAR / 2, ADMIN);
+
+    //get the discount applied
+    uint256 discount = getAppliedDiscount(getV3Report(DEFAULT_FEED_1_V3), getLinkQuote(), USER);
+
+    //fee should be half the default
+    assertEq(discount, FEE_SCALAR / 2);
+  }
+
+  function test_GlobalDiscountIsOverridenByIndividualDiscountNative() public {
+    //set the global discount to 50%
+    setSubscriberGlobalDiscount(USER, address(native), FEE_SCALAR / 2, ADMIN);
+    setSubscriberDiscount(USER, DEFAULT_FEED_1_V3, address(native), FEE_SCALAR / 4, ADMIN);
+
+    //get the discount applied
+    uint256 discount = getAppliedDiscount(getV3Report(DEFAULT_FEED_1_V3), getNativeQuote(), USER);
+
+    //fee should be half the default
+    assertEq(discount, FEE_SCALAR / 4);
+  }
+
+  function test_GlobalDiscountIsOverridenByIndividualDiscountLink() public {
+    //set the global discount to 50%
+    setSubscriberGlobalDiscount(USER, address(link), FEE_SCALAR / 2, ADMIN);
+    setSubscriberDiscount(USER, DEFAULT_FEED_1_V3, address(link), FEE_SCALAR / 4, ADMIN);
+
+    //get the discount applied
+    uint256 discount = getAppliedDiscount(getV3Report(DEFAULT_FEED_1_V3), getLinkQuote(), USER);
+
+    //fee should be half the default
+    assertEq(discount, FEE_SCALAR / 4);
+  }
+
+  function test_GlobalDiscountIsUpdatedAfterBeingSetToZeroLink() public {
+    //set the global discount to 50%
+    setSubscriberGlobalDiscount(USER, address(link), FEE_SCALAR / 2, ADMIN);
+
+    //get the discount applied
+    uint256 discount = getAppliedDiscount(getV3Report(DEFAULT_FEED_1_V3), getLinkQuote(), USER);
+
+    //fee should be half the default
+    assertEq(discount, FEE_SCALAR / 2);
+
+    //set the global discount to zero
+    setSubscriberGlobalDiscount(USER, address(link), 0, ADMIN);
+
+    //get the discount applied
+    discount = getAppliedDiscount(getV3Report(DEFAULT_FEED_1_V3), getLinkQuote(), USER);
+
+    //fee should be zero
+    assertEq(discount, 0);
+  }
+
+  function test_GlobalDiscountIsUpdatedAfterBeingSetToZeroNative() public {
+    //set the global discount to 50%
+    setSubscriberGlobalDiscount(USER, address(native), FEE_SCALAR / 2, ADMIN);
+
+    //get the discount applied
+    uint256 discount = getAppliedDiscount(getV3Report(DEFAULT_FEED_1_V3), getNativeQuote(), USER);
+
+    //fee should be half the default
+    assertEq(discount, FEE_SCALAR / 2);
+
+    //set the global discount to zero
+    setSubscriberGlobalDiscount(USER, address(native), 0, ADMIN);
+
+    //get the discount applied
+    discount = getAppliedDiscount(getV3Report(DEFAULT_FEED_1_V3), getNativeQuote(), USER);
+
+    //fee should be zero
+    assertEq(discount, 0);
+  }
+
+  function test_GlobalDiscountCantBeSetToMoreThanMaximum() public {
+    //should revert with invalid discount
+    vm.expectRevert(INVALID_DISCOUNT_ERROR);
+
+    //set the global discount to 101%
+    setSubscriberGlobalDiscount(USER, address(native), FEE_SCALAR + 1, ADMIN);
+  }
+
+  function test_onlyOwnerCanSetGlobalDiscount() public {
+    //should revert with unauthorized
+    vm.expectRevert(ONLY_CALLABLE_BY_OWNER_ERROR);
+
+    //set the global discount to 50%
+    setSubscriberGlobalDiscount(USER, address(native), FEE_SCALAR / 2, USER);
+  }
 }