add getAPYs

Author: 0xh3rman

bsc/hub_reader/src/HubReader.sol

@@ -24,6 +24,13 @@ contract HubReader {
         stakeHub = IStakeHub(0x0000000000000000000000000000000000002002);
     }
 
+    /*
+     * @dev Get validators by offset and limit (pagination)
+     * @param offset The offset to query validators
+     * @param limit The limit to query validators
+     *
+     * @return The validators
+     */
     function getValidators(
         uint16 offset,
         uint16 limit
@@ -54,6 +61,14 @@ contract HubReader {
         return validators;
     }
 
+    /*
+     * @dev Get current delegations of a delegator
+     * @param delegator The address of the delegator
+     * @param offset The offset to query validators
+     * @param limit The limit to query validators
+     *
+     * @return The delegations of the delegator
+     */
     function getDelegations(
         address delegator,
         uint16 offset,
@@ -88,4 +103,35 @@ contract HubReader {
         }
         return delegations;
     }
+
+    /*
+     * @dev Get APYs of an array of validators at a given timestamp
+     * @param operatorAddr The address of the validator
+     * @param timestamp The timestamp of the block
+     *
+     * @return The APYs of the validator in basis points, e.g. 195 is 1.95%
+     */
+    function getAPYs(
+        address[] memory operatorAddrs,
+        uint256 timestamp
+    ) external view returns (uint64[] memory) {
+        uint256 dayIndex = timestamp / stakeHub.BREATHE_BLOCK_INTERVAL();
+        uint256 length = operatorAddrs.length;
+        uint64[] memory apys = new uint64[](length);
+        for (uint256 i = 0; i < length; i++) {
+            uint256 total = stakeHub.getValidatorTotalPooledBNBRecord(
+                operatorAddrs[i],
+                dayIndex
+            );
+            uint256 reward = stakeHub.getValidatorRewardRecord(
+                operatorAddrs[i],
+                dayIndex
+            );
+            if (total == 0 || reward == 0) {
+                continue;
+            }
+            apys[i] = uint64((reward * 365 * 10000) / total);
+        }
+        return apys;
+    }
 }

bsc/hub_reader/src/interface/IStakeHub.sol

@@ -15,6 +15,8 @@ struct Commission {
 }
 
 interface IStakeHub {
+    function BREATHE_BLOCK_INTERVAL() external view returns (uint256);
+
     function getValidators(
         uint256 offset,
         uint256 limit

bsc/hub_reader/test/HubReader.t.sol

@@ -12,7 +12,7 @@ contract ValidatorsTest is Test {
     }
 
     function test_getValidators() public view {
-        uint16 limit = 30;
+        uint16 limit = 10;
         Validator[] memory validators = reader.getValidators(0, limit);
         assertTrue(validators.length <= limit);
 
@@ -43,4 +43,18 @@ contract ValidatorsTest is Test {
         );
         assertTrue(delegations[0].amount > 0);
     }
+
+    function test_getAPY() public view {
+        uint256 timestamp = 1715477981;
+        address[] memory operatorAddrs = new address[](3);
+        operatorAddrs[0] = address(0x343dA7Ff0446247ca47AA41e2A25c5Bbb230ED0A);
+        operatorAddrs[1] = address(0xF2B1d86DC7459887B1f7Ce8d840db1D87613Ce7f);
+        operatorAddrs[2] = address(0x773760b0708a5Cc369c346993a0c225D8e4043B1);
+
+        uint64[] memory apys = reader.getAPYs(operatorAddrs, timestamp);
+
+        assertEq(apys[0], 193);
+        assertEq(apys[1], 331);
+        assertEq(apys[2], 287);
+    }
 }