fix: adjust setEpochDuration

src/contracts/vault/v1.1/VaultImplementation.sol

@@ -551,44 +551,33 @@ contract VaultImplementation is VaultStorage, AccessControlUpgradeable, Reentran
         }
 
         if (nextEpochDurationInitInternal != 0 && nextEpochDurationInitInternal <= Time.timestamp()) {
-            uint256 currentEpoch_ = currentEpoch();
-            uint48 currentEpochStart_ = currentEpochStart();
-
             prevEpochInitInternal = epochInitInternal;
             prevEpochDurationInternal = epochDurationInternal;
             prevEpochDurationInitInternal = epochDurationInitInternal;
-            epochInitInternal = currentEpoch_;
+            epochInitInternal = nextEpochInitInternal;
             epochDurationInternal = nextEpochDurationInternal;
-            epochDurationInitInternal = currentEpochStart_;
+            epochDurationInitInternal = nextEpochDurationInitInternal;
             epochDurationSetEpochsDelayInternal = nextEpochDurationSetEpochsDelayInternal;
-            nextEpochInitInternal = 0;
-            nextEpochDurationInternal = 0;
-            nextEpochDurationInitInternal = 0;
-            nextEpochDurationSetEpochsDelayInternal = 0;
         }
 
         if (epochDurationInternal > epochDuration_) {
             revert InvalidNewEpochDuration();
         }
 
-        if (nextEpochDurationInitInternal != 0) {
-            nextEpochInitInternal = 0;
-            nextEpochDurationInternal = 0;
-            nextEpochDurationInitInternal = 0;
-            nextEpochDurationSetEpochsDelayInternal = 0;
-        } else if (epochDurationInternal == epochDuration_) {
+        if (
+            epochDurationInternal == epochDuration_
+                && epochDurationSetEpochsDelayInternal == epochDurationSetEpochsDelay_
+        ) {
             revert AlreadySet();
         }
 
-        if (epochDurationInternal != epochDuration_) {
-            nextEpochInitInternal = currentEpoch() + epochDurationSetEpochsDelayInternal;
-            nextEpochDurationInternal = epochDuration_;
-            nextEpochDurationInitInternal =
-                (currentEpochStart() + epochDurationSetEpochsDelayInternal * epochDurationInternal).toUint48();
-            nextEpochDurationSetEpochsDelayInternal = epochDurationSetEpochsDelay_;
-        }
+        nextEpochInitInternal = currentEpoch() + epochDurationSetEpochsDelayInternal;
+        nextEpochDurationInternal = epochDuration_;
+        nextEpochDurationInitInternal =
+            (currentEpochStart() + epochDurationSetEpochsDelayInternal * epochDurationInternal).toUint48();
+        nextEpochDurationSetEpochsDelayInternal = epochDurationSetEpochsDelay_;
 
-        emit SetEpochDuration(epochDuration_);
+        emit SetEpochDuration(epochDuration_, epochDurationSetEpochsDelay_);
     }
 
     /**

src/interfaces/vault/v1.1/IVault.sol

@@ -195,8 +195,9 @@ interface IVault is IVaultStorage, IAccessControl, IERC165, IERC3156FlashLender
     /**
      * @notice Emitted when a epoch duration is set (can be accepted after `epochDurationSetEpochsDelay` epochs).
      * @param epochDuration epoch duration
+     * @param epochDurationSetEpochsDelay delay for the epoch duration set in epochs
      */
-    event SetEpochDuration(uint48 epochDuration);
+    event SetEpochDuration(uint48 epochDuration, uint256 epochDurationSetEpochsDelay);
 
     /**
      * @notice Emitted when a pending epoch duration is accepted.

test/vault/v1.1/Vault.t.sol

@@ -2961,16 +2961,16 @@ contract VaultTest is Test {
         assertEq(vault.prevEpochInitInternal(), 0);
         assertEq(vault.prevEpochDurationInternal(), epochDuration);
         assertEq(vault.prevEpochDurationInitInternal(), blockTimestamp - 3 * epochDuration);
-        assertEq(vault.nextEpochInitInternal(), 0);
-        assertEq(vault.nextEpochDurationInternal(), 0);
-        assertEq(vault.nextEpochDurationInitInternal(), 0);
+        assertEq(vault.nextEpochInitInternal(), 3 + 5);
+        assertEq(vault.nextEpochDurationInternal(), newEpochDuration);
+        assertEq(vault.nextEpochDurationInitInternal(), blockTimestamp + 5 * newEpochDuration);
         assertEq(vault.epochStart(0), blockTimestamp - 3 * epochDuration);
         assertEq(vault.epochStart(1), blockTimestamp - (3 - 1) * epochDuration);
         assertEq(vault.epochAt(uint48(blockTimestamp + epochDuration)), 3);
         assertEq(vault.epochAt(uint48(blockTimestamp + newEpochDuration)), 3 + 1);
         assertEq(vault.epochDurationSetEpochsDelay(), 5);
         assertEq(vault.epochDurationSetEpochsDelayInternal(), 5);
-        assertEq(vault.nextEpochDurationSetEpochsDelayInternal(), 0);
+        assertEq(vault.nextEpochDurationSetEpochsDelayInternal(), 3);
 
         _setEpochDuration(alice, newEpochDuration2);
 
@@ -3079,15 +3079,20 @@ contract VaultTest is Test {
     function test_SetEpochDurationRevertAlreadySet(
         uint48 epochDuration
     ) public {
-        epochDuration = uint48(bound(epochDuration, 1, 50 weeks));
+        epochDuration = uint48(bound(epochDuration, 2, 50 weeks));
 
         uint256 blockTimestamp = vm.getBlockTimestamp();
         blockTimestamp = blockTimestamp + 1_720_700_948;
         vm.warp(blockTimestamp);
 
-        vault = _getVault(epochDuration);
+        vault = _getVault(epochDuration - 1);
 
         _grantEpochDurationSetRole(alice, alice);
+        _setEpochDuration(alice, epochDuration);
+
+        blockTimestamp = blockTimestamp + vault.epochDurationSetEpochsDelay() * (epochDuration - 1);
+        vm.warp(blockTimestamp);
+
         vm.expectRevert(IVault.AlreadySet.selector);
         _setEpochDuration(alice, epochDuration);
     }