feat(protocol): add getLastVerifiedBlock and getLastSyncedBlock

packages/protocol/contracts/L1/TaikoL1.sol

@@ -183,11 +183,37 @@ contract TaikoL1 is EssentialContract, ITaikoL1, TaikoEvents, TaikoErrors {
     {
         return LibUtils.getTransition(state, getConfig(), _blockId, _tid);
     }
+
+    /// @notice Returns information about the last verified block.
+    /// @return blockId_ The last verified block's ID.
+    /// @return blockHash_ The last verified block's blockHash.
+    /// @return stateRoot_ The last verified block's stateRoot.
+    function getLastVerifiedBlock()
+        public
+        view
+        returns (uint64 blockId_, bytes32 blockHash_, bytes32 stateRoot_)
+    {
+        blockId_ = state.slotB.lastVerifiedBlockId;
+        (blockHash_, stateRoot_) = LibUtils.getBlockInfo(state, getConfig(), blockId_);
+    }
+
+    /// @notice Returns information about the last synchronized block.
+    /// @return blockId_ The last verified block's ID.
+    /// @return blockHash_ The last verified block's blockHash.
+    /// @return stateRoot_ The last verified block's stateRoot.
+    function getLastSyncedBlock()
+        public
+        view
+        returns (uint64 blockId_, bytes32 blockHash_, bytes32 stateRoot_)
+    {
+        blockId_ = state.slotA.lastSyncedBlockId;
+        (blockHash_, stateRoot_) = LibUtils.getBlockInfo(state, getConfig(), blockId_);
+    }
+
     /// @notice Gets the state variables of the TaikoL1 contract.
     /// @dev This method can be deleted once node/client stops using it.
     /// @return State variables stored at SlotA.
     /// @return State variables stored at SlotB.
-
     function getStateVariables()
         public
         view

packages/protocol/contracts/L1/libs/LibUtils.sol

@@ -109,6 +109,26 @@ library LibUtils {
         }
     }
 
+    function getBlockInfo(
+        TaikoData.State storage _state,
+        TaikoData.Config memory _config,
+        uint64 _blockId
+    )
+        internal
+        view
+        returns (bytes32 blockHash_, bytes32 stateRoot_)
+    {
+        (TaikoData.Block storage blk, uint64 slot) = getBlock(_state, _config, _blockId);
+
+        if (blk.verifiedTransitionId != 0) {
+            TaikoData.TransitionState storage transition =
+                _state.transitions[slot][blk.verifiedTransitionId];
+
+            blockHash_ = transition.blockHash;
+            stateRoot_ = transition.stateRoot;
+        }
+    }
+
     function isPostDeadline(
         uint256 _tsTimestamp,
         uint256 _lastUnpausedAt,