From 364cece660710b8835522ad25ce46511d81efebb Mon Sep 17 00:00:00 2001
From: jonastheis <4181434+jonastheis@users.noreply.github.com>
Date: Thu, 27 Mar 2025 19:53:38 +0800
Subject: [PATCH 1/2] change FinalizedL1MessageQueueIndex to
 NextUnfinalizedL1MessageQueueIndex

---
 rollup/l1/reader.go | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/rollup/l1/reader.go b/rollup/l1/reader.go
index f2b5ce6c7e76..7812b702a1fa 100644
--- a/rollup/l1/reader.go
+++ b/rollup/l1/reader.go
@@ -72,7 +72,7 @@ func NewReader(ctx context.Context, config Config, l1Client Client) (*Reader, er
 	return &reader, nil
 }
 
-func (r *Reader) FinalizedL1MessageQueueIndex(blockNumber uint64) (uint64, error) {
+func (r *Reader) NextUnfinalizedL1MessageQueueIndex(blockNumber uint64) (uint64, error) {
 	data, err := r.l1MessageQueueABI.Pack(nextUnfinalizedQueueIndex)
 	if err != nil {
 		return 0, fmt.Errorf("failed to pack %s: %w", nextUnfinalizedQueueIndex, err)
@@ -92,11 +92,7 @@ func (r *Reader) FinalizedL1MessageQueueIndex(blockNumber uint64) (uint64, error
 	}
 
 	next := parsedResult.Uint64()
-	if next == 0 {
-		return 0, nil
-	}
-
-	return next - 1, nil
+	return next, nil
 }
 
 func (r *Reader) LatestFinalizedBatchIndex(blockNumber uint64) (uint64, error) {

From 4c305f00034379f9fb82938e916604e614c46f89 Mon Sep 17 00:00:00 2001
From: Morty <70688412+yiweichi@users.noreply.github.com>
Date: Sat, 19 Apr 2025 23:14:56 +0800
Subject: [PATCH 2/2] feat(L1Reader): add GetFinalizedStateRootByBatchIndex
 (#1165)

* feat(L1Reader): add GetFinalizedStateRootByBatchIndex

* fix: FinalizedL1MessageQueueIndex return type

* fix: get state root batchIndex type
---
 rollup/l1/reader.go | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/rollup/l1/reader.go b/rollup/l1/reader.go
index 7812b702a1fa..e479b7dd9dd0 100644
--- a/rollup/l1/reader.go
+++ b/rollup/l1/reader.go
@@ -23,6 +23,7 @@ const (
 	finalizeBatchEventName    = "FinalizeBatch"
 	nextUnfinalizedQueueIndex = "nextUnfinalizedQueueIndex"
 	lastFinalizedBatchIndex   = "lastFinalizedBatchIndex"
+	finalizedStateRoots       = "finalizedStateRoots"
 
 	defaultRollupEventsFetchBlockRange = 100
 )
@@ -117,6 +118,28 @@ func (r *Reader) LatestFinalizedBatchIndex(blockNumber uint64) (uint64, error) {
 	return parsedResult.Uint64(), nil
 }
 
+func (r *Reader) GetFinalizedStateRootByBatchIndex(blockNumber uint64, batchIndex uint64) (common.Hash, error) {
+	data, err := r.scrollChainABI.Pack(finalizedStateRoots, big.NewInt(int64(batchIndex)))
+	if err != nil {
+		return common.Hash{}, fmt.Errorf("failed to pack %s: %w", finalizedStateRoots, err)
+	}
+
+	result, err := r.client.CallContract(r.ctx, ethereum.CallMsg{
+		To:   &r.config.ScrollChainAddress,
+		Data: data,
+	}, new(big.Int).SetUint64(blockNumber))
+	if err != nil {
+		return common.Hash{}, fmt.Errorf("failed to call %s: %w", finalizedStateRoots, err)
+	}
+
+	var parsedResult common.Hash
+	if err = r.scrollChainABI.UnpackIntoInterface(&parsedResult, finalizedStateRoots, result); err != nil {
+		return common.Hash{}, fmt.Errorf("failed to unpack result: %w", err)
+	}
+
+	return parsedResult, nil
+}
+
 // GetLatestFinalizedBlockNumber fetches the block number of the latest finalized block from the L1 chain.
 func (r *Reader) GetLatestFinalizedBlockNumber() (uint64, error) {
 	header, err := r.client.HeaderByNumber(r.ctx, big.NewInt(int64(rpc.FinalizedBlockNumber)))