From 34d3bd2c39a6e1bd99a222318483418e8e53f608 Mon Sep 17 00:00:00 2001
From: Giulio <giulio.rebuffo@gmail.com>
Date: Sun, 7 Jan 2024 17:11:04 +0100
Subject: [PATCH] save

---
 cl/beacon/handler/builder.go | 69 ++++++++++++++++++++++++++++++++++++
 cl/beacon/handler/format.go  |  2 +-
 cl/beacon/handler/handler.go |  1 +
 3 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100644 cl/beacon/handler/builder.go

diff --git a/cl/beacon/handler/builder.go b/cl/beacon/handler/builder.go
new file mode 100644
index 00000000000..d7174008681
--- /dev/null
+++ b/cl/beacon/handler/builder.go
@@ -0,0 +1,69 @@
+package handler
+
+import (
+	"net/http"
+
+	libcommon "github.com/ledgerwatch/erigon-lib/common"
+	"github.com/ledgerwatch/erigon/cl/beacon/beaconhttp"
+	"github.com/ledgerwatch/erigon/cl/clparams"
+	"github.com/ledgerwatch/erigon/cl/persistence/beacon_indicies"
+	"github.com/ledgerwatch/erigon/cl/phase1/core/state"
+)
+
+func (a *ApiHandler) GetEth1V1BuilderStatesExpectedWit(w http.ResponseWriter, r *http.Request) (*beaconResponse, error) {
+	ctx := r.Context()
+
+	tx, err := a.indiciesDB.BeginRo(ctx)
+	if err != nil {
+		return nil, err
+	}
+	defer tx.Rollback()
+
+	blockId, err := stateIdFromRequest(r)
+	if err != nil {
+		return nil, beaconhttp.NewEndpointError(http.StatusBadRequest, err.Error())
+	}
+	root, httpStatus, err := a.blockRootFromStateId(ctx, tx, blockId)
+	if err != nil {
+		return nil, beaconhttp.NewEndpointError(httpStatus, err.Error())
+	}
+	slot, err := beacon_indicies.ReadBlockSlotByBlockRoot(tx, root)
+	if err != nil {
+		return nil, err
+	}
+	if slot == nil {
+		return nil, beaconhttp.NewEndpointError(http.StatusNotFound, "state not found")
+	}
+	if a.beaconChainCfg.GetCurrentStateVersion(*slot/a.beaconChainCfg.SlotsPerEpoch) < clparams.CapellaVersion {
+		return nil, beaconhttp.NewEndpointError(http.StatusBadRequest, "the specified state is not a capella state")
+	}
+	headRoot, _, err := a.forkchoiceStore.GetHead()
+	if err != nil {
+		return nil, err
+	}
+	if root == headRoot {
+		s, cn := a.syncedData.HeadState()
+		defer cn()
+		return newBeaconResponse(state.ExpectedWithdrawals(s)).withFinalized(false), nil
+	}
+	lookAhead := 1024
+	for currSlot := *slot + 1; currSlot < *slot+uint64(lookAhead); currSlot++ {
+		if currSlot > a.syncedData.HeadSlot() {
+			return nil, beaconhttp.NewEndpointError(http.StatusNotFound, "state not found")
+		}
+		blockRoot, err := beacon_indicies.ReadCanonicalBlockRoot(tx, currSlot)
+		if err != nil {
+			return nil, err
+		}
+		if blockRoot == (libcommon.Hash{}) {
+			continue
+		}
+		blk, err := a.blockReader.ReadBlockByRoot(ctx, tx, blockRoot)
+		if err != nil {
+			return nil, err
+		}
+		return newBeaconResponse(blk.Block.Body.ExecutionPayload.Withdrawals).withFinalized(false), nil
+	}
+
+	return nil, beaconhttp.NewEndpointError(http.StatusNotFound, "state not found")
+}
diff --git a/cl/beacon/handler/format.go b/cl/beacon/handler/format.go
index 7baa88b42f2..3a96cf6e8c0 100644
--- a/cl/beacon/handler/format.go
+++ b/cl/beacon/handler/format.go
@@ -170,7 +170,7 @@ func stateIdFromRequest(r *http.Request) (*segmentID, error) {
 
 	stateId := chi.URLParam(r, "state_id")
 	if !regex.MatchString(stateId) {
-		return nil, fmt.Errorf("invalid path variable: {block_id}")
+		return nil, fmt.Errorf("invalid path variable: {state_id}")
 	}
 
 	if stateId == "head" {
diff --git a/cl/beacon/handler/handler.go b/cl/beacon/handler/handler.go
index eb2fc2e90f6..9ead9cb0b2f 100644
--- a/cl/beacon/handler/handler.go
+++ b/cl/beacon/handler/handler.go
@@ -49,6 +49,7 @@ func (a *ApiHandler) init() {
 	// otterscn specific ones are commented as such
 	r.Route("/eth", func(r chi.Router) {
 		r.Route("/v1", func(r chi.Router) {
+			r.Get("/builder/states/{state_id}/expected_withdrawals", beaconhttp.HandleEndpointFunc(a.GetEth1V1BuilderStatesExpectedWit))
 			r.Get("/events", http.NotFound)
 			r.Route("/node", func(r chi.Router) {
 				r.Get("/health", a.GetEthV1NodeHealth)