From a1de39d25c40a5e654db6fb9c2bf6b90c6558473 Mon Sep 17 00:00:00 2001
From: Giulio rebuffo <giulio.rebuffo@gmail.com>
Date: Tue, 22 Nov 2022 15:36:08 +0100
Subject: [PATCH] added beacon state-transition first structure (#6105)

---
 .../cl-core/transition/process_slots.go       | 23 +++++++++++++++++++
 .../cl-core/transition/state_transistor.go    | 21 +++++++++++++++++
 2 files changed, 44 insertions(+)
 create mode 100644 cmd/erigon-cl/cl-core/transition/process_slots.go
 create mode 100644 cmd/erigon-cl/cl-core/transition/state_transistor.go

diff --git a/cmd/erigon-cl/cl-core/transition/process_slots.go b/cmd/erigon-cl/cl-core/transition/process_slots.go
new file mode 100644
index 000000000..0e98458d9
--- /dev/null
+++ b/cmd/erigon-cl/cl-core/transition/process_slots.go
@@ -0,0 +1,23 @@
+package transition
+
+import (
+	"github.com/ledgerwatch/erigon/cl/cltypes"
+)
+
+// transitionSlot is called each time there is a new slot to process
+func (s *StateTransistor) transitionSlot(state *cltypes.BeaconState) error {
+	previousStateRoot, err := state.HashTreeRoot()
+	if err != nil {
+		return err
+	}
+	state.StateRoots[state.Slot/s.beaconConfig.SlotsPerHistoricalRoot] = previousStateRoot
+	if state.LatestBlockHeader.Root == [32]byte{} {
+		state.LatestBlockHeader.Root = previousStateRoot
+	}
+	previousBlockRoot, err := state.LatestBlockHeader.HashTreeRoot()
+	if err != nil {
+		return err
+	}
+	state.BlockRoots[state.Slot/s.beaconConfig.SlotsPerHistoricalRoot] = previousBlockRoot
+	return nil
+}
diff --git a/cmd/erigon-cl/cl-core/transition/state_transistor.go b/cmd/erigon-cl/cl-core/transition/state_transistor.go
new file mode 100644
index 000000000..74301c935
--- /dev/null
+++ b/cmd/erigon-cl/cl-core/transition/state_transistor.go
@@ -0,0 +1,21 @@
+package transition
+
+import (
+	"github.com/ledgerwatch/erigon/cl/clparams"
+	"github.com/ledgerwatch/erigon/cl/cltypes"
+)
+
+// StateTransistor takes care of state transition
+type StateTransistor struct {
+	state         *cltypes.BeaconState
+	beaconConfig  *clparams.BeaconChainConfig
+	genesisConfig *clparams.GenesisConfig
+}
+
+func New(state *cltypes.BeaconState, beaconConfig *clparams.BeaconChainConfig, genesisConfig *clparams.GenesisConfig) *StateTransistor {
+	return &StateTransistor{
+		state:         state,
+		beaconConfig:  beaconConfig,
+		genesisConfig: genesisConfig,
+	}
+}