[sovereign] Save last notarized cross chain headers in epoch start data

data/block/sovereignChainHeader.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"math/big"
 
+	"github.com/multiversx/mx-chain-core-go/core"
 	"github.com/multiversx/mx-chain-core-go/core/check"
 	"github.com/multiversx/mx-chain-core-go/data"
 	"github.com/multiversx/mx-chain-core-go/data/headerVersionData"
@@ -631,18 +632,40 @@ func (sch *SovereignChainHeader) SetAccumulatedFeesInEpoch(value *big.Int) error
 	return nil
 }
 
-// GetEpochStartHandler returns epoch start header handler as for metachain, but without last finalized headers
+// GetEpochStartHandler returns epoch start header handler as for metachain, but with last finalized headers from main chain, if found.
 func (sch *SovereignChainHeader) GetEpochStartHandler() data.EpochStartHandler {
 	if sch == nil {
 		return nil
 	}
 
+	lastFinalizedCrossChainHeaderData := EpochStartShardData{
+		ShardID:    sch.EpochStart.LastFinalizedCrossChainHeader.ShardID,
+		Epoch:      sch.EpochStart.LastFinalizedCrossChainHeader.Epoch,
+		Round:      sch.EpochStart.LastFinalizedCrossChainHeader.Round,
+		Nonce:      sch.EpochStart.LastFinalizedCrossChainHeader.Nonce,
+		HeaderHash: sch.EpochStart.LastFinalizedCrossChainHeader.HeaderHash,
+	}
+
+	epochStartShardData := make([]EpochStartShardData, 0)
+	if lastFinalizedCrossChainHeaderData.ShardID == core.MainChainShardId {
+		epochStartShardData = append(epochStartShardData, lastFinalizedCrossChainHeaderData)
+	}
+
 	return &EpochStart{
-		LastFinalizedHeaders: make([]EpochStartShardData, 0),
+		LastFinalizedHeaders: epochStartShardData,
 		Economics:            sch.EpochStart.Economics,
 	}
 }
 
+// GetLastFinalizedCrossChainHeaderHandler returns the last finalized cross chain header data
+func (sch *SovereignChainHeader) GetLastFinalizedCrossChainHeaderHandler() data.EpochStartChainDataHandler {
+	if sch == nil {
+		return nil
+	}
+
+	return &sch.EpochStart.LastFinalizedCrossChainHeader
+}
+
 // GetShardInfoHandlers returns empty slice
 func (sch *SovereignChainHeader) GetShardInfoHandlers() []data.ShardDataHandler {
 	if sch == nil {
@@ -705,3 +728,58 @@ func (omb *OutGoingMiniBlockHeader) SetAggregatedSignatureOutGoingOperations(sig
 func (omb *OutGoingMiniBlockHeader) IsInterfaceNil() bool {
 	return omb == nil
 }
+
+// SetShardID sets the epoch start shardID
+func (essd *EpochStartCrossChainData) SetShardID(shardID uint32) error {
+	if essd == nil {
+		return data.ErrNilPointerReceiver
+	}
+
+	essd.ShardID = shardID
+
+	return nil
+}
+
+// SetEpoch sets the epoch start epoch
+func (essd *EpochStartCrossChainData) SetEpoch(epoch uint32) error {
+	if essd == nil {
+		return data.ErrNilPointerReceiver
+	}
+
+	essd.Epoch = epoch
+
+	return nil
+}
+
+// SetRound sets the epoch start round
+func (essd *EpochStartCrossChainData) SetRound(round uint64) error {
+	if essd == nil {
+		return data.ErrNilPointerReceiver
+	}
+
+	essd.Round = round
+
+	return nil
+}
+
+// SetNonce sets the epoch start nonce
+func (essd *EpochStartCrossChainData) SetNonce(nonce uint64) error {
+	if essd == nil {
+		return data.ErrNilPointerReceiver
+	}
+
+	essd.Nonce = nonce
+
+	return nil
+}
+
+// SetHeaderHash sets the epoch start header hash
+func (essd *EpochStartCrossChainData) SetHeaderHash(hash []byte) error {
+	if essd == nil {
+		return data.ErrNilPointerReceiver
+	}
+
+	essd.HeaderHash = hash
+
+	return nil
+}