interface.go

package process

import (
	"math/big"
	"time"

	"github.com/ElrondNetwork/elrond-go/core"
	"github.com/ElrondNetwork/elrond-go/data"
	"github.com/ElrondNetwork/elrond-go/data/block"
	"github.com/ElrondNetwork/elrond-go/data/rewardTx"
	"github.com/ElrondNetwork/elrond-go/data/smartContractResult"
	"github.com/ElrondNetwork/elrond-go/data/state"
	"github.com/ElrondNetwork/elrond-go/data/transaction"
	"github.com/ElrondNetwork/elrond-go/epochStart"
	"github.com/ElrondNetwork/elrond-go/p2p"
	"github.com/ElrondNetwork/elrond-go/process/block/bootstrapStorage"
	"github.com/ElrondNetwork/elrond-go/process/block/processedMb"
	"github.com/ElrondNetwork/elrond-go/sharding"
	"github.com/ElrondNetwork/elrond-go/storage"
	"github.com/ElrondNetwork/elrond-vm-common"
	"github.com/ElrondNetwork/elrond-vm-common/parsers"
)

// TransactionProcessor is the main interface for transaction execution engine
type TransactionProcessor interface {
	ProcessTransaction(transaction *transaction.Transaction) (vmcommon.ReturnCode, error)
	IsInterfaceNil() bool
}

// RewardTransactionProcessor is the interface for reward transaction execution engine
type RewardTransactionProcessor interface {
	ProcessRewardTransaction(rewardTx *rewardTx.RewardTx) error
	IsInterfaceNil() bool
}

// RewardTransactionPreProcessor prepares the processing of reward transactions
type RewardTransactionPreProcessor interface {
	AddComputedRewardMiniBlocks(computedRewardMiniblocks block.MiniBlockSlice)
	IsInterfaceNil() bool
}

// SmartContractResultProcessor is the main interface for smart contract result execution engine
type SmartContractResultProcessor interface {
	ProcessSmartContractResult(scr *smartContractResult.SmartContractResult) (vmcommon.ReturnCode, error)
	IsInterfaceNil() bool
}

// TxTypeHandler is an interface to calculate the transaction type
type TxTypeHandler interface {
	ComputeTransactionType(tx data.TransactionHandler) TransactionType
	IsInterfaceNil() bool
}

// TxValidator can determine if a provided transaction handler is valid or not from the process point of view
type TxValidator interface {
	CheckTxValidity(txHandler TxValidatorHandler) error
	CheckTxWhiteList(data InterceptedData) error
	IsInterfaceNil() bool
}

// TxValidatorHandler defines the functionality that is needed for a TxValidator to validate a transaction
type TxValidatorHandler interface {
	SenderShardId() uint32
	ReceiverShardId() uint32
	Nonce() uint64
	SenderAddress() []byte
	Fee() *big.Int
}

// HdrValidatorHandler defines the functionality that is needed for a HdrValidator to validate a header
type HdrValidatorHandler interface {
	Hash() []byte
	HeaderHandler() data.HeaderHandler
}

// HeaderValidator can determine if a provided header handler is valid or not from the process point of view
type HeaderValidator interface {
	HeaderValidForProcessing(headerHandler HdrValidatorHandler) error
	IsInterfaceNil() bool
}

// InterceptedDataFactory can create new instances of InterceptedData
type InterceptedDataFactory interface {
	Create(buff []byte) (InterceptedData, error)
	IsInterfaceNil() bool
}

// InterceptedData represents the interceptor's view of the received data
type InterceptedData interface {
	CheckValidity() error
	IsForCurrentShard() bool
	IsInterfaceNil() bool
	Hash() []byte
	Type() string
	Identifiers() [][]byte
	String() string
}

// InterceptorProcessor further validates and saves received data
type InterceptorProcessor interface {
	Validate(data InterceptedData, fromConnectedPeer core.PeerID) error
	Save(data InterceptedData, fromConnectedPeer core.PeerID, topic string) error
	RegisterHandler(handler func(topic string, hash []byte, data interface{}))
	IsInterfaceNil() bool
}

// InterceptorThrottler can monitor the number of the currently running interceptor go routines
type InterceptorThrottler interface {
	CanProcess() bool
	StartProcessing()
	EndProcessing()
	IsInterfaceNil() bool
}

// TransactionCoordinator is an interface to coordinate transaction processing using multiple processors
type TransactionCoordinator interface {
	RequestMiniBlocks(header data.HeaderHandler)
	RequestBlockTransactions(body *block.Body)
	IsDataPreparedForProcessing(haveTime func() time.Duration) error

	SaveBlockDataToStorage(body *block.Body) error
	RestoreBlockDataFromStorage(body *block.Body) (int, error)
	RemoveBlockDataFromPool(body *block.Body) error

	ProcessBlockTransaction(body *block.Body, haveTime func() time.Duration) error

	CreateBlockStarted()
	CreateMbsAndProcessCrossShardTransactionsDstMe(
		header data.HeaderHandler,
		processedMiniBlocksHashes map[string]struct{},

		haveTime func() bool,
	) (block.MiniBlockSlice, uint32, bool, error)
	CreateMbsAndProcessTransactionsFromMe(haveTime func() bool) block.MiniBlockSlice
	CreatePostProcessMiniBlocks() block.MiniBlockSlice
	CreateMarshalizedData(body *block.Body) map[string][][]byte
	GetAllCurrentUsedTxs(blockType block.Type) map[string]data.TransactionHandler

	CreateReceiptsHash() ([]byte, error)
	VerifyCreatedBlockTransactions(hdr data.HeaderHandler, body *block.Body) error
	IsInterfaceNil() bool
}

// SmartContractProcessor is the main interface for the smart contract caller engine
type SmartContractProcessor interface {
	ExecuteSmartContractTransaction(tx data.TransactionHandler, acntSrc, acntDst state.UserAccountHandler) (vmcommon.ReturnCode, error)
	DeploySmartContract(tx data.TransactionHandler, acntSrc state.UserAccountHandler) (vmcommon.ReturnCode, error)
	ProcessIfError(acntSnd state.UserAccountHandler, txHash []byte, tx data.TransactionHandler, returnCode string, returnMessage []byte, snapshot int) error
	IsPayable(address []byte) (bool, error)
	IsInterfaceNil() bool
}

// IntermediateTransactionHandler handles transactions which are not resolved in only one step
type IntermediateTransactionHandler interface {
	AddIntermediateTransactions(txs []data.TransactionHandler) error
	CreateAllInterMiniBlocks() []*block.MiniBlock
	VerifyInterMiniBlocks(body *block.Body) error
	SaveCurrentIntermediateTxToStorage() error
	GetAllCurrentFinishedTxs() map[string]data.TransactionHandler
	CreateBlockStarted()
	GetCreatedInShardMiniBlock() *block.MiniBlock
	RemoveProcessedResultsFor(txHashes [][]byte)
	IsInterfaceNil() bool
}

// DataMarshalizer defines the behavior of a structure that is able to marshalize containing data
type DataMarshalizer interface {
	CreateMarshalizedData(txHashes [][]byte) ([][]byte, error)
}

// TransactionVerifier interface validates if the transaction is good and if it should be processed
type TransactionVerifier interface {
	IsTransactionValid(tx data.TransactionHandler) error
}

// TransactionFeeHandler processes the transaction fee
type TransactionFeeHandler interface {
	CreateBlockStarted()
	GetAccumulatedFees() *big.Int
	GetDeveloperFees() *big.Int
	ProcessTransactionFee(cost *big.Int, devFee *big.Int, txHash []byte)
	RevertFees(txHashes [][]byte)
	IsInterfaceNil() bool
}

// PreProcessor is an interface used to prepare and process transaction data
type PreProcessor interface {
	CreateBlockStarted()
	IsDataPrepared(requestedTxs int, haveTime func() time.Duration) error

	RemoveTxBlockFromPools(body *block.Body, miniBlockPool storage.Cacher) error
	RestoreTxBlockIntoPools(body *block.Body, miniBlockPool storage.Cacher) (int, error)
	SaveTxBlockToStorage(body *block.Body) error

	ProcessBlockTransactions(body *block.Body, haveTime func() bool) error
	RequestBlockTransactions(body *block.Body) int

	RequestTransactionsForMiniBlock(miniBlock *block.MiniBlock) int
	ProcessMiniBlock(miniBlock *block.MiniBlock, haveTime func() bool) ([][]byte, error)
	CreateAndProcessMiniBlocks(haveTime func() bool) (block.MiniBlockSlice, error)

	GetAllCurrentUsedTxs() map[string]data.TransactionHandler
	IsInterfaceNil() bool
}

// BlockProcessor is the main interface for block execution engine
type BlockProcessor interface {
	ProcessBlock(header data.HeaderHandler, body data.BodyHandler, haveTime func() time.Duration) error
	CommitBlock(header data.HeaderHandler, body data.BodyHandler) error
	RevertAccountState(header data.HeaderHandler)
	PruneStateOnRollback(currHeader data.HeaderHandler, prevHeader data.HeaderHandler)
	RevertStateToBlock(header data.HeaderHandler) error
	CreateNewHeader(round uint64, nonce uint64) data.HeaderHandler
	RestoreBlockIntoPools(header data.HeaderHandler, body data.BodyHandler) error
	CreateBlock(initialHdr data.HeaderHandler, haveTime func() bool) (data.HeaderHandler, data.BodyHandler, error)
	ApplyProcessedMiniBlocks(processedMiniBlocks *processedMb.ProcessedMiniBlockTracker)
	MarshalizedDataToBroadcast(header data.HeaderHandler, body data.BodyHandler) (map[uint32][]byte, map[string][][]byte, error)
	DecodeBlockBody(dta []byte) data.BodyHandler
	DecodeBlockHeader(dta []byte) data.HeaderHandler
	SetNumProcessedObj(numObj uint64)
	IsInterfaceNil() bool
}

// ValidatorStatisticsProcessor is the main interface for validators' consensus participation statistics
type ValidatorStatisticsProcessor interface {
	UpdatePeerState(header data.HeaderHandler, cache map[string]data.HeaderHandler) ([]byte, error)
	RevertPeerState(header data.HeaderHandler) error
	GetPeerAccount(address []byte) (state.PeerAccountHandler, error)
	Process(shardValidatorInfo data.ShardValidatorInfoHandler) error
	IsInterfaceNil() bool
	RootHash() ([]byte, error)
	ResetValidatorStatisticsAtNewEpoch(vInfos map[uint32][]*state.ValidatorInfo) error
	GetValidatorInfoForRootHash(rootHash []byte) (map[uint32][]*state.ValidatorInfo, error)
	ProcessRatingsEndOfEpoch(validatorInfos map[uint32][]*state.ValidatorInfo, epoch uint32) error
	Commit() ([]byte, error)
	DisplayRatings(epoch uint32)
	SetLastFinalizedRootHash([]byte)
	LastFinalizedRootHash() []byte
}

// TransactionLogProcessor is the main interface for saving logs generated by smart contract calls
type TransactionLogProcessor interface {
	GetLog(txHash []byte) (data.LogHandler, error)
	SaveLog(txHash []byte, tx data.TransactionHandler, vmLogs []*vmcommon.LogEntry) error
	IsInterfaceNil() bool
}

// TransactionLogProcessorDatabase is interface the  for saving logs also in RAM
type TransactionLogProcessorDatabase interface {
	GetLogFromCache(txHash []byte) (data.LogHandler, bool)
	EnableLogToBeSavedInCache()
	Clean()
	IsInterfaceNil() bool
}

// ValidatorsProvider is the main interface for validators' provider
type ValidatorsProvider interface {
	GetLatestValidators() map[string]*state.ValidatorApiResponse
	IsInterfaceNil() bool
}

// Checker provides functionality to checks the integrity and validity of a data structure
type Checker interface {
	// IntegrityAndValidity does both validity and integrity checks on the data structure
	IntegrityAndValidity(coordinator sharding.Coordinator) error
	// Integrity checks only the integrity of the data
	Integrity(coordinator sharding.Coordinator) error
	// IsInterfaceNil returns true if there is no value under the interface
	IsInterfaceNil() bool
}

// HeaderConstructionValidator provides functionality to verify header construction
type HeaderConstructionValidator interface {
	IsHeaderConstructionValid(currHdr, prevHdr data.HeaderHandler) error
	IsInterfaceNil() bool
}

// SigVerifier provides functionality to verify a signature of a signed data structure that holds also the verifying parameters
type SigVerifier interface {
	VerifySig() error
}

// SignedDataValidator provides functionality to check the validity and signature of a data structure
type SignedDataValidator interface {
	SigVerifier
	Checker
}

// HashAccesser interface provides functionality over hashable objects
type HashAccesser interface {
	SetHash([]byte)
	Hash() []byte
}

// Bootstrapper is an interface that defines the behaviour of a struct that is able
// to synchronize the node
type Bootstrapper interface {
	Close() error
	AddSyncStateListener(func(isSyncing bool))
	GetNodeState() core.NodeState
	StartSyncingBlocks()
	SetStatusHandler(handler core.AppStatusHandler) error
	IsInterfaceNil() bool
}

// ForkDetector is an interface that defines the behaviour of a struct that is able
// to detect forks
type ForkDetector interface {
	AddHeader(header data.HeaderHandler, headerHash []byte, state BlockHeaderState, selfNotarizedHeaders []data.HeaderHandler, selfNotarizedHeadersHashes [][]byte) error
	RemoveHeader(nonce uint64, hash []byte)
	CheckFork() *ForkInfo
	GetHighestFinalBlockNonce() uint64
	GetHighestFinalBlockHash() []byte
	ProbableHighestNonce() uint64
	ResetFork()
	SetRollBackNonce(nonce uint64)
	RestoreToGenesis()
	GetNotarizedHeaderHash(nonce uint64) []byte
	ResetProbableHighestNonce()
	IsInterfaceNil() bool
}

// InterceptorsContainer defines an interceptors holder data type with basic functionality
type InterceptorsContainer interface {
	Get(key string) (Interceptor, error)
	Add(key string, val Interceptor) error
	AddMultiple(keys []string, interceptors []Interceptor) error
	Replace(key string, val Interceptor) error
	Remove(key string)
	Len() int
	Iterate(handler func(key string, interceptor Interceptor) bool)
	IsInterfaceNil() bool
}

// InterceptorsContainerFactory defines the functionality to create an interceptors container
type InterceptorsContainerFactory interface {
	Create() (InterceptorsContainer, error)
	IsInterfaceNil() bool
}

// PreProcessorsContainer defines an PreProcessors holder data type with basic functionality
type PreProcessorsContainer interface {
	Get(key block.Type) (PreProcessor, error)
	Add(key block.Type, val PreProcessor) error
	AddMultiple(keys []block.Type, preprocessors []PreProcessor) error
	Replace(key block.Type, val PreProcessor) error
	Remove(key block.Type)
	Len() int
	Keys() []block.Type
	IsInterfaceNil() bool
}

// PreProcessorsContainerFactory defines the functionality to create an PreProcessors container
type PreProcessorsContainerFactory interface {
	Create() (PreProcessorsContainer, error)
	IsInterfaceNil() bool
}

// IntermediateProcessorContainer defines an IntermediateProcessor holder data type with basic functionality
type IntermediateProcessorContainer interface {
	Get(key block.Type) (IntermediateTransactionHandler, error)
	Add(key block.Type, val IntermediateTransactionHandler) error
	AddMultiple(keys []block.Type, preprocessors []IntermediateTransactionHandler) error
	Replace(key block.Type, val IntermediateTransactionHandler) error
	Remove(key block.Type)
	Len() int
	Keys() []block.Type
	IsInterfaceNil() bool
}

// IntermediateProcessorsContainerFactory defines the functionality to create an IntermediateProcessors container
type IntermediateProcessorsContainerFactory interface {
	Create() (IntermediateProcessorContainer, error)
	IsInterfaceNil() bool
}

// VirtualMachinesContainer defines a virtual machine holder data type with basic functionality
type VirtualMachinesContainer interface {
	Close() error
	Get(key []byte) (vmcommon.VMExecutionHandler, error)
	Add(key []byte, val vmcommon.VMExecutionHandler) error
	AddMultiple(keys [][]byte, vms []vmcommon.VMExecutionHandler) error
	Replace(key []byte, val vmcommon.VMExecutionHandler) error
	Remove(key []byte)
	Len() int
	Keys() [][]byte
	IsInterfaceNil() bool
}

// VirtualMachinesContainerFactory defines the functionality to create a virtual machine container
type VirtualMachinesContainerFactory interface {
	Create() (VirtualMachinesContainer, error)
	BlockChainHookImpl() BlockChainHookHandler
	IsInterfaceNil() bool
}

// EpochStartTriggerHandler defines that actions which are needed by processor for start of epoch
type EpochStartTriggerHandler interface {
	Update(round uint64, nonce uint64)
	IsEpochStart() bool
	Epoch() uint32
	MetaEpoch() uint32
	EpochStartRound() uint64
	SetProcessed(header data.HeaderHandler, body data.BodyHandler)
	RevertStateToBlock(header data.HeaderHandler) error
	EpochStartMetaHdrHash() []byte
	GetSavedStateKey() []byte
	LoadState(key []byte) error
	IsInterfaceNil() bool
	SetFinalityAttestingRound(round uint64)
	EpochFinalityAttestingRound() uint64
	RequestEpochStartIfNeeded(interceptedHeader data.HeaderHandler)
}

// EpochBootstrapper defines the actions needed by bootstrapper
type EpochBootstrapper interface {
	SetCurrentEpochStartRound(round uint64)
	IsInterfaceNil() bool
}

// PendingMiniBlocksHandler is an interface to keep unfinalized miniblocks
type PendingMiniBlocksHandler interface {
	AddProcessedHeader(handler data.HeaderHandler) error
	RevertHeader(handler data.HeaderHandler) error
	GetPendingMiniBlocks(shardID uint32) [][]byte
	SetPendingMiniBlocks(shardID uint32, mbHashes [][]byte)
	IsInterfaceNil() bool
}

// BlockChainHookHandler defines the actions which should be performed by implementation
type BlockChainHookHandler interface {
	IsPayable(address []byte) (bool, error)
	SetCurrentHeader(hdr data.HeaderHandler)
	GetBuiltInFunctions() BuiltInFunctionContainer
	NewAddress(creatorAddress []byte, creatorNonce uint64, vmType []byte) ([]byte, error)
	IsInterfaceNil() bool
}

// Interceptor defines what a data interceptor should do
// It should also adhere to the p2p.MessageProcessor interface so it can wire to a p2p.Messenger
type Interceptor interface {
	ProcessReceivedMessage(message p2p.MessageP2P, fromConnectedPeer core.PeerID) error
	SetInterceptedDebugHandler(handler InterceptedDebugger) error
	RegisterHandler(handler func(topic string, hash []byte, data interface{}))
	IsInterfaceNil() bool
}

// TopicHandler defines the functionality needed by structs to manage topics and message processors
type TopicHandler interface {
	HasTopic(name string) bool
	CreateTopic(name string, createChannelForTopic bool) error
	RegisterMessageProcessor(topic string, handler p2p.MessageProcessor) error
	IsInterfaceNil() bool
}

// DataPacker can split a large slice of byte slices in smaller packets
type DataPacker interface {
	PackDataInChunks(data [][]byte, limit int) ([][]byte, error)
	IsInterfaceNil() bool
}

// RequestHandler defines the methods through which request to data can be made
type RequestHandler interface {
	SetEpoch(epoch uint32)
	RequestShardHeader(shardID uint32, hash []byte)
	RequestMetaHeader(hash []byte)
	RequestMetaHeaderByNonce(nonce uint64)
	RequestShardHeaderByNonce(shardID uint32, nonce uint64)
	RequestTransaction(destShardID uint32, txHashes [][]byte)
	RequestUnsignedTransactions(destShardID uint32, scrHashes [][]byte)
	RequestRewardTransactions(destShardID uint32, txHashes [][]byte)
	RequestMiniBlock(destShardID uint32, miniblockHash []byte)
	RequestMiniBlocks(destShardID uint32, miniblocksHashes [][]byte)
	RequestTrieNodes(destShardID uint32, hashes [][]byte, topic string)
	RequestStartOfEpochMetaBlock(epoch uint32)
	RequestInterval() time.Duration
	SetNumPeersToQuery(key string, intra int, cross int) error
	GetNumPeersToQuery(key string) (int, int, error)
	IsInterfaceNil() bool
}

// CallArgumentsParser defines the functionality to parse transaction data into call arguments
type CallArgumentsParser interface {
	ParseData(data string) (string, [][]byte, error)
	IsInterfaceNil() bool
}

// DeployArgumentsParser defines the functionality to parse transaction data into call arguments
type DeployArgumentsParser interface {
	ParseData(data string) (*parsers.DeployArgs, error)
	IsInterfaceNil() bool
}

// StorageArgumentsParser defines the functionality to parse transaction data into call arguments
type StorageArgumentsParser interface {
	CreateDataFromStorageUpdate(storageUpdates []*vmcommon.StorageUpdate) string
	GetStorageUpdates(data string) ([]*vmcommon.StorageUpdate, error)
	IsInterfaceNil() bool
}

// ArgumentsParser defines the functionality to parse transaction data into arguments and code for smart contracts
type ArgumentsParser interface {
	ParseCallData(data string) (string, [][]byte, error)
	ParseDeployData(data string) (*parsers.DeployArgs, error)

	CreateDataFromStorageUpdate(storageUpdates []*vmcommon.StorageUpdate) string
	GetStorageUpdates(data string) ([]*vmcommon.StorageUpdate, error)
	IsInterfaceNil() bool
}

// BlockSizeThrottler defines the functionality of adapting the node to the network speed/latency when it should send a
// block to its peers which should be received in a limited time frame
type BlockSizeThrottler interface {
	GetCurrentMaxSize() uint32
	Add(round uint64, size uint32)
	Succeed(round uint64)
	ComputeCurrentMaxSize()
	IsInterfaceNil() bool
}

// RewardsHandler will return information about rewards
type RewardsHandler interface {
	LeaderPercentage() float64
	ProtocolSustainabilityPercentage() float64
	ProtocolSustainabilityAddress() string
	MinInflationRate() float64
	MaxInflationRate(year uint32) float64
	IsInterfaceNil() bool
}

// EndOfEpochEconomics defines the functionality that is needed to compute end of epoch economics data
type EndOfEpochEconomics interface {
	ComputeEndOfEpochEconomics(metaBlock *block.MetaBlock) (*block.Economics, error)
	VerifyRewardsPerBlock(metaBlock *block.MetaBlock, correctedProtocolSustainability *big.Int) error
	IsInterfaceNil() bool
}

// FeeHandler is able to perform some economics calculation on a provided transaction
type FeeHandler interface {
	DeveloperPercentage() float64
	MaxGasLimitPerBlock(shardID uint32) uint64
	ComputeGasLimit(tx TransactionWithFeeHandler) uint64
	ComputeFee(tx TransactionWithFeeHandler) *big.Int
	CheckValidityTxValues(tx TransactionWithFeeHandler) error
	MinGasPrice() uint64
	IsInterfaceNil() bool
}

// TransactionWithFeeHandler represents a transaction structure that has economics variables defined
type TransactionWithFeeHandler interface {
	GetGasLimit() uint64
	GetGasPrice() uint64
	GetData() []byte
	GetRcvAddr() []byte
	GetValue() *big.Int
}

// SmartContractToProtocolHandler is able to translate data from smart contract state into protocol changes
type SmartContractToProtocolHandler interface {
	UpdateProtocol(body *block.Body, nonce uint64) error
	IsInterfaceNil() bool
}

// PeerChangesHandler will create the peer changes data for current block and will verify them
type PeerChangesHandler interface {
	PeerChanges() []block.PeerData
	VerifyPeerChanges(peerChanges []block.PeerData) error
	IsInterfaceNil() bool
}

// TimeCacher defines the cache that can keep a record for a bounded time
type TimeCacher interface {
	Add(key string) error
	Upsert(key string, span time.Duration) error
	Has(key string) bool
	Sweep()
	IsInterfaceNil() bool
}

// PeerBlackListCacher can determine if a certain peer id is or not blacklisted
type PeerBlackListCacher interface {
	Upsert(pid core.PeerID, span time.Duration) error
	Has(pid core.PeerID) bool
	Sweep()
	IsInterfaceNil() bool
}

// PeerShardMapper can return the public key of a provided peer ID
type PeerShardMapper interface {
	GetPeerInfo(pid core.PeerID) core.P2PPeerInfo
	IsInterfaceNil() bool
}

// NetworkConnectionWatcher defines a watchdog functionality used to specify if the current node
// is still connected to the rest of the network
type NetworkConnectionWatcher interface {
	IsConnectedToTheNetwork() bool
	IsInterfaceNil() bool
}

// SCQuery represents a prepared query for executing a function of the smart contract
type SCQuery struct {
	ScAddress []byte
	FuncName  string
	Arguments [][]byte
}

// GasHandler is able to perform some gas calculation
type GasHandler interface {
	Init()
	SetGasConsumed(gasConsumed uint64, hash []byte)
	SetGasRefunded(gasRefunded uint64, hash []byte)
	GasConsumed(hash []byte) uint64
	GasRefunded(hash []byte) uint64
	TotalGasConsumed() uint64
	TotalGasRefunded() uint64
	RemoveGasConsumed(hashes [][]byte)
	RemoveGasRefunded(hashes [][]byte)
	ComputeGasConsumedByMiniBlock(*block.MiniBlock, map[string]data.TransactionHandler) (uint64, uint64, error)
	ComputeGasConsumedByTx(txSenderShardId uint32, txReceiverShardId uint32, txHandler data.TransactionHandler) (uint64, uint64, error)
	IsInterfaceNil() bool
}

// BootStorer is the interface needed by bootstrapper to read/write data in storage
type BootStorer interface {
	SaveLastRound(round int64) error
	Put(round int64, bootData bootstrapStorage.BootstrapData) error
	Get(round int64) (bootstrapStorage.BootstrapData, error)
	GetHighestRound() int64
	IsInterfaceNil() bool
}

// BootstrapperFromStorage is the interface needed by boot component to load data from storage
type BootstrapperFromStorage interface {
	LoadFromStorage() error
	GetHighestBlockNonce() uint64
	IsInterfaceNil() bool
}

// RequestBlockBodyHandler is the interface needed by process block
type RequestBlockBodyHandler interface {
	GetBlockBodyFromPool(headerHandler data.HeaderHandler) (data.BodyHandler, error)
}

// InterceptedHeaderSigVerifier is the interface needed at interceptors level to check that a header's signature is correct
type InterceptedHeaderSigVerifier interface {
	VerifyRandSeedAndLeaderSignature(header data.HeaderHandler) error
	VerifySignature(header data.HeaderHandler) error
	IsInterfaceNil() bool
}

// InterceptedHeaderIntegrityVerifier is the interface needed at interceptors level to check that a header's integrity
// is correct
type InterceptedHeaderIntegrityVerifier interface {
	Verify(header data.HeaderHandler) error
	IsInterfaceNil() bool
}

// BlockTracker defines the functionality for node to track the blocks which are received from network
type BlockTracker interface {
	AddCrossNotarizedHeader(shradID uint32, crossNotarizedHeader data.HeaderHandler, crossNotarizedHeaderHash []byte)
	AddSelfNotarizedHeader(shardID uint32, selfNotarizedHeader data.HeaderHandler, selfNotarizedHeaderHash []byte)
	AddTrackedHeader(header data.HeaderHandler, hash []byte)
	CheckBlockAgainstFinal(headerHandler data.HeaderHandler) error
	CheckBlockAgainstRounder(headerHandler data.HeaderHandler) error
	CheckBlockAgainstWhitelist(interceptedData InterceptedData) bool
	CleanupHeadersBehindNonce(shardID uint32, selfNotarizedNonce uint64, crossNotarizedNonce uint64)
	CleanupInvalidCrossHeaders(metaNewEpoch uint32, metaRoundAttestingEpoch uint64)
	ComputeLongestChain(shardID uint32, header data.HeaderHandler) ([]data.HeaderHandler, [][]byte)
	ComputeLongestMetaChainFromLastNotarized() ([]data.HeaderHandler, [][]byte, error)
	ComputeLongestShardsChainsFromLastNotarized() ([]data.HeaderHandler, [][]byte, map[uint32][]data.HeaderHandler, error)
	DisplayTrackedHeaders()
	GetCrossNotarizedHeader(shardID uint32, offset uint64) (data.HeaderHandler, []byte, error)
	GetLastCrossNotarizedHeader(shardID uint32) (data.HeaderHandler, []byte, error)
	GetLastCrossNotarizedHeadersForAllShards() (map[uint32]data.HeaderHandler, error)
	GetLastSelfNotarizedHeader(shardID uint32) (data.HeaderHandler, []byte, error)
	GetSelfNotarizedHeader(shardID uint32, offset uint64) (data.HeaderHandler, []byte, error)
	GetTrackedHeaders(shardID uint32) ([]data.HeaderHandler, [][]byte)
	GetTrackedHeadersForAllShards() map[uint32][]data.HeaderHandler
	GetTrackedHeadersWithNonce(shardID uint32, nonce uint64) ([]data.HeaderHandler, [][]byte)
	IsShardStuck(shardID uint32) bool
	RegisterCrossNotarizedHeadersHandler(func(shardID uint32, headers []data.HeaderHandler, headersHashes [][]byte))
	RegisterSelfNotarizedHeadersHandler(func(shardID uint32, headers []data.HeaderHandler, headersHashes [][]byte))
	RemoveLastNotarizedHeaders()
	RestoreToGenesis()
	ShouldAddHeader(headerHandler data.HeaderHandler) bool
	IsInterfaceNil() bool
}

// FloodPreventer defines the behavior of a component that is able to signal that too many events occurred
// on a provided identifier between Reset calls
type FloodPreventer interface {
	IncreaseLoad(pid core.PeerID, size uint64) error
	ApplyConsensusSize(size int)
	Reset()
	IsInterfaceNil() bool
}

// TopicFloodPreventer defines the behavior of a component that is able to signal that too many events occurred
// on a provided identifier between Reset calls, on a given topic
type TopicFloodPreventer interface {
	IncreaseLoad(pid core.PeerID, topic string, numMessages uint32) error
	ResetForTopic(topic string)
	ResetForNotRegisteredTopics()
	SetMaxMessagesForTopic(topic string, maxNum uint32)
	IsInterfaceNil() bool
}

// P2PAntifloodHandler defines the behavior of a component able to signal that the system is too busy (or flooded) processing
// p2p messages
type P2PAntifloodHandler interface {
	CanProcessMessage(message p2p.MessageP2P, fromConnectedPeer core.PeerID) error
	CanProcessMessagesOnTopic(pid core.PeerID, topic string, numMessages uint32, totalSize uint64, sequence []byte) error
	ApplyConsensusSize(size int)
	SetDebugger(debugger AntifloodDebugger) error
	BlacklistPeer(peer core.PeerID, reason string, duration time.Duration)
	IsOriginatorEligibleForTopic(pid core.PeerID, topic string) error
	IsInterfaceNil() bool
}

// PeerValidatorMapper can determine the peer info from a peer id
type PeerValidatorMapper interface {
	GetPeerInfo(pid core.PeerID) core.P2PPeerInfo
	IsInterfaceNil() bool
}

// SCQueryService defines how data should be get from a SC account
type SCQueryService interface {
	ExecuteQuery(query *SCQuery) (*vmcommon.VMOutput, error)
	IsInterfaceNil() bool
}

// EpochStartDataCreator defines the functionality for node to create epoch start data
type EpochStartDataCreator interface {
	CreateEpochStartData() (*block.EpochStart, error)
	VerifyEpochStartDataForMetablock(metaBlock *block.MetaBlock) error
	IsInterfaceNil() bool
}

// EpochStartRewardsCreator defines the functionality for the metachain to create rewards at end of epoch
type EpochStartRewardsCreator interface {
	CreateRewardsMiniBlocks(metaBlock *block.MetaBlock, validatorsInfo map[uint32][]*state.ValidatorInfo) (block.MiniBlockSlice, error)
	VerifyRewardsMiniBlocks(metaBlock *block.MetaBlock, validatorsInfo map[uint32][]*state.ValidatorInfo) error
	GetProtocolSustainabilityRewards() *big.Int
	CreateMarshalizedData(body *block.Body) map[string][][]byte
	GetRewardsTxs(body *block.Body) map[string]data.TransactionHandler
	SaveTxBlockToStorage(metaBlock *block.MetaBlock, body *block.Body)
	DeleteTxsFromStorage(metaBlock *block.MetaBlock, body *block.Body)
	RemoveBlockDataFromPools(metaBlock *block.MetaBlock, body *block.Body)
	IsInterfaceNil() bool
}

// EpochStartValidatorInfoCreator defines the functionality for the metachain to create validator statistics at end of epoch
type EpochStartValidatorInfoCreator interface {
	CreateValidatorInfoMiniBlocks(validatorInfo map[uint32][]*state.ValidatorInfo) (block.MiniBlockSlice, error)
	VerifyValidatorInfoMiniBlocks(miniblocks []*block.MiniBlock, validatorsInfo map[uint32][]*state.ValidatorInfo) error
	SaveValidatorInfoBlocksToStorage(metaBlock *block.MetaBlock, body *block.Body)
	DeleteValidatorInfoBlocksFromStorage(metaBlock *block.MetaBlock)
	RemoveBlockDataFromPools(metaBlock *block.MetaBlock, body *block.Body)
	IsInterfaceNil() bool
}

// ValidityAttester is able to manage the valid blocks
type ValidityAttester interface {
	CheckBlockAgainstFinal(headerHandler data.HeaderHandler) error
	CheckBlockAgainstRounder(headerHandler data.HeaderHandler) error
	CheckBlockAgainstWhitelist(interceptedData InterceptedData) bool
	IsInterfaceNil() bool
}

// MiniBlockProvider defines what a miniblock data provider should do
type MiniBlockProvider interface {
	GetMiniBlocks(hashes [][]byte) ([]*MiniblockAndHash, [][]byte)
	GetMiniBlocksFromPool(hashes [][]byte) ([]*MiniblockAndHash, [][]byte)
	IsInterfaceNil() bool
}

// BuiltinFunction defines the methods for the built-in protocol smart contract functions
type BuiltinFunction interface {
	ProcessBuiltinFunction(acntSnd, acntDst state.UserAccountHandler, vmInput *vmcommon.ContractCallInput) (*vmcommon.VMOutput, error)
	IsInterfaceNil() bool
}

// BuiltInFunctionContainer defines the methods for the built-in protocol container
type BuiltInFunctionContainer interface {
	Get(key string) (BuiltinFunction, error)
	Add(key string, function BuiltinFunction) error
	Replace(key string, function BuiltinFunction) error
	Remove(key string)
	Len() int
	Keys() map[string]struct{}
	IsInterfaceNil() bool
}

// RoundTimeDurationHandler defines the methods to get the time duration of a round
type RoundTimeDurationHandler interface {
	TimeDuration() time.Duration
	IsInterfaceNil() bool
}

// Rounder defines the actions which should be handled by a round implementation
type Rounder interface {
	Index() int64
	IsInterfaceNil() bool
}

// SelectionChance defines the actions which should be handled by a round implementation
type SelectionChance interface {
	GetMaxThreshold() uint32
	GetChancePercent() uint32
}

// RatingsInfoHandler defines the information needed for the rating computation
type RatingsInfoHandler interface {
	StartRating() uint32
	MaxRating() uint32
	MinRating() uint32
	SignedBlocksThreshold() float32
	MetaChainRatingsStepHandler() RatingsStepHandler
	ShardChainRatingsStepHandler() RatingsStepHandler
	SelectionChances() []SelectionChance
	IsInterfaceNil() bool
}

// RatingsStepHandler defines the information needed for the rating computation on shards or meta
type RatingsStepHandler interface {
	ProposerIncreaseRatingStep() int32
	ProposerDecreaseRatingStep() int32
	ValidatorIncreaseRatingStep() int32
	ValidatorDecreaseRatingStep() int32
	ConsecutiveMissedBlocksPenalty() float32
}

// ValidatorInfoSyncer defines the method needed for validatorInfoProcessing
type ValidatorInfoSyncer interface {
	SyncMiniBlocks(metaBlock *block.MetaBlock) ([][]byte, data.BodyHandler, error)
	IsInterfaceNil() bool
}

//RatingChanceHandler provides the methods needed for the computation of chances from the Rating
type RatingChanceHandler interface {
	//GetMaxThreshold returns the threshold until this ChancePercentage holds
	GetMaxThreshold() uint32
	//GetChancePercentage returns the percentage for the RatingChanceHandler
	GetChancePercentage() uint32
	//IsInterfaceNil verifies if the interface is nil
	IsInterfaceNil() bool
}

// WhiteListHandler is the interface needed to add whitelisted data
type WhiteListHandler interface {
	Remove(keys [][]byte)
	Add(keys [][]byte)
	IsWhiteListed(interceptedData InterceptedData) bool
	IsInterfaceNil() bool
}

// InterceptedDebugger defines an interface for debugging the intercepted data
type InterceptedDebugger interface {
	LogReceivedHashes(topic string, hashes [][]byte)
	LogProcessedHashes(topic string, hashes [][]byte, err error)
	IsInterfaceNil() bool
}

// AntifloodDebugger defines an interface for debugging the antiflood behavior
type AntifloodDebugger interface {
	AddData(pid core.PeerID, topic string, numRejected uint32, sizeRejected uint64, sequence []byte, isBlacklisted bool)
	Close() error
	IsInterfaceNil() bool
}

// MiniblockAndHash holds the info related to a miniblock and its hash
type MiniblockAndHash struct {
	Miniblock *block.MiniBlock
	Hash      []byte
}

// PoolsCleaner defines the functionality to clean pools for old records
type PoolsCleaner interface {
	Close() error
	StartCleaning()
	IsInterfaceNil() bool
}

// EpochHandler defines what a component which handles current epoch should be able to do
type EpochHandler interface {
	MetaEpoch() uint32
	IsInterfaceNil() bool
}

// EpochStartEventNotifier provides Register and Unregister functionality for the end of epoch events
type EpochStartEventNotifier interface {
	RegisterHandler(handler epochStart.ActionHandler)
	UnregisterHandler(handler epochStart.ActionHandler)
	IsInterfaceNil() bool
}

// NodesCoordinator provides Validator methods needed for the peer processing
type NodesCoordinator interface {
	GetAllEligibleValidatorsPublicKeys(epoch uint32) (map[uint32][][]byte, error)
	GetAllWaitingValidatorsPublicKeys(epoch uint32) (map[uint32][][]byte, error)
	GetAllLeavingValidatorsPublicKeys(epoch uint32) (map[uint32][][]byte, error)
	IsInterfaceNil() bool
}