core

type Backend interface {
	MessageConstructor
	Verifier

	// BuildProposal builds a new block proposal
	BuildProposal(blockNumber uint64) []byte

	// InsertBlock inserts a proposal with the specified committed seals
	InsertBlock(proposal []byte, committedSeals []*messages.CommittedSeal)

	// ID returns the validator's ID
	ID() []byte

	// MaximumFaultyNodes returns the maximum number of faulty nodes based
	// on the validator set.
	MaximumFaultyNodes() uint64

	// Quorum returns what is the quorum size for the
	// specified block height.
	Quorum(blockHeight uint64) uint64
}

type IBFT struct {
	// contains filtered or unexported fields
}

type Logger interface {
	Info(msg string, args ...interface{})
	Debug(msg string, args ...interface{})
	Error(msg string, args ...interface{})
}

type MessageConstructor interface {
	// BuildPrePrepareMessage builds a PREPREPARE message based on the passed in proposal
	BuildPrePrepareMessage(
		proposal []byte,
		certificate *proto.RoundChangeCertificate,
		view *proto.View,
	) *proto.Message

	// BuildPrepareMessage builds a PREPARE message based on the passed in proposal
	BuildPrepareMessage(proposalHash []byte, view *proto.View) *proto.Message

	// BuildCommitMessage builds a COMMIT message based on the passed in proposal
	BuildCommitMessage(proposalHash []byte, view *proto.View) *proto.Message

	// BuildRoundChangeMessage builds a ROUND_CHANGE message based on the passed in proposal
	BuildRoundChangeMessage(
		proposal []byte,
		certificate *proto.PreparedCertificate,
		view *proto.View,
	) *proto.Message
}

type Messages interface {
	// Messages modifiers //
	AddMessage(message *proto.Message)
	PruneByHeight(height uint64)

	// Messages fetchers //
	GetValidMessages(
		view *proto.View,
		messageType proto.MessageType,
		isValid func(*proto.Message) bool,
	) []*proto.Message
	GetMostRoundChangeMessages(minRound, height uint64) []*proto.Message

	// Messages subscription handlers //
	Subscribe(details messages.SubscriptionDetails) *messages.Subscription
	Unsubscribe(id messages.SubscriptionID)
}

type Transport interface {
	// Multicast multicasts the message to other peers
	Multicast(message *proto.Message)
}

type Verifier interface {
	// IsValidBlock checks if the proposed block is child of parent
	IsValidBlock(block []byte) bool

	// IsValidSender checks if signature is from sender
	IsValidSender(msg *proto.Message) bool

	// IsProposer checks if the passed in ID is the Proposer for current view (sequence, round)
	IsProposer(id []byte, height, round uint64) bool

	// IsValidProposalHash checks if the hash matches the proposal
	IsValidProposalHash(proposal, hash []byte) bool

	// IsValidCommittedSeal checks if the seal for the proposal is valid
	IsValidCommittedSeal(proposal []byte, committedSeal *messages.CommittedSeal) bool
}