pt

type AccID uint64

type BigChain interface {
	Fetch(ctx context.Context, accID AccID, limit int) ([]Txn, *Settings, error)
}

type Chain interface {
	ListUnspentTxns(accID AccID) []Txn
	PutTo(accID AccID, txns []Txn)
	GetLastHash(accID AccID) Hash
	GetBalance(accID AccID) int64
	GetLastTxn(accID AccID) *Txn
	GetLastNTxns(accID AccID, n int) []Txn
	Reset(AccID)
}

type Hash [32]byte

type ID uint64

type Preloader interface {
	Preload(context.Context, AccID) error
	Reset(context.Context, AccID)
}

type PublicKey []byte

type Pusher interface {
	Push(ctx context.Context, txns []Txn) error
}

type Router interface {
	// Returns host which is responsible for given key.
	// Key usually is an AccountID
	GetHostByKey(key string) string
	// All nodes hostnames of the cluster
	Nodes() []string
	// Sets cluster nodes
	SetNodes(nodes []string)
	// Checks if given node is our own, so we must process request not redirect it
	IsSelf(node string) bool
}

type Settings struct {
	ID                 ID
	Account            AccID
	PublicKey          PublicKey
	PrevHash, Hash     Hash
	VerifyTransferSign bool
	DataHash           Hash
	Sign               Sign
}

type SettingsChain interface {
	GetLastSettings(AccID) *Settings
	GetLastHash(AccID) Hash
	Put(*Settings)
	Reset(AccID)
}

type SettingsID struct {
	AccID
	ID
}

type SettingsProcessor interface {
	ProcessSettings(ctx context.Context, s *Settings) (SettingsResult, error)
	GetLastSettings(ctx context.Context, acc AccID) (*Settings, error)
}

type SettingsPusher interface {
	PushSettings(ctx context.Context, sett *Settings) error
}

type SettingsResult struct {
	SettingsID SettingsID // Last Settings ID
	Hash       Hash       // Hash Settings Hash
}

type Sign [72]byte

type Transfer struct {
	Sender     AccID
	Batch      []*TransferItem // Receivers and amounts
	Sign       Sign            // Request sign. It will be kept at first transaction of the batch
	PrevHash   Hash            // Hash of last output transaction for Sender account
	SettingsID ID              // Current account settings ID for Sender account
}

type TransferItem struct {
	Receiver AccID
	Amount   int64
}

type TransferProcessor interface {
	ProcessTransfer(ctx context.Context, t Transfer) (TransferResult, error)
	GetPrevHash(ctx context.Context, acc AccID) (Hash, error)
	GetBalance(ctx context.Context, acc AccID) (int64, error)
	SetPusher(Pusher)
	SetPreloader(Preloader)
	SetSettingsChain(SettingsChain)
}

type TransferResult struct {
	TxnID      TxnID // TxnID of the first transaction in the batch
	Hash       Hash  // Hash of last transaction in the batch
	SettingsId ID    // Current settings ID
}

type Txn struct {
	// Account incremental id for output transactions.
	ID               ID
	Sender, Receiver AccID
	Amount           int64
	// Balance of the Sender account at the time just after this transaction has been processed.
	Balance int64

	// Account settings id at the moment of this transaction processing.
	SettingsID ID

	// Stores ID of Receiver output transaction when this transaction was taken into account.
	// Set by Receiver. 0 if not spent yet.
	// It's not used for transaction Hash calculation.
	SpentBy ID
	// Previous transaction hash of the same Sender.
	PrevHash Hash
	// Hash is an hash of corrent transaction.
	Hash Hash
	// Transfer Sign.
	// If more that one transactions were in the batch only first contains sign of the whole request
	Sign Sign
}

type TxnID struct {
	AccID
	ID
}