client

type Acceptor interface {
	// AcceptBroadcastTx returns an error if any of the transactions
	// should not be accepted, or if the batch must not be broadcast.
	AcceptBroadcastTx(
		ctx context.Context,
		userAddress string,
		transactions ...Transaction,
	) error

	// AcceptBroadcastTxRemoval returns an error if any of the transactions
	// should not be accepted, or if the batch must not be broadcast.
	AcceptBroadcastTxRemoval(
		ctx context.Context,
		userAddress string,
		transactions ...Transaction,
	) error

	// RollbackTx should execute custom business logic such as removing data
	// previously committed for a transaction batch that is being rollbacked.
	RollbackTx(
		ctx context.Context,
		userAddress string,
		transactions ...Transaction,
	) error

	// RollbackTxRemoval should execute custom business logic such as removing
	// data previously committed for a removal operation that is rollbacked.
	RollbackTxRemoval(
		ctx context.Context,
		userAddress string,
		transactions ...Transaction,
	) error
}

type BroadcastStatus struct {
	Error    error
	TxHashes [][]byte
}

type Client interface {
	// BroadcastTx sends an error to a notifier if any of the transactions
	// fails basic verification, or if we fail to get a majority approval
	// for the broadcast operation from healthy relays.
	//
	// This method should broadcast the transactions to all other relays and
	// iff the calls to [Acceptor#AcceptBroadcastTx] by relays are successful,
	// it should commit the transactions data.
	// If commitment does not succeed for any reason outside of the scope of
	// acceptance, e.g. hd failure, this method calls [Acceptor#RollbackTx]
	// and broadcasts a RollbackTxs message to other relays' mempool reactor.
	//
	// If any error happens during the broadcast process, the transactions
	// data must be discarded.
	// Otherwise, it should eventually persist the transactions data using
	// active relays of one or many networks. The ChainID used for persisting
	// data must be built using the userAddress and the [Transaction#Fingerprint].
	BroadcastTx(
		ctx context.Context,
		userAddress string,
		relays []string,
		notifier chan<- BroadcastStatus,
		transactions ...Transaction,
	)

	// BroadcastTxRemoval sends an error to a notifier if any of the removal
	// operations fail verification, or if we fail to get a majority approval
	// for the broadcast operation from healthy relays.
	//
	// This method should broadcast the remove operations to all other relays
	// and iff the calls to [Acceptor#AcceptBroadcastTxRemoval] by relays are
	// successful, it should completely remove the persisted data.
	//
	// If any error happens during the broadcast process or during verification,
	// the removal operations data must be discarded.
	// Otherwise, it should eventually persist the removal operations data using
	// active relays of so-called *removal history networks*. The ChainID used
	// for persisting removal operations must be built using the userAddress
	// and the [Transaction#Fingerprint] will be prefixed with `delete_`.
	BroadcastTxRemoval(
		ctx context.Context,
		userAddress string,
		relays []string,
		notifier chan<- BroadcastStatus,
		transactions ...Transaction,
	)
}

type ContextKey string

type DefaultAcceptor struct{}

type DefaultClient struct{}

type DefaultServer struct{}

type Server interface {
	io.Closer

	// GetAcceptor returns the injected [Acceptor] implementation.
	GetAcceptor() Acceptor

	// MustStart executes a replication backend.
	MustStart()
}

type Transaction struct {
	Data        []byte
	Fingerprint string
}