package whisper

import (
	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/p2p/enode"
)

// EventType used to define known envelope events.
type EventType string

const (
	// EventEnvelopeSent fires when envelope was sent to a peer.
	EventEnvelopeSent EventType = "envelope.sent"
	// EventEnvelopeExpired fires when envelop expired
	EventEnvelopeExpired EventType = "envelope.expired"
	// EventEnvelopeReceived is sent once envelope was received from a peer.
	// EventEnvelopeReceived must be sent to the feed even if envelope was previously in the cache.
	// And event, ideally, should contain information about peer that sent envelope to us.
	EventEnvelopeReceived EventType = "envelope.received"
	// EventBatchAcknowledged is sent when batch of envelopes was acknowledged by a peer.
	EventBatchAcknowledged EventType = "batch.acknowleged"
	// EventEnvelopeAvailable fires when envelop is available for filters
	EventEnvelopeAvailable EventType = "envelope.available"
	// EventMailServerRequestSent fires when such request is sent.
	EventMailServerRequestSent EventType = "mailserver.request.sent"
	// EventMailServerRequestCompleted fires after mailserver sends all the requested messages
	EventMailServerRequestCompleted EventType = "mailserver.request.completed"
	// EventMailServerRequestExpired fires after mailserver the request TTL ends.
	// This event is independent and concurrent to EventMailServerRequestCompleted.
	// Request should be considered as expired only if expiry event was received first.
	EventMailServerRequestExpired EventType = "mailserver.request.expired"
	// EventMailServerEnvelopeArchived fires after an envelope has been archived
	EventMailServerEnvelopeArchived EventType = "mailserver.envelope.archived"
	// EventMailServerSyncFinished fires when the sync of messages is finished.
	EventMailServerSyncFinished EventType = "mailserver.sync.finished"
)

// EnvelopeEvent used for envelopes events.
type EnvelopeEvent struct {
	Event EventType
	Topic TopicType
	Hash  common.Hash
	Batch common.Hash
	Peer  enode.ID
	Data  interface{}
}

// SyncEventResponse is a response from the Mail Server
// form which the peer received envelopes.
type SyncEventResponse struct {
	Cursor []byte
	Error  string
}