package syncapi

import (
	"context"
	"encoding/json"
	"time"
)

// Outbound passes this server's ephemeral events on to other servers.
//
// Typing notifications, read receipts and to-device messages are not room
// events and never go through the roomserver, so the federation queue
// cannot pick them up from there; the sync API, which is where they are
// written, hands them over instead. Only what a local user did is handed
// over — the same calls are how an EDU from another server is taken in,
// and passing those on again would echo them back to where they came
// from.
//
// Every method must return quickly: they are called on the request path
// of the client that typed, read or sent.
type Outbound interface {
	Typing(ctx context.Context, roomID, userID string, typing bool, timeout time.Duration)
	Receipt(ctx context.Context, roomID, userID, receiptType, eventID, threadID string, ts int64)
	ToDevice(ctx context.Context, sender, eventType string, messages map[string]map[string]json.RawMessage)
}

// SetOutbound connects the federation queue. It is a setter rather than an
// option because the queue is built after the sync API's dependencies and
// before the sync API is serving, and nil — no federation — is a valid
// value throughout.
func (s *API) SetOutbound(o Outbound) { s.outbound = o }