package port

// StreamEvent represents an event to be published on a stream.
type StreamEvent struct {
	ID   string // Event ID for Last-Event-ID support
	Type string
	Data map[string]any
}

// StreamPublisher defines operations for managing SSE event streams.
type StreamPublisher interface {
	// Subscribe creates a subscription to events for the given stream ID.
	// Returns a channel that will receive events and a cleanup function.
	Subscribe(streamID string) (<-chan StreamEvent, func())

	// SubscribeFromID creates a subscription starting from a specific event ID.
	// This is used for reconnection with Last-Event-ID support.
	// Events since lastEventID will be replayed before new events are delivered.
	SubscribeFromID(streamID string, lastEventID string) (<-chan StreamEvent, func())

	// Publish sends an event to all subscribers of a stream.
	// Returns the generated event ID.
	Publish(streamID string, event StreamEvent) string

	// Close closes a stream and all its subscriptions.
	Close(streamID string)
}