package streaming

import "encoding/json"

type EventType int8

const (
	// Sent when an error occurs
	// Payload: {code:int, message:string}
	EventTypeError EventType = 1
	// Sent when echoing back received messages
	// Payload: <received message>
	EventTypeEcho EventType = 2
	// Sent on a new post being created
	// Payload: <post object>
	EventTypePost EventType = 3

	// Receive events
	// Subscribe to a new event
	EventTypeSubscribe EventType = 126
	// Unsubscribe from an event
	EventTypeUnsubscribe EventType = 127
)

func (et EventType) Valid() bool {
	switch et {
	case EventTypeError:
		return true
	case EventTypeEcho:
		return true
	case EventTypePost:
		return true
	case EventTypeSubscribe:
		return true
	case EventTypeUnsubscribe:
		return true
	default:
		return false
	}
}

// Returns true if this event can be subscribed to/unsubscribed from
func (et EventType) ValidReceive() bool {
	if !et.Valid() {
		return false
	}

	switch et {
	case EventTypeError, EventTypeSubscribe, EventTypeUnsubscribe:
		return false
	default:
		return true
	}
}

type Event struct {
	Type EventType `json:"t"`
	Data any       `json:"d"`
}

type ErrorEvent struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
}

type IncomingEvent struct {
	Type EventType       `json:"t"`
	Data json.RawMessage `json:"d"` // this is a RawMessage so we can easily unmarshal it later
}