Messenger/packages/core/src/events/index.ts

// Realtime event taxonomy (spec section 3). Every live feature is an event on
// the same receive socket; these names are the contract between backend
// publishers and client handlers. Payload shapes are added alongside features.
//
//   Bucket A — durable, must be correct → through the backend (persist, publish)
//   Bucket B — ephemeral, throwaway     → published, not persisted
//   Bucket C — connection-derived       → Centrifugo built-in presence
//
// EventType is the single source of truth for every event `type` value — never
// write the raw string literal anywhere; reference EventType.* instead.

import type { Message } from '../types/message';
import type { Conversation } from '../types/conversation';

export const EventType = {
  // Bucket A
  MessageNew: 'message.new',
  MessageEdit: 'message.edit',
  MessageDelete: 'message.delete',
  ReactionAdd: 'reaction.add',
  ReactionRemove: 'reaction.remove',
  ReadReceipt: 'read.receipt',
  LastSeen: 'last_seen',
  ConversationNew: 'conversation.new',
  ConversationMembership: 'conversation.membership',
  ProfileUpdate: 'profile.update',

  // Bucket B
  TypingStart: 'typing.start',
  TypingStop: 'typing.stop',
  RecordingAudio: 'recording.audio',
  RecordingVideo: 'recording.video',

  // Bucket C
  Presence: 'presence',
} as const;

export type EventType = (typeof EventType)[keyof typeof EventType];

// --- Realtime event payloads (published by the backend, handled by clients) ---
// Each `type` field is derived from EventType so a typo is a compile error.

export interface MessageNewEvent {
  type: typeof EventType.MessageNew;
  message: Message;
}

export interface MessageEditEvent {
  type: typeof EventType.MessageEdit;
  message: Message;
}

export interface MessageDeleteEvent {
  type: typeof EventType.MessageDelete;
  conversationId: string;
  messageId: string;
}

// Published to a user's personal channel when a new conversation involving them
// is created (a DM someone started, or a group they were added to) so it appears
// in their list immediately.
export interface ConversationNewEvent {
  type: typeof EventType.ConversationNew;
  conversation: Conversation;
}

export type ConversationMembershipAction = 'added' | 'removed';

export interface ConversationMembershipEvent {
  type: typeof EventType.ConversationMembership;
  action: ConversationMembershipAction;
  conversationId: string;
  userId: string;
}

export interface ReactionEvent {
  type: typeof EventType.ReactionAdd | typeof EventType.ReactionRemove;
  conversationId: string;
  messageId: string;
  emoji: string;
  userId: string;
}

export interface ReadReceiptEvent {
  type: typeof EventType.ReadReceipt;
  conversationId: string;
  userId: string;
  seq: number;
}

export interface TypingEvent {
  type: typeof EventType.TypingStart | typeof EventType.TypingStop;
  conversationId: string;
  userId: string;
}

export interface ProfileUpdateEvent {
  type: typeof EventType.ProfileUpdate;
  userId: string;
  displayName: string;
  avatarUrl: string | null;
}