Messenger/server/internal/realtime/events.go

// Package realtime implements the WebSocket hub: real-time delivery of
// conversation events (messages, typing, presence, read receipts).
package realtime

import (
	"encoding/json"
	"time"
)

// Event type constants sent over the wire.
const (
	EventMessageCreated      = "message.created"
	EventTyping              = "typing"
	EventPresence            = "presence"
	EventRead                = "read"
	EventConversationAdded   = "conversation.added"
	EventConversationRemoved = "conversation.removed"
	EventMemberAdded         = "member.added"
	EventMemberRemoved       = "member.removed"
	EventReactionAdded       = "reaction.added"
	EventReactionRemoved     = "reaction.removed"
)

// Presence status values.
const (
	StatusOnline  = "online"
	StatusOffline = "offline"
)

// MessageCreated is published when a message is stored.
type MessageCreated struct {
	TempID         string     `json:"temp_id,omitempty"`
	ConversationID int64      `json:"conversation_id"`
	MessageID      int64      `json:"message_id"`
	SenderID       int64      `json:"sender_id"`
	Body           string     `json:"body"`
	MediaID        *int64     `json:"media_id,omitempty"`
	Media          *MediaInfo `json:"media,omitempty"`
	CreatedAt      time.Time  `json:"created_at"`
}

// MediaInfo mirrors attachment metadata delivered with a message event.
type MediaInfo struct {
	ID          int64  `json:"id"`
	Filename    string `json:"filename"`
	ContentType string `json:"content_type"`
	Size        int64  `json:"size"`
	URL         string `json:"url"`
	ThumbURL    string `json:"thumb_url,omitempty"`
}

// Typing is published when a user starts or stops typing in a conversation.
type Typing struct {
	ConversationID int64 `json:"conversation_id"`
	UserID         int64 `json:"user_id"`
	IsTyping       bool  `json:"is_typing"`
}

// Presence is published when a user comes online or goes offline.
type Presence struct {
	UserID int64  `json:"user_id"`
	Status string `json:"status"`
}

// Read is published when a user marks messages in a conversation as read.
type Read struct {
	ConversationID int64 `json:"conversation_id"`
	UserID         int64 `json:"user_id"`
	MessageID      int64 `json:"message_id"`
}

// ConversationChanged is sent to a user when they gain or lose a conversation.
type ConversationChanged struct {
	ConversationID int64 `json:"conversation_id"`
}

// MemberChanged is published when a user joins or leaves a conversation.
type MemberChanged struct {
	ConversationID int64 `json:"conversation_id"`
	UserID         int64 `json:"user_id"`
}

// ReactionChanged is published when a reaction is added to or removed from a message.
type ReactionChanged struct {
	ConversationID int64  `json:"conversation_id"`
	MessageID      int64  `json:"message_id"`
	UserID         int64  `json:"user_id"`
	Emoji          string `json:"emoji"`
}

// envelope is the wire format for every message, both inbound and outbound.
type envelope struct {
	Type string          `json:"type"`
	Data json.RawMessage `json:"data"`
}

// clientTyping is sent by the client to signal typing state.
type clientTyping struct {
	ConversationID int64 `json:"conversation_id"`
	IsTyping       bool  `json:"is_typing"`
}

// clientRead is sent by the client to mark messages as read.
type clientRead struct {
	ConversationID int64 `json:"conversation_id"`
	MessageID      int64 `json:"message_id"`
}