backend barebone done, big chunk of work done

server/internal/realtime/events.go

@@ -0,0 +1,70 @@
+// 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"
+)
+
+// 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"`
+	CreatedAt      time.Time `json:"created_at"`
+}
+
+// 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"`
+}
+
+// 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"`
+}