Initialize project with basic structure, including Docker configuration, backend and frontend setup, environment configuration, and essential files for development.

backend/internal/realtime/hub.go

@@ -0,0 +1,51 @@
+package realtime
+
+import (
+	"encoding/json"
+	"sync"
+)
+
+type Event struct {
+	Topic string          `json:"topic"`
+	Data  json.RawMessage `json:"data"`
+}
+
+type Hub struct {
+	mu   sync.RWMutex
+	subs map[string]map[chan Event]struct{}
+}
+
+func New() *Hub { return &Hub{subs: make(map[string]map[chan Event]struct{})} }
+
+func (h *Hub) Publish(topic string, value any) {
+	data, err := json.Marshal(value)
+	if err != nil {
+		return
+	}
+	h.mu.RLock()
+	defer h.mu.RUnlock()
+	for _, key := range []string{"*", topic} {
+		for ch := range h.subs[key] {
+			select {
+			case ch <- Event{Topic: topic, Data: data}:
+			default:
+			}
+		}
+	}
+}
+
+func (h *Hub) Subscribe(topic string) (<-chan Event, func()) {
+	ch := make(chan Event, 16)
+	h.mu.Lock()
+	if h.subs[topic] == nil {
+		h.subs[topic] = make(map[chan Event]struct{})
+	}
+	h.subs[topic][ch] = struct{}{}
+	h.mu.Unlock()
+	return ch, func() {
+		h.mu.Lock()
+		delete(h.subs[topic], ch)
+		close(ch)
+		h.mu.Unlock()
+	}
+}