sse + ocr replanish

backend/internal/service/events.go

@@ -0,0 +1,54 @@
+package service
+
+import (
+	"context"
+	"sync"
+
+	"github.com/google/uuid"
+)
+
+type Event struct {
+	Type string
+	Data string
+}
+
+type EventBroker struct {
+	mu          sync.RWMutex
+	subscribers map[string]chan Event
+}
+
+func NewEventBroker() *EventBroker {
+	return &EventBroker{
+		subscribers: make(map[string]chan Event),
+	}
+}
+
+func (b *EventBroker) Subscribe(ctx context.Context) (<-chan Event, string) {
+	id := uuid.New().String()
+	ch := make(chan Event, 16)
+
+	b.mu.Lock()
+	b.subscribers[id] = ch
+	b.mu.Unlock()
+
+	go func() {
+		<-ctx.Done()
+		b.mu.Lock()
+		delete(b.subscribers, id)
+		close(ch)
+		b.mu.Unlock()
+	}()
+
+	return ch, id
+}
+
+func (b *EventBroker) Publish(eventType, data string) {
+	b.mu.RLock()
+	defer b.mu.RUnlock()
+	for _, ch := range b.subscribers {
+		select {
+		case ch <- Event{Type: eventType, Data: data}:
+		default:
+		}
+	}
+}