Big One

t/internal/events/bus.go

@@ -0,0 +1,38 @@
+// Package events defines a simple event handler system
+package events
+
+import "sync"
+
+type Handler func(event any)
+
+type Bus struct {
+	mu       sync.RWMutex
+	handlers map[string][]Handler
+}
+
+func NewBus() *Bus {
+	return &Bus{
+		handlers: make(map[string][]Handler),
+	}
+}
+
+func (b *Bus) On(eventType any, h Handler) {
+	key := typeKey(eventType)
+
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	b.handlers[key] = append(b.handlers[key], h)
+}
+
+func (b *Bus) Emit(event any) {
+	key := typeKey(event)
+
+	b.mu.RLock()
+	handlers := append([]Handler{}, b.handlers[key]...)
+	b.mu.RUnlock()
+
+	for _, h := range handlers {
+		h(event)
+	}
+}