yess

event/event_bus.go

@@ -0,0 +1,45 @@
+package event
+
+import (
+	"errors"
+	"reflect"
+)
+
+type HandlerInst interface {
+	Default(event any) (err error)
+}
+
+type OnStart struct{}
+type OnLoopCycle struct{}
+
+var HandlerDone = errors.New("handler done")
+
+func FindHandlers(inst HandlerInst) (handlers map[reflect.Type]reflect.Value) {
+	handlers = make(map[reflect.Type]reflect.Value)
+	t := reflect.TypeOf(inst)
+	v := reflect.ValueOf(inst)
+	for i := 0; i < t.NumMethod(); i++ {
+		method := t.Method(i)
+		if method.Type.NumIn() != 2 || method.Type.NumOut() != 1 {
+			continue
+		}
+		if method.Type.Out(0) != reflect.TypeFor[error]() {
+			continue
+		}
+		eventType := method.Type.In(1)
+		handlers[eventType] = v.Method(i)
+	}
+	return
+}
+
+func Fire(inst HandlerInst, event any, handlers map[reflect.Type]reflect.Value) (err error) {
+	if handler, ok := handlers[reflect.TypeOf(event)]; ok {
+		errV := handler.Call([]reflect.Value{reflect.ValueOf(event)})[0]
+		if !errV.IsNil() {
+			err = errV.Interface().(error)
+		}
+	} else {
+		err = inst.Default(event)
+	}
+	return
+}