contract

type Event interface {
	Name() string

	Payload() any

	Timestamp() time.Time

	StopPropagation()

	IsPropagationStopped() bool
}

type EventDispatcher interface {
	AddListener(eventName string, listener EventListener, priority int) ListenerRegistration

	RemoveListener(registration ListenerRegistration) bool

	AddSubscriber(subscriber EventSubscriber)

	RemoveSubscriber(subscriber EventSubscriber) int

	/* Dispatch runs the listeners registered for the event's name in descending priority order. The first listener error aborts the remaining listeners and is returned alongside the (partially dispatched) event; callers decide the policy for partial dispatch. */
	Dispatch(runtimeInstance runtimecontract.Runtime, event Event) (Event, error)

	/* DispatchName behaves like Dispatch for the given event name and payload: listeners run in descending priority order and the first listener error aborts the remaining listeners. */
	DispatchName(runtimeInstance runtimecontract.Runtime, eventName string, payload any) (Event, error)
}

type EventDispatcherInspector interface {
	RegisteredEvents() []RegisteredEvent
}

type EventListener func(runtimeInstance runtimecontract.Runtime, event Event) error

type EventSubscriber interface {
	SubscribedEvents() map[string][]SubscribedEvent
}

type ListenerRegistration struct {
	EventName  string
	ListenerId uint64
}

type RegisteredEvent struct {
	EventName string               `json:"eventName"`
	Listeners []RegisteredListener `json:"listeners"`
}

type RegisteredListener struct {
	Priority     int    `json:"priority"`
	Source       string `json:"source"`
	Owner        string `json:"owner"`
	ListenerId   string `json:"listenerId"`
	ListenerName string `json:"listenerName"`
}

type RequiredListenerRegistrar interface {
	MarkListenerRequired(registration ListenerRegistration)

	MarkListenerMaySkipRequiredListeners(registration ListenerRegistration)
}

type SubscribedEvent interface {
	Listener() EventListener

	Priority() int
}