package events

import (
	"context"
	"sync"
)

// Once returns fn wrapped so it runs at most once.
func Once(fn func()) func() {
	if fn == nil {
		return func() {}
	}
	var once sync.Once
	return func() { once.Do(fn) }
}

// CallRelease runs Release on PostCreated or PostedToDiscord when set.
func CallRelease(ev any) {
	switch e := ev.(type) {
	case PostCreated:
		if e.Release != nil {
			e.Release()
		}
	case PostedToDiscord:
		if e.Release != nil {
			e.Release()
		}
	}
}

// SubscribeRelease runs PostedToDiscord.Release on the worker.
func SubscribeRelease(bus *Bus) {
	if bus == nil {
		return
	}
	bus.Subscribe(func(_ context.Context, ev any) {
		if _, ok := ev.(PostedToDiscord); ok {
			CallRelease(ev)
		}
	})
}