package uatomic

import "sync/atomic"

// Atom is a generic wrapper for atomic.Value.
type Atom[T comparable] struct {
	value atomic.Value
}

type atomWrapper[T comparable] struct { value T }

// CompareAndSwap executes the compare-and-swap operation for the Atom.
func (atom *Atom[T]) CompareAndSwap(old, neww T) (swapped bool) {
	return atom.value.CompareAndSwap(
		atomWrapper[T] { value: old },
		atomWrapper[T] { value: neww })
}

func (atom *Atom[T]) Load() T {
	return castSafe[T](atom.value.Load)
}

func (atom *Atom[T]) Store(val T) {
	atom.value.Store(val)
}

func (atom *Atom[T]) Swap(neww T) T {
	return castSafe[T](atom.value.Swap(neww))
}

func castSafe[T comparable](value any) T {
	var zero T
	if value == nil {
		return zero
	} else {
		return value.(T)
	}
}