package gentools

func ApplyUpdate[T any](dst *T, value *T) {
	if value != nil {
		*dst = *value
	}
}

func ApplyUpdatePtr[T any](dst **T, value *T) {
	if value != nil {
		*dst = ShallowCopy(value)
	}
}

func ApplyUpdateSlice[T any](dst *[]T, value []T) {
	if value != nil {
		*dst = append([]T{}, value...)
	}
}

func ApplyUpdateNonZero[T comparable](dst *T, value *T) {
	var zero T
	if value != nil && *value != zero {
		*dst = *value
	}
}

func ApplyUpdateNilZero[T comparable](dst **T, value *T) {
	if value != nil {
		var zero T

		if *value == zero {
			*dst = nil
		} else {
			valueCopy := *value
			*dst = &valueCopy
		}
	}
}

func ApplyMapUpdate[K comparable, V any](dst *map[K]V, src map[K]*V) {
	if *dst == nil {
		dst = &map[K]V{}
	}
	for key, value := range src {
		if value != nil {
			(*dst)[key] = *value
		} else {
			delete(*dst, key)
		}
	}
}

func ApplyUpdateMapNilZero[K comparable, V comparable](dst *map[K]V, src map[K]V) {
	var zero V
	if *dst == nil {
		dst = &map[K]V{}
	}
	for key, value := range src {
		if value != zero {
			(*dst)[key] = value
		} else {
			delete(*dst, key)
		}
	}
}