package hostwrite

import "context"

// Selection carries the original work and rendered inputs across a callback.
// The receiver uses With at its final local effect, never a new hostname lookup.
// Network waits belong outside With; remote effects need a provider that binds
// the request to this selection and refuses a successor at publication.
type Selection struct {
	Host     string
	Work     Work
	Identity Identity
}

func (s Selection) With(ctx context.Context, effect func() error) error {
	if ctx == nil || s.Host == "" || s.Work == nil || effect == nil {
		return ErrUnavailable
	}
	return s.Work.With(ctx, s.Identity, effect)
}

type Callback func(context.Context, Selection) error