package surf

import "net/http"

// LocaleResolver is an optional backpack-published service that selects a
// validated locale code for a request. When none is published, surf keeps
// writing the raw Accept-Language header onto the request context.
type LocaleResolver interface {
	// Resolve returns a validated locale code for r. It may set cookies on w
	// and must not store request locale on a process-wide variable.
	Resolve(w http.ResponseWriter, r *http.Request) string
	// Rewrite returns a request whose URL has a valid enabled locale prefix
	// stripped so routing sees the unprefixed path, or r unchanged.
	Rewrite(r *http.Request) *http.Request
}