package kvm2

import (
	"strings"
)

// The providerID is hosts/<host>/domains/<name>. Host names are validated at
// config load to contain no slash, and domain names come from NameFromUID,
// so a strict four-segment split is enough to parse it.
const (
	idHostsSegment   = "hosts"
	idDomainsSegment = "domains"
)

func formatProviderID(host, name string) string {
	return idHostsSegment + "/" + host + "/" + idDomainsSegment + "/" + name
}

// parseProviderID splits an ID back into host and domain name. Anything
// that is not exactly hosts/<host>/domains/<name> with both non-empty is
// ErrPermanent: no retry will make it resolve.
func parseProviderID(id string) (host, name string, err error) {
	parts := strings.Split(id, "/")
	if len(parts) != 4 || parts[0] != idHostsSegment || parts[2] != idDomainsSegment || parts[1] == "" || parts[3] == "" {
		return "", "", permanentf("malformed providerID %q: want hosts/<host>/domains/<name>", id)
	}
	return parts[1], parts[3], nil
}