// checkVersion makes a best-effort attempt to verify that fleetctl is at least as new as the
// latest fleet version found registered in the cluster. If any errors are encountered or fleetctl
// is >= the latest version found, it returns true. If it is < the latest found version, it returns
// false and a scary warning to the user.
func checkVersion(cReg registry.ClusterRegistry) (string, bool) {
	fv := version.SemVersion
	lv, err := cReg.LatestDaemonVersion()
	if err != nil {
		log.Errorf("error attempting to check latest fleet version in Registry: %v", err)
	} else if lv != nil && fv.LessThan(*lv) {
		return fmt.Sprintf(oldVersionWarning, fv.String(), lv.String()), false
	}
	return "", true
}

func ensureEngineVersionMatch(cReg registry.ClusterRegistry, expect int) bool {
	v, err := cReg.EngineVersion()
	if err != nil {
		log.Errorf("Unable to determine cluster engine version")
		return false
	}

	if v < expect {
		err = cReg.UpdateEngineVersion(v, expect)
		if err != nil {
			log.Errorf("Failed updating cluster engine version from %d to %d: %v", v, expect, err)
			return false
		}
		log.Infof("Updated cluster engine version from %d to %d", v, expect)
	} else if v > expect {
		log.Debugf("Cluster engine version higher than local engine version (%d > %d), unable to participate", v, expect)
		return false
	}

	return true
}