package hostclaim

// IsOrphan is §5.1 step 5. The caller reads the record FIRST and this
// claim AFTER it (R3-2). Each incarnation gets exactly one claim attempt,
// and a record exists only after that attempt succeeded, so a claim read
// after the record that does not name recordInc means recordInc can never
// become the holder. A creating holder is named by Holder, so it is
// covered. An absent claim is a legacy host (Q2), never an orphan. The
// caller deletes only with DeleteIfMatch on the ETag it read.
func IsOrphan(recordInc string, claimReadAfterRecord Observed) bool {
	if claimReadAfterRecord.Absent || claimReadAfterRecord.Claim == nil {
		return false
	}
	h := claimReadAfterRecord.Claim.Holder
	return h == nil || h.Incarnation != recordInc
}