Parse hotel cancellation policies and distinguish guarantee vs deposit semantics

Steps

1. Locate the cancellation policy object in the rate/offer response — field names vary by API (e.g. cancellationPolicies[], policies.cancellations[], cancel_penalties[]); always read API-specific docs for structure.
2. Parse each policy rule: extract the deadline (ISO 8601 datetime), the penalty_amount or penalty_percentage, and the currency; convert the deadline to UTC for internal logic and to hotel-local time for user display.
3. A 'free cancellation until' date means the guest can cancel with no charge before that datetime — after the deadline, the penalty applies; model this as a sorted list of deadline/penalty pairs.
4. Guarantee means the hotel will hold the room but charge the card only at check-in (or no-show/late cancel); deposit means a partial or full charge is taken immediately at booking — check the rate's guarantee_type or deposit_policy fields.
5. For non-refundable rates, the full amount may be charged at booking — confirm this with a user-facing warning before completing the order; do not treat non-refundable the same as a penalized cancellation.
6. Store the raw policy string alongside your parsed version — hotels sometimes update policies and your parsed snapshot is the legally relevant one at time of booking.