A Vine voucher is really a specific type of FlatRate voucher but because
a Vine voucher can be used by mutiple enterprise, it can be considered
different enough to warrant it's own class.
It still share a lot of the behaviour of a FlatRate voucher, so to avoid
duplication, all the shared functionality have been moved to a
Vouchers::FlatRatable concern.
We want to keep the voucher adjustment associated with the Voucher
event when the voucher as been soft deleted, as we use this
functionality as activate/deactivate feature
Voucher adjustment have complicated calculation that prevent us from
using Spree::Calculator, and we need to override CalculatedAdjustments
method, so no point using it.
We still keep the same methods to stay as consitent as possible in
regards to adjustments
At the time when we can apply a voucher to an order (payment step) we
don't have any data on possible taxes and payment fees. These are
calculated when we move to the summary step. So voucher are applied in
two step:
- create an "open" voucher adjustment on the order when a customer enters
a voucher code.
- when we move to the summary step, recalulate the amount and
possible tax for the voucher adjustment, once taxes and payment fees
have been included in the order. And then close the original and update
order to reflect the changes
The checkout payment step will also show a warning.
The amount used is stored in the adjustment created, so we will be able
to track how much has been used down the line.
