This commit is the continuity of a42c27f9 that fixed some bugs.
One of the bug was that a discount was only applied on price without taxes.
E.G: A $100 product with 20% excluded tax would cost $120 but a 50% discount
would give the user only $50 discount and not $60 as expected.
User would lose $10 discount.
With these fixes, the discount line would correctly be set to $60 but since the
discount line would not have tax, the merchant would lose the discount amount
on the tax, in this case 50% of $20.
This commit will improve this case by adding a tax on a discount line.
Thus, since a global discount can be applied to multiple products having
different taxes or even multiple taxes on the same product, a discount line
should be split for every product taxes the discount applies on.
Obviously, this is a big behavior change, even if the discount is now finally
correct: the discount is applied on the total price and the merchant does not
lose any taxes.
To make it more clear, the discount lines description will mention on which
taxes it is applied.
There won't be any changes in the e-commerce since we will group the discount
lines so it will appear as before even if there are multiple lines. This is
only possible because we don't show taxes on line on the e-commerce.
This commit also fixes more complex flows/use cases.
Note: Fixes & flows will be illustrated with a SO but the behavior is the
same with a cart on front-end.
== Fixes ==
===========================================================================
The biggest flow that needed to be fixed is when a promotion program give a
reward on the next order.
Let's illustrate with a promotion program giving a free `product_B` on next
order (so it will generate a coupon) if the SO meets the requirements.
The requirements are: buy a `product_A` and buy for at least $600.
(This program needs a code: 'free_b_on_next')
1. If the SO has a `product_A` and over $600, applying the promotion code
`free_b_on_next` will error saying that `product_B` is not in the cart.
This error should not appear, since the `product_B` is the reward for
the next sale order that will use the generated coupon.
Anyway, if you add `product_B` and apply the promotion code `free_b_on_next`
to generate the coupon to check the rest of the flow. It will generate the
coupon and send email to the customer.
2. Every time you will apply the promotion code `free_b_on_next`, it will
regenerate a new coupon and resend a new email to the client.
Then, create a second SO, add 2 `product_B` and try to apply the generated
coupon from the first SO.
3. It will error saying that the $600 requirement is not met.
It should not since the requirement was only required to generate the
coupon on the first SO. User has now a coupon to enjoy a free `product_B`
and should not buy $600.
Anyway, let's add some products to meet the 600$ requirement to check the rest
of the flow.
4. It will now error saying that `product_A` is not in the cart.
As bug 3., it should not since this requirement was also required to
generate the coupon on the first SO.
Anyway, let's add `product_A` to meet the requirement to check the rest of the
flow.
5. Updating the promotions will remove the reward and you won't be able to
reapply the coupon since it was `used`.
This bug was even more critical in front-end since any action on the cart
will recompute the coupons and automatically delete the reward after adding
it. The customer never saw the reward on his cart.
This bug is related to 3. and 4. Indeed, when recomputing coupons, it will
remove programs that are not applicable anymore. The code wrongly think it is
the case with this coupon since we don't have $600 or a `product_A`.
`_remove_invalid_reward_lines` should treat coupon coming from a promotion
program set on `next_order` differently and not filter on requirements.
===========================================================================
6. (extension of 2.) Every time an user would meet the requirements of a
promotion program generating a coupon for a next order, it would generate a
coupon and send an email.
E.g: If buy 2 iPads get 1 for free on next order. If user add and remove iPad
for some reason, every time he has 2 iPads in his cart it will receive
an email with a new coupon.
6'. When applying a promotion code that will reward next order, it will not be
set in the SO `code_promo_program_id` (I did not change that behavior since
it could make sense to be able to apply another coupon that will give -20%
on current order).
This will allow applying multiple promotion rewarding a next order and/or a
promotion rewarding current order. (Which would not be possible if was
stored on `code_promo_program_id` since you can only apply one code on an
order)
But this cause a bug: since the promotion program is not stored on the order,
every time you will apply the coupon it will generate a new coupon and send
an email.
So if you work on a draft sale order and do some tests, it will send many
emails to customer..
7. Having multiple global discounts (on the whole SO) was forbidden: you can't
apply a coupon promotion or a program promotion if there is already a global
coupon discount or a global promotion discount with code. But still you could
apply a global discount if there were a global promotion discount automatically
applied (without a code).
8. On the generate coupon wizard, if you select `Number of Selected Customers`,
by default it is set to 'Match all records (X records)'.
But when you click on generate, it won't generate anything even if visually
it selected every partner by default.
This is because the domain default value is an empty string. Thus, the domain
widget is selecting everything but once it is sent back to the server, since
it's an empty string it won't get through the `if` condition.
It was even weirder when you add something to the domain and remove it, you
then visually come back to where you were at the beginning but the domain got
changed from '' to '[]' so in this case it will generate the coupon for every
partner.
== More like improvements ==
1. `action_cancel` and `action_confirm` would handle correctly the states of the
applied and generated coupons (valid, consumed, expired..).
But `action_draft` would not handle the states at all.
2. The generated coupon on a SO are now sent by email only when the SO is validated.
This is part of the fix n°2 on coupon being generated multiple times and sent by
email multiple times.
The coupon sent by email was not usable anyway since it would error saying the
SO that generated the coupon was not validated.
3. Discount line limited to a max amount (set in the program) will mention on
the line description that the discount is limited.
This will avoid cases where you don't understand why 50% discount of $2000
SO shows $40.
4. If you archive a program and there is still some SO containing this program's
reward line, these line will be 'floating free' and will never be updated or
removed. Indeed, the `_remove_invalid_reward_lines` is basically checking
which programs could be applied on the order and which one are applied on the
order. If a program is applied on the order but is not supposed to, his
reward line will be removed.
Of course, since the program got archived, it won't get retrieve and the line
will never get removed. Even if the case of a free iPad: if you buy an iPad
and you removed the paid iPad from the SO. The free iPad will remain forever.
Note: We can't remove these discount line directly when archiving a program
because there might be quotations that we don't want to modify since it
is waiting for customer confirmation.
Improved behavior:
- Archiving a program archives its related reward product but unarchiving
the program does not unarchived the product.
task-1866977
opw-1832967
opw-1857843
Closes#2224
Comes with https://github.com/odoo/odoo/pull/24971
Romain Derie
034fb31c40