As reported [on Meta](https://meta.discourse.org/t/discourse-subscriptions/140818/352?u=justin), moderators could access all of the subscriptions data (plugins/prices/subscribers) and manage them. This should not be the case, so this PR adds a route constraint to 404 moderators from these routes.
Adds full support to create coupon/promo codes in the Admin > Plugins > Subscriptions section of the plugin. The Create Coupon button opens a form on the same page, and the active checkboxes toggle the active status of the coupon code.
The code in the plugin needed a dramatic cleanup. This refactor collapses the Plan/Product/Subscription controllers on the backend into one new controller: `SubscribeController`.
This reduces N+1 calls to the back end during the subscription process and simplifies use of the code.
I've also removed a bunch of dead code and refactored some logic into methods for easier readability. No feature/functionality changes in this commit; only refactoring. However, refactoring will allow for implementation of better anonymous user handling, so this is largely a foundation to enable making that change.
Previously, when a user canceled a subscription, the access would revoke
immediately on Discourse vs. at the end of the billing period. This
commit changes the behavior to remove membership at the end of the
billing period using Stripe's `cancel_at_period_end` attribute on the
Subscription object.
This commit now requires the setup of webhooks for subscription
processing to occur correctly.
Building off the foundation of using the Prices API, this PR adds the ability to create a one-time purchase plan for any product, which then can add a user to the specified plan group.
Some things to be aware of:
One-time purchases cannot have trials.
One-time purchases use the Invoice API instead of Subscriptions. Invoices are created then charged immediately.
Users should receive emails for these invoices directly from Stripe just like subscriptions.
Justin DiRose
Rimian Perkins
Angus McLeod
Chris Beach