* Fix it so that if upgrades are disabled, only the payment button is disabled instead of the whole page.
* Fix it so that disabling upgrades with DANBOORU_USER_UPGRADES_ENABLED="false" works.
Add a Restricted user level. Restricted users are level 10, below
Members. New users start out as Restricted if they sign up from a proxy
or an IP recently used by another user.
Restricted users can't update or edit any public content on the site
until they verify their email address, at which point they're promoted
to Member. Restricted users are only allowed to do personal actions
like keep favorites, keep favgroups and saved searches, mark dmails as
read or deleted, or mark forum posts as read.
The restricted state already existed before, the only change here is
that now it's an actual user level instead of a hidden state. Before it
was based on two hidden flags on the user, the `requires_verification`
flag (set when a user signs up from a proxy, etc), and the `is_verified`
flag (set after the user verifies their email). Making it a user level
means that now the Restricted status will be shown publicly.
Introducing a new level below Member means that we have to change every
`is_member?` check to `!is_anonymous` for every place where we used
`is_member?` to check that the current user is logged in.
Add links to the Stripe payment page and the Stripe receipt page on
completed user upgrades.
The Stripe payment link is a link to the payment details on the Stripe
dashboard and is only visible to the owner.
* Add a frequently asked questions section.
* Add nicer looking upgrade buttons.
* Format the page nicer.
* Prevent users from attempting invalid upgrades on users that are
already Platinum or above.
Add a model to store the status of user upgrades.
* Store the upgrade purchaser and the upgrade receiver (these are
different for a gifted upgrade, the same for a self upgrade).
* Store the upgrade type: gold, platinum, or gold-to-platinum upgrades.
* Store the upgrade status:
** pending: User is still on the Stripe checkout page, no payment
received yet.
** processing: User has completed checkout, but the checkout status in
Stripe is still 'unpaid'.
** complete: We've received notification from Stripe that the payment
has gone through and the user has been upgraded.
* Store the Stripe checkout ID, to cross-reference the upgrade record on
Danbooru with the checkout record on Stripe.
This is the upgrade flow:
* When the user clicks the upgrade button on the upgrade page, we call
POST /user_upgrades and create a pending UserUpgrade.
* We redirect the user to the checkout page on Stripe.
* When the user completes checkout on Stripe, Stripe sends us a webhook
notification at POST /webhooks/receive.
* When we receive the webhook, we check the payment status, and if it's
paid we mark the UserUpgrade as complete and upgrade the user.
* After Stripe sees that we have successfully processed the webhook,
they redirect the user to the /user_upgrades/:id page, where we show
the user their upgrade receipt.
