This leverages our existing Discord OAuth implementation. Any users with a linked Discord account will be able to log in immediately. When logging in, we request the `email` scope in addition to `identity`, so existing users will be prompted one time to accept the new permissions. On subsequent logins, Discord will skip the prompt.
When linking your Discord account to an existing HMN account, we continue to only request the `identity` scope, so we do not receive the user's Discord email.
Both login and linking go through the same Discord OAuth callback. All flows through the callback try to achieve the same end goal: a logged-in HMN user with a linked Discord account.
Linking works the same as it ever has. Login, however, is different because we do not have a session ID to use as the OAuth state. To account for this, I have added a `pending_login` table that stores a secure unique ID and the eventual destination URL. These pending logins expire after 10 minutes. When we receive the OAuth callback, we look up the pending login by the OAuth `state` and immediately delete it. The destination URL will be used to redirect the user to the right place.
If we have a `discord_user` entry for the OAuth'd Discord user, we immediately log the user into the associated HMN account. This is the typical login case. If we do not have a `discord_user`, but there is exactly one HMN user with the same email address as the Discord user, we will link the two accounts and log into the HMN account.
(It is possible for multiple HMN accounts to have the same email, because we don't have a uniqueness constraint there. We fail the login in this case rather than link to the wrong account.)
Finally, if no associated HMN user exists, a new one will be created. It will use the Discord user's username, email, and avatar. This user will have no password, but they can set or reset a password through the usual flows.
Co-authored-by: Ben Visness <bvisness@gmail.com>
Reviewed-on: hmn/hmn#106
Clean up several TODOs
Implement the full disconnect / resume flow
Detect zombied connections and restart
Implement the random delay on reconnect
Implement message sending!!
(with a goofy feedback loop on the echo bot)
Fix the feedback loop in the echo bot
Clean up the Discord gateway code
Many things are methods now to reduce the amount of explicit plumbing.
Connection handling should be a little more robust, and we have an
actual error handling strategy now.
Allow sending multiple Discord messages at once
Delete irrelevant tests
uhh, start rate limiting
Add per-route rate limiting
Add global rate limit handling
Handle context cancellation in Discord REST code
Allow changing buckets per route
Add the showcase rejection bot
Add library bot
Asaf Gartner
bvisness
Ben Visness