Add in-app notifications for comments

[keyserj]

Describe your issue

TBD

Solution you'd like

No response

Alternatives you've considered

No response

Additional context

No response

Technical ideas and questions

No response

[keyserj]

related to #238

[keyserj]

Design thoughts:

UX

Red is "need to have", blue is "nice to have". I'm leaning towards including Watches/Subscriptions right away (at least the structure, potentially the UX could be future), and read/unread as a future thing.

(if no watches/subscriptions right away, notifications would always be sent to the topic's creator and thread participants, with everyone given the option to turn off all Ameliorate emails).

User Drawer

/notifications Page

Email Notification (similar to GitHub's)

In-Topic UX

Technical Flow Pseudocode

API create comment route

• emit("commentCreated", comment)

Event "commentCreated" handler (synchronous, just separated for organization)

• if author has no "ignore" topic watch: subscribe author to comment's thread
• get users to send to
  • subscribers to thread OR watchers ("all") of topic
• createNotifications(users)
  • build and send emails if userConfig.receiveEmailNotifications === true

Schemas

• haven't solidified these yet, wondering what is needed to support the above UX
• looked at notification services (diagram), considered novu the most, but ultimately doesn't seem like it's worth to use their service (they don't have any watch logic, would want infra in the repo but "novu as code" docs say in-progress)

UserConfig Schema

• username
• receiveEmailNotifications: boolean (default true)

UserNotification Schema

• notifiedUsername
• commentId (optional if other sources in future) (used for building email, plus in-app row will show comment's topic and link)
• message
  • what to put here when email and in-app use different text?
  • could go no message and build when needed via related comment, but this wouldn't allow system messages
    • maybe could just directly use email for system messages?
• ~link to source~ (notification row will build link via comment)
• reason: "subscribed" | "watching" (for email explanation and unsubscribe)
• time
• unread (can add later with implementation)

Watch Schema

• watcherUsername
• topicId
• what ("participatingOrMentions", "all", "ignore")

Subscription Schema

• subscriberUsername
• topicId
• rootCommentId

Questions

• does it seem reasonable to add email to user?
  • because can't pull from auth0 for every email, auth0 limits to 5 user-info requests/minute
  • main concern is PII security, but it might be ok if it's excluded from all API calls?
• no idea what to do for topic-changed notifications, seems like those should always be digest-ed because there's no commits to group changes