UI for email subscription

[umputun]

With the backend part in place (thx to @paskal) we can integrate it on the UI side. This should be something similar to email-based login, i.e:

1. Add a link "subscribe to email notification"
2. Click on this link will ask for email and show confirmation dialog expecting a token
3. Token will be sent to the user by email, the same way as we send confirmations for email auth
4. Subscribed user should be able to unsubscribe from UI

API for email notifications documented in the readme

@Reeywhaar - let me know if you want to handle this one, should be very similar to email auth you did before.

[umputun]

related: #495 #494

[paskal]

1. https://www.mailgun.com/ is the easiest way to get a server for email notifications, docker-compose configuration for it would look similar to this:

           - NOTIFY_EMAIL_HOST=smtp.eu.mailgun.org
           - [email protected]
           - NOTIFY_EMAIL_PASSWORD=password
           - [email protected]
           - NOTIFY_EMAIL_PORT=465
           - NOTIFY_EMAIL_TLS=true
   

2. remark.rest file has working examples of requests to run against local docker-compose setup, after which you will have chosen email account verified and receiving notifications.
3. A note on the implementation: when users subscribing to email notifications, they will get all replies to all their comments on the site.
4. A small fix to apply with implementing this feature: email verification currently have text Copy and paste this text into “token” field on comments page — it should be changed to something like on email verification page when it will be know how it will be named.
   https://github.com/umputun/remark/blob/d23d119d70e015d65aaf155713f615056181df96/backend/app/notify/email.go#L128
   

[akellbl4]

@umputun I can do it. Where should be placed subscribe button?

[paskal]

Another note: /config endpoint now has email_notifications boolean property which tells UI if notifications interface should be enabled.

[umputun]

@akellbl4 sorry, missed your question. Thx for volunteering, appreciate it.

This subscribe button (link?) should be around other subscriptions

In some other ticket, I have proposed to change the plain list of subscriptions to something under dropdown or whatever control makes sense. As far as I recall the problem on the UI side was how to make it mobile-friendly. Feel free to propose any improvements for this block, as of now all this "subscribe" part is way too visible for such a non-primary functionality.

[akellbl4]

@umputun I made UI example, If it is good for you I will go to logic.

[paskal]

3. A note on the implementation: when users subscribing to email notifications, they will get all replies to all their comments on the site.

Unfortunately at this very moment that’s the only variant of email subscription.

[paskal]

I would suggest having something like Subscribe to <Thread via RSS><Site via RSS><Replies via RSS><Replies via Email> which will decrease occupied space as well.

[akellbl4]

@umputun @paskal something like that?

[paskal]

LGTM, but I wonder how would it look and feel like from mobile.

[umputun]

yeah. I'd call "Email" as "Replies via email", or even better would make two sections with headers (RSS and Email) in each one

[akellbl4]

I think it is the best variant :)

[umputun]

nice

[akellbl4]

@paskal I wrote some code for sending email verification but I won't receive emails with a token. At the same time, the email login works fine.
You can checkout my code from here maybe I did something wrong. I am not sure.