[FOLLOW-UP] Scheduled messages feature

How to use GitHub

• Please use the 👍 reaction to show that you are affected by the same issue.
• Please don't comment if you have no relevant information to add. It's just extra noise for everyone subscribed to this issue.
• Subscribe to receive notifications on status change and new comments.

• Original ref: #3954
• Frontend follow-up to #16509

API:

• Dashboard widget as an option to see messages scheduled for the next X days?
• File shares and other rich objects?
• Reply to original thread message doesn't have a parent
• #16777
• If there is an upcoming scheduled message less than 24 hours from now the buttons turns into a secondary button
  • Ref https://github.com/nextcloud/spreed/pull/14270
• actorDisplayName is missing (although the question is if we really need it, as we only schedule messages for ourselves?)

Frontend:

• Client should periodically check for timed out messages (to not render them in client)?
• 3 messages scheduled to be sent in aria-label for the toggle or more visible hint?
• mentions migh be rendered (from available data)?
• mentions hint should not be shown when editing scheduled message
• If there is an upcoming scheduled message less than 24 hours from now the buttons turns into a secondary button?
• Scheduled thread replies should indicate they are aiming at some thread
• Visibility of 'Show scheduled messages' toggle (disappears when the input field is focused / filled / in call / in sidebar)?
• Visibility of Input field when showing scheduled messages (should be hidden / disabled)?
• When error, appearance of toggle button should be changed (error variant)
• When error, failed messages should be shown differently (currently as temp messages)
• In the list of scheduled messages show "Send at" in the date separators, so Send at December 18th
• the appearance of toggle button is animated (input field shrinks and button appears)
• already visible toggle button should have a little animation to confirm that the message was scheduled
• Scheduled message view should block regular send and only allow scheduled message creation
• Retain schedule timestamps between conversation switch, like mesage drafts

https://github.com/user-attachments/assets/af51f624-ba98-48ee-8ecb-36b5159b679c