Web Push on every status change

[marek-saji]

• [client] Subscribe for push notifications
• [server] When status changes:
  • to occupied/error: push to all clients, don’t clear them
  • to free: push to first client, remove from queue
  • if status does not change for some time, push to next subscribed client, remove from queue
• [client] Upon receiving a status in SW, send to all clients and make them update the UI
  • If client is marked as „subscribed”, show notification
• [client] If push notifications are allowed, use them instead of /check

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• [ ] Clients with no push support (and SSR) should get occupied while push queue is not empty

[marek-saji]

Terrible idea. Push would be sent even if user left page long time ago. If we ever want real time, we should use WebSockets.