Custom Apps for Permissions, Analysis and Search


We are thinking of using next-cloud as an On-Prem file storage solution.
We have a few questions regarding our needs:

  1. Is it possible to add a custom permissions component or app that will send the authorization request (create or access a file) to an external service and according to it’s response determine whether the user is permitted to do the action?
  2. Is it possible to author apps for NC with nodeJs or .Net Core by satisfying a certain interface implementation instead of Php?
  3. Can we add a custom app that will process and anylyse the file before entering the system?
  4. Is there an app the searches the contents of files and indexes it? (To Solr or similier)


We found out ways for questions 3 and 4.
Does anyone have experience implementing the first 2 questions?

Thanks in advance,