Nextcloud API get files/folders recursively

Question

I am trying to do the following with Nextcloud and PHP and googling didn't yield any results:

I have a Folderstructure like so:

Parent
   --> Child1
   --> Child2
         File1
         File2
         File3
   --> Child3
         File1
         File2
       --> SubChild1
           File1
           File2
           -->SubSubchild1
              File1

So it's a lot of folders and files, sometimes 1 level deep, sometimes empty and sometimes several levels deep.

I need to generate a list in PHP of all the shared folders withe their shared files and subfolders.

So far I have only succeeded in getting Nextcloud to show me all the subfolders and files of on folder. In my example above I could see the contents of Child3 (File1, File2 and Subchild1) but not the contens of SubChild1. I did this by using:

https://my-nextcloud.instance//ocs/v2.php/apps/files_sharing/api/v1/shares?format=json&path=Parent/Child3&subfiles=true

That would mean that I had to make a curl-call to the API for every Subfolder I have... that makes this very clumsy and slow... especially since I don`t know how deep the folder-structure will go in the future....

Are there any better ways? What am I missing? Any help or pointers in the right direction would be greatly appreciated!