memory: new "affiliation" metadata for files:

this affiliation is similar to pubsub affiliation, for now only `owner` is used.
Affiliation is set when possible (peer_jid is set notably).

sat/memory/memory.py

@@ -22,6 +22,7 @@ import copy
 import shortuuid
 import mimetypes
 import time
+from typing import Optional, Tuple
 from pathlib import Path
 from uuid import uuid4
 from collections import namedtuple
@@ -1182,23 +1183,34 @@ class Memory(object):
 
     ## Files ##
 
-    def checkFilePermission(self, file_data, peer_jid, perms_to_check):
-        """check that an entity has the right permission on a file
+    def checkFilePermission(
+            self,
+            file_data: dict,
+            peer_jid: Optional[jid.JID],
+            perms_to_check: Optional[Tuple[str]],
+            set_affiliation: bool = False
+    ) -> None:
+        """Check that an entity has the right permission on a file
 
-        @param file_data(dict): data of one file, as returned by getFiles
-        @param peer_jid(jid.JID): entity trying to access the file
-        @param perms_to_check(tuple[unicode]): permissions to check
+        @param file_data: data of one file, as returned by getFiles
+        @param peer_jid: entity trying to access the file
+        @param perms_to_check: permissions to check
             tuple of C.ACCESS_PERM_*
-        @param check_parents(bool): if True, also check all parents until root node
+        @param check_parents: if True, also check all parents until root node
+        @parma set_affiliation: if True, "affiliation" metadata will be set
         @raise exceptions.PermissionError: peer_jid doesn't have all permission
             in perms_to_check for file_data
         @raise exceptions.InternalError: perms_to_check is invalid
         """
+        # TODO: knowing if user is owner is not enough, we need to check permission
+        #   to see if user can modify/delete files, and set corresponding affiliation (publisher, member)
         if peer_jid is None and perms_to_check is None:
             return
         peer_jid = peer_jid.userhostJID()
         if peer_jid == file_data["owner"]:
-            # the owner has all rights
+            if set_affiliation:
+                file_data['affiliation'] = 'owner'
+            # the owner has all rights, nothing to check
             return
         if not C.ACCESS_PERMS.issuperset(perms_to_check):
             raise exceptions.InternalError(_("invalid permission"))
@@ -1383,7 +1395,7 @@ class Memory(object):
             to_remove = []
             for file_data in files:
                 try:
-                    self.checkFilePermission(file_data, peer_jid, perms_to_check)
+                    self.checkFilePermission(file_data, peer_jid, perms_to_check, set_affiliation=True)
                 except exceptions.PermissionError:
                     to_remove.append(file_data)
             for file_data in to_remove: