Add a function to fetch the system resource.

1 files changed, 21 insertions, 0 deletions

diff --git a/gn_auth/auth/authorisation/resources/system/models.py b/gn_auth/auth/authorisation/resources/system/models.py
index 7c176aa..303b0ac 100644
--- a/gn_auth/auth/authorisation/resources/system/models.py
+++ b/gn_auth/auth/authorisation/resources/system/models.py
@@ -4,11 +4,15 @@ from functools import reduce
 from typing import Sequence
 
 from gn_auth.auth.db import sqlite3 as db
+from gn_auth.auth.errors import NotFoundError
 
 from gn_auth.auth.authentication.users import User
 
 from gn_auth.auth.authorisation.roles import Role
 from gn_auth.auth.authorisation.privileges import Privilege
+from gn_auth.auth.authorisation.resources.base import (
+    Resource,
+    resource_from_dbrow)
 
 def __organise_privileges__(acc, row):
     role_id = UUID(row["role_id"])
@@ -24,6 +28,7 @@ def __organise_privileges__(acc, row):
              (Privilege(row["privilege_id"], row["privilege_description"]),)))
     }
 
+
 def user_roles_on_system(conn: db.DbConnection, user: User) -> Sequence[Role]:
     """
     Retrieve all roles assigned to the `user` that act on `system` resources.
@@ -45,3 +50,19 @@ def user_roles_on_system(conn: db.DbConnection, user: User) -> Sequence[Role]:
         return tuple(reduce(
             __organise_privileges__, cursor.fetchall(), {}).values())
     return tuple()
+
+
+def system_resource(conn: db.DbConnection) -> Resource:
+    """Retrieve the system resource."""
+    with db.cursor(conn) as cursor:
+        cursor.execute(
+            "SELECT resource_categories.*, resources.resource_id, "
+            "resources.resource_name, resources.public "
+            "FROM resource_categories INNER JOIN resources "
+            "ON resource_categories.resource_category_id=resources.resource_category_id "
+            "WHERE resource_categories.resource_category_key='system'")
+        row = cursor.fetchone()
+        if row:
+            return resource_from_dbrow(row)
+
+    raise NotFoundError("Could not find a system resource!")