1 files changed, 47 insertions, 0 deletions
diff --git a/gn_auth/auth/authorisation/resources/system/models.py b/gn_auth/auth/authorisation/resources/system/models.py
new file mode 100644
index 0000000..7c176aa
--- /dev/null
+++ b/gn_auth/auth/authorisation/resources/system/models.py
@@ -0,0 +1,47 @@
+"""Base functions and utilities for system resources."""
+from uuid import UUID
+from functools import reduce
+from typing import Sequence
+
+from gn_auth.auth.db import sqlite3 as db
+
+from gn_auth.auth.authentication.users import User
+
+from gn_auth.auth.authorisation.roles import Role
+from gn_auth.auth.authorisation.privileges import Privilege
+
+def __organise_privileges__(acc, row):
+    role_id = UUID(row["role_id"])
+    role = acc.get(role_id, Role(
+        role_id, row["role_name"], bool(int(row["user_editable"])), tuple()))
+    return {
+        **acc,
+        role_id: Role(
+            role.role_id,
+            role.role_name,
+            role.user_editable,
+            (role.privileges +
+             (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.
+    """
+    with db.cursor(conn) as cursor:
+        role_ids_query = (
+            "SELECT ur.role_id FROM user_roles AS ur INNER JOIN resources AS r "
+            "ON ur.resource_id=r.resource_id "
+            "INNER JOIN resource_categories AS rc "
+            "ON r.resource_category_id=rc.resource_category_id "
+            "WHERE user_id=? AND rc.resource_category_key='system'")
+        cursor.execute(
+            "SELECT r.*, p.* FROM roles AS r "
+            "INNER JOIN role_privileges AS rp ON r.role_id=rp.role_id "
+            "INNER JOIN privileges AS p ON rp.privilege_id=p.privilege_id "
+            f"WHERE r.role_id IN ({role_ids_query})",
+            (str(user.user_id),))
+
+        return tuple(reduce(
+            __organise_privileges__, cursor.fetchall(), {}).values())
+    return tuple()