Issue 2276 - Handle groups in notification.json requests

sitescripts/notifications/web/notification.py

Index: sitescripts/notifications/web/notification.py
===================================================================
new file mode 100644
--- /dev/null
+++ b/sitescripts/notifications/web/notification.py
@@ -0,0 +1,101 @@
+# coding: utf-8
+
+# This file is part of the Adblock Plus web scripts,
+# Copyright (C) 2006-2015 Eyeo GmbH
+#
+# Adblock Plus is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# Adblock Plus is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+
+import copy
+import json
+import random
+import time
+import urlparse
+
+from sitescripts.notifications.parser import load_notifications
+from sitescripts.web import url_handler
+
+def _determine_groups(version, notifications):
+  version_groups = dict(x.split("/") for x in version.split("-")[1:]
+                        if x.count("/") == 1)
+  groups = []
+  for notification in notifications:
+    if "variants" not in notification:
+      continue
+    group_id = notification["id"]
+    if group_id in version_groups:
+      groups.append({"id": group_id, "variant": int(version_groups[group_id])})
+  return groups
+
+def _assign_groups(notifications):
+  groups = []
+  selection = random.random()
+  start = 0
+  for notification in notifications:
+    if "variants" not in notification:
+      continue
+    group = {"id": notification["id"], "variant": 0}
+    groups.append(group)
+    for i, variant in enumerate(notification["variants"]):
+      sample_size = variant["sample"]
+      end = start + sample_size
+      selected = sample_size > 0 and start <= selection <= end
+      start = end
+      if selected:
+        group["variant"] = i + 1
+        break
+  return groups
+
+def _get_active_variant(notifications, groups):
+  for group in groups:
+    group_id = group["id"]
+    variant = group["variant"]
+    if variant == 0:
+      continue
+    notification = next(x for x in notifications if x["id"] == group_id)
+    notification = copy.deepcopy(notification)
+    notification.update(notification["variants"][variant - 1])
+    for key_to_remove in ("sample", "variants"):
+      notification.pop(key_to_remove, None)
+    return notification
+
+def _generate_version(groups):
+  version = time.strftime("%Y%m%d%H%M", time.gmtime())
+  for group in groups:
+    version += "-%s/%s" % (group["id"], group["variant"])
+  return version
+
+def _create_response(notifications, groups):
+  active_variant = _get_active_variant(notifications, groups)
+  if active_variant:
+    notifications = [active_variant]
+  else:
+    notifications = [x for x in notifications if "variants" not in x]
+  response = {
+    "version": _generate_version(groups),
+    "notifications": notifications
+  }
+  return json.dumps(response, ensure_ascii=False, indent=2,
+                    separators=(",", ": "), sort_keys=True)
+
+@url_handler("/notification.json")
+def notification(environ, start_response):
+  params = urlparse.parse_qs(environ.get("QUERY_STRING", ""))
+  version = params.get("lastVersion", [""])[0]
+  notifications = load_notifications()
+  groups = _determine_groups(version, notifications)
+  if not groups:
+    groups = _assign_groups(notifications)
+  response = _create_response(notifications, groups)
+  start_response("200 OK",
+                 [("Content-Type", "application/json; charset=utf-8")])
+  return response.encode("utf-8")