Implemented support for returning richer HTTP responses on webhooks.

A `WebhookEvent` hook can now return a tuple in the format `(data,
http_code, headers)` in order to customize the HTTP status code and the
headers of a response.

platypush/backend/http/app/routes/hook.py

@@ -1,7 +1,6 @@
 import json
 
-from flask import Blueprint, abort, request
-from flask.wrappers import Response
+from flask import Blueprint, abort, request, make_response
 
 from platypush.backend.http.app import template_folder
 from platypush.backend.http.app.utils import logger, send_message
@@ -61,14 +60,31 @@ def hook_route(hook_name):
 
     try:
         send_message(event)
+        rs = make_response(json.dumps({'status': 'ok', **event_args}))
+        headers = {}
+        status_code = 200
 
         # If there are matching hooks, wait for their completion before returning
         if matching_hooks:
-            return event.wait_response(timeout=60)
+            rs = event.wait_response(timeout=60)
+            try:
+                rs = json.loads(rs.decode())  # type: ignore
+            except Exception:
+                pass
 
-        return Response(
-            json.dumps({'status': 'ok', **event_args}), mimetype='application/json'
-        )
+            if isinstance(rs, dict) and '___data___' in rs:
+                # data + http_code + custom_headers return format
+                headers = rs.get('___headers___', {})
+                status_code = rs.get('___code___', status_code)
+                rs = rs['___data___']
+
+            rs = make_response(rs)
+        else:
+            headers = {'Content-Type': 'application/json'}
+
+        rs.status_code = status_code
+        rs.headers.update(headers)
+        return rs
     except Exception as e:
         logger().exception(e)
         logger().error('Error while dispatching webhook event %s: %s', event, str(e))

platypush/message/event/http/hook.py

@@ -58,6 +58,23 @@ class WebhookEvent(Event):
 
     def send_response(self, response):
         output = response.output
+        if isinstance(output, tuple):
+            # A 3-sized tuple where the second element is an int and the third
+            # is a dict represents an HTTP response in the format `(data,
+            # http_code headers)`.
+            if (
+                len(output) == 3
+                and isinstance(output[1], int)
+                and isinstance(output[2], dict)
+            ):
+                output = {
+                    '___data___': output[0],
+                    '___code___': output[1],
+                    '___headers___': output[2],
+                }
+            else:
+                # Normalize tuples to lists before serialization
+                output = list(output)
         if isinstance(output, (dict, list)):
             output = json.dumps(output)