[WIP] Python: rest_api cleanup

python/rest-api/rest_api.py

@@ -5,8 +5,6 @@ from operator import attrgetter
 
 VALID_HTTP_METHODS = ['GET', 'POST']
 
-def dump(obj):
-    return obj.__dict__
 
 class User:
     def __init__(self, name):
@@ -42,7 +40,7 @@ class User:
         return user
 
 
-class Registry:
+class MethodRegistry:
     def __init__(self):
         self.methods = {k: {} for k in VALID_HTTP_METHODS }
 
@@ -50,57 +48,75 @@ class Registry:
 
         def actual_decorator(f):
 
-            self.methods[http_method][url] = f
-
             @wraps(f)
-            def _impl(f_self, *f_args, **f_kwargs):
-                return f(f_self, *f_args, **f_kwargs)
+            def _wrapper(f_self, payload):
+
+                if payload:
+                    payload = json.loads(payload)
+
+                f_result = f(f_self, payload)
+
+                return json.dumps(f_result, default=lambda obj: obj.__dict__, sort_keys=True)
+
+            self.methods[http_method][url] = _wrapper
+
         return actual_decorator
 
+
 class RestAPI:
 
-    registry = Registry()
+    registry = MethodRegistry()
 
     def __init__(self, database=None):
         self._users = {user['name'] : User.from_dict(user) for user in database['users']} if database else {}
 
+    def _process_request(self, method, url, payload):
+        methods = self.registry.methods[method]
+        if url in methods.keys():
+#            try:
+#                return methods[url](self, payload)
+#            except json.JSONDecodeError:
+#                return 'Bad request'
+#            finally:
+#                return 'Internal server error'
+#        else:
+#            return 'Not found'
+
+            return methods[url](self, payload)
+
+    def get(self, url, payload=None):
+        return self._process_request('GET', url, payload)
+
+    def post(self, url, payload=None):
+        return self._process_request('POST', url, payload)
+
     @registry.register_url('/users', 'GET')
     def users(self, payload=None):
         if payload:
-            requested_users = json.loads(payload)['users']
+            requested_users = payload['users']
             response = [user for user in self._users.values() if user.name in requested_users]
         else:
             response = [user for user in self._users.values()]
 
-        return json.dumps({'users': response}, default=dump, sort_keys=True)
+        return {'users': response}
 
     @registry.register_url('/add', 'POST')
     def add(self, payload=None):
-        payload = json.loads(payload)
-        user = User(payload['user'])
+
+        name = payload['user']
+        user = User(name)
         self._users[user.name] = user
-        return json.dumps(user, default=dump)
+        return user
 
     @registry.register_url('/iou', 'POST')
     def iou(self, payload=None):
-        payload = json.loads(payload)
+
         lender = payload['lender']
         borrower = payload['borrower']
         amount = payload['amount']
+
         self._users[lender].lend(borrower, amount)
         self._users[borrower].borrow(lender, amount)
-        return json.dumps({'users': sorted([self._users[lender], self._users[borrower]], key=attrgetter('name'))}, default=dump, sort_keys=True)
 
-    def get(self, url, payload=None):
-        methods = self.registry.methods['GET']
-        if url in methods.keys():
-            return methods[url](self, payload)
-        else:
-            raise Exception('Error 404')
+        return {'users': sorted([self._users[lender], self._users[borrower]], key=attrgetter('name'))}
 
-    def post(self, url, payload=None):
-        methods = self.registry.methods['POST']
-        if url in methods.keys():
-            return methods[url](self, payload)
-        else:
-            raise Exception('Error 404')