From 69f1ffe661c3c137239bdac7cb172c5383afbc56 Mon Sep 17 00:00:00 2001
From: Dmitry Kokorin <d.kokorin@npp-crts.ru>
Date: Tue, 29 Jun 2021 19:23:21 +0300
Subject: [PATCH] [WIP] Python: rest_api

---
 python/rest-api/rest_api.py | 100 ++++++++++++++++++++++++------------
 1 file changed, 66 insertions(+), 34 deletions(-)

diff --git a/python/rest-api/rest_api.py b/python/rest-api/rest_api.py
index 5cdc776..08d4176 100644
--- a/python/rest-api/rest_api.py
+++ b/python/rest-api/rest_api.py
@@ -1,51 +1,83 @@
 import json
-from enum import Enum
+from collections import defaultdict
 from functools import wraps
 
 VALID_HTTP_METHODS = ['GET', 'POST']
 
-def register_url(url, http_method):
-    def actual_decorator(f):
-        @wraps(f)
-        def _impl(self, *f_args, **f_kwargs):
-            RestAPI._register_url(self, f, url, http_method)
-            return f(self, *f_args, **f_kwargs)
-    return actual_decorator
+
+class User:
+    def __init__(self, name):
+        self.name = name
+        self.owes = defaultdict(float)
+        self.owed_by = defaultdict(float)
+        self.balance = 0.0
+
+    def lend(self, lender_name, amount):
+        self.owed_by[lender_name] += amount
+        if not self.owed_by[lender_name]:
+            del self.owed_by[lender_name]
+
+    def borrow(self, borrower_name, amount):
+        self.owes[borrower_name] += amount
+        if not self.owed_by[borrower_name]:
+            del self.owed_by[borrower_name]
+
+    def to_json(self):
+        return json.dumps(self.__dict__)
+
+class Registry:
+    def __init__(self):
+        self.methods = {k: {} for k in VALID_HTTP_METHODS }
+
+    def register_url(self, url, http_method):
+
+        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)
+        return actual_decorator
 
 class RestAPI:
+
+    registry = Registry()
+
     def __init__(self, database=None):
-        self._rest_methods = {}
         self._database = database if database else {}
+        self._users = {}
 
-    def get(self, url, payload=None):
-        methods = self._rest_methods['GET']
-        if url in methods.keys():
-            return methods[url](payload)
-        else:
-            raise Exception('Error 404')
-
-    def post(self, url, payload=None):
-        methods = self._rest_methods['POST']
-        if url in methods.keys():
-            return methods[url](payload)
-        else:
-            raise Exception('Error 404')
-
-    def _register_url(self, f, url, http_method):
-
-        if http_method not in VALID_HTTP_METHODS:
-            raise Exception('Invalid Http method')
-
-        self._rest_methods[http_method][url] = f
-
-    @register_url('/users', 'GET')
+    @registry.register_url('/users', 'GET')
     def users(self, payload=None):
         pass
 
-    @register_url('/add', 'POST')
+    @registry.register_url('/add', 'POST')
     def add(self, payload=None):
-        pass
+        try:
+            payload = json.loads(payload)
+            user = User(payload['user'])
+            self._users[user.name] = user
+            return user.to_json()
+        except:
+            pass
 
-    @register_url('/iou', 'POST')
+    @registry.register_url('/iou', 'POST')
     def iou(self, payload=None):
         pass
+
+    def get(self, url, payload=None):
+        methods = self.registry.methods['GET']
+        if url in methods.keys():
+            return methods[url](self, payload)
+        return ''
+#        else:
+#            raise Exception('Error 404')
+
+    def post(self, url, payload=None):
+        methods = self.registry.methods['POST']
+        if url in methods.keys():
+            return methods[url](self, payload)
+        return ''
+#        else:
+#            raise Exception('Error 404')