from rest_framework import serializers, status from rest_framework.views import APIView from rest_framework.response import Response from django.contrib.auth import authenticate, login, logout from django.contrib.auth.models import User from .serializers import OrderSerializer, MakeOrderSerializer from .models import Order from .nick_generator.nick_generator import NickGenerator from robohash import Robohash from scipy.stats import entropy from math import log2 import numpy as np import hashlib from pathlib import Path from datetime import timedelta from django.utils import timezone # .env expiration_time = 8 avatar_path = Path('frontend/static/assets/avatars') avatar_path.mkdir(parents=True, exist_ok=True) # Create your views here. class MakeOrder(APIView): serializer_class = MakeOrderSerializer def post(self,request): serializer = self.serializer_class(data=request.data) if serializer.is_valid(): otype = serializer.data.get('type') currency = serializer.data.get('currency') amount = serializer.data.get('amount') payment_method = serializer.data.get('payment_method') premium = serializer.data.get('premium') satoshis = serializer.data.get('satoshis') is_explicit = serializer.data.get('is_explicit') # query if the user is already a maker or taker, return error queryset = Order.objects.filter(maker=request.user.id) if queryset.exists(): return Response({'Bad Request':'You are already maker of an order'},status=status.HTTP_400_BAD_REQUEST) queryset = Order.objects.filter(taker=request.user.id) if queryset.exists(): return Response({'Bad Request':'You are already taker of an order'},status=status.HTTP_400_BAD_REQUEST) # Creates a new order in db order = Order( type=otype, currency=currency, amount=amount, payment_method=payment_method, premium=premium, satoshis=satoshis, is_explicit=is_explicit, expires_at= timezone.now()+timedelta(hours=expiration_time), maker=request.user) order.save() if not serializer.is_valid(): return Response(status=status.HTTP_400_BAD_REQUEST) return Response(OrderSerializer(order).data, status=status.HTTP_201_CREATED) class OrderView(APIView): serializer_class = OrderSerializer lookup_url_kwarg = 'order_id' def get(self, request, format=None): order_id = request.GET.get(self.lookup_url_kwarg) if order_id != None: order = Order.objects.filter(id=order_id) # check if exactly one order is found in the db if len(order) == 1 : order = order[0] data = self.serializer_class(order).data nickname = request.user.username # Check if requester is participant in the order and add boolean to response data['is_participant'] = (str(order.maker) == nickname or str(order.taker) == nickname) #To do fix: data['status_message'] = Order.Status.get(order.status).label data['status_message'] = Order.Status.WFB.label # Hardcoded WFB, should use order.status value. data['maker_nick'] = str(order.maker) data['taker_nick'] = str(order.taker) if data['is_participant']: return Response(data, status=status.HTTP_200_OK) else: # Non participants should not see the status or who is the taker data.pop('status','status_message','taker','taker_nick') return Response(data, status=status.HTTP_200_OK) return Response({'Order Not Found':'Invalid Order Id'},status=status.HTTP_404_NOT_FOUND) return Response({'Bad Request':'Order ID parameter not found in request'}, status=status.HTTP_400_BAD_REQUEST) class UserGenerator(APIView): lookup_url_kwarg = 'token' NickGen = NickGenerator( lang='English', use_adv=False, use_adj=True, use_noun=True, max_num=999) def get(self,request, format=None): ''' Get a new user derived from a high entropy token - Request has a high-entropy token, - Generates new nickname and avatar. - Creates login credentials (new User object) Response with Avatar and Nickname. ''' token = request.GET.get(self.lookup_url_kwarg) # Compute token entropy value, counts = np.unique(list(token), return_counts=True) shannon_entropy = entropy(counts, base=62) bits_entropy = log2(len(value)**len(token)) # Start preparing payload context = {'token_shannon_entropy': shannon_entropy, 'token_bits_entropy': bits_entropy} # Deny user gen if entropy below 128 bits or 0.7 shannon heterogeneity if bits_entropy < 128 or shannon_entropy < 0.7: context['bad_request'] = 'The token does not have enough entropy' return Response(context, status=status.HTTP_400_BAD_REQUEST) # Hashes the token, only 1 iteration. Maybe more is better. hash = hashlib.sha256(str.encode(token)).hexdigest() # generate nickname nickname = self.NickGen.short_from_SHA256(hash, max_length=18)[0] context['nickname'] = nickname # generate avatar rh = Robohash(hash) rh.assemble(roboset='set1') # bgset='any' for backgrounds ON # replaces image if existing (in of case nickname collusion avatar would change!) with open(avatar_path.joinpath(nickname+".png"), "wb") as f: rh.img.save(f, format="png") # Create new credentials if nickname is new if len(User.objects.filter(username=nickname)) == 0: User.objects.create_user(username=nickname, password=token, is_staff=False) user = authenticate(request, username=nickname, password=token) login(request, user) return Response(context, status=status.HTTP_201_CREATED) else: user = authenticate(request, username=nickname, password=token) if user is not None: login(request, user) # Sends the welcome back message, only if created +30 mins ago if request.user.date_joined < (timezone.now()-timedelta(minutes=30)): context['found'] = 'We found your Robosat. Welcome back!' return Response(context, status=status.HTTP_202_ACCEPTED) else: # It is unlikely (1/20 Billions) but maybe the nickname is taken context['found'] = 'Bad luck, this nickname is taken' context['bad_request'] = 'Enter a different token' return Response(context, status=status.HTTP_403_FORBIDDEN) def delete(self,request): user = User.objects.get(id = request.user.id) # TO DO. Pressing give me another will delete the logged in user # However it might be a long time recovered user # Only delete if user live is < 5 minutes if user is not None: avatar_file = avatar_path.joinpath(str(request.user)+".png") avatar_file.unlink() # Unsafe if avatar does not exist. logout(request) user.delete() return Response({'user_deleted':'User deleted permanently'},status=status.HTTP_301_MOVED_PERMANENTLY) return Response(status=status.HTTP_403_FORBIDDEN) class BookView(APIView): serializer_class = OrderSerializer def get(self,request, format=None): currency = request.GET.get('currency') type = request.GET.get('type') queryset = Order.objects.filter(currency=currency, type=type) if len(queryset)== 0: return Response({'not_found':'No orders found, be the first to make one'}, status=status.HTTP_404_NOT_FOUND) book_data = [] for order in queryset: data = OrderSerializer(order).data user = User.objects.filter(id=data['maker']) if len(user) == 1: data['maker_nick'] = user[0].username # TODO avoid sending status and takers for book views #data.pop('status','taker') book_data.append(data) return Response(book_data, status=status.HTTP_200_OK)