Add cancel taker penalty time

.env-sample

@@ -5,6 +5,8 @@ MARKET_PRICE_API = 'https://blockchain.info/ticker'
 FEE = 0.002
 # Bond size in percentage %     
 BOND_SIZE = 0.01
+# Time out penalty for canceling takers in MINUTES
+PENALTY_TIMEOUT = 2
 
 # Trade limits in satoshis
 MIN_TRADE = 10000 

api/logics.py

@@ -10,6 +10,7 @@ FEE = float(config('FEE'))
 BOND_SIZE = float(config('BOND_SIZE'))
 MARKET_PRICE_API = config('MARKET_PRICE_API')
 ESCROW_USERNAME = config('ESCROW_USERNAME')
+PENALTY_TIMEOUT = int(config('PENALTY_TIMEOUT'))
 
 MIN_TRADE = int(config('MIN_TRADE'))
 MAX_TRADE = int(config('MAX_TRADE'))
@@ -21,6 +22,7 @@ EXP_TRADE_ESCR_INVOICE = int(config('EXP_TRADE_ESCR_INVOICE'))
 BOND_EXPIRY = int(config('BOND_EXPIRY'))
 ESCROW_EXPIRY = int(config('ESCROW_EXPIRY'))
 
+
 class Logics():
 
     def validate_already_maker_or_taker(user):
@@ -40,11 +42,17 @@ class Logics():
         if order.t0_satoshis < MIN_TRADE:
             return False, {'bad_request': 'Your order is too small. It is worth '+'{:,}'.format(order.t0_satoshis)+' Sats now. But limit is '+'{:,}'.format(MIN_TRADE)+ ' Sats'}
         return True, None
-        
-    def take(order, user):
-        order.taker = user
-        order.status = Order.Status.TAK
-        order.save()
+
+    @classmethod    
+    def take(cls, order, user):
+        is_penalized, time_out = cls.is_penalized(user)
+        if is_penalized:
+            return False, {'bad_request',f'You need to wait {time_out} seconds to take an order'}
+        else:
+            order.taker = user
+            order.status = Order.Status.TAK
+            order.save()
+            return True, None
 
     def is_buyer(order, user):
         is_maker = order.maker == user
@@ -167,6 +175,18 @@ class Logics():
         order.save()
         return True, None
 
+    def is_penalized(user):
+        ''' Checks if a user that is not participant of orders
+        has a limit on taking or making a order'''
+        
+        if user.profile.penalty_expiration:
+            if user.profile.penalty_expiration > timezone.now():
+                time_out = (user.profile.penalty_expiration - timezone.now()).seconds
+                return True, time_out
+
+        return False, None
+
+
     @classmethod
     def cancel_order(cls, order, user, state=None):
 
@@ -181,12 +201,24 @@ class Logics():
 
         # 2) When maker cancels after bond
             '''The order dissapears from book and goes to cancelled. 
-            Maker is charged a small amount of sats, to prevent DDOS 
-            on the LN node and order book'''
+            Maker is charged the bond to prevent DDOS 
+            on the LN node and order book. TODO Only charge a small part 
+            of the bond (requires maker submitting an invoice)'''
+        
 
         # 3) When taker cancels before bond
             ''' The order goes back to the book as public.
             LNPayment "order.taker_bond" is deleted() '''
+        elif order.status == Order.Status.TAK and order.taker == user:
+            # adds a timeout penalty
+            user.profile.penalty_expiration = timezone.now() + timedelta(seconds=PENALTY_TIMEOUT)
+            user.save()
+
+            order.taker = None
+            order.status = Order.Status.PUB
+            order.save()
+
+            return True, None
 
         # 4) When taker or maker cancel after bond (before escrow)
             '''The order goes into cancelled status if maker cancels.

api/models.py

@@ -158,6 +158,9 @@ class Profile(models.Model):
     # RoboHash
     avatar = models.ImageField(default="static/assets/misc/unknown_avatar.png", verbose_name='Avatar', blank=True)
 
+    # Penalty expiration (only used then taking/cancelling repeatedly orders in the book before comitting bond)
+    penalty_expiration = models.DateTimeField(null=True)
+
     @receiver(post_save, sender=User)
     def create_user_profile(sender, instance, created, **kwargs):
         if created:

api/utils.py

@@ -5,7 +5,7 @@ import ring
 
 storage = {}
 
-@ring.dict(storage, expire=10) #keeps in cache for 10 seconds
+@ring.dict(storage, expire=30) #keeps in cache for 30 seconds
 def get_exchange_rate(currency):
     # TODO Add fallback Public APIs and error handling
     # Think about polling price data in a different way (e.g. store locally every t seconds)

api/views.py

@@ -105,6 +105,11 @@ class OrderView(viewsets.ViewSet):
 
         data = ListOrderSerializer(order).data
 
+        # if user is under a limit (penalty), inform him
+        is_penalized, time_out = Logics.is_penalized(request.user)
+        if is_penalized:
+            data['penalty'] = time_out
+
         # Add booleans if user is maker, taker, partipant, buyer or seller
         data['is_maker'] = order.maker == request.user
         data['is_taker'] = order.taker == request.user
@@ -207,7 +212,9 @@ class OrderView(viewsets.ViewSet):
                 valid, context = Logics.validate_already_maker_or_taker(request.user)
                 if not valid: return Response(context, status=status.HTTP_409_CONFLICT)
 
-                Logics.take(order, request.user)
+                valid, context = Logics.take(order, request.user)
+                if not valid: return Response(context, status=status.HTTP_403_FORBIDDEN)
+
             else: Response({'bad_request':'This order is not public anymore.'}, status.HTTP_400_BAD_REQUEST)
 
         # Any other action is only allowed if the user is a participant

frontend/src/components/OrderPage.js

@@ -1,5 +1,5 @@
 import React, { Component } from "react";
-import { Paper, CircularProgress, Button , Grid, Typography, List, ListItem, ListItemText, ListItemAvatar, Avatar, Divider, Box, LinearProgress} from "@mui/material"
+import { Alert, Paper, CircularProgress, Button , Grid, Typography, List, ListItem, ListItemText, ListItemAvatar, Avatar, Divider, Box, LinearProgress} from "@mui/material"
 import TradeBox from "./TradeBox";
 
 function msToTime(duration) {
@@ -101,6 +101,7 @@ export default class OrderPage extends Component {
             isTaker: data.is_taker,
             isBuyer: data.is_buyer,
             isSeller: data.is_seller,
+            penalty: data.penalty,
             expiresAt: data.expires_at,
             badRequest: data.bad_request,
             bondInvoice: data.bond_invoice,
@@ -249,6 +250,18 @@ export default class OrderPage extends Component {
             </ListItem>
             <LinearDeterminate />
             </List>
+            
+            {/* If the user has a penalty/limit */}
+            {this.state.penalty ? 
+            <>
+              <Divider />
+              <Grid item xs={12} align="center">
+                <Alert severity="warning" sx={{maxWidth:360}}>
+                  You cannot take an order yet! Wait {this.state.penalty} seconds 
+                </Alert>  
+              </Grid>
+            </>
+            : null} 
 
           </Paper>
         </Grid>