Add HTLC model and placeholder functions

api/admin.py

@@ -2,7 +2,7 @@ from django.contrib import admin
 from django.db import models 
 from django.contrib.auth.models import Group, User
 from django.contrib.auth.admin import UserAdmin
-from .models import Order, Profile
+from .models import Order, LNPayment, Profile
 
 admin.site.unregister(Group)
 admin.site.unregister(User)
@@ -24,7 +24,13 @@ class EUserAdmin(UserAdmin):
 
 @admin.register(Order)
 class OrderAdmin(admin.ModelAdmin):
-    list_display = ('id','type','maker','taker','status','amount','currency','created_at','expires_at', 'invoice')
+    list_display = ('id','type','maker','taker','status','amount','currency','created_at','expires_at', 'buyer_invoice','maker_bond','taker_bond','trade_escrow')
+    list_display_links = ['id']
+    pass
+
+@admin.register(LNPayment)
+class LNPaymentAdmin(admin.ModelAdmin):
+    list_display = ('id','concept','status','amount','type','invoice','secret','expires_at','sender','receiver')
     list_display_links = ['id']
     pass
 

api/lightning.py

@@ -0,0 +1,41 @@
+import random
+import string
+
+#######
+# Placeholder functions
+# Should work with LND (maybe c-lightning in the future)
+
+class LNNode():
+    '''
+    Place holder functions to interact with Lightning Node
+    '''
+    
+    def gen_hodl_invoice():
+        '''Generates hodl invoice to publish an order'''
+        return ''.join(random.choices(string.ascii_uppercase + string.digits, k=80))
+
+    def validate_hodl_invoice_locked():
+        '''Generates hodl invoice to publish an order'''
+        return True
+
+    def validate_ln_invoice(invoice):
+        '''Checks if a LN invoice is valid'''
+        return True
+
+    def pay_buyer_invoice(invoice):
+        '''Sends sats to buyer'''
+        return True
+
+    def charge_hodl_htlcs(invoice):
+        '''Charges a LN hodl invoice'''
+        return True
+
+    def free_hodl_htlcs(invoice):
+        '''Returns sats'''
+        return True
+
+    
+    
+
+    
+

api/models.py

@@ -11,8 +11,50 @@ from pathlib import Path
 #############################
 # TODO
 # Load hparams from .env file
-min_satoshis_trade = 10*1000
-max_satoshis_trade = 500*1000
+
+MIN_TRADE = 10*1000  #In sats
+MAX_TRADE = 500*1000
+FEE = 0.002 # Trade fee in %
+BOND_SIZE = 0.01 # Bond in %
+
+
+class LNPayment(models.Model):
+
+    class Types(models.IntegerChoices):
+        NORM = 0, 'Regular invoice' # Only outgoing HTLCs will be regular invoices (Non-hodl)
+        HODL = 1, 'Hodl invoice'
+
+    class Concepts(models.IntegerChoices):
+        MAKEBOND = 0, 'Maker bond'
+        TAKEBOND = 1, 'Taker-buyer bond'
+        TRESCROW = 2, 'Trade escrow'
+        PAYBUYER = 3, 'Payment to buyer'
+
+    class Status(models.IntegerChoices):
+        INVGEN = 0, 'Hodl invoice was generated'
+        LOCKED = 1, 'Hodl invoice has HTLCs locked'
+        CHRGED = 2, 'Hodl invoice was charged'
+        RETNED = 3, 'Hodl invoice was returned'
+        MISSNG = 4, 'Buyer invoice is missing'
+        IVALID = 5, 'Buyer invoice is valid'
+        INPAID = 6, 'Buyer invoice was paid'
+        INFAIL = 7, 'Buyer invoice routing failed'
+
+    # payment use case
+    type = models.PositiveSmallIntegerField(choices=Types.choices, null=False, default=Types.HODL)
+    concept = models.PositiveSmallIntegerField(choices=Concepts.choices, null=False, default=Concepts.MAKEBOND)
+    status = models.PositiveSmallIntegerField(choices=Status.choices, null=False, default=Status.INVGEN)
+    
+    # payment details
+    invoice = models.CharField(max_length=300, unique=False, null=True, default=None)
+    secret = models.CharField(max_length=300, unique=False, null=True, default=None)
+    expires_at = models.DateTimeField()
+    amount = models.DecimalField(max_digits=9, decimal_places=4, validators=[MinValueValidator(MIN_TRADE*BOND_SIZE), MaxValueValidator(MAX_TRADE*(1+BOND_SIZE+FEE))])
+    
+    # payment relationals
+    sender = models.ForeignKey(User, related_name='sender', on_delete=models.CASCADE, null=True, default=None)
+    receiver = models.ForeignKey(User, related_name='receiver', on_delete=models.CASCADE, null=True, default=None)
+
 
 class Order(models.Model):
     
@@ -25,7 +67,7 @@ class Order(models.Model):
         EUR = 2, 'EUR'
         ETH = 3, 'ETH'
 
-    class Status(models.TextChoices):
+    class Status(models.IntegerChoices):
         WFB = 0, 'Waiting for bond'
         PUB = 1, 'Published in order book'
         DEL = 2, 'Deleted from order book'
@@ -48,35 +90,36 @@ class Order(models.Model):
         EXP = 19, 'Expired'
 
     # order info
-    status = models.PositiveSmallIntegerField(choices=Status.choices, null=False, default=int(Status.WFB))
+    status = models.PositiveSmallIntegerField(choices=Status.choices, null=False, default=Status.WFB)
     created_at = models.DateTimeField(auto_now_add=True)
     expires_at = models.DateTimeField()
 
     # order details
     type = models.PositiveSmallIntegerField(choices=Types.choices, null=False)
     currency = models.PositiveSmallIntegerField(choices=Currencies.choices, null=False)
-    amount = models.DecimalField(max_digits=9, decimal_places=4, validators=[MinValueValidator(0.00001)])
+    amount = models.DecimalField(max_digits=9, decimal_places=4, validators=[MinValueValidator(MIN_TRADE), MaxValueValidator(MAX_TRADE)])
     payment_method = models.CharField(max_length=30, null=False, default="Not specified")
+
+    # order pricing method. A explicit amount of sats, or a relative premium above/below market.
+    is_explicit = models.BooleanField(default=False, null=False)
+    # marked to marked
     premium = models.DecimalField(max_digits=5, decimal_places=2, default=0, null=True, validators=[MinValueValidator(-100), MaxValueValidator(999)])
-    satoshis = models.PositiveBigIntegerField(null=True, validators=[MinValueValidator(min_satoshis_trade), MaxValueValidator(max_satoshis_trade)])
-    is_explicit = models.BooleanField(default=False, null=False) # pricing method. A explicit amount of sats, or a relative premium above/below market.
+    t0_market_satoshis = models.PositiveBigIntegerField(null=True, validators=[MinValueValidator(MIN_TRADE), MaxValueValidator(MAX_TRADE)])
+    # explicit
+    satoshis = models.PositiveBigIntegerField(null=True, validators=[MinValueValidator(MIN_TRADE), MaxValueValidator(MAX_TRADE)])
     
     # order participants
     maker = models.ForeignKey(User, related_name='maker', on_delete=models.CASCADE, null=True, default=None)  # unique = True, a maker can only make one order
     taker = models.ForeignKey(User, related_name='taker', on_delete=models.SET_NULL, null=True, default=None)  # unique = True, a taker can only take one order
     
     # order collateral
-    has_maker_bond = models.BooleanField(default=False, null=False)
-    has_taker_bond = models.BooleanField(default=False, null=False)
-    has_trade_collat = models.BooleanField(default=False, null=False)
-
-    maker_bond_secret = models.CharField(max_length=300, unique=False, null=True, default=None)
-    taker_bond_secret = models.CharField(max_length=300, unique=False, null=True, default=None)
-    trade_collat_secret = models.CharField(max_length=300, unique=False, null=True, default=None)
+    maker_bond = models.ForeignKey(LNPayment, related_name='maker_bond', on_delete=models.SET_NULL, null=True, default=None)
+    taker_bond = models.ForeignKey(LNPayment, related_name='taker_bond', on_delete=models.SET_NULL, null=True, default=None)
+    trade_escrow = models.ForeignKey(LNPayment, related_name='trade_escrow', on_delete=models.SET_NULL, null=True, default=None)
 
     # buyer payment LN invoice
-    has_invoice = models.BooleanField(default=False, null=False) # has invoice and is valid
-    invoice = models.CharField(max_length=300, unique=False, null=True, default=None)
+    buyer_invoice = models.ForeignKey(LNPayment, related_name='buyer_invoice', on_delete=models.SET_NULL, null=True, default=None)
+
 
 class Profile(models.Model):
 

api/views.py

@@ -8,7 +8,8 @@ from django.contrib.auth import authenticate, login, logout
 from django.contrib.auth.models import User
 
 from .serializers import ListOrderSerializer, MakeOrderSerializer, UpdateOrderSerializer
-from .models import Order
+from .models import Order, LNPayment
+from .lightning import LNNode
 
 from .nick_generator.nick_generator import NickGenerator
 from robohash import Robohash
@@ -39,11 +40,6 @@ def validate_already_maker_or_taker(request):
     
     return True, None
 
-def validate_ln_invoice(invoice):
-    '''Checks if a LN invoice is valid'''
-    #TODO
-    return True
-
 # Create your views here.
 
 class OrderMakerView(CreateAPIView):
@@ -68,7 +64,7 @@ class OrderMakerView(CreateAPIView):
             # Creates a new order in db
             order = Order(
                 type=otype,
-                status=int(Order.Status.PUB), # TODO orders are public by default for the moment. Future it will be WFB (waiting for bond)
+                status=Order.Status.PUB, # TODO orders are public by default for the moment. Future it will be WFB (waiting for bond)
                 currency=currency,
                 amount=amount,
                 payment_method=payment_method,
@@ -105,11 +101,11 @@ class OrderView(viewsets.ViewSet):
                 data['is_maker'] = str(order.maker) == nickname
                 data['is_taker'] = str(order.taker) == nickname
                 data['is_participant'] = data['is_maker'] or data['is_taker']
-                data['is_buyer'] = (data['is_maker'] and order.type == int(Order.Types.BUY)) or (data['is_taker'] and order.type == int(Order.Types.SELL))
-                data['is_seller'] = (data['is_maker'] and order.type == int(Order.Types.SELL)) or (data['is_taker'] and order.type == int(Order.Types.BUY))
+                data['is_buyer'] = (data['is_maker'] and order.type == Order.Types.BUY) or (data['is_taker'] and order.type == Order.Types.SELL)
+                data['is_seller'] = (data['is_maker'] and order.type == Order.Types.SELL) or (data['is_taker'] and order.type == Order.Types.BUY)
                 
                 # If not a participant and order is not public, forbid.
-                if not data['is_participant'] and order.status != int(Order.Status.PUB):
+                if not data['is_participant'] and order.status != Order.Status.PUB:
                     return Response({'bad_request':'Not allowed to see this order'},status.HTTP_403_FORBIDDEN)
 
                 # return nicks too
@@ -142,28 +138,28 @@ class OrderView(viewsets.ViewSet):
             invoice = serializer.data.get('invoice')
 
         # If this is an empty POST request (no invoice), it must be taker request!
-        if not invoice and order.status == int(Order.Status.PUB):
+        if not invoice and order.status == Order.Status.PUB:
             
             valid, response = validate_already_maker_or_taker(request)
             if not valid:
                 return response
 
             order.taker = self.request.user
-            order.status = int(Order.Status.TAK)
+            order.status = Order.Status.TAK
 
             #TODO REPLY WITH HODL INVOICE
             data = ListOrderSerializer(order).data
 
         # An invoice came in! update it
         elif invoice:
-            if validate_ln_invoice(invoice):
+            if LNNode.validate_ln_invoice(invoice):
                 order.invoice = invoice
 
             #TODO Validate if request comes from PARTICIPANT AND BUYER
 
                 #If the order status was Payment Failed. Move foward to invoice Updated.
-                if order.status == int(Order.Status.FAI):
-                    order.status = int(Order.Status.UPI)
+                if order.status == Order.Status.FAI:
+                    order.status = Order.Status.UPI
 
             else:
                 return Response({'bad_request':'Invalid Lightning Network Invoice. It starts by LNTB...'})