added Token model and static price redeem

hello/models.py

@@ -0,0 +1,21 @@
+from django.db import models
+from django.utils import timezone
+
+
+class Token(models.Model):
+    '''
+        A model representing a token given to the user.
+    '''
+
+    created = models.DateTimeField(default=timezone.now)
+
+    '''
+        The value of the token, given to the user, which is a hashid of the
+        database id.
+    '''
+    value = models.CharField(max_length=100, null=True, default=None)
+
+    '''
+        True when the token has successfully been redeemed, False otherwise.
+    '''
+    redeemed = models.BooleanField(default=False)

hello/settings.py

@@ -33,6 +33,8 @@
 TWO1_USERNAME = os.environ.get("TWO1_USERNAME")
 WALLET = Two1Wallet.import_from_mnemonic(mnemonic=TWO1_WALLET_MNEMONIC)
 
+HASHIDS_SALT = os.environ.get("HASHIDS_SALT")
+
 
 # Quick-start development settings - unsuitable for production
 # See https://docs.djangoproject.com/en/1.8/howto/deployment/checklist/

hello/urls.py

@@ -20,5 +20,6 @@
 urlpatterns = [
     url(r'^admin/', include(admin.site.urls)),
     url(r'^buy$', hello.views.buy),
+    url(r'^redeem$', hello.views.redeem),
     url(r'^manifest$', hello.views.manifest),
 ]

hello/views.py

@@ -1,16 +1,59 @@
+import sys
 import yaml
+import hashids
+import logging
 
-from django.http import HttpResponse, JsonResponse
+from django.core.exceptions import ObjectDoesNotExist
+from django.http import JsonResponse
 from rest_framework.decorators import api_view
 from two1.bitserv.django import payment
 
 from hello import settings
+from hello.models import Token
+
+hasher = hashids.Hashids(salt=settings.HASHIDS_SALT, min_length=5)
+
+logger = logging.getLogger(__name__)
+logging.basicConfig(stream=sys.stdout, level=logging.INFO)
 
 
 @api_view(['GET'])
 @payment.required(100)
 def buy(request):
-    return HttpResponse('Hello 21!', status=200)
+    new_token = Token.objects.create()
+    new_token.value = hasher.encode(new_token.id)
+    new_token.save()
+
+    return JsonResponse({'token': new_token.value}, status=200)
+
+
+def _redeem(token):
+    try:
+        requested_token = Token.objects.get(value=token)
+
+        if requested_token.redeemed:
+            raise ValueError()
+    except ObjectDoesNotExist:
+        logger.error('User requested token {} that does not exist'.format(token))
+        return JsonResponse({'success': False, 'error': 'Invalid or redeemed token.'}, status=400)
+    except ValueError:
+        logger.error('User requested token {} that was already redeemed'.format(token))
+        return JsonResponse({'success': False, 'error': 'Invalid or redeemed token.'}, status=400)
+
+    requested_token.redeemed = True
+    requested_token.save()
+
+    return JsonResponse({'success': True, "message": "Thanks!"}, status=200)
+
+
+@api_view(['POST'])
+def redeem(request):
+    try:
+        token = request.data['token']
+    except KeyError:
+        return JsonResponse({'error': 'POST data must include "token"'}, status=400)
+
+    return _redeem(token)
 
 
 @api_view(['GET'])