fix credit management command

payment/management/commands/grant_user_credit.py

@@ -1,24 +1,33 @@
+from decimal import Decimal
+
 from django.core.management.base import BaseCommand
 from django.contrib.auth.models import User
 
+ACTIONS = ("debit", "redeem", "credit", "cash")
 class Command(BaseCommand):
     help = "grant (or debit or redeem) credit to a user. \
     Usage: grant_user_credit <username> <amount> <action>\
     amount is dollars or 'all' "
-    args = "<username> <amount> <action>"
 
-    def handle(self, username, amount, action="credit", *args, **kwargs):
-        if action not in ("debit", "redeem", "credit"):
-            print('action should be  in ("debit", "redeem", "credit")')
+    def add_arguments(self, parser):
+        parser.add_argument('username', type=str, help="user to credit")    
+        parser.add_argument('amount', type=str, help="amount to credit")    
+        parser.add_argument('action', type=str, help="credit/debit/redeem/cash")    
+
+    def handle(self, username, amount, action, **options):
+        if action not in ACTIONS:
+            self.stdout.write('action should be  in %s' % str(ACTIONS))
             return
         user = User.objects.get(username=username)
         if amount == 'all':
             amount = user.credit.available
-        if action in ("debit", "redeem" ):
-            amount = -int(amount)
-        elif action == "credit":
-            amount = int(amount)
-        notify = action != "redeem"
-        user.credit.add_to_balance(amount, notify=notify)
-        print("{}ed ${} from {}".format(action, amount, username))
-        print("{} now has a balance of {} credits".format(username, user.credit.balance))
+        if action == 'redeem':
+            user.credit.use_pledge(amount)
+        else:
+            amount = Decimal(amount)
+            if action in ("debit", "cash"):
+                amount = - amount
+            user.credit.add_to_balance(amount, notify=action != "cash")
+        self.stdout.write("{}ed ${} from {}".format(action, amount, username))
+        self.stdout.write("{} now has a balance of {} credits".format(
+            username, user.credit.balance))