little performance tweaks

[bluechips.git] / bluechips / model / expenditure.py

diff --git a/bluechips/model/expenditure.py b/bluechips/model/expenditure.py
index 88d65b3b6ae52649cd62bc1723a4c69a981d671f..9d0fc7e0f981ad2719f2435789199a934b5c5bca 100644 (file)
--- a/bluechips/model/expenditure.py
+++ b/bluechips/model/expenditure.py
@@ -1,11 +1,20 @@
-from user import User
-from split import Split
+from bluechips.model.user import User
+from bluechips.model.split import Split
 from bluechips.model import meta
-from bluechips.lib.helpers import round_currency
+from bluechips.model.types import Currency
 from decimal import Decimal
+from datetime import datetime
 import random
 
 class Expenditure(object):
+    def __init__(self, spender=None, amount=Currency(0), description=u"",
+                 date=None):
+        self.spender = spender
+        self.amount = amount
+        self.description = description
+        if self.date == None:
+            self.date = datetime.now()
+    
     def __repr__(self):
         return '<Expenditure: spender: %s spent: %s>' % (self.spender,
                                                          self.amount)
@@ -19,6 +28,16 @@ class Expenditure(object):
         split_percentage = Decimal(100) / Decimal(residents.count())
         self.split(dict((resident, split_percentage) for resident in residents))
     
+    def update_split(self):
+        """
+        Re-split an expenditure using the same percentages as what is
+        currently in the database
+        """
+        
+        old_splits = meta.Session.query(Split).filter(Split.expenditure==self)
+        split_dict = dict((s.user, Decimal(int(s.share))) for s in old_splits)
+        self.split(split_dict)
+    
     def split(self, split_dict):
         """
         Split up an expenditure.
@@ -41,30 +60,41 @@ class Expenditure(object):
         
         total = sum(split_dict.itervalues())
         
-        for user, share in split_dict.iteritems():
-            split_dict[user] = share / total
+        for user, share in split_dict.items():
+            if share == 0:
+                del split_dict[user]
+            else:
+                split_dict[user] = share / total
             
         amounts_dict = dict()
         
         for user, share in split_dict.iteritems():
-            amounts_dict[user] = round_currency(split_dict[user] * self.amount)
+            amounts_dict[user] = Currency(split_dict[user] * self.amount)
         
         difference = self.amount - sum(amounts_dict.itervalues())
         
         if difference > 0:
-            for i in xrange(difference * 100):
+            for i in xrange(difference):
                 winner = random.choice(amounts_dict.keys())
-                amounts_dict[winner] += Decimal('0.01')
+                amounts_dict[winner] += Currency(1)
         elif difference < 0:
-            for i in xrange(difference * -100):
+            for i in xrange(-difference):
                 winner = random.choice(amounts_dict.keys())
-                amounts_dict[winner] -= Decimal('0.01')
+                amounts_dict[winner] -= Currency(1)
         
         for user, share in amounts_dict.iteritems():
-            s = Split()
-            s.expenditure = self
-            s.user = user
-            s.share = share
-            meta.Session.save(s)
+            s = Split(self, user, share)
+            meta.Session.add(s)
+
+    def involves(self, user):
+        "Returns True if ``user`` is involved in this expenditure."
+        return any((split.user == user) and (split.share != 0)
+                   for split in self.splits)
+
+    def share(self, user):
+        "Return the share corresponding to ``user``."
+        shares = dict((split.user, split.share)
+                      for split in self.splits)
+        return shares.get(user, Currency(0))
 
 __all__ = ['Expenditure']