forked from uncloud/uncloud
93 lines
3.2 KiB
Python
93 lines
3.2 KiB
Python
from functools import reduce
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from datetime import datetime
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from rest_framework import mixins
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from rest_framework.viewsets import GenericViewSet
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from django.db.models import Q
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from .models import Bill, Payment, PaymentMethod, Order
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from django.utils import timezone
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from django.core.exceptions import ObjectDoesNotExist
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from calendar import monthrange
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def sum_amounts(entries):
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return reduce(lambda acc, entry: acc + entry.amount, entries, 0)
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def get_balance_for(user):
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bills = sum_amounts(Bill.objects.filter(owner=user))
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payments = sum_amounts(Payment.objects.filter(owner=user))
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return payments - bills
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def get_payment_method_for(user):
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methods = PaymentMethod.objects.filter(owner=user)
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for method in methods:
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# Do we want to do something with non-primary method?
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if method.primary:
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return method
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return None
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def beginning_of_month(year, month):
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tz = timezone.get_current_timezone()
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return datetime(year=year, month=month, day=1, tzinfo=tz)
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def end_of_month(year, month):
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(_, days) = monthrange(year, month)
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tz = timezone.get_current_timezone()
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return datetime(year=year, month=month, day=days,
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hour=23, minute=59, second=59, tzinfo=tz)
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def generate_bills_for(year, month, user, allowed_delay):
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# /!\ We exclusively work on the specified year and month.
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# Default values for next bill (if any). Only saved at the end of
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# this method, if relevant.
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next_bill = Bill(owner=user,
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starting_date=beginning_of_month(year, month),
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ending_date=end_of_month(year, month),
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creation_date=timezone.now(),
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due_date=timezone.now() + allowed_delay)
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# Select all orders active on the request period.
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orders = Order.objects.filter(
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Q(ending_date__gt=next_bill.starting_date) | Q(ending_date__isnull=True),
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owner=user)
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# Check if there is already a bill covering the order and period pair:
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# * Get latest bill by ending_date: previous_bill.ending_date
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# * If previous_bill.ending_date is before next_bill.ending_date, a new
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# bill has to be generated.
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unpaid_orders = []
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for order in orders:
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try:
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previous_bill = order.bill.latest('ending_date')
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except ObjectDoesNotExist:
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previous_bill = None
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if previous_bill == None or previous_bill.ending_date < next_bill.ending_date:
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unpaid_orders.append(order)
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# Commit next_bill if it there are 'unpaid' orders.
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if len(unpaid_orders) > 0:
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next_bill.save()
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# It is not possible to register many-to-many relationship before
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# the two end-objects are saved in database.
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for order in unpaid_orders:
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order.bill.add(next_bill)
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# TODO: use logger.
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print("Generated bill {} (amount: {}) for user {}."
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.format(next_bill.uuid, next_bill.total, user))
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return next_bill
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# Return None if no bill was created.
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class ProductViewSet(mixins.CreateModelMixin,
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mixins.RetrieveModelMixin,
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mixins.ListModelMixin,
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GenericViewSet):
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"""
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A customer-facing viewset that provides default `create()`, `retrieve()`
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and `list()`.
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"""
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pass
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