import calendar import datetime import decimal from dateutil import relativedelta from django.contrib.contenttypes.models import ContentType from django.utils import timezone from django.utils.translation import ugettext_lazy as _ from orchestra.utils import plugins from orchestra.utils.python import AttrDict from . import settings, helpers class ServiceHandler(plugins.Plugin): """ Separates all the logic of billing handling from the model allowing to better customize its behaviout Relax and enjoy the journey. """ _VOLUME = 'VOLUME' _COMPENSATION = 'COMPENSATION' model = None __metaclass__ = plugins.PluginMount def __init__(self, service): self.service = service def __getattr__(self, attr): return getattr(self.service, attr) @classmethod def get_plugin_choices(cls): choices = super(ServiceHandler, cls).get_plugin_choices() return [('', _("Default"))] + choices def get_content_type(self): if not self.model: return self.content_type app_label, model = self.model.split('.') return ContentType.objects.get_by_natural_key(app_label, model.lower()) def matches(self, instance): safe_locals = { 'instance': instance, 'obj': instance, instance._meta.model_name: instance, } return eval(self.match, safe_locals) def get_metric(self, instance): if self.metric: safe_locals = { instance._meta.model_name: instance } return eval(self.metric, safe_locals) def get_billing_point(self, order, bp=None, **options): not_cachable = self.billing_point == self.FIXED_DATE and options.get('fixed_point') if not_cachable or bp is None: bp = options.get('billing_point', timezone.now().date()) if not options.get('fixed_point'): msg = ("Support for '%s' period and '%s' point is not implemented" % (self.get_billing_period_display(), self.get_billing_point_display())) if self.billing_period == self.MONTHLY: date = bp if self.payment_style == self.PREPAY: date += relativedelta.relativedelta(months=1) else: date = timezone.now().date() if self.billing_point == self.ON_REGISTER: day = order.registered_on.day elif self.billing_point == self.FIXED_DATE: day = 1 else: raise NotImplementedError(msg) bp = datetime.date(year=date.year, month=date.month, day=day) elif self.billing_period == self.ANUAL: if self.billing_point == self.ON_REGISTER: month = order.registered_on.month day = order.registered_on.day elif self.billing_point == self.FIXED_DATE: month = settings.SERVICES_SERVICE_ANUAL_BILLING_MONTH day = 1 else: raise NotImplementedError(msg) year = bp.year if self.payment_style == self.POSTPAY: year = bp.year - relativedelta.relativedelta(years=1) if bp.month >= month: year = bp.year + 1 bp = datetime.date(year=year, month=month, day=day) elif self.billing_period == self.NEVER: bp = order.registered_on else: raise NotImplementedError(msg) if self.on_cancel != self.NOTHING and order.cancelled_on and order.cancelled_on < bp: bp = order.cancelled_on return bp # def aligned(self, date): # if self.granularity == self.DAILY: # return date # elif self.granularity == self.MONTHLY: # return datetime.date(year=date.year, month=date.month, day=1) # elif self.granularity == self.ANUAL: # return datetime.date(year=date.year, month=1, day=1) # raise NotImplementedError def get_price_size(self, ini, end): rdelta = relativedelta.relativedelta(end, ini) if self.billing_period == self.MONTHLY: size = rdelta.years * 12 size += rdelta.months days = calendar.monthrange(end.year, end.month)[1] size += decimal.Decimal(rdelta.days)/days elif self.billing_period == self.ANUAL: size = rdelta.years size += decimal.Decimal(rdelta.months)/12 days = 366 if calendar.isleap(end.year) else 365 size += decimal.Decimal(rdelta.days)/days elif self.billing_period == self.NEVER: size = 1 else: raise NotImplementedError return decimal.Decimal(size) def get_pricing_slots(self, ini, end): day = 1 month = settings.SERVICES_SERVICE_ANUAL_BILLING_MONTH if self.billing_point == self.ON_REGISTER: day = ini.day month = ini.month period = self.get_pricing_period() rdelta = self.get_pricing_rdelta() if period == self.MONTHLY: ini = datetime.date(year=ini.year, month=ini.month, day=day) elif period == self.ANUAL: ini = datetime.date(year=ini.year, month=month, day=day) elif period == self.NEVER: yield ini, end raise StopIteration else: raise NotImplementedError while True: next = ini + rdelta yield ini, next if next >= end: break ini = next def get_pricing_rdelta(self): period = self.get_pricing_period() if period == self.MONTHLY: return relativedelta.relativedelta(months=1) elif period == self.ANUAL: return relativedelta.relativedelta(years=1) elif period == self.NEVER: return None def generate_discount(self, line, dtype, price): line.discounts.append(AttrDict(**{ 'type': dtype, 'total': price, })) def generate_line(self, order, price, *dates, **kwargs): if len(dates) == 2: ini, end = dates elif len(dates) == 1: ini, end = dates[0], dates[0] else: raise AttributeError metric = kwargs.pop('metric', 1) discounts = kwargs.pop('discounts', ()) computed = kwargs.pop('computed', False) if kwargs: raise AttributeError size = self.get_price_size(ini, end) if not computed: price = price * size subtotal = self.nominal_price * size * metric line = AttrDict(**{ 'order': order, 'subtotal': subtotal, 'ini': ini, 'end': end, 'size': size, 'metric': metric, 'discounts': [], }) discounted = 0 for dtype, dprice in discounts: self.generate_discount(line, dtype, dprice) discounted += dprice subtotal += discounted if subtotal > price: self.generate_discount(line, self._VOLUME, price-subtotal) return line def assign_compensations(self, givers, receivers, **options): compensations = [] for order in givers: if order.billed_until and order.cancelled_on and order.cancelled_on < order.billed_until: interval = helpers.Interval(order.cancelled_on, order.billed_until, order) compensations.append(interval) for order in receivers: if not order.billed_until or order.billed_until < order.new_billed_until: # receiver ini = order.billed_until or order.registered_on end = order.cancelled_on or datetime.date.max interval = helpers.Interval(ini, end) compensations, used_compensations = helpers.compensate(interval, compensations) order._compensations = used_compensations for comp in used_compensations: comp.order.new_billed_until = min(comp.order.billed_until, comp.ini, getattr(comp.order, 'new_billed_until', datetime.date.max)) if options.get('commit', True): for order in givers: if hasattr(order, 'new_billed_until'): order.billed_until = order.new_billed_until order.save(update_fields=['billed_until']) def apply_compensations(self, order, only_beyond=False): dsize = 0 ini = order.billed_until or order.registered_on end = order.new_billed_until beyond = end cend = None for comp in getattr(order, '_compensations', []): intersect = comp.intersect(helpers.Interval(ini=ini, end=end)) if intersect: cini, cend = intersect.ini, intersect.end if comp.end > beyond: cend = comp.end if only_beyond: cini = beyond elif not only_beyond: continue dsize += self.get_price_size(cini, cend) # Extend billing point a little bit to benefit from a substantial discount elif comp.end > beyond and (comp.end-comp.ini).days > 3*(comp.ini-beyond).days: cend = comp.end dsize += self.get_price_size(comp.ini, cend) return dsize, cend def get_register_or_renew_events(self, porders, ini, end): counter = 0 for order in porders: bu = getattr(order, 'new_billed_until', order.billed_until) if bu: registered = order.registered_on if registered > ini and registered <= end: counter += 1 if registered != bu and bu > ini and bu <= end: counter += 1 if order.billed_until and order.billed_until != bu: if registered != order.billed_until and order.billed_until > ini and order.billed_until <= end: counter += 1 return counter def bill_concurrent_orders(self, account, porders, rates, ini, end): # Concurrent # Get pricing orders priced = {} for ini, end, orders in helpers.get_chunks(porders, ini, end): size = self.get_price_size(ini, end) metric = len(orders) interval = helpers.Interval(ini=ini, end=end) for position, order in enumerate(orders, start=1): csize = 0 compensations = getattr(order, '_compensations', []) # Compensations < new_billed_until for comp in compensations: intersect = comp.intersect(interval) if intersect: csize += self.get_price_size(intersect.ini, intersect.end) price = self.get_price(account, metric, position=position, rates=rates) price = price * size cprice = price * csize if order in priced: priced[order][0] += price priced[order][1] += cprice else: priced[order] = (price, cprice) lines = [] for order, prices in priced.iteritems(): discounts = () # Generate lines and discounts from order.nominal_price price, cprice = prices # Compensations > new_billed_until dsize, new_end = self.apply_compensations(order, only_beyond=True) cprice += dsize*price if cprice: discounts = ( (self._COMPENSATION, -cprice), ) if new_end: size = self.get_price_size(order.new_billed_until, new_end) price += price*size order.new_billed_until = new_end line = self.generate_line(order, price, ini, new_end or end, discounts=discounts, computed=True) lines.append(line) return lines def bill_registered_or_renew_events(self, account, porders, rates): # Before registration lines = [] rdelta = self.get_pricing_rdelta() if not rdelta: raise NotImplementedError for position, order in enumerate(porders, start=1): if hasattr(order, 'new_billed_until'): pend = order.billed_until or order.registered_on pini = pend - rdelta metric = self.get_register_or_renew_events(porders, pini, pend) price = self.get_price(account, metric, position=position, rates=rates) ini = order.billed_until or order.registered_on end = order.new_billed_until discounts = () dsize, new_end = self.apply_compensations(order) if dsize: discounts=( (self._COMPENSATION, -dsize*price), ) if new_end: order.new_billed_until = new_end end = new_end line = self.generate_line(order, price, ini, end, discounts=discounts) lines.append(line) return lines def bill_with_orders(self, orders, account, **options): # For the "boundary conditions" just think that: # date(2011, 1, 1) is equivalent to datetime(2011, 1, 1, 0, 0, 0) # In most cases: # ini >= registered_date, end < registered_date # boundary lookup and exclude cancelled and billed orders_ = [] bp = None ini = datetime.date.max end = datetime.date.min for order in orders: cini = order.registered_on if order.billed_until: # exclude cancelled and billed if self.on_cancel != self.REFUND: if order.cancelled_on and order.billed_until > order.cancelled_on: continue cini = order.billed_until bp = self.get_billing_point(order, bp=bp, **options) order.new_billed_until = bp ini = min(ini, cini) end = max(end, bp) orders_.append(order) orders = orders_ # Compensation related_orders = account.orders.filter(service=self.service) if self.payment_style == self.PREPAY and self.on_cancel == self.COMPENSATE: # Get orders pending for compensation givers = list(related_orders.givers(ini, end)) givers.sort(cmp=helpers.cmp_billed_until_or_registered_on) orders.sort(cmp=helpers.cmp_billed_until_or_registered_on) self.assign_compensations(givers, orders, **options) rates = self.get_rates(account) has_billing_period = self.billing_period != self.NEVER has_pricing_period = self.get_pricing_period() != self.NEVER if rates and (has_billing_period or has_pricing_period): concurrent = has_billing_period and not has_pricing_period if not concurrent: rdelta = self.get_pricing_rdelta() ini -= rdelta porders = related_orders.pricing_orders(ini, end) porders = list(set(orders).union(set(porders))) porders.sort(cmp=helpers.cmp_billed_until_or_registered_on) if concurrent: # Periodic billing with no pricing period lines = self.bill_concurrent_orders(account, porders, rates, ini, end) else: # Periodic and one-time billing with pricing period lines = self.bill_registered_or_renew_events(account, porders, rates) else: # No rates optimization or one-time billing without pricing period lines = [] price = self.nominal_price # Calculate nominal price for order in orders: ini = order.billed_until or order.registered_on end = order.new_billed_until discounts = () dsize, new_end = self.apply_compensations(order) if dsize: discounts=( (self._COMPENSATION, -dsize*price), ) if new_end: order.new_billed_until = new_end end = new_end line = self.generate_line(order, price, ini, end, discounts=discounts) lines.append(line) return lines def bill_with_metric(self, orders, account, **options): lines = [] bp = None for order in orders: bp = self.get_billing_point(order, bp=bp, **options) if (self.billing_period != self.NEVER and self.get_pricing_period() == self.NEVER and self.payment_style == self.PREPAY and order.billed_on): # Recharge if self.payment_style == self.PREPAY and order.billed_on: rini = order.billed_on charged = None new_metric, new_price = 0, 0 for cini, cend, metric in order.get_metric(rini, bp, changes=True): if charged is None: charged = metric size = self.get_price_size(cini, cend) new_price += self.get_price(order, metric) * size new_metric += metric size = self.get_price_size(rini, bp) old_price = self.get_price(order, charged) * size if new_price > old_price: metric = new_metric - charged price = new_price - old_price lines.append(self.generate_line(order, price, rini, bp, metric=metric, computed=True)) if order.billed_until and order.cancelled_on and order.cancelled_on >= order.billed_until: continue if self.billing_period != self.NEVER: ini = order.billed_until or order.registered_on # Periodic billing if bp <= ini: continue order.new_billed_until = bp if self.get_pricing_period() == self.NEVER: # Changes (Mailbox disk-like) for cini, cend, metric in order.get_metric(ini, bp, changes=True): price = self.get_price(order, metric) lines.append(self.generate_line(order, price, cini, cend, metric=metric)) elif self.get_pricing_period() == self.billing_period: # pricing_slots (Traffic-like) if self.payment_style == self.PREPAY: raise NotImplementedError for cini, cend in self.get_pricing_slots(ini, bp): metric = order.get_metric(cini, cend) price = self.get_price(order, metric) lines.append(self.generate_line(order, price, cini, cend, metric=metric)) else: raise NotImplementedError else: # One-time billing if order.billed_until: continue date = timezone.now().date() order.new_billed_until = date if self.get_pricing_period() == self.NEVER: # get metric (Job-like) metric = order.get_metric(date) price = self.get_price(order, metric) lines.append(self.generate_line(order, price, date, metric=metric)) else: raise NotImplementedError return lines def generate_bill_lines(self, orders, account, **options): if options.get('proforma', False): options['commit'] = False if not self.metric: lines = self.bill_with_orders(orders, account, **options) else: lines = self.bill_with_metric(orders, account, **options) if options.get('commit', True): now = timezone.now().date() for line in lines: order = line.order order.billed_on = now order.billed_until = getattr(order, 'new_billed_until', order.billed_until) order.save(update_fields=['billed_on', 'billed_until']) return lines