viewutil.py

import re
import operator
from decimal import Decimal

from django.db.models import Count, Sum, Max, Avg, Q
from django.db.models.functions import Coalesce
from django.http import Http404
from django.contrib.auth import get_user_model
from django.db import transaction
from django.conf import settings
from django.urls import reverse

from .models import *
from . import filters
from functools import reduce


def cmp(a, b):
  """Python 3 doesn't have cmp() built in anymore, so use this replacement logic."""
  return (a > b) - (a < b)

def get_default_email_host_user():
  return getattr(settings, 'EMAIL_HOST_USER', '')

def get_default_email_from_user():
  return getattr(settings, 'EMAIL_FROM_USER', get_default_email_host_user())

def admin_url(obj):
  return reverse("admin:%s_%s_change" % (obj._meta.app_label, obj._meta.object_name.lower()), args=(obj.pk,), current_app=obj._meta.app_label)

# Adapted from http://djangosnippets.org/snippets/1474/
def get_request_server_url(request):
    if request:
        return request.build_absolute_uri('/').rstrip('/')  # Get hostname only, no leading slashes
    else:
        raise Exception("Request was null.")

def get_referer_site(request):
  origin = request.META.get('HTTP_ORIGIN', None)
  if origin != None:
    return re.sub(r'^https?:/\/', '', origin)
  else:
    return None

def get_event(event):
  if event:
    if isinstance(event, Event):
        return event
    try:
      if re.match(r'^\d+$', event):
        return Event.objects.get(id=event)
      else:
        return Event.objects.get(short=event)
    except Event.DoesNotExist:
      raise Http404
  e = Event()
  e.id = None
  e.name = 'All Events'
  return e

def request_params(request):
  if request.method == 'GET':
    return request.GET
  elif request.method == 'POST':
    return request.POST
  else:
    raise Exception("No request parameters associated with this request method.")


_1ToManyBidsAggregateFilter = Q(bids__donation__transactionstate='COMPLETED')
_1ToManyDonationAggregateFilter = Q(donation__transactionstate='COMPLETED')
DonationBidAggregateFilter = _1ToManyDonationAggregateFilter
DonorAggregateFilter = _1ToManyDonationAggregateFilter
EventAggregateFilter = _1ToManyDonationAggregateFilter
PrizeWinnersFilter = Q(prizewinner__acceptcount_gt=0) | Q(prizewinner__pendingcount__gt=0)

# http://stackoverflow.com/questions/5722767/django-mptt-get-descendants-for-a-list-of-nodes
def get_tree_queryset_descendants(model, nodes, include_self=False):
  if not nodes:
    return nodes
  filters = []
  for n in nodes:
    lft, rght = n.lft, n.rght
    if include_self:
      lft -=1
      rght += 1
    filters.append(Q(tree_id=n.tree_id, lft__gt=lft, rght__lt=rght))
  q = reduce(operator.or_, filters)
  return model.objects.filter(q).order_by(*model._meta.ordering)

# http://stackoverflow.com/questions/6471354/efficient-function-to-retrieve-a-queryset-of-ancestors-of-an-mptt-queryset
def get_tree_queryset_ancestors(model, nodes):
  tree_list = {}
  query = Q()
  for node in nodes:
    if node.tree_id not in tree_list:
      tree_list[node.tree_id] = []
    parent =  node.parent.pk if node.parent is not None else None,
    if parent not in tree_list[node.tree_id]:
      tree_list[node.tree_id].append(parent)
      query |= Q(lft__lt=node.lft, rght__gt=node.rght, tree_id=node.tree_id)
    return model.objects.filter(query).order_by(*model._meta.ordering)

def get_tree_queryset_all(model, nodes):
  filters = []
  for node in nodes:
    filters.append(Q(tree_id=node.tree_id))
  q = reduce(operator.or_, filters)
  return model.objects.filter(q).order_by(*model._meta.ordering)

ModelAnnotations = {
  'event'        : {
    'amount': Coalesce(Sum('donation__amount', only=EventAggregateFilter), Decimal('0.00')),
    'count': Count('donation', only=EventAggregateFilter),
    'max': Coalesce(Max('donation__amount', only=EventAggregateFilter), Decimal('0.00')),
    'avg': Coalesce(Avg('donation__amount', only=EventAggregateFilter), Decimal('0.00')),
  },
  'prize' : { 'numwinners': Count('prizewinner', only=PrizeWinnersFilter), },
}

def find_people(people_list):
  result = []
  for person in people_list:
      try:
        d = Donor.objects.get(alias__iequals=person)
        result.append(d)
      except:
        pass
  return result

def prizecmp(a,b):
  # if both prizes are run-linked, sort them that way
  if a.startrun and b.startrun:
    return cmp(a.startrun.starttime,b.startrun.starttime) or cmp(a.endrun.endtime,b.endrun.endtime) or cmp(a.name,b.name)
  # else if they're both time-linked, sort them that way
  if a.starttime and b.starttime:
    return cmp(a.starttime,b.starttime) or cmp(a.endtime,b.endtime) or cmp(a.name,b.name)
  # run-linked prizes are listed after time-linked and non-linked
  if a.startrun and not b.startrun:
    return 1
  if b.startrun and not a.startrun:
    return -1
  # time-linked prizes are listed after non-linked
  if a.starttime and not b.starttime:
    return 1
  if b.starttime and not a.starttime:
    return -1
  # sort by category or name as a fallback
  return cmp(a.category,b.category) or cmp(a.name,b.name)

EVENT_SELECT = 'admin-event'

def get_selected_event(request):
  evId = request.session.get(EVENT_SELECT, None)
  if evId:
    return Event.objects.get(pk=evId)
  else:
    return None

def set_selected_event(request, event):
  if event:
    request.session[EVENT_SELECT] = event.id
  else:
    request.session[EVENT_SELECT] = None

def get_donation_prize_contribution(prize, donation, secondaryAmount=None):
  if prize.contains_draw_time(donation.timereceived):
    amount = secondaryAmount if secondaryAmount != None else donation.amount
    if prize.sumdonations or amount >= prize.minimumbid:
      return amount
  return None

def get_donation_prize_info(donation):
  """ Attempts to find a list of all prizes this donation gives the donor eligibility for.
    Does _not_ attempt to relate this information to any _past_ eligibility.
    Returns the set as a list of {'prize','amount'} dictionaries. """
  prizeList = []
  for ticket in donation.tickets.all():
    contribAmount = get_donation_prize_contribution(ticket.prize, donation, ticket.amount)
    if contribAmount != None:
      prizeList.append({'prize': ticket.prize, 'amount': contribAmount})
  for timeprize in filters.run_model_query( 'prize', params={ 'feed': 'current', 'ticketdraw': False, 'offset': donation.timereceived, 'noslice': True } ):
    contribAmount = get_donation_prize_contribution(timeprize, donation)
    if contribAmount != None:
      prizeList.append({'prize': timeprize, 'amount': contribAmount})
  return prizeList

def tracker_log(category, message='', event=None, user=None):
  Log.objects.create(category=category, message=message, event=event, user=user)

def merge_bids(rootBid, bids):
  for bid in bids:
    if bid != rootBid:
      for donationBid in bid.bids.all():
        donationBid.bid = rootBid
        donationBid.save()
      for suggestion in bid.suggestions.all():
        suggestion.bid = rootBid
        suggestion.save()
      bid.delete()
  rootBid.save()
  return rootBid

def merge_donors(rootDonor, donors):
  for other in donors:
    if other != rootDonor:
      for donation in other.donation_set.all():
        donation.donor = rootDonor
        donation.save()
      for prizewin in other.prizewinner_set.all():
        prizewin.winner = rootDonor
        prizewin.save()
      other.delete()
  rootDonor.save()
  return rootDonor

def autocreate_donor_user(donor):
    AuthUser = get_user_model()

    if not donor.user:
        with transaction.atomic():
            try:
                linkUser = AuthUser.objects.get(email=donor.email)
            except AuthUser.MultipleObjectsReturned:
                message = 'Multiple users found for email {0}, when trying to mail donor {1} for prizes'.format(donor.email, donor.id)
                tracker_log('prize', message)
                raise Exception(message)
            except AuthUser.DoesNotExist:
                targetUsername = donor.email
                if donor.alias and not AuthUser.objects.filter(username=donor.alias):
                    targetUsername = donor.alias
                linkUser = AuthUser.objects.create(username=targetUsername, email=donor.email, first_name=donor.firstname, last_name=donor.lastname, is_active=False)
            donor.user = linkUser
            donor.save()

    return donor.user