from decimal import Decimal from typing import Iterable, Optional, Tuple, Type from django.conf import settings from django.core.validators import MinValueValidator from django.db import models from ..core.config import config from ..utils.autoupdate import inform_changed_data, inform_deleted_data from ..utils.models import SET_NULL_AND_AUTOUPDATE class BaseVote(models.Model): """ All subclasses must have option attribute with the related name "votes" """ weight = models.DecimalField( default=Decimal("1"), validators=[MinValueValidator(Decimal("-2"))], max_digits=15, decimal_places=6, ) value = models.CharField(max_length=1, choices=(("Y", "Y"), ("N", "N"), ("A", "A"))) user = models.ForeignKey( settings.AUTH_USER_MODEL, default=None, null=True, blank=True, on_delete=SET_NULL_AND_AUTOUPDATE, ) class Meta: abstract = True class BaseOption(models.Model): """ All subclasses must have poll attribute with the related name "options" """ vote_class: Optional[Type["BaseVote"]] = None class Meta: abstract = True @property def yes(self) -> Decimal: return self.sum_weight("Y") @property def no(self) -> Decimal: return self.sum_weight("N") @property def abstain(self) -> Decimal: return self.sum_weight("A") def sum_weight(self, value): # We could do this in a nice .aggregate(Sum...) querystatement, # but these might be expensive DB queries, because they are not preloaded. # With this in-logic-counting, we operate inmemory. weight_sum = Decimal(0) for vote in self.votes.all(): if vote.value == value: weight_sum += vote.weight return weight_sum @classmethod def get_vote_class(cls): if cls.vote_class is None: raise NotImplementedError( f"The option class {cls} has to have an attribute vote_class." ) return cls.vote_class def get_votes(self): """ Return a QuerySet with all vote objects related to this option. """ return self.get_vote_class().objects.filter(option=self) def pseudoanonymize(self): for vote in self.get_votes(): vote.user = None vote.save() def reset(self): # Delete votes votes = self.get_votes() votes_id = [vote.id for vote in votes] votes.delete() collection = self.get_vote_class().get_collection_string() inform_deleted_data((collection, id) for id in votes_id) # update self because the changed voted relation inform_changed_data(self) class BasePoll(models.Model): option_class: Optional[Type["BaseOption"]] = None STATE_CREATED = 1 STATE_STARTED = 2 STATE_FINISHED = 3 STATE_PUBLISHED = 4 STATES = ( (STATE_CREATED, "Created"), (STATE_STARTED, "Started"), (STATE_FINISHED, "Finished"), (STATE_PUBLISHED, "Published"), ) state = models.IntegerField(choices=STATES, default=STATE_CREATED) TYPE_ANALOG = "analog" TYPE_NAMED = "named" TYPE_PSEUDOANONYMOUS = "pseudoanonymous" TYPES = ( (TYPE_ANALOG, "analog"), (TYPE_NAMED, "nominal"), (TYPE_PSEUDOANONYMOUS, "non-nominal"), ) type = models.CharField(max_length=64, blank=False, null=False, choices=TYPES) title = models.CharField(max_length=255, blank=True, null=False) groups = models.ManyToManyField(settings.AUTH_GROUP_MODEL, blank=True) voted = models.ManyToManyField(settings.AUTH_USER_MODEL, blank=True) db_votesvalid = models.DecimalField( null=True, blank=True, validators=[MinValueValidator(Decimal("-2"))], max_digits=15, decimal_places=6, ) db_votesinvalid = models.DecimalField( null=True, blank=True, validators=[MinValueValidator(Decimal("-2"))], max_digits=15, decimal_places=6, ) db_votescast = models.DecimalField( null=True, blank=True, validators=[MinValueValidator(Decimal("-2"))], max_digits=15, decimal_places=6, ) PERCENT_BASE_YN = "YN" PERCENT_BASE_YNA = "YNA" PERCENT_BASE_VALID = "valid" PERCENT_BASE_CAST = "cast" PERCENT_BASE_DISABLED = "disabled" PERCENT_BASES: Iterable[Tuple[str, str]] = ( (PERCENT_BASE_YN, "Yes/No"), (PERCENT_BASE_YNA, "Yes/No/Abstain"), (PERCENT_BASE_VALID, "All valid ballots"), (PERCENT_BASE_CAST, "All casted ballots"), (PERCENT_BASE_DISABLED, "Disabled (no percents)"), ) # type: ignore onehundred_percent_base = models.CharField( max_length=8, blank=False, null=False, choices=PERCENT_BASES ) MAJORITY_SIMPLE = "simple" MAJORITY_TWO_THIRDS = "two_thirds" MAJORITY_THREE_QUARTERS = "three_quarters" MAJORITY_DISABLED = "disabled" MAJORITY_METHODS = ( (MAJORITY_SIMPLE, "Simple majority"), (MAJORITY_TWO_THIRDS, "Two-thirds majority"), (MAJORITY_THREE_QUARTERS, "Three-quarters majority"), (MAJORITY_DISABLED, "Disabled"), ) majority_method = models.CharField( max_length=14, blank=False, null=False, choices=MAJORITY_METHODS ) class Meta: abstract = True def get_votesvalid(self): if self.type == self.TYPE_ANALOG: return self.db_votesvalid else: return Decimal(self.amount_users_voted_with_individual_weight()) def set_votesvalid(self, value): if self.type != self.TYPE_ANALOG: raise ValueError("Do not set votesvalid for non analog polls") self.db_votesvalid = value votesvalid = property(get_votesvalid, set_votesvalid) def get_votesinvalid(self): if self.type == self.TYPE_ANALOG: return self.db_votesinvalid else: return Decimal(0) def set_votesinvalid(self, value): if self.type != self.TYPE_ANALOG: raise ValueError("Do not set votesinvalid for non analog polls") self.db_votesinvalid = value votesinvalid = property(get_votesinvalid, set_votesinvalid) def get_votescast(self): if self.type == self.TYPE_ANALOG: return self.db_votescast else: return Decimal(self.amount_users_voted()) def set_votescast(self, value): if self.type != self.TYPE_ANALOG: raise ValueError("Do not set votescast for non analog polls") self.db_votescast = value votescast = property(get_votescast, set_votescast) def amount_users_voted(self): return len(self.voted.all()) def amount_users_voted_with_individual_weight(self): if config["users_activate_vote_weight"]: return sum(user.vote_weight for user in self.voted.all()) else: return self.amount_users_voted() def create_options(self): """ Should be called after creation of this model. """ raise NotImplementedError() @classmethod def get_option_class(cls): if cls.option_class is None: raise NotImplementedError( f"The poll class {cls} has to have an attribute option_class." ) return cls.option_class def get_options(self): """ Returns the option objects for the poll. """ return self.options.all() @classmethod def get_vote_class(cls): return cls.get_option_class().get_vote_class() def get_votes(self): """ Return a QuerySet with all vote objects related to this poll. """ return self.get_vote_class().objects.filter(option__poll__id=self.id) def pseudoanonymize(self): for option in self.get_options(): option.pseudoanonymize() def reset(self): for option in self.get_options(): option.reset() self.voted.clear() # Reset state self.state = BasePoll.STATE_CREATED if self.type == self.TYPE_ANALOG: self.votesvalid = None self.votesinvalid = None self.votescast = None self.save()