# -*- coding: utf-8 -*-

from django.core.urlresolvers import reverse
from django.db import models
from django.utils.datastructures import SortedDict
from django.utils.translation import ugettext as _
from django.utils.translation import ugettext_lazy, ugettext_noop

from openslides.config.api import config
from openslides.poll.models import (BaseOption, BasePoll, BaseVote,
                                    CollectInvalid, CollectVotesCast,
                                    PublishPollMixin)
from openslides.projector.models import RelatedModelMixin, SlideMixin
from openslides.utils.models import AbsoluteUrlMixin
from openslides.utils.person import PersonField
from openslides.utils.utils import html_strong


class AssignmentCandidate(RelatedModelMixin, models.Model):
    """
    Many2Many table between an assignment and the candidates.
    """
    assignment = models.ForeignKey("Assignment")
    person = PersonField(db_index=True)
    elected = models.BooleanField(default=False)
    blocked = models.BooleanField(default=False)

    class Meta:
        unique_together = ("assignment", "person")

    def __unicode__(self):
        return unicode(self.person)

    def get_related_model(self):
        """
        Returns the assignment
        """
        return self.assignment


class Assignment(SlideMixin, AbsoluteUrlMixin, models.Model):
    slide_callback_name = 'assignment'

    STATUS = (
        ('sea', ugettext_lazy('Searching for candidates')),
        ('vot', ugettext_lazy('Voting')),
        ('fin', ugettext_lazy('Finished')),
    )

    name = models.CharField(max_length=100, verbose_name=ugettext_lazy("Name"))
    description = models.TextField(null=True, blank=True, verbose_name=ugettext_lazy("Description"))
    posts = models.PositiveSmallIntegerField(verbose_name=ugettext_lazy("Number of available posts"))
    poll_description_default = models.CharField(
        max_length=79, null=True, blank=True,
        verbose_name=ugettext_lazy("Default comment on the ballot paper"))
    status = models.CharField(max_length=3, choices=STATUS, default='sea')

    class Meta:
        permissions = (
            ('can_see_assignment', ugettext_noop('Can see elections')),  # TODO: Add plural s to the codestring
            ('can_nominate_other', ugettext_noop('Can nominate another person')),
            ('can_nominate_self', ugettext_noop('Can nominate oneself')),
            ('can_manage_assignment', ugettext_noop('Can manage elections')),  # TODO: Add plural s also to the codestring
        )
        ordering = ('name',)
        verbose_name = ugettext_noop('Election')

    def __unicode__(self):
        return self.name

    def get_absolute_url(self, link='detail'):
        if link == 'detail':
            url = reverse('assignment_detail', args=[str(self.pk)])
        elif link == 'update':
            url = reverse('assignment_update', args=[str(self.pk)])
        elif link == 'delete':
            url = reverse('assignment_delete', args=[str(self.pk)])
        else:
            url = super(Assignment, self).get_absolute_url(link)
        return url

    def get_slide_context(self, **context):
        context.update({
            'polls': self.poll_set.filter(published=True),
            'vote_results': self.vote_results(only_published=True)})
        return super(Assignment, self).get_slide_context(**context)

    def set_status(self, status):
        status_dict = dict(self.STATUS)
        if status not in status_dict:
            raise ValueError(_('%s is not a valid status.') % html_strong(status))
        if self.status == status:
            raise ValueError(
                _('The election status is already %s.') % html_strong(status_dict[status]))
        self.status = status
        self.save()

    def run(self, candidate, person=None):
        """
        run for a vote
        candidate: The user who will be a candidate
        person: The user who chooses the candidate
        """
        # TODO: don't make any permission checks here.
        #       Use other Exceptions
        if self.is_candidate(candidate):
            raise NameError(_('<b>%s</b> is already a candidate.') % candidate)
        if not person.has_perm("assignment.can_manage_assignment") and self.status != 'sea':
            raise NameError(_('The candidate list is already closed.'))
        candidature = self.assignment_candidates.filter(person=candidate)
        if candidature and candidate != person and \
                not person.has_perm("assignment.can_manage_assignment"):
            # if the candidature is blocked and anotherone tries to run the
            # candidate
            raise NameError(
                _('%s does not want to be a candidate.') % candidate)
        elif candidature:
            candidature[0].blocked = False
            candidature[0].save()
        else:
            AssignmentCandidate(assignment=self, person=candidate).save()

    def delrun(self, candidate, blocked=True):
        """
        stop running for a vote
        """
        try:
            candidature = self.assignment_candidates.get(person=candidate)
        except AssignmentCandidate.DoesNotExist:
            raise Exception(_('%s is no candidate') % candidate)

        if not candidature.blocked:
            if blocked:
                candidature.blocked = True
                candidature.save()
            else:
                candidature.delete()
        else:
            candidature.delete()

    def is_candidate(self, person):
        """
        return True, if person is a candidate.
        """
        try:
            return self.assignment_candidates.filter(person=person).exclude(blocked=True).exists()
        except AttributeError:
            return False

    def is_blocked(self, person):
        """
        return True, if the person is blockt for candidature.
        """
        return self.assignment_candidates.filter(person=person).filter(blocked=True).exists()

    @property
    def assignment_candidates(self):
        return AssignmentCandidate.objects.filter(assignment=self)

    @property
    def candidates(self):
        return self.get_participants(only_candidate=True)

    @property
    def elected(self):
        return self.get_participants(only_elected=True)

    def get_participants(self, only_elected=False, only_candidate=False):
        candidates = self.assignment_candidates.exclude(blocked=True)

        assert not (only_elected and only_candidate)

        if only_elected:
            candidates = candidates.filter(elected=True)

        if only_candidate:
            candidates = candidates.filter(elected=False)

        participants = []
        for candidate in candidates.all():
            participants.append(candidate.person)
        participants.sort(key=lambda person: person.sort_name)
        return participants
        #return candidates.values_list('person', flat=True)

    def set_elected(self, person, value=True):
        candidate = self.assignment_candidates.get(person=person)
        candidate.elected = value
        candidate.save()

    def is_elected(self, person):
        return person in self.elected

    def gen_poll(self):
        poll = AssignmentPoll.objects.create(
            assignment=self, description=self.poll_description_default)
        poll.set_options([{'candidate': person} for person in self.candidates])
        return poll

    def vote_results(self, only_published):
        """
        returns a table represented as a list with all candidates from all
        related polls and their vote results.
        """
        vote_results_dict = SortedDict()
        # All polls related to this assigment
        polls = self.poll_set.all()
        if only_published:
            polls = polls.filter(published=True)
        # All PollOption-Objects related to this assignment
        options = []
        for poll in polls:
            options += poll.get_options()

        options.sort(key=lambda option: option.candidate.sort_name)

        for option in options:
            candidate = option.candidate
            if candidate in vote_results_dict:
                continue
            vote_results_dict[candidate] = []
            for poll in polls:
                votes = {}
                try:
                    # candidate related to this poll
                    poll_option = poll.get_options().get(candidate=candidate)
                    for vote in poll_option.get_votes():
                        votes[vote.value] = vote.print_weight()
                except AssignmentOption.DoesNotExist:
                    # candidate not in related to this poll
                    votes = None
                vote_results_dict[candidate].append(votes)
        return vote_results_dict

    def get_agenda_title(self):
        return self.name

    def get_agenda_title_supplement(self):
        return '(%s)' % _('Assignment')


class AssignmentVote(BaseVote):
    option = models.ForeignKey('AssignmentOption')


class AssignmentOption(BaseOption):
    poll = models.ForeignKey('AssignmentPoll')
    candidate = PersonField()
    vote_class = AssignmentVote

    def __unicode__(self):
        return unicode(self.candidate)


class AssignmentPoll(RelatedModelMixin, CollectInvalid, CollectVotesCast,
                     PublishPollMixin, AbsoluteUrlMixin, BasePoll):
    option_class = AssignmentOption
    assignment = models.ForeignKey(Assignment, related_name='poll_set')
    yesnoabstain = models.NullBooleanField()
    description = models.CharField(
        max_length=79, null=True, blank=True,
        verbose_name=ugettext_lazy("Comment on the ballot paper"))

    def __unicode__(self):
        return _("Ballot %d") % self.get_ballot()

    def get_absolute_url(self, link='update'):
        if link == 'update':
            url = reverse('assignment_poll_view', args=[str(self.pk)])
        elif link == 'delete':
            url = reverse('assignment_poll_delete', args=[str(self.pk)])
        else:
            url = super(AssignmentPoll, self).get_absolute_url(link)
        return url

    def get_assignment(self):
        return self.assignment

    def get_related_model(self):
        return self.assignment

    def get_vote_values(self):
        if self.yesnoabstain is None:
            if config['assignment_poll_vote_values'] == 'votes':
                self.yesnoabstain = False
            elif config['assignment_poll_vote_values'] == 'yesnoabstain':
                self.yesnoabstain = True
            else:
                # candidates <= available posts -> yes/no/abstain
                if len(self.assignment.candidates) <= (self.assignment.posts - len(self.assignment.elected)):
                    self.yesnoabstain = True
                else:
                    self.yesnoabstain = False
            self.save()
        if self.yesnoabstain:
            return [ugettext_noop('Yes'), ugettext_noop('No'), ugettext_noop('Abstain')]
        else:
            return [ugettext_noop('Votes')]

    def get_ballot(self):
        return self.assignment.poll_set.filter(id__lte=self.id).count()

    def append_pollform_fields(self, fields):
        fields.append('description')