from django.shortcuts import redirect, get_object_or_404
from django.views.generic import ListView, DetailView, RedirectView
from django.views.generic.edit import UpdateView, CreateView, DeleteView, FormView
from django.core.urlresolvers import reverse_lazy, reverse
from django.utils.translation import ugettext_lazy as _
from django.forms.models import modelform_factory
from django.core.exceptions import PermissionDenied, ObjectDoesNotExist, ImproperlyConfigured
from django.forms import CheckboxSelectMultiple
from django.utils import timezone
from django.conf import settings
from django import forms

from core.views import CanViewMixin, CanEditMixin, CanEditPropMixin, CanCreateMixin
from django.db.models.query import QuerySet
from django.views.generic.edit import FormMixin
from core.views.forms import SelectDateTime
from election.models import Election, Role, Candidature, ElectionList, Vote

from ajax_select.fields import AutoCompleteSelectField


# Custom form field

class VoteCheckbox(forms.ModelMultipleChoiceField):
    """
        Used to replace ModelMultipleChoiceField but with
        automatic backend verification
    """
    def __init__(self, queryset, max_choice, required=True, widget=None, label=None,
                 initial=None, help_text='', *args, **kwargs):
        self.max_choice = max_choice
        widget = forms.CheckboxSelectMultiple()
        super(VoteCheckbox, self).__init__(queryset, None, required, widget, label,
                                           initial, help_text, *args, **kwargs)

    def clean(self, value):
        qs = super(VoteCheckbox, self).clean(value)
        self.validate(qs)
        return qs

    def validate(self, qs):
        if qs.count() > self.max_choice:
            raise forms.ValidationError(_("You have selected too much candidates."), code='invalid')


# Forms


class CandidateForm(forms.Form):
    """ Form to candidate """
    user = AutoCompleteSelectField('users', label=_('User to candidate'), help_text=None, required=True)
    program = forms.CharField(widget=forms.Textarea)

    def __init__(self, election_id, *args, **kwargs):
        super(CandidateForm, self).__init__(*args, **kwargs)
        self.fields['role'] = forms.ModelChoiceField(Role.objects.filter(election__id=election_id))
        self.fields['election_list'] = forms.ModelChoiceField(ElectionList.objects.filter(election__id=election_id))


class VoteForm(forms.Form):
    def __init__(self, election, user, *args, **kwargs):
        super(VoteForm, self).__init__(*args, **kwargs)
        for role in election.role.all():
            if not role.user_has_voted(user):
                cand = role.candidature
                if role.max_choice > 1:
                    self.fields[role.title] = VoteCheckbox(cand, role.max_choice, required=False)
                else:
                    self.fields[role.title] = forms.ModelChoiceField(cand, required=False,
                                                                        widget=forms.RadioSelect(), empty_label=_("Blank vote"))


# Display elections


class ElectionsListView(CanViewMixin, ListView):
    """
    A list with all responsabilities and their candidates
    """
    model = Election
    template_name = 'election/election_list.jinja'

    def get_queryset(self):
        qs = super(ElectionsListView, self).get_queryset()
        today = timezone.now()
        qs = qs.filter(end_date__gte=today, start_date__lte=today)
        return qs


class ElectionDetailView(CanViewMixin, DetailView):
    """
    Details an election responsability by responsability
    """
    model = Election
    template_name = 'election/election_detail.jinja'
    pk_url_kwarg = "election_id"

    def get_context_data(self, **kwargs):
        """ Add additionnal data to the template """
        kwargs = super(ElectionDetailView, self).get_context_data(**kwargs)
        kwargs['candidate_form'] = CandidateForm(self.get_object().id)
        kwargs['election_form'] = VoteForm(self.get_object(), self.request.user)
        kwargs['user'] = self.request.user
        return kwargs


# Form view

class CandidatureCreateView(CanCreateMixin, FormView):
    """
    View dedicated to a cundidature creation
    """
    form_class = CandidateForm
    template_name = 'core/page_prop.jinja'

    def dispatch(self, request, *arg, **kwargs):
        self.election_id = kwargs['election_id']
        return super(CandidatureCreateView, self).dispatch(request, *arg, **kwargs)

    def get_form_kwargs(self):
        kwargs = super(CandidatureCreateView, self).get_form_kwargs()
        kwargs['election_id'] = self.election_id
        return kwargs

    def create_candidature(self, data):
        cand = Candidature(
                role=data['role'],
                user=data['user'],
                election_list=data['election_list'],
                program=data['program']
            )
        cand.save()

    def form_valid(self, form):
        """
            Verify that the selected user is in candidate group
        """
        data = form.clean()
        res = super(FormView, self).form_valid(form)
        data['election'] = Election.objects.get(id=self.election_id)
        if(data['election'].can_candidate(data['user'])):
            self.create_candidature(data)
            return res
        return res

    def get_success_url(self, **kwargs):
        return reverse_lazy('election:detail', kwargs={'election_id': self.election_id})


class VoteFormView(CanCreateMixin, FormView):
    """
    Alows users to vote
    """
    form_class = VoteForm
    template_name = 'election/election_detail.jinja'

    def dispatch(self, request, *arg, **kwargs):
        self.election = get_object_or_404(Election, pk=kwargs['election_id'])
        return super(VoteFormView, self).dispatch(request, *arg, **kwargs)

    def vote(self, data):
        for key in data.keys():
            if isinstance(data[key], QuerySet):
                if data[key].count() > 0:
                    vote = Vote(role=data[key].first().role)
                    vote.save()
                for el in data[key]:
                    vote.candidature.add(el)
            elif data[key] is not None:
                vote = Vote(role=data[key].role)
                vote.save()
                vote.candidature.add(data[key])
            self.election.role.get(title=key).has_voted.add(self.request.user)

    def get_form_kwargs(self):
        kwargs = super(VoteFormView, self).get_form_kwargs()
        kwargs['election'] = self.election
        kwargs['user'] = self.request.user
        return kwargs

    def form_valid(self, form):
        """
            Verify that the user is part in a vote group
        """
        data = form.clean()
        res = super(FormView, self).form_valid(form)
        for grp in self.election.vote_groups.all():
            if self.request.user.is_in_group(grp):
                self.vote(data)
                return res
        return res

    def get_success_url(self, **kwargs):
        return reverse_lazy('election:detail', kwargs={'election_id': self.election.id})

    def get_context_data(self, **kwargs):
        """ Add additionnal data to the template """
        kwargs = super(VoteFormView, self).get_context_data(**kwargs)
        kwargs['candidate_form'] = CandidateForm(self.election.id)
        kwargs['object'] = self.election
        kwargs['election'] = self.election
        kwargs['election_form'] = self.get_form()
        return kwargs


# Create views


class ElectionCreateView(CanCreateMixin, CreateView):
    model = Election
    form_class = modelform_factory(Election,
        fields=['title', 'description', 'start_candidature', 'end_candidature', 'start_date', 'end_date',
                'edit_groups', 'view_groups', 'vote_groups', 'candidature_groups'],
        widgets={
            'edit_groups': CheckboxSelectMultiple,
            'view_groups': CheckboxSelectMultiple,
            'edit_groups': CheckboxSelectMultiple,
            'vote_groups': CheckboxSelectMultiple,
            'candidature_groups': CheckboxSelectMultiple,
            'start_date': SelectDateTime,
            'end_date': SelectDateTime,
            'start_candidature': SelectDateTime,
            'end_candidature': SelectDateTime,
        })
    template_name = 'core/page_prop.jinja'

    def get_success_url(self, **kwargs):
        return reverse_lazy('election:detail', kwargs={'election_id': self.object.id})


class RoleCreateView(CanCreateMixin, CreateView):
    model = Role
    form_class = modelform_factory(Role,
        fields=['title', 'election', 'title', 'description', 'max_choice'])
    template_name = 'core/page_prop.jinja'

    def form_valid(self, form):
        """
            Verify that the user can edit proprely
        """
        obj = form.instance
        res = super(CreateView, self).form_valid
        if obj.election:
            for grp in obj.election.edit_groups.all():
                if self.request.user.is_in_group(grp):
                    return res(form)
        raise PermissionDenied

    def get_success_url(self, **kwargs):
        return reverse_lazy('election:detail', kwargs={'election_id': self.object.election.id})


class ElectionListCreateView(CanCreateMixin, CreateView):
    model = ElectionList
    form_class = modelform_factory(ElectionList,
        fields=['title', 'election'])
    template_name = 'core/page_prop.jinja'

    def form_valid(self, form):
        """
            Verify that the user can vote on this election
        """
        obj = form.instance
        res = super(CreateView, self).form_valid
        if obj.election:
            for grp in obj.election.candidature_groups.all():
                if self.request.user.is_in_group(grp):
                    return res(form)
            for grp in obj.election.edit_groups.all():
                if self.request.user.is_in_group(grp):
                    return res(form)
        raise PermissionDenied

    def get_success_url(self, **kwargs):
        return reverse_lazy('election:detail', kwargs={'election_id': self.object.election.id})