from django import forms
from django.contrib import messages
from django.core.exceptions import PermissionDenied
from django.core.files import File
from django.core.urlresolvers import reverse
from django.db import transaction
from django.db.models import Count
from django.forms import inlineformset_factory
from django.shortcuts import get_object_or_404, redirect
from django.utils.functional import cached_property
from django.utils.translation import ugettext_lazy as _
from django.views.generic import (
    CreateView, DeleteView, DetailView, FormView, ListView, UpdateView,
)

from pretix.base.models import Organizer, Team, TeamInvite, User
from pretix.base.models.event import EventMetaProperty
from pretix.base.models.organizer import TeamAPIToken
from pretix.base.services.mail import SendMailException, mail
from pretix.control.forms.organizer import (
    EventMetaPropertyForm, OrganizerDisplaySettingsForm, OrganizerForm,
    OrganizerSettingsForm, OrganizerUpdateForm, TeamForm,
)
from pretix.control.permissions import OrganizerPermissionRequiredMixin
from pretix.control.signals import nav_organizer
from pretix.helpers.urls import build_absolute_uri
from pretix.presale.style import regenerate_organizer_css


class OrganizerList(ListView):
    model = Organizer
    context_object_name = 'organizers'
    template_name = 'pretixcontrol/organizers/index.html'
    paginate_by = 30

    def get_queryset(self):
        if self.request.user.is_superuser:
            return Organizer.objects.all()
        else:
            return Organizer.objects.filter(pk__in=self.request.user.teams.values_list('organizer', flat=True))


class InviteForm(forms.Form):
    user = forms.EmailField(required=False, label=_('User'))


class TokenForm(forms.Form):
    name = forms.CharField(required=False, label=_('Token name'))


class OrganizerDetailViewMixin:
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['nav_organizer'] = []
        ctx['organizer'] = self.request.organizer

        for recv, retv in nav_organizer.send(sender=self.request.organizer, request=self.request,
                                             organizer=self.request.organizer):
            ctx['nav_organizer'] += retv
        ctx['nav_organizer'].sort(key=lambda n: n['label'])
        return ctx

    def get_object(self, queryset=None) -> Organizer:
        return self.request.organizer


class OrganizerDetail(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, DetailView):
    model = Organizer
    template_name = 'pretixcontrol/organizers/detail.html'
    permission = None
    context_object_name = 'organizer'

    def get_object(self, queryset=None) -> Organizer:
        return self.request.organizer

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['events'] = self.request.organizer.events.all()
        return ctx


class OrganizerTeamView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, DetailView):
    model = Organizer
    template_name = 'pretixcontrol/organizers/teams.html'
    permission = 'can_change_permissions'
    context_object_name = 'organizer'


class OrganizerSettingsFormView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, FormView):
    model = Organizer
    permission = 'can_change_organizer_settings'

    def get_form_kwargs(self):
        kwargs = super().get_form_kwargs()
        kwargs['obj'] = self.request.organizer
        return kwargs

    @transaction.atomic
    def post(self, request, *args, **kwargs):
        form = self.get_form()
        if form.is_valid():
            form.save()
            if form.has_changed():
                self.request.organizer.log_action(
                    'pretix.organizer.settings', user=self.request.user, data={
                        k: (form.cleaned_data.get(k).name
                            if isinstance(form.cleaned_data.get(k), File)
                            else form.cleaned_data.get(k))
                        for k in form.changed_data
                    }
                )
            messages.success(self.request, _('Your changes have been saved.'))
            return redirect(self.get_success_url())
        else:
            messages.error(self.request, _('We could not save your changes. See below for details.'))
            return self.get(request)


class OrganizerDisplaySettings(OrganizerSettingsFormView):
    model = Organizer
    form_class = OrganizerDisplaySettingsForm
    template_name = 'pretixcontrol/organizers/display.html'
    permission = 'can_change_organizer_settings'

    def get_success_url(self) -> str:
        return reverse('control:organizer.display', kwargs={
            'organizer': self.request.organizer.slug,
        })

    @transaction.atomic
    def post(self, request, *args, **kwargs):
        form = self.get_form()
        if form.is_valid():
            form.save()
            if form.has_changed():
                self.request.organizer.log_action(
                    'pretix.organizer.settings', user=self.request.user, data={
                        k: (form.cleaned_data.get(k).name
                            if isinstance(form.cleaned_data.get(k), File)
                            else form.cleaned_data.get(k))
                        for k in form.changed_data
                    }
                )
            regenerate_organizer_css.apply_async(args=(self.request.organizer.pk,))
            messages.success(self.request, _('Your changes have been saved. Please note that it can '
                                             'take a short period of time until your changes become '
                                             'active.'))
            return redirect(self.get_success_url())
        else:
            messages.error(self.request, _('We could not save your changes. See below for details.'))
            return self.get(request)


class OrganizerUpdate(OrganizerPermissionRequiredMixin, UpdateView):
    model = Organizer
    form_class = OrganizerUpdateForm
    template_name = 'pretixcontrol/organizers/edit.html'
    permission = 'can_change_organizer_settings'
    context_object_name = 'organizer'

    @cached_property
    def object(self) -> Organizer:
        return self.request.organizer

    def get_object(self, queryset=None) -> Organizer:
        return self.object

    @cached_property
    def sform(self):
        return OrganizerSettingsForm(
            obj=self.object,
            prefix='settings',
            data=self.request.POST if self.request.method == 'POST' else None,
            files=self.request.FILES if self.request.method == 'POST' else None
        )

    def get_context_data(self, *args, **kwargs) -> dict:
        context = super().get_context_data(*args, **kwargs)
        context['sform'] = self.sform
        context['formset'] = self.formset
        return context

    @transaction.atomic
    def form_valid(self, form):
        self.save_formset(self.object)
        self.sform.save()
        if self.sform.has_changed():
            self.request.organizer.log_action(
                'pretix.organizer.settings',
                user=self.request.user,
                data={
                    k: (self.sform.cleaned_data.get(k).name
                        if isinstance(self.sform.cleaned_data.get(k), File)
                        else self.sform.cleaned_data.get(k))
                    for k in self.sform.changed_data
                }
            )
        if form.has_changed():
            self.request.organizer.log_action(
                'pretix.organizer.changed',
                user=self.request.user,
                data={k: form.cleaned_data.get(k) for k in form.changed_data}
            )
        messages.success(self.request, _('Your changes have been saved.'))
        return super().form_valid(form)

    def get_form_kwargs(self):
        kwargs = super().get_form_kwargs()
        if self.request.user.is_superuser:
            kwargs['domain'] = True
        return kwargs

    def get_success_url(self) -> str:
        return reverse('control:organizer.edit', kwargs={
            'organizer': self.request.organizer.slug,
        })

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        form = self.get_form()
        if form.is_valid() and self.sform.is_valid() and self.formset.is_valid():
            return self.form_valid(form)
        else:
            return self.form_invalid(form)

    @cached_property
    def formset(self):
        formsetclass = inlineformset_factory(
            Organizer, EventMetaProperty,
            form=EventMetaPropertyForm, can_order=False, can_delete=True, extra=0
        )
        return formsetclass(self.request.POST if self.request.method == "POST" else None,
                            instance=self.object, queryset=self.object.meta_properties.all())

    def save_formset(self, obj):
        for form in self.formset.initial_forms:
            if form in self.formset.deleted_forms:
                if not form.instance.pk:
                    continue
                form.instance.delete()
                form.instance.pk = None
            elif form.has_changed():
                form.save()

        for form in self.formset.extra_forms:
            if not form.has_changed():
                continue
            if self.formset._should_delete_form(form):
                continue
            form.instance.organizer = obj
            form.save()


class OrganizerCreate(CreateView):
    model = Organizer
    form_class = OrganizerForm
    template_name = 'pretixcontrol/organizers/create.html'
    context_object_name = 'organizer'

    def dispatch(self, request, *args, **kwargs):
        if not request.user.is_superuser:
            raise PermissionDenied()  # TODO
        return super().dispatch(request, *args, **kwargs)

    @transaction.atomic
    def form_valid(self, form):
        messages.success(self.request, _('The new organizer has been created.'))
        ret = super().form_valid(form)
        t = Team.objects.create(
            organizer=form.instance, name=_('Administrators'),
            all_events=True, can_create_events=True, can_change_teams=True,
            can_change_organizer_settings=True, can_change_event_settings=True, can_change_items=True,
            can_view_orders=True, can_change_orders=True, can_view_vouchers=True, can_change_vouchers=True
        )
        t.members.add(self.request.user)
        return ret

    def get_success_url(self) -> str:
        return reverse('control:organizers')


class TeamListView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, ListView):
    model = Team
    template_name = 'pretixcontrol/organizers/teams.html'
    permission = 'can_change_teams'
    context_object_name = 'teams'

    def get_queryset(self):
        return self.request.organizer.teams.annotate(
            memcount=Count('members', distinct=True),
            eventcount=Count('limit_events', distinct=True),
            invcount=Count('invites', distinct=True)
        ).all()


class TeamCreateView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, CreateView):
    model = Team
    template_name = 'pretixcontrol/organizers/team_edit.html'
    permission = 'can_change_teams'
    form_class = TeamForm

    def get_form_kwargs(self):
        kwargs = super().get_form_kwargs()
        kwargs['organizer'] = self.request.organizer
        return kwargs

    def get_object(self, queryset=None):
        return get_object_or_404(Team, organizer=self.request.organizer, pk=self.kwargs.get('team'))

    def get_success_url(self):
        return reverse('control:organizer.team', kwargs={
            'organizer': self.request.organizer.slug,
            'team': self.object.pk
        })

    def form_valid(self, form):
        messages.success(self.request, _('The team has been created. You can now add members to the team.'))
        form.instance.organizer = self.request.organizer
        ret = super().form_valid(form)
        form.instance.members.add(self.request.user)
        form.instance.log_action('pretix.team.created', user=self.request.user, data={
            k: getattr(self.object, k) if k != 'limit_events' else [e.id for e in getattr(self.object, k).all()]
            for k in form.changed_data
        })
        return ret

    def form_invalid(self, form):
        messages.error(self.request, _('Your changes could not be saved.'))
        return super().form_invalid(form)


class TeamUpdateView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, UpdateView):
    model = Team
    template_name = 'pretixcontrol/organizers/team_edit.html'
    permission = 'can_change_teams'
    context_object_name = 'team'
    form_class = TeamForm

    def get_form_kwargs(self):
        kwargs = super().get_form_kwargs()
        kwargs['organizer'] = self.request.organizer
        return kwargs

    def get_object(self, queryset=None):
        return get_object_or_404(Team, organizer=self.request.organizer, pk=self.kwargs.get('team'))

    def get_success_url(self):
        return reverse('control:organizer.team', kwargs={
            'organizer': self.request.organizer.slug,
            'team': self.object.pk
        })

    def form_valid(self, form):
        if form.has_changed():
            self.object.log_action('pretix.team.changed', user=self.request.user, data={
                k: getattr(self.object, k) if k != 'limit_events' else [e.id for e in getattr(self.object, k).all()]
                for k in form.changed_data
            })
        messages.success(self.request, _('Your changes have been saved.'))
        return super().form_valid(form)

    def form_invalid(self, form):
        messages.error(self.request, _('Your changes could not be saved.'))
        return super().form_invalid(form)


class TeamDeleteView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, DeleteView):
    model = Team
    template_name = 'pretixcontrol/organizers/team_delete.html'
    permission = 'can_change_teams'
    context_object_name = 'team'

    def get_object(self, queryset=None):
        return get_object_or_404(Team, organizer=self.request.organizer, pk=self.kwargs.get('team'))

    def get_success_url(self):
        return reverse('control:organizer.teams', kwargs={
            'organizer': self.request.organizer.slug,
        })

    def get_context_data(self, *args, **kwargs) -> dict:
        context = super().get_context_data(*args, **kwargs)
        context['possible'] = self.is_allowed()
        return context

    def is_allowed(self) -> bool:
        return self.request.organizer.teams.exclude(pk=self.kwargs.get('team')).filter(
            can_change_teams=True, members__isnull=False
        ).exists()

    @transaction.atomic
    def delete(self, request, *args, **kwargs):
        success_url = self.get_success_url()
        self.object = self.get_object()
        if self.is_allowed():
            self.object.log_action('pretix.team.deleted', user=self.request.user)
            self.object.delete()
            messages.success(request, _('The selected team has been deleted.'))
            return redirect(success_url)
        else:
            messages.error(request, _('The selected team cannot be deleted.'))
            return redirect(success_url)


class TeamMemberView(OrganizerDetailViewMixin, OrganizerPermissionRequiredMixin, DetailView):
    template_name = 'pretixcontrol/organizers/team_members.html'
    context_object_name = 'team'
    permission = 'can_change_teams'
    model = Team

    def get_object(self, queryset=None):
        return get_object_or_404(Team, organizer=self.request.organizer, pk=self.kwargs.get('team'))

    @cached_property
    def add_form(self):
        return InviteForm(data=(self.request.POST
                                if self.request.method == "POST" and "user" in self.request.POST else None))

    @cached_property
    def add_token_form(self):
        return TokenForm(data=(self.request.POST
                               if self.request.method == "POST" and "name" in self.request.POST else None))

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['add_form'] = self.add_form
        ctx['add_token_form'] = self.add_token_form
        return ctx

    def _send_invite(self, instance):
        try:
            mail(
                instance.email,
                _('pretix account invitation'),
                'pretixcontrol/email/invitation.txt',
                {
                    'user': self,
                    'organizer': self.request.organizer.name,
                    'team': instance.team.name,
                    'url': build_absolute_uri('control:auth.invite', kwargs={
                        'token': instance.token
                    })
                },
                event=None,
                locale=self.request.LANGUAGE_CODE
            )
        except SendMailException:
            pass  # Already logged

    @transaction.atomic
    def post(self, request, *args, **kwargs):
        self.object = self.get_object()

        if 'remove-member' in request.POST:
            try:
                user = User.objects.get(pk=request.POST.get('remove-member'))
            except User.DoesNotExist:
                pass
            else:
                other_admin_teams = self.request.organizer.teams.exclude(pk=self.object.pk).filter(
                    can_change_teams=True, members__isnull=False
                ).exists()
                if not other_admin_teams and self.object.can_change_teams and self.object.members.count() == 1:
                    messages.error(self.request, _('You cannot remove the last member from this team as noone would '
                                                   'be left with the permission to change teams.'))
                    return redirect(self.get_success_url())
                else:
                    self.object.members.remove(user)
                    self.object.log_action(
                        'pretix.team.member.removed', user=self.request.user, data={
                            'email': user.email,
                            'user': user.pk
                        }
                    )
                    messages.success(self.request, _('The member has been removed from the team.'))
                    return redirect(self.get_success_url())

        elif 'remove-invite' in request.POST:
            try:
                invite = self.object.invites.get(pk=request.POST.get('remove-invite'))
            except TeamInvite.DoesNotExist:
                messages.error(self.request, _('Invalid invite selected.'))
                return redirect(self.get_success_url())
            else:
                invite.delete()
                self.object.log_action(
                    'pretix.team.invite.deleted', user=self.request.user, data={
                        'email': invite.email
                    }
                )
                messages.success(self.request, _('The invite has been revoked.'))
                return redirect(self.get_success_url())

        elif 'remove-token' in request.POST:
            try:
                token = self.object.tokens.get(pk=request.POST.get('remove-token'))
            except TeamAPIToken.DoesNotExist:
                messages.error(self.request, _('Invalid token selected.'))
                return redirect(self.get_success_url())
            else:
                token.active = False
                token.save()
                self.object.log_action(
                    'pretix.team.token.deleted', user=self.request.user, data={
                        'name': token.name
                    }
                )
                messages.success(self.request, _('The token has been revoked.'))
                return redirect(self.get_success_url())

        elif "user" in self.request.POST and self.add_form.is_valid() and self.add_form.has_changed():

            try:
                user = User.objects.get(email=self.add_form.cleaned_data['user'])
            except User.DoesNotExist:
                if self.object.invites.filter(email=self.add_form.cleaned_data['user']).exists():
                    messages.error(self.request, _('This user already has been invited for this team.'))
                    return self.get(request, *args, **kwargs)

                invite = self.object.invites.create(email=self.add_form.cleaned_data['user'])
                self._send_invite(invite)
                self.object.log_action(
                    'pretix.team.invite.created', user=self.request.user, data={
                        'email': self.add_form.cleaned_data['user']
                    }
                )
                messages.success(self.request, _('The new member has been invited to the team.'))
                return redirect(self.get_success_url())
            else:
                if self.object.members.filter(pk=user.pk).exists():
                    messages.error(self.request, _('This user already has permissions for this team.'))
                    return self.get(request, *args, **kwargs)

                self.object.members.add(user)
                self.object.log_action(
                    'pretix.team.member.added', user=self.request.user,
                    data={
                        'email': user.email,
                        'user': user.pk,
                    }
                )
                messages.success(self.request, _('The new member has been added to the team.'))
                return redirect(self.get_success_url())

        elif "name" in self.request.POST and self.add_token_form.is_valid() and self.add_token_form.has_changed():
            token = self.object.tokens.create(name=self.add_token_form.cleaned_data['name'])
            self.object.log_action(
                'pretix.team.token.created', user=self.request.user, data={
                    'name': self.add_token_form.cleaned_data['name'],
                    'id': token.pk
                }
            )
            messages.success(self.request, _('A new API token has been created with the following secret: {}\n'
                                             'Please copy this secret to a safe place. You will not be able to '
                                             'view it again here.').format(token.token))
            return redirect(self.get_success_url())
        else:
            messages.error(self.request, _('Your changes could not be saved.'))
            return self.get(request, *args, **kwargs)

    def get_success_url(self) -> str:
        return reverse('control:organizer.team', kwargs={
            'organizer': self.request.organizer.slug,
            'team': self.object.pk
        })