#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
    openslides.participant.views
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    Views for the participant app.

    :copyright: 2011–2013 by OpenSlides team, see AUTHORS.
    :license: GNU GPL, see LICENSE for more details.
"""

try:
    import qrcode
except ImportError:
    draw_qrcode = False
else:
    draw_qrcode = True

from cStringIO import StringIO

from django.contrib import messages
from django.contrib.auth.decorators import login_required
from django.contrib.auth.forms import PasswordChangeForm
from django.contrib.auth.views import login as django_login
from django.core.urlresolvers import reverse
from django.shortcuts import redirect
from django.utils.translation import ugettext as _
from django.utils.translation import activate, ugettext_lazy
from reportlab.lib import colors
from reportlab.lib.units import cm
from reportlab.platypus import (Image, LongTable, Paragraph, SimpleDocTemplate,
                                Spacer, Table, TableStyle)

from openslides.config.api import config
from openslides.projector.projector import Widget
from openslides.utils.pdf import stylesheet
from openslides.utils.template import Tab
from openslides.utils.utils import (delete_default_permissions, html_strong,
                                    template)
from openslides.utils.views import (CreateView, DeleteView, DetailView,
                                    FormView, ListView, PDFView,
                                    PermissionMixin, QuestionView,
                                    RedirectView, SingleObjectMixin, UpdateView)

from .api import gen_password, gen_username, import_users
from .forms import (GroupForm, UserCreateForm, UserImportForm, UsersettingsForm,
                    UserUpdateForm)
from .models import get_protected_perm, Group, User


class UserOverview(ListView):
    """
    Show all participants (users).
    """
    permission_required = 'participant.can_see_participant'
    template_name = 'participant/overview.html'
    context_object_name = 'users'

    def get_queryset(self):
        query = User.objects
        if config['participant_sort_users_by_first_name']:
            query = query.order_by('first_name')
        else:
            query = query.order_by('last_name')
        return query.all()

    def get_context_data(self, **kwargs):
        context = super(UserOverview, self).get_context_data(**kwargs)
        all_users = User.objects.count()
        # context vars
        context.update({
            'allusers': all_users,
            'request_user': self.request.user})
        return context


class UserDetailView(DetailView, PermissionMixin):
    """
    Classed based view to show a specific user in the interface.
    """
    permission_required = 'participant.can_see_participant'
    model = User
    template_name = 'participant/user_detail.html'
    context_object_name = 'shown_user'


class UserCreateView(CreateView):
    """
    Create a new participant.
    """
    permission_required = 'participant.can_manage_participant'
    template_name = 'participant/edit.html'
    model = User
    context_object_name = 'edit_user'
    form_class = UserCreateForm
    success_url_name = 'user_overview'
    url_name_args = []

    def manipulate_object(self, form):
        self.object.username = gen_username(
            form.cleaned_data['first_name'], form.cleaned_data['last_name'])
        if not self.object.default_password:
            self.object.default_password = gen_password()
        self.object.set_password(self.object.default_password)

    def post_save(self, form):
        super(UserCreateView, self).post_save(form)
        # TODO: find a better solution that makes the following lines obsolete
        # Background: motion.models.use_post_save adds already the registerd group
        # to new user but super(..).post_save(form) removes it and sets only the
        # groups selected in the form (without 'registered')
        # workaround: add registered group again manually
        from openslides.participant.api import get_registered_group  # TODO: Test, if global import is possible
        registered = get_registered_group()
        self.object.groups.add(registered)


class UserUpdateView(UpdateView):
    """
    Update an existing participant.
    """
    permission_required = 'participant.can_manage_participant'
    template_name = 'participant/edit.html'
    model = User
    context_object_name = 'edit_user'
    form_class = UserUpdateForm
    success_url_name = 'user_overview'
    url_name_args = []

    def get_form_kwargs(self, *args, **kwargs):
        form_kwargs = super(UserUpdateView, self).get_form_kwargs(*args, **kwargs)
        form_kwargs.update({'request': self.request})
        return form_kwargs

    def manipulate_object(self, form):
        self.object.username = form.cleaned_data['user_name']

    def post_save(self, form):
        super(UserUpdateView, self).post_save(form)
        # TODO: find a better solution that makes the following lines obsolete
        # Background: motion.models.use_post_save adds already the registerd group
        # to new user but super(..).post_save(form) removes it and sets only the
        # groups selected in the form (without 'registered')
        # workaround: add registered group again manually
        from openslides.participant.api import get_registered_group  # TODO: Test, if global import is possible
        registered = get_registered_group()
        self.object.groups.add(registered)


class UserDeleteView(DeleteView):
    """
    Delete an participant.
    """
    permission_required = 'participant.can_manage_participant'
    model = User
    success_url_name = 'user_overview'
    url_name_args = []

    def pre_redirect(self, request, *args, **kwargs):
        if self.object == self.request.user:
            messages.error(request, _("You can not delete yourself."))
        else:
            super(UserDeleteView, self).pre_redirect(request, *args, **kwargs)

    def pre_post_redirect(self, request, *args, **kwargs):
        if self.object == self.request.user:
            messages.error(self.request, _("You can not delete yourself."))
        else:
            super(UserDeleteView, self).pre_post_redirect(request, *args, **kwargs)


class SetUserStatusView(RedirectView, SingleObjectMixin):
    """
    Activate or deactivate an user.
    """
    permission_required = 'participant.can_manage_participant'
    allow_ajax = True
    url_name = 'user_overview'
    model = User

    def pre_redirect(self, request, *args, **kwargs):
        self.object = self.get_object()
        action = kwargs['action']
        if action == 'activate':
            self.object.is_active = True
        elif action == 'deactivate':
            if self.object.user == self.request.user:
                messages.error(request, _("You can not deactivate yourself."))
                return
            self.object.is_active = False
        elif action == 'toggle':
            self.object.is_active = not self.object.is_active
        self.object.save()
        return super(SetUserStatusView, self).pre_redirect(request, *args, **kwargs)

    def get_ajax_context(self, **kwargs):
        context = super(SetUserStatusView, self).get_ajax_context(**kwargs)
        context['active'] = self.object.is_active
        return context


class ParticipantsListPDF(PDFView):
    """
    Generate the userliste as PDF.
    """
    permission_required = 'participant.can_see_participant'
    filename = ugettext_lazy("Participant-list")
    document_title = ugettext_lazy('List of Participants')

    def append_to_pdf(self, story):
        data = [['#', _('Title'), _('Last Name'), _('First Name'),
                 _('Structure level'), _('Group'), _('Committee')]]
        if config['participant_sort_users_by_first_name']:
            sort = 'first_name'
        else:
            sort = 'last_name'
        counter = 0
        for user in User.objects.all().order_by(sort):
            counter += 1
            groups = ''
            for group in user.groups.all():
                if group.pk != 2:
                    groups += "%s<br/>" % unicode(_(group.name))
            data.append([
                counter,
                Paragraph(user.title, stylesheet['Tablecell']),
                Paragraph(user.last_name, stylesheet['Tablecell']),
                Paragraph(user.first_name, stylesheet['Tablecell']),
                Paragraph(user.structure_level, stylesheet['Tablecell']),
                Paragraph(groups, stylesheet['Tablecell']),
                Paragraph(user.committee, stylesheet['Tablecell'])])
        t = LongTable(data, style=[
            ('VALIGN', (0, 0), (-1, -1), 'TOP'),
            ('LINEABOVE', (0, 0), (-1, 0), 2, colors.black),
            ('LINEABOVE', (0, 1), (-1, 1), 1, colors.black),
            ('LINEBELOW', (0, -1), (-1, -1), 2, colors.black),
            ('ROWBACKGROUNDS', (0, 1), (-1, -1),
                (colors.white, (.9, .9, .9)))])
        t._argW[0] = 0.75 * cm
        story.append(t)


class ParticipantsPasswordsPDF(PDFView):
    """
    Generate the Welcomepaper for the users.
    """
    permission_required = 'participant.can_manage_participant'
    filename = ugettext_lazy("Participant-passwords")
    top_space = 0

    def get_template(self, buffer):
        return SimpleDocTemplate(
            buffer, topMargin=-6, bottomMargin=-6,
            leftMargin=0, rightMargin=0, showBoundary=False)

    def build_document(self, pdf_document, story):
        pdf_document.build(story)

    def append_to_pdf(self, story):
        data = []
        participant_pdf_system_url = config["participant_pdf_system_url"]
        participant_pdf_welcometext = config["participant_pdf_welcometext"]
        if config['participant_sort_users_by_first_name']:
            sort = 'first_name'
        else:
            sort = 'last_name'
        # create qrcode image object from system url
        if draw_qrcode:
            qrcode_img = qrcode.make(participant_pdf_system_url)
            img_stream = StringIO()
            qrcode_img.save(img_stream, 'PNG')
            img_stream.seek(0)
            size = 2 * cm
            I = Image(img_stream, width=size, height=size)
        for user in User.objects.all().order_by(sort):
            cell = []
            cell.append(Spacer(0, 0.8 * cm))
            cell.append(Paragraph(_("Account for OpenSlides"),
                        stylesheet['Password_title']))
            cell.append(Paragraph(_("for %s") % (user),
                        stylesheet['Password_subtitle']))
            cell.append(Spacer(0, 0.5 * cm))
            cell.append(Paragraph(_("User: %s") % (user.username),
                        stylesheet['Monotype']))
            cell.append(
                Paragraph(
                    _("Password: %s")
                    % (user.default_password), stylesheet['Monotype']))
            cell.append(
                Paragraph(participant_pdf_system_url, stylesheet['Monotype']))
            if draw_qrcode:
                cell.append(I)
            cell2 = []
            cell2.append(Spacer(0, 0.8 * cm))
            if participant_pdf_welcometext is not None:
                cell2.append(Paragraph(
                    participant_pdf_welcometext.replace('\r\n', '<br/>'),
                    stylesheet['Ballot_subtitle']))

            data.append([cell, cell2])

        # add empty table line if no participants available
        if not data:
            data.append(['', ''])
        # build table
        t = Table(data, 10.5 * cm, 7.42 * cm)
        t.setStyle(TableStyle([
            ('LEFTPADDING', (0, 0), (0, -1), 30),
            ('LINEBELOW', (0, 0), (-1, 0), 0.25, colors.grey),
            ('LINEBELOW', (0, 1), (-1, 1), 0.25, colors.grey),
            ('LINEBELOW', (0, 1), (-1, -1), 0.25, colors.grey),
            ('VALIGN', (0, 0), (-1, -1), 'TOP'),
        ]))
        story.append(t)


class UserImportView(FormView):
    """
    Import Users via csv.
    """
    permission_required = 'participant.can_manage_participant'
    template_name = 'participant/import.html'
    form_class = UserImportForm
    success_url_name = 'user_overview'

    def form_valid(self, form):
        # check for valid encoding (will raise UnicodeDecodeError if not)
        success, error_messages = import_users(self.request.FILES['csvfile'])
        for message in error_messages:
            messages.error(self.request, message)
        if success:
            messages.success(
                self.request,
                _('%d new participants were successfully imported.') % success)
        return super(UserImportView, self).form_valid(form)


class ResetPasswordView(SingleObjectMixin, QuestionView):
    """
    Set the Passwort for a user to his default password.
    """
    permission_required = 'participant.can_manage_participant'
    model = User
    allow_ajax = True
    question_message = ugettext_lazy('Do you really want to reset the password?')

    def get(self, request, *args, **kwargs):
        self.object = self.get_object()
        return super(ResetPasswordView, self).get(request, *args, **kwargs)

    def get_redirect_url(self, **kwargs):
        return reverse('user_edit', args=[self.object.id])

    def on_clicked_yes(self):
        self.object.reset_password()

    def get_final_message(self):
        return _('The Password for %s was successfully reset.') % html_strong(self.object)


class GroupOverview(ListView):
    """
    Overview over all groups.
    """
    permission_required = 'participant.can_manage_participant'
    template_name = 'participant/group_overview.html'
    context_object_name = 'groups'
    model = Group


class GroupDetailView(DetailView, PermissionMixin):
    """
    Classed based view to show a specific group in the interface.
    """
    permission_required = 'participant.can_manage_participant'
    model = Group
    template_name = 'participant/group_detail.html'
    context_object_name = 'group'

    def get_context_data(self, *args, **kwargs):
        context = super(GroupDetailView, self).get_context_data(*args, **kwargs)
        query = User.objects
        if config['participant_sort_users_by_first_name']:
            query = query.order_by('first_name')
        else:
            query = query.order_by('last_name')
        context['group_members'] = query.filter(django_user__groups__in=[context['group']])
        return context


class GroupCreateView(CreateView):
    """
    Create a new group.
    """
    permission_required = 'participant.can_manage_participant'
    template_name = 'participant/group_edit.html'
    context_object_name = 'group'
    model = Group
    form_class = GroupForm
    success_url_name = 'user_group_overview'
    url_name_args = []

    def get(self, request, *args, **kwargs):
        delete_default_permissions()
        return super(GroupCreateView, self).get(request, *args, **kwargs)


class GroupUpdateView(UpdateView):
    """
    Update an existing group.
    """
    permission_required = 'participant.can_manage_participant'
    template_name = 'participant/group_edit.html'
    model = Group
    context_object_name = 'group'
    form_class = GroupForm
    success_url_name = 'user_group_overview'
    url_name_args = []

    def get(self, request, *args, **kwargs):
        delete_default_permissions()
        return super(GroupUpdateView, self).get(request, *args, **kwargs)

    def get_form_kwargs(self, *args, **kwargs):
        form_kwargs = super(GroupUpdateView, self).get_form_kwargs(*args, **kwargs)
        form_kwargs.update({'request': self.request})
        return form_kwargs


class GroupDeleteView(DeleteView):
    """
    Delete a group.
    """
    permission_required = 'participant.can_manage_participant'
    model = Group
    success_url_name = 'user_group_overview'
    url_name_args = []

    def pre_redirect(self, request, *args, **kwargs):
        if not self.is_protected_from_deleting():
            super(GroupDeleteView, self).pre_redirect(request, *args, **kwargs)

    def pre_post_redirect(self, request, *args, **kwargs):
        if not self.is_protected_from_deleting():
            super(GroupDeleteView, self).pre_post_redirect(request, *args, **kwargs)

    def is_protected_from_deleting(self):
        """
        Checks whether the group is protected.
        """
        if self.object.pk in [1, 2]:
            messages.error(self.request, _('You can not delete this group.'))
            return True
        if (not self.request.user.is_superuser and
            get_protected_perm() in self.object.permissions.all() and
            not Group.objects.exclude(pk=self.object.pk).filter(
                permissions__in=[get_protected_perm()],
                user__pk=self.request.user.pk).exists()):
            messages.error(
                self.request,
                _('You can not delete the last group containing the permission '
                  'to manage participants you are in.'))
            return True
        return False


def login(request):
    extra_content = {}
    try:
        admin = User.objects.get(pk=1)
        if admin.check_password(admin.default_password):
            user_data = {
                'user': html_strong(admin.username),
                'password': html_strong(admin.default_password)}

            extra_content['first_time_message'] = _(
                "Installation was successfully! Use %(user)s "
                "(password: %(password)s) for first login.<br>"
                "<strong>Important:</strong> Please change the password after "
                "first login! Otherwise this message still appears for "
                "everyone  and could be a security risk.") % user_data

            extra_content['next'] = reverse('password_change')
    except User.DoesNotExist:
        pass
    return django_login(request, template_name='participant/login.html', extra_context=extra_content)


@login_required
@template('participant/settings.html')
def user_settings(request):
    """
    Edit own user account.
    """
    if request.method == 'POST':
        form_user = UsersettingsForm(request.POST, instance=request.user)
        if form_user.is_valid():
            user = form_user.save(commit=False)
            user.username = form_user.cleaned_data['user_name']
            user.save()
            language = request.LANGUAGE_CODE = \
                request.session['django_language'] = form_user.cleaned_data['language']
            activate(language)
            messages.success(request, _('User settings successfully saved.'))
        else:
            messages.error(request, _('Please check the form for errors.'))
    else:
        language = request.session.get('django_language', request.LANGUAGE_CODE)
        form_user = UsersettingsForm(instance=request.user, initial={'language': language})

    return {
        'form': form_user,
        'edituser': request.user,
    }


@login_required
@template('participant/password_change.html')
def user_settings_password(request):
    """
    Edit own password.
    """
    if request.method == 'POST':
        form = PasswordChangeForm(request.user, request.POST)
        if form.is_valid():
            form.save()
            messages.success(request, _('Password successfully changed.'))
            return redirect(reverse('dashboard'))
        else:
            messages.error(request, _('Please check the form for errors.'))
    else:
        form = PasswordChangeForm(user=request.user)

    return {
        'form': form,
    }


def register_tab(request):
    """
    Registers the participant tab.
    """
    selected = request.path.startswith('/participant/')
    return Tab(
        title=_('Participants'),
        app='participant',
        url=reverse('user_overview'),
        permission=(
            request.user.has_perm('participant.can_see_participant') or
            request.user.has_perm('participant.can_manage_participant')),
        selected=selected)


def get_widgets(request):
    """
    Returns all widgets of the participant app. This is a user_widget
    and a group_widget.
    """
    return [get_user_widget(request), get_group_widget(request)]


def get_user_widget(request):
    """
    Provides a widget with all users. This is for short activation of
    user slides.
    """
    return Widget(
        request,
        name='user',
        display_name=_('Participants'),
        template='participant/user_widget.html',
        context={'users': User.objects.all()},
        permission_required='projector.can_manage_projector',
        default_column=1,
        default_weight=60)


def get_group_widget(request):
    """
    Provides a widget with all groups. This is for short activation of
    group slides.
    """
    return Widget(
        request,
        name='group',
        display_name=_('Groups'),
        template='participant/group_widget.html',
        context={'groups': Group.objects.all()},
        permission_required='projector.can_manage_projector',
        default_column=1,
        default_weight=70)