#!/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 urllib import urlencode
from urlparse import parse_qs

from reportlab.lib import colors
from reportlab.lib.units import cm
from reportlab.platypus import (
    SimpleDocTemplate, Paragraph, LongTable, Spacer, Table, TableStyle, Image)

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 _, ugettext_lazy, activate

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

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


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'

    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'

    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'

    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, QuestionMixin, RedirectView):
    """
    Set the Passwort for a user to his default password.
    """
    permission_required = 'participant.can_manage_participant'
    model = User
    allow_ajax = True
    question = 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 case_yes(self):
        self.object.reset_password()

    def get_success_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'

    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'

    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'

    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(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):
            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': html_strong(admin.username),
                    'password': html_strong(admin.default_password)}
            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)