# SPDX-License-Identifier: AGPL-3.0-or-later
"""FreedomBox app for configuring date and time."""

import logging
import subprocess

from django.contrib import messages
from django.utils.translation import gettext as _

from plinth.views import AppView

from . import privileged
from .forms import DateTimeForm

logger = logging.getLogger(__name__)


class DateTimeAppView(AppView):
    """Serve configuration page."""

    form_class = DateTimeForm
    app_id = 'datetime'

    def get_initial(self):
        """Return the values to fill in the form."""
        status = super().get_initial()
        status['time_zone'] = self.get_current_time_zone() or 'none'
        return status

    @staticmethod
    def get_current_time_zone():
        """Get current time zone."""
        try:
            process = subprocess.run(
                ['timedatectl', 'show', '--property', 'Timezone', '--value'],
                stdout=subprocess.PIPE, check=True)
            return process.stdout.decode().strip()
        except subprocess.CalledProcessError:
            return None

    def form_valid(self, form):
        """Change the timezone."""
        old_status = form.initial
        new_status = form.cleaned_data

        if old_status['time_zone'] != new_status['time_zone'] and \
           new_status['time_zone'] != 'none':
            try:
                privileged.set_timezone(new_status['time_zone'])
            except Exception as exception:
                messages.error(
                    self.request,
                    _('Error setting time zone: {exception}').format(
                        exception=exception))
            else:
                messages.success(self.request, _('Time zone set'))

        return super().form_valid(form)