# SPDX-License-Identifier: AGPL-3.0-or-later
"""
FreedomBox app for configuring OpenVPN server.
"""

import logging

from django.contrib import messages
from django.http import HttpResponse
from django.shortcuts import redirect
from django.template.response import TemplateResponse
from django.utils.translation import ugettext as _
from django.views.decorators.http import require_POST

from plinth import actions, daemon
from plinth.modules import config, openvpn

from .forms import OpenVpnForm

logger = logging.getLogger(__name__)

setup_process = None


def index(request):
    """Serve configuration page."""
    status = get_status()

    if status['setup_running']:
        _collect_setup_result(request)

    form = None

    if request.method == 'POST':
        form = OpenVpnForm(request.POST, prefix='openvpn')
        # pylint: disable=E1101
        if form.is_valid():
            _apply_changes(request, status, form.cleaned_data)
            status = get_status()
            form = OpenVpnForm(initial=status, prefix='openvpn')
    else:
        form = OpenVpnForm(initial=status, prefix='openvpn')

    return TemplateResponse(
        request, 'openvpn.html', {
            'app_id': 'openvpn',
            'app_info': openvpn.app.info,
            'port_forwarding_info': openvpn.port_forwarding_info,
            'status': status,
            'form': form,
            'show_status_block': True,
            'is_running': status['is_running'],
            'has_diagnostics': True,
            'is_enabled': status['enabled'],
        })


@require_POST
def setup(request):
    """Start the setup process."""
    global setup_process
    if not openvpn.is_setup() and not setup_process:
        setup_process = actions.superuser_run('openvpn', ['setup'],
                                              run_in_background=True)

    openvpn.app.enable()

    return redirect('openvpn:index')


def profile(request):
    """Provide the user's profile for download."""
    username = request.user.username
    domainname = config.get_domainname()

    if not config.get_domainname():
        domainname = config.get_hostname()

    profile_string = actions.superuser_run(
        'openvpn', ['get-profile', username, domainname])

    response = HttpResponse(profile_string,
                            content_type='application/x-openvpn-profile')
    response['Content-Disposition'] = \
        'attachment; filename={username}.ovpn'.format(username=username)

    return response


def get_status():
    """Get the current settings from OpenVPN server."""

    return {
        'is_setup': openvpn.is_setup(),
        'setup_running': bool(setup_process),
        'enabled': openvpn.app.is_enabled(),
        'is_running': daemon.app_is_running(openvpn.app)
    }


def _collect_setup_result(request):
    """Handle setup process is completion."""
    global setup_process
    if not setup_process:
        return

    return_code = setup_process.poll()

    # Setup process is not complete yet
    if return_code is None:
        return

    if not return_code:
        messages.success(request, _('Setup completed.'))
    else:
        messages.info(request, _('Setup failed.'))

    setup_process = None


def _apply_changes(request, old_status, new_status):
    """Apply the changes."""
    modified = False

    if old_status['enabled'] != new_status['enabled']:
        if new_status['enabled']:
            openvpn.app.enable()
        else:
            openvpn.app.disable()

        modified = True

    if modified:
        messages.success(request, _('Configuration updated'))
    else:
        messages.info(request, _('Setting unchanged'))