#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

import html.parser
import ssl
from urllib import parse
from urllib import request

from tempest.common import utils
from tempest import config
from tempest.lib import decorators
from tempest import test

CONF = config.CONF


class HorizonHTMLParser(html.parser.HTMLParser):
    csrf_token = None
    region = None
    login = None

    def _find_name(self, attrs, name):
        for attrpair in attrs:
            if attrpair[0] == 'name' and attrpair[1] == name:
                return True
        return False

    def _find_value(self, attrs):
        for attrpair in attrs:
            if attrpair[0] == 'value':
                return attrpair[1]
        return None

    def _find_attr_value(self, attrs, attr_name):
        for attrpair in attrs:
            if attrpair[0] == attr_name:
                return attrpair[1]
        return None

    def handle_starttag(self, tag, attrs):
        if tag == 'input':
            if self._find_name(attrs, 'csrfmiddlewaretoken'):
                self.csrf_token = self._find_value(attrs)
            if self._find_name(attrs, 'region'):
                self.region = self._find_value(attrs)
        if tag == 'form':
            self.login = self._find_attr_value(attrs, 'action')


class TestDashboardBasicOps(test.BaseTestCase):

    """The test suite for dashboard basic operations

    This is a basic scenario test:
    * checks that the login page is available
    * logs in as a regular user
    * checks that the user home page loads without error
    """
    opener = None

    credentials = ['primary']

    @classmethod
    def skip_checks(cls):
        super(TestDashboardBasicOps, cls).skip_checks()
        if not CONF.service_available.horizon:
            raise cls.skipException("Horizon support is required")

    @classmethod
    def setup_credentials(cls):
        cls.set_network_resources()
        super(TestDashboardBasicOps, cls).setup_credentials()

    def check_login_page(self):
        response = self._get_opener().open(CONF.dashboard.dashboard_url).read()
        self.assertIn("id_username", response.decode("utf-8"))

    def user_login(self, username, password):
        response = self._get_opener().open(CONF.dashboard.dashboard_url).read()

        # Grab the CSRF token and default region
        parser = HorizonHTMLParser()
        parser.feed(response.decode("utf-8"))

        # construct login url for dashboard, discovery accommodates non-/ web
        # root for dashboard
        login_url = parse.urljoin(CONF.dashboard.dashboard_url, parser.login)

        # Prepare login form request
        req = request.Request(login_url)
        req.add_header('Content-type', 'application/x-www-form-urlencoded')
        req.add_header('Referer', CONF.dashboard.dashboard_url)

        # Pass the default domain name regardless of the auth version in order
        # to test the scenario of when horizon is running with keystone v3
        params = {'username': username,
                  'password': password,
                  'region': parser.region,
                  'domain': CONF.auth.default_credentials_domain_name,
                  'csrfmiddlewaretoken': parser.csrf_token}
        self._get_opener().open(req, parse.urlencode(params).encode())

    def check_home_page(self):
        response = self._get_opener().open(CONF.dashboard.dashboard_url).read()
        self.assertIn('Overview', response.decode("utf-8"))

    def _get_opener(self):
        if not self.opener:
            if (CONF.dashboard.disable_ssl_certificate_validation and
                    self._ssl_default_context_supported()):
                ctx = ssl.create_default_context()
                ctx.check_hostname = False
                ctx.verify_mode = ssl.CERT_NONE
                self.opener = request.build_opener(
                    request.HTTPSHandler(context=ctx),
                    request.HTTPCookieProcessor())
            else:
                self.opener = request.build_opener(
                    request.HTTPCookieProcessor())
        return self.opener

    def _ssl_default_context_supported(self):
        return (hasattr(ssl, 'create_default_context'))

    @decorators.attr(type='smoke')
    @decorators.idempotent_id('4f8851b1-0e69-482b-b63b-84c6e76f6c80')
    @utils.services('dashboard')
    def test_basic_scenario(self):
        creds = self.os_primary.credentials
        self.check_login_page()
        self.user_login(creds.username, creds.password)
        self.check_home_page()