import os
import re
import urllib

from django.conf import settings
from django.contrib.auth import SESSION_KEY, REDIRECT_FIELD_NAME
from django.contrib.auth.forms import AuthenticationForm
from django.contrib.sites.models import Site, RequestSite
from django.contrib.auth.models import User
from django.test import TestCase
from django.core import mail
from django.core.exceptions import SuspiciousOperation
from django.core.urlresolvers import reverse

class AuthViewsTestCase(TestCase):
    """
    Helper base class for all the follow test cases.
    """
    fixtures = ['authtestdata.json']
    urls = 'django.contrib.auth.urls'

    def setUp(self):
        self.old_LANGUAGES = settings.LANGUAGES
        self.old_LANGUAGE_CODE = settings.LANGUAGE_CODE
        settings.LANGUAGES = (('en', 'English'),)
        settings.LANGUAGE_CODE = 'en'
        self.old_TEMPLATE_DIRS = settings.TEMPLATE_DIRS
        settings.TEMPLATE_DIRS = (
            os.path.join(
                os.path.dirname(__file__),
                'templates'
            )
        ,)

    def tearDown(self):
        settings.LANGUAGES = self.old_LANGUAGES
        settings.LANGUAGE_CODE = self.old_LANGUAGE_CODE
        settings.TEMPLATE_DIRS = self.old_TEMPLATE_DIRS

class PasswordResetTest(AuthViewsTestCase):

    def test_email_not_found(self):
        "Error is raised if the provided email address isn't currently registered"
        response = self.client.get('/password_reset/')
        self.assertEquals(response.status_code, 200)
        response = self.client.post('/password_reset/', {'email': 'not_a_real_email@email.com'})
        self.assertContains(response, "That e-mail address doesn't have an associated user account")
        self.assertEquals(len(mail.outbox), 0)

    def test_email_found(self):
        "Email is sent if a valid email address is provided for password reset"
        response = self.client.post('/password_reset/', {'email': 'staffmember@example.com'})
        self.assertEquals(response.status_code, 302)
        self.assertEquals(len(mail.outbox), 1)
        self.assert_("http://" in mail.outbox[0].body)

    def test_admin_reset(self):
        "If the reset view is marked as being for admin, the HTTP_HOST header is used for a domain override."
        response = self.client.post('/admin_password_reset/',
            {'email': 'staffmember@example.com'},
            HTTP_HOST='adminsite.com'
        )
        self.assertEqual(response.status_code, 302)
        self.assertEqual(len(mail.outbox), 1)
        self.assertTrue("http://adminsite.com" in mail.outbox[0].body)
        self.assertEqual(settings.DEFAULT_FROM_EMAIL, mail.outbox[0].from_email)

    def test_poisoned_http_host(self):
        "Poisoned HTTP_HOST headers can't be used for reset emails"
        # This attack is based on the way browsers handle URLs. The colon
        # should be used to separate the port, but if the URL contains an @,
        # the colon is interpreted as part of a username for login purposes,
        # making 'evil.com' the request domain. Since HTTP_HOST is used to
        # produce a meaningful reset URL, we need to be certain that the
        # HTTP_HOST header isn't poisoned. This is done as a check when get_host()
        # is invoked, but we check here as a practical consequence.
        def test_host_poisoning():
            self.client.post('/password_reset/',
                {'email': 'staffmember@example.com'},
                HTTP_HOST='www.example:dr.frankenstein@evil.tld'
            )
        self.assertRaises(SuspiciousOperation, test_host_poisoning)
        self.assertEqual(len(mail.outbox), 0)

    def test_poisoned_http_host_admin_site(self):
        "Poisoned HTTP_HOST headers can't be used for reset emails on admin views"
        def test_host_poisoning():
            self.client.post('/admin_password_reset/',
                {'email': 'staffmember@example.com'},
                HTTP_HOST='www.example:dr.frankenstein@evil.tld'
            )
        self.assertRaises(SuspiciousOperation, test_host_poisoning)
        self.assertEqual(len(mail.outbox), 0)

    def _test_confirm_start(self):
        # Start by creating the email
        response = self.client.post('/password_reset/', {'email': 'staffmember@example.com'})
        self.assertEquals(response.status_code, 302)
        self.assertEquals(len(mail.outbox), 1)
        return self._read_signup_email(mail.outbox[0])

    def _read_signup_email(self, email):
        urlmatch = re.search(r"https?://[^/]*(/.*reset/\S*)", email.body)
        self.assert_(urlmatch is not None, "No URL found in sent email")
        return urlmatch.group(), urlmatch.groups()[0]

    def test_confirm_valid(self):
        url, path = self._test_confirm_start()
        response = self.client.get(path)
        # redirect to a 'complete' page:
        self.assertEquals(response.status_code, 200)
        self.assert_("Please enter your new password" in response.content)

    def test_confirm_invalid(self):
        url, path = self._test_confirm_start()
        # Let's munge the token in the path, but keep the same length,
        # in case the URLconf will reject a different length.
        path = path[:-5] + ("0"*4) + path[-1]

        response = self.client.get(path)
        self.assertEquals(response.status_code, 200)
        self.assert_("The password reset link was invalid" in response.content)

    def test_confirm_invalid_post(self):
        # Same as test_confirm_invalid, but trying
        # to do a POST instead.
        url, path = self._test_confirm_start()
        path = path[:-5] + ("0"*4) + path[-1]

        response = self.client.post(path, {'new_password1': 'anewpassword',
                                           'new_password2':' anewpassword'})
        # Check the password has not been changed
        u = User.objects.get(email='staffmember@example.com')
        self.assert_(not u.check_password("anewpassword"))

    def test_confirm_complete(self):
        url, path = self._test_confirm_start()
        response = self.client.post(path, {'new_password1': 'anewpassword',
                                           'new_password2': 'anewpassword'})
        # It redirects us to a 'complete' page:
        self.assertEquals(response.status_code, 302)
        # Check the password has been changed
        u = User.objects.get(email='staffmember@example.com')
        self.assert_(u.check_password("anewpassword"))

        # Check we can't use the link again
        response = self.client.get(path)
        self.assertEquals(response.status_code, 200)
        self.assert_("The password reset link was invalid" in response.content)

    def test_confirm_different_passwords(self):
        url, path = self._test_confirm_start()
        response = self.client.post(path, {'new_password1': 'anewpassword',
                                           'new_password2':' x'})
        self.assertEquals(response.status_code, 200)
        self.assert_("The two password fields didn't match" in response.content)

class ChangePasswordTest(AuthViewsTestCase):

    def login(self, password='password'):
        response = self.client.post('/login/', {
            'username': 'testclient',
            'password': password
            }
        )
        self.assertEquals(response.status_code, 302)
        self.assert_(response['Location'].endswith(settings.LOGIN_REDIRECT_URL))

    def fail_login(self, password='password'):
        response = self.client.post('/login/', {
            'username': 'testclient',
            'password': password
            }
        )
        self.assertEquals(response.status_code, 200)
        self.assert_("Please enter a correct username and password. Note that both fields are case-sensitive." in response.content)

    def logout(self):
        response = self.client.get('/logout/')

    def test_password_change_fails_with_invalid_old_password(self):
        self.login()
        response = self.client.post('/password_change/', {
            'old_password': 'donuts',
            'new_password1': 'password1',
            'new_password2': 'password1',
            }
        )
        self.assertEquals(response.status_code, 200)
        self.assert_("Your old password was entered incorrectly. Please enter it again." in response.content)

    def test_password_change_fails_with_mismatched_passwords(self):
        self.login()
        response = self.client.post('/password_change/', {
            'old_password': 'password',
            'new_password1': 'password1',
            'new_password2': 'donuts',
            }
        )
        self.assertEquals(response.status_code, 200)
        self.assert_("The two password fields didn't match." in response.content)

    def test_password_change_succeeds(self):
        self.login()
        response = self.client.post('/password_change/', {
            'old_password': 'password',
            'new_password1': 'password1',
            'new_password2': 'password1',
            }
        )
        self.assertEquals(response.status_code, 302)
        self.assert_(response['Location'].endswith('/password_change/done/'))
        self.fail_login()
        self.login(password='password1')

class LoginTest(AuthViewsTestCase):

    def test_current_site_in_context_after_login(self):
        response = self.client.get(reverse('django.contrib.auth.views.login'))
        self.assertEquals(response.status_code, 200)
        site = Site.objects.get_current()
        self.assertEquals(response.context['site'], site)
        self.assertEquals(response.context['site_name'], site.name)
        self.assert_(isinstance(response.context['form'], AuthenticationForm), 
                     'Login form is not an AuthenticationForm')

    def test_security_check(self, password='password'):
        login_url = reverse('django.contrib.auth.views.login')

        # Those URLs should not pass the security check
        for bad_url in ('http://example.com',
                        'http:///example.com',
                        'https://example.com',
                        'ftp://exampel.com',
                        '///example.com',
                        '//example.com',
                        'javascript:alert("XSS")'):

            nasty_url = '%(url)s?%(next)s=%(bad_url)s' % {
                'url': login_url,
                'next': REDIRECT_FIELD_NAME,
                'bad_url': urllib.quote(bad_url)
            }
            response = self.client.post(nasty_url, {
                'username': 'testclient',
                'password': password,
                }
            )
            self.assertEquals(response.status_code, 302)
            self.assertFalse(bad_url in response['Location'], "%s should be blocked" % bad_url)

        # Now, these URLs have an other URL as a GET parameter and therefore
        # should be allowed
        for url_ in ('http://example.com', 'https://example.com',
                    'ftp://exampel.com',  '//example.com'):
            safe_url = '%(url)s?%(next)s=/view/?param=%(safe_param)s' % {
                'url': login_url,
                'next': REDIRECT_FIELD_NAME,
                'safe_param': urllib.quote(url_)
            }
            response = self.client.post(safe_url, {
                    'username': 'testclient',
                    'password': password,
                }
            )
            self.assertEquals(response.status_code, 302)
            self.assertTrue('/view/?param=%s' % url_ in response['Location'], "/view/?param=%s should be allowed" % url_)

        
class LogoutTest(AuthViewsTestCase):
    urls = 'django.contrib.auth.tests.urls'

    def login(self, password='password'):
        response = self.client.post('/login/', {
            'username': 'testclient',
            'password': password
            }
        )
        self.assertEquals(response.status_code, 302)
        self.assert_(response['Location'].endswith(settings.LOGIN_REDIRECT_URL))
        self.assert_(SESSION_KEY in self.client.session)

    def confirm_logged_out(self):
        self.assert_(SESSION_KEY not in self.client.session)

    def test_logout_default(self):
        "Logout without next_page option renders the default template"
        self.login()
        response = self.client.get('/logout/')
        self.assertEquals(200, response.status_code)
        self.assert_('Logged out' in response.content)
        self.confirm_logged_out()

    def test_logout_with_next_page_specified(self): 
        "Logout with next_page option given redirects to specified resource"
        self.login()
        response = self.client.get('/logout/next_page/')
        self.assertEqual(response.status_code, 302)
        self.assert_(response['Location'].endswith('/somewhere/'))
        self.confirm_logged_out()

    def test_logout_with_redirect_argument(self):
        "Logout with query string redirects to specified resource"
        self.login()
        response = self.client.get('/logout/?next=/login/')
        self.assertEqual(response.status_code, 302)
        self.assert_(response['Location'].endswith('/login/'))
        self.confirm_logged_out()

    def test_logout_with_custom_redirect_argument(self):
        "Logout with custom query string redirects to specified resource"
        self.login()
        response = self.client.get('/logout/custom_query/?follow=/somewhere/')
        self.assertEqual(response.status_code, 302)
        self.assert_(response['Location'].endswith('/somewhere/'))
        self.confirm_logged_out()