from __future__ import with_statement

import urllib

from django.db import models
from django.contrib.contenttypes.models import ContentType
from django.contrib.contenttypes.views import shortcut
from django.contrib.sites.models import Site
from django.http import HttpRequest, Http404
from django.test import TestCase
from django.utils.encoding import smart_str


class FooWithoutUrl(models.Model):
    """
    Fake model not defining ``get_absolute_url`` for
    :meth:`ContentTypesTests.test_shortcut_view_without_get_absolute_url`"""
    name = models.CharField(max_length=30, unique=True)

    def __unicode__(self):
        return self.name


class FooWithUrl(FooWithoutUrl):
    """
    Fake model defining ``get_absolute_url`` for
    :meth:`ContentTypesTests.test_shortcut_view`
    """

    def get_absolute_url(self):
        return "/users/%s/" % urllib.quote(smart_str(self.name))


class ContentTypesTests(TestCase):

    def setUp(self):
        self.old_Site_meta_installed = Site._meta.installed
        ContentType.objects.clear_cache()

    def tearDown(self):
        Site._meta.installed = self.old_Site_meta_installed
        ContentType.objects.clear_cache()

    def test_lookup_cache(self):
        """
        Make sure that the content type cache (see ContentTypeManager)
        works correctly. Lookups for a particular content type -- by model or
        by ID -- should hit the database only on the first lookup.
        """

        # At this point, a lookup for a ContentType should hit the DB
        with self.assertNumQueries(1):
            ContentType.objects.get_for_model(ContentType)

        # A second hit, though, won't hit the DB, nor will a lookup by ID
        with self.assertNumQueries(0):
            ct = ContentType.objects.get_for_model(ContentType)
        with self.assertNumQueries(0):
            ContentType.objects.get_for_id(ct.id)

        # Once we clear the cache, another lookup will again hit the DB
        ContentType.objects.clear_cache()
        with self.assertNumQueries(1):
            ContentType.objects.get_for_model(ContentType)

    def test_get_for_models_empty_cache(self):
        # Empty cache.
        with self.assertNumQueries(1):
            cts = ContentType.objects.get_for_models(ContentType, FooWithUrl)
        self.assertEqual(cts, {
            ContentType: ContentType.objects.get_for_model(ContentType),
            FooWithUrl: ContentType.objects.get_for_model(FooWithUrl),
        })

    def test_get_for_models_partial_cache(self):
        # Partial cache
        ContentType.objects.get_for_model(ContentType)
        with self.assertNumQueries(1):
            cts = ContentType.objects.get_for_models(ContentType, FooWithUrl)
        self.assertEqual(cts, {
            ContentType: ContentType.objects.get_for_model(ContentType),
            FooWithUrl: ContentType.objects.get_for_model(FooWithUrl),
        })

    def test_get_for_models_full_cache(self):
        # Full cache
        ContentType.objects.get_for_model(ContentType)
        ContentType.objects.get_for_model(FooWithUrl)
        with self.assertNumQueries(0):
            cts = ContentType.objects.get_for_models(ContentType, FooWithUrl)
        self.assertEqual(cts, {
            ContentType: ContentType.objects.get_for_model(ContentType),
            FooWithUrl: ContentType.objects.get_for_model(FooWithUrl),
        })

    def test_shortcut_view(self):
        """
        Check that the shortcut view (used for the admin "view on site"
        functionality) returns a complete URL regardless of whether the sites
        framework is installed
        """

        request = HttpRequest()
        request.META = {
            "SERVER_NAME": "Example.com",
            "SERVER_PORT": "80",
        }
        user_ct = ContentType.objects.get_for_model(FooWithUrl)
        obj = FooWithUrl.objects.create(name="john")

        if Site._meta.installed:
            current_site = Site.objects.get_current()
            response = shortcut(request, user_ct.id, obj.id)
            self.assertEqual("http://%s/users/john/" % current_site.domain,
                             response._headers.get("location")[1])

        Site._meta.installed = False
        response = shortcut(request, user_ct.id, obj.id)
        self.assertEqual("http://Example.com/users/john/",
                         response._headers.get("location")[1])

    def test_shortcut_view_without_get_absolute_url(self):
        """
        Check that the shortcut view (used for the admin "view on site"
        functionality) returns 404 when get_absolute_url is not defined.
        """

        request = HttpRequest()
        request.META = {
            "SERVER_NAME": "Example.com",
            "SERVER_PORT": "80",
        }
        user_ct = ContentType.objects.get_for_model(FooWithoutUrl)
        obj = FooWithoutUrl.objects.create(name="john")

        self.assertRaises(Http404, shortcut, request, user_ct.id, obj.id)

    def test_missing_model(self):
        """
        Ensures that displaying content types in admin (or anywhere) doesn't
        break on leftover content type records in the DB for which no model
        is defined anymore.
        """
        ct = ContentType.objects.create(
            name = 'Old model',
            app_label = 'contenttypes',
            model = 'OldModel',
        )
        self.assertEqual(unicode(ct), u'Old model')
