"""
Tests for the throttling implementations in the permissions module.
"""
import time

from django.conf.urls.defaults import patterns
from django.test import TestCase
from django.utils import simplejson as json
from django.contrib.auth.models import User
from django.core.cache import cache

from djangorestframework.compat import RequestFactory
from djangorestframework.views import View
from djangorestframework.permissions import PerUserThrottling, PerViewThrottling, PerResourceThrottling, ConfigurationException
from djangorestframework.resources import FormResource

class MockView(View):
    permissions = ( PerUserThrottling, )
    throttle = '3/sec' # 3 requests per second

    def get(self, request):
        return 'foo'

class MockView1(MockView):
    permissions = ( PerViewThrottling, )

class MockView2(MockView):
    permissions = ( PerResourceThrottling, )
    #No resource set
    
class MockView3(MockView2):    
    resource = FormResource
    
class ThrottlingTests(TestCase):
    urls = 'djangorestframework.tests.throttling'   
    
    def setUp(self):
        """Reset the cache so that no throttles will be active"""
        cache.clear()
        self.factory = RequestFactory()
        
    def test_requests_are_throttled(self):
        """Ensure request rate is limited"""
        request = self.factory.get('/')
        for dummy in range(4):
            response = MockView.as_view()(request)
        self.assertEqual(503, response.status_code)
        
    def test_request_throttling_expires(self):
        """
        Ensure request rate is limited for a limited duration only
        """
        # Explicitly set the timer, overridding time.time()
        MockView.permissions[0].timer = lambda self: 0

        request = self.factory.get('/')
        for dummy in range(4):
            response = MockView.as_view()(request)
        self.assertEqual(503, response.status_code)

        # Advance the timer by one second
        MockView.permissions[0].timer = lambda self: 1

        response = MockView.as_view()(request)
        self.assertEqual(200, response.status_code)
        
    def ensure_is_throttled(self, view, expect):
        request = self.factory.get('/')
        request.user = User.objects.create(username='a')
        for dummy in range(3):
            response = view.as_view()(request)
        request.user = User.objects.create(username='b')
        response = view.as_view()(request)
        self.assertEqual(expect, response.status_code)
        
    def test_request_throttling_is_per_user(self):
        """Ensure request rate is only limited per user, not globally for PerUserThrottles"""
        self.ensure_is_throttled(MockView, 200)
        
    def test_request_throttling_is_per_view(self):
        """Ensure request rate is limited globally per View for PerViewThrottles"""
        self.ensure_is_throttled(MockView1, 503)
        
    def test_request_throttling_is_per_resource(self):
        """Ensure request rate is limited globally per Resource for PerResourceThrottles"""        
        self.ensure_is_throttled(MockView3, 503)