import datetime
from django.utils import timezone
from django.urls import reverse
from django.test import TestCase

from .models import Question


def create_question(question_text, days):
    """
    Creates a question with the given `question_text` and published the
    given number of `days` offset to now (negative for questions published
    in the past, positive for questions that have yet to be published).
    """
    time = timezone.now() + datetime.timedelta(days=days)
    return Question.objects.create(question_text=question_text, pub_date=time)


class QuestionMethodTests(TestCase):

    def test_was_published_with_future_quetsion(self):
        """
        was_published recently() should be false ofr future dates.
        """
        time = timezone.now() + datetime.timedelta(days=30)
        future_question = Question(pub_date=time)
        self.assertIs(future_question.was_published_recently(), False)

    def test_was_published_with_old_quetsion(self):
        """
        was_published_recently() should return false for questions whose
        pub_date is older than 1 day
        """
        time = timezone.now() - datetime.timedelta(days=30)
        old_question = Question(pub_date=time)
        self.assertIs(old_question.was_published_recently(), False)

    def test_was_published_recently_with_recent_question(self):
        """
        was_published_recently() should return true for qeustions
        whose pub_date is within last day,
        """
        time = timezone.now() - datetime.timedelta(hours=1)
        recent_question = Question(pub_date=time)
        self.assertIs(recent_question.was_published_recently(), True)

    class QuestionViewTests(TestCase):
        def test_idex_view_with_no_questions(self):
            """
            If no questions exist, an appropriate message should be displayed.
            """
            response = self.client.get(reverse('polls:index'))
            self.assertEqual(response.status_code, 200)
            self.assertContains(response, "No polls are available.")
            self.assertQuerysetEqual(response.context['latest_question_list'], [])

        def test_index_view_with_a_past_question(self):
            """
            Questions with a pub_date in the past should be displayed on the
            index page.
            """
            create_question(question_text="Past question.", days=-30)
            response = self.client.get(reverse('polls:index'))
            self.assertQuerysetEqual(
                response.context['latest_question_list'],
                ['<Question: Past question.>']
            )

        def test_index_view_with_a_future_question(self):
            """
            Questions with a pub_date in the future should not be displayed on
            the index page.
            """
            create_question(question_text="Future question.", days=30)
            response = self.client.get(reverse('polls:index'))
            self.assertContains(response, "No polls are available.")
            self.assertQuerysetEqual(response.context['latest_question_list'], [])

        def test_index_view_with_future_question_and_past_question(self):
            """
            Even if both past and future questions exist, only past questions
            should be displayed.
            """
            create_question(question_text="Past question.", days=-30)
            create_question(question_text="Future question.", days=30)
            response = self.client.get(reverse('polls:index'))
            self.assertQuerysetEqual(
                response.context['latest_question_list'],
                ['<Question: Past question.>']
            )

        def test_index_view_with_two_past_questions(self):
            """
            The questions index page may display multiple questions.
            """
            create_question(question_text="Past question 1.", days=-30)
            create_question(question_text="Past question 2.", days=-5)
            response = self.client.get(reverse('polls:index'))
            self.assertQuerysetEqual(
                response.context['latest_question_list'],
                ['<Question: Past question 2.>', '<Question: Past question 1.>']
            )

    class QuestionIndexDetailTests(TestCase):

        def test_detail_view_with_a_future_question(self):
            """
            The detail view of a question with a pub_date in the future should
            return a 404 not found.
            """
            future_question = create_question(question_text='Future question.', days=5)
            url = reverse('polls:detail', args=(future_question.id,))
            response = self.client.get(url)
            self.assertEqual(response.status_code, 404)

        def test_detail_view_with_a_past_question(self):
            """
            The detail view of a question with a pub_date in the past should
            display the question's text.
            """
            past_question = create_question(question_text='Past Question.', days=-5)
            url = reverse('polls:detail', args=(past_question.id,))
            response = self.client.get(url)
            self.assertContains(response, past_question.question_text)