import lxml.html

from django.contrib.messages import get_messages
from django.test import override_settings, TestCase
from django.urls import reverse
from django.utils import html

from apps.dashboard.forms import (
    DUPLICATE_ITEM_ERROR,
    EMPTY_ITEM_ERROR,
)
from apps.dashboard.models import Item, List
from apps.lyric.models import User


class HomePageTest(TestCase):
    def test_uses_home_template(self):
        response = self.client.get('/')
        self.assertTemplateUsed(response, 'apps/dashboard/home.html')

    def test_renders_input_form(self):
        response = self.client.get('/')
        parsed = lxml.html.fromstring(response.content)
        forms = parsed.cssselect('form[method=POST]')
        self.assertIn("/dashboard/new_list", [form.get("action") for form in forms])
        [form] = [form for form in forms if form.get("action") == "/dashboard/new_list"]
        inputs = form.cssselect("input")
        self.assertIn("text", [input.get("name") for input in inputs])

class NewListTest(TestCase):
    def test_can_save_a_POST_request(self):
        self. client.post("/dashboard/new_list", data={"text": "A new list item"})
        self.assertEqual(Item.objects.count(), 1)
        new_item = Item.objects.get()
        self.assertEqual(new_item.text, "A new list item")

    def test_redirects_after_POST(self):
        response = self.client.post("/dashboard/new_list", data={"text": "A new list item"})
        new_list = List.objects.get()
        self.assertRedirects(response, f"/dashboard/list/{new_list.id}/")

    # Post invalid input helper
    def post_invalid_input(self):
        return self.client.post("/dashboard/new_list", data={"text": ""})

    def test_for_invalid_input_nothing_saved_to_db(self):
        self.post_invalid_input()
        self.assertEqual(Item.objects.count(), 0)

    def test_for_invalid_input_renders_list_template(self):
        response = self.post_invalid_input()
        self.assertEqual(response.status_code, 200)
        self.assertTemplateUsed(response, "apps/dashboard/home.html")

    def test_for_invalid_input_shows_error_on_page(self):
        response = self.post_invalid_input()
        self.assertContains(response, html.escape(EMPTY_ITEM_ERROR))

class ListViewTest(TestCase):
    def test_uses_list_template(self):
        mylist = List.objects.create()
        response = self.client.get(f"/dashboard/list/{mylist.id}/")
        self.assertTemplateUsed(response, "apps/dashboard/list.html")

    def test_renders_input_form(self):
        mylist = List.objects.create()
        url = f"/dashboard/list/{mylist.id}/"
        response = self.client.get(url)
        parsed = lxml.html.fromstring(response.content)
        forms = parsed.cssselect("form[method=POST]")
        self.assertIn(url, [form.get("action") for form in forms])
        [form] = [form for form in forms if form.get("action") == url]
        inputs = form.cssselect("input")
        self.assertIn("text", [input.get("name") for input in inputs])

    def test_displays_only_items_for_that_list(self):
        # Given/Arrange
        correct_list = List.objects.create()
        Item.objects.create(text="itemey 1", list=correct_list)
        Item.objects.create(text="itemey 2", list=correct_list)
        other_list = List.objects.create()
        Item.objects.create(text="other list item", list=other_list)
        # When/Act
        response = self.client.get(f"/dashboard/list/{correct_list.id}/")
        # Then/Assert
        self.assertContains(response, "itemey 1")
        self.assertContains(response, "itemey 2")
        self.assertNotContains(response, "other list item")

    def test_can_save_a_POST_request_to_an_existing_list(self):
        other_list = List.objects.create()
        correct_list = List.objects.create()

        self.client.post(
            f"/dashboard/list/{correct_list.id}/",
            data={"text": "A new item for an existing list"},
        )

        self.assertEqual(Item.objects.count(), 1)
        new_item = Item.objects.get()
        self.assertEqual(new_item.text, "A new item for an existing list")
        self.assertEqual(new_item.list, correct_list)

    def test_POST_redirects_to_list_view(self):
        other_list = List.objects.create()
        correct_list = List.objects.create()

        response = self.client.post(
            f"/dashboard/list/{correct_list.id}/",
            data={"text": "A new item for an existing list"},
        )

        self.assertRedirects(response, f"/dashboard/list/{correct_list.id}/")

    # Post invalid input helper
    def post_invalid_input(self):
        mylist = List.objects.create()
        return self.client.post(f"/dashboard/list/{mylist.id}/", data={"text": ""})

    def test_for_invalid_input_nothing_saved_to_db(self):
        self.post_invalid_input()
        self.assertEqual(Item.objects.count(), 0)

    def test_for_invalid_input_renders_list_template(self):
        response = self.post_invalid_input()
        self.assertEqual(response.status_code, 200)
        self.assertTemplateUsed(response, "apps/dashboard/list.html")

    def test_for_invalid_input_shows_error_on_page(self):
        response = self.post_invalid_input()
        self.assertContains(response, html.escape(EMPTY_ITEM_ERROR))

    def test_for_invalid_input_sets_is_invalid_class(self):
        response = self.post_invalid_input()
        parsed = lxml.html.fromstring(response.content)
        [input] = parsed.cssselect("input[name=text]")
        self.assertIn("is-invalid", set(input.classes))

    def test_duplicate_item_validation_errors_end_up_on_lists_page(self):
        list1 = List.objects.create()
        Item.objects.create(list=list1, text="lorem ipsum")

        response = self.client.post(
            f"/dashboard/list/{list1.id}/",
            data={"text": "lorem ipsum"},
        )

        expected_error = html.escape(DUPLICATE_ITEM_ERROR)
        self.assertContains(response, expected_error)
        self.assertTemplateUsed(response, "apps/dashboard/list.html")
        self.assertEqual(Item.objects.all().count(), 1)

class MyListsTest(TestCase):
    def test_my_lists_url_renders_my_lists_template(self):
        user = User.objects.create(email="a@b.cde")
        self.client.force_login(user)
        response = self.client.get(f"/dashboard/users/{user.id}/")
        self.assertTemplateUsed(response, "apps/dashboard/my_lists.html")

    def test_passes_correct_owner_to_template(self):
        User.objects.create(email="wrongowner@example.com")
        correct_user = User.objects.create(email="a@b.cde")
        self.client.force_login(correct_user)
        response = self.client.get(f"/dashboard/users/{correct_user.id}/")
        self.assertEqual(response.context["owner"], correct_user)

    def test_list_owner_is_saved_if_user_is_authenticated(self):
        user = User.objects.create(email="a@b.cde")
        self.client.force_login(user)
        self.client.post("/dashboard/new_list", data={"text": "new item"})
        new_list = List.objects.get()
        self.assertEqual(new_list.owner, user)

    def test_my_lists_redirects_if_not_logged_in(self):
        user  = User.objects.create(email="a@b.cde")
        response = self.client.get(f"/dashboard/users/{user.id}/")
        self.assertRedirects(response, "/")

    def test_my_lists_returns_403_for_wrong_user(self):
        # create two users, login as user_a, request user_b's my_lists url
        user1 = User.objects.create(email="a@b.cde")
        user2 = User.objects.create(email="wrongowner@example.com")
        self.client.force_login(user2)
        response = self.client.get(f"/dashboard/users/{user1.id}/")
        # assert 403
        self.assertEqual(response.status_code, 403)

class ShareListTest(TestCase):
    def test_post_to_share_list_url_redirects_to_list(self):
        our_list = List.objects.create()
        alice = User.objects.create(email="alice@example.com")
        response = self.client.post(
            f"/dashboard/list/{our_list.id}/share_list",
            data={"recipient": "alice@example.com"},
        )
        self.assertRedirects(response, f"/dashboard/list/{our_list.id}/")

    def test_post_with_email_adds_user_to_shared_with(self):
        our_list = List.objects.create()
        alice = User.objects.create(email="alice@example.com")
        self.client.post(
            f"/dashboard/list/{our_list.id}/share_list",
            data={"recipient": "alice@example.com"},
        )
        self.assertIn(alice, our_list.shared_with.all())

    def test_post_with_nonexistent_email_redirects_to_list(self):
        our_list = List.objects.create()
        response = self.client.post(
            f"/dashboard/list/{our_list.id}/share_list",
            data={"recipient": "nobody@example.com"},
        )
        self.assertRedirects(response, f"/dashboard/list/{our_list.id}/")

    def test_share_list_does_not_add_owner_as_recipient(self):
        owner = User.objects.create(email="owner@example.com")
        our_list = List.objects.create(owner=owner)
        self.client.force_login(owner)
        self.client.post(reverse("share_list", args=[our_list.id]),
                         data={"recipient": "owner@example.com"})
        self.assertNotIn(owner, our_list.shared_with.all())

    @override_settings(MESSAGE_STORAGE='django.contrib.messages.storage.session.SessionStorage')
    def test_share_list_shows_privacy_safe_message(self):
        our_list = List.objects.create()
        response = self.client.post(
            f"/dashboard/list/{our_list.id}/share_list",
            data={"recipient": "nobody@example.com"},
            follow=True,
        )
        messages = list(get_messages(response.wsgi_request))
        self.assertEqual(
            str(messages[0]),
            "An invite has been sent if that address is registered.",
        )

class ViewAuthListTest(TestCase):
    def setUp(self):
        self.owner = User.objects.create(email="disco@example.com")
        self.our_list = List.objects.create(owner=self.owner)

    def test_anonymous_user_is_redirected(self):
        response = self.client.get(reverse("view_list", args=[self.our_list.id]))
        self.assertRedirects(response, "/")

    def test_non_owner_non_shared_user_gets_403(self):
        stranger = User.objects.create(email="stranger@example.com")
        self.client.force_login(stranger)
        response = self.client.get(reverse("view_list", args=[self.our_list.id]))
        self.assertEqual(response.status_code, 403)

    def test_shared_with_user_can_access_list(self):
        guest = User.objects.create(email="guest@example.com")
        self.our_list.shared_with.add(guest)
        self.client.force_login(guest)
        response = self.client.get(reverse("view_list", args=[self.our_list.id]))
        self.assertEqual(response.status_code, 200)