import asyncio
import pytest
from unittest.mock import patch, MagicMock
from utils.news import fetch_rss


class TestFetchRss:
    """Тесты функции fetch_rss() — получение и парсинг RSS-ленты."""

    @patch("utils.news._session.get")
    def test_fetch_rss_success_rss20(self, mock_get):
        """Успешный ответ RSS 2.0 должен вернуть список статей."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>Статья 1</title>
      <link>https://habr.com/1</link>
      <guid isPermaLink="true">https://habr.com/1</guid>
      <pubDate>Mon, 28 May 2026 10:00:00 +0000</pubDate>
      <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Автор 1</dc:creator>
      <category>AI</category>
      <category>ML</category>
    </item>
    <item>
      <title>Статья 2</title>
      <guid isPermaLink="true">https://habr.com/2</guid>
      <pubDate>Mon, 28 May 2026 12:00:00 +0000</pubDate>
      <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Автор 2</dc:creator>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert len(result) == 2
        assert result[0]["title"] == "Статья 1"
        assert result[0]["link"] == "https://habr.com/1"
        assert result[0]["pub_date"] == "Mon, 28 May 2026 10:00:00 +0000"
        assert result[0]["creator"] == "Автор 1"
        assert result[0]["tags"] == ["AI", "ML"]
        assert result[1]["title"] == "Статья 2"
        assert result[1]["creator"] == "Автор 2"
        assert result[1]["tags"] == []

    @patch("utils.news._session.get")
    def test_fetch_rss_success_atom(self, mock_get):
        """Успешный ответ Atom должен вернуть список статей."""
        atom_content = """<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <entry>
    <title>Atom статья 1</title>
    <link href="https://habr.com/atom/1" />
    <published>2026-05-28T10:00:00Z</published>
    <author><name>Atom автор</name></author>
    <category>AI</category>
  </entry>
</feed>""".encode()
        mock_response = MagicMock()
        mock_response.content = atom_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/atom"))
        assert result is not None
        assert len(result) == 1
        assert result[0]["title"] == "Atom статья 1"
        assert result[0]["link"] == "https://habr.com/atom/1"
        assert result[0]["pub_date"] == "2026-05-28T10:00:00Z"
        assert result[0]["creator"] == "Atom автор"
        assert result[0]["tags"] == ["AI"]

    @patch("utils.news._session.get")
    def test_fetch_rss_empty_items(self, mock_get):
        """RSS без items должен вернуть пустой список."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result == []

    @patch("utils.news._session.get")
    def test_fetch_rss_no_matching_format(self, mock_get):
        """Неизвестный формат XML должен вернуть пустой список."""
        xml_content = """<?xml version="1.0"?>
<unknown></unknown>""".encode()
        mock_response = MagicMock()
        mock_response.content = xml_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/xml"))
        assert result == []

    @patch("utils.news._session.get")
    def test_fetch_rss_missing_title(self, mock_get):
        """Статья без title должна получить 'Без названия'."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>Без title</title>
      <guid isPermaLink="true">https://habr.com/1</guid>
      <pubDate>Mon, 28 May 2026 10:00:00 +0000</pubDate>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert result[0]["title"] == "Без title"
        assert result[0]["link"] == "https://habr.com/1"
        assert result[0]["pub_date"] == "Mon, 28 May 2026 10:00:00 +0000"
        assert result[0]["creator"] == ""
        assert result[0]["tags"] == []

    @patch("utils.news._session.get")
    def test_fetch_rss_missing_guid(self, mock_get):
        """Статья без guid isPermaLink должна иметь пустую ссылку."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>Без guid</title>
      <link>https://habr.com/1</link>
      <guid>https://habr.com/1</guid>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert result[0]["title"] == "Без guid"
        assert result[0]["link"] == ""

    @patch("utils.news._session.get")
    def test_fetch_rss_limit_to_10(self, mock_get):
        """Больше 10 items должно быть обрезано до 10."""
        items = "\n".join(
            f"""    <item>
      <title>Статья {i}</title>
      <guid isPermaLink="true">https://habr.com/{i}</guid>
      <pubDate>Mon, 28 May 2026 10:00:00 +0000</pubDate>
    </item>"""
            for i in range(15)
        )
        rss_content = (f"""<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    {items}
  </channel>
</rss>""").encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert len(result) == 10
        assert result[0]["title"] == "Статья 0"
        assert result[9]["title"] == "Статья 9"

    @patch("utils.news._session.get")
    def test_fetch_rss_http_error(self, mock_get):
        """HTTP-ошибка должна вернуть None."""
        import requests
        mock_get.side_effect = requests.exceptions.HTTPError("404 Not Found")
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is None

    @patch("utils.news._session.get")
    def test_fetch_rss_connection_error(self, mock_get):
        """Ошибка соединения должна вернуть None."""
        import requests
        mock_get.side_effect = requests.exceptions.ConnectionError("No connection")
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is None

    @patch("utils.news._session.get")
    def test_fetch_rss_timeout(self, mock_get):
        """Таймаут должен вернуть None."""
        import requests
        mock_get.side_effect = requests.exceptions.Timeout("Request timed out")
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is None

    @patch("utils.news._session.get")
    def test_fetch_rss_ssl_error(self, mock_get):
        """SSLError должен вернуть None."""
        import requests
        mock_get.side_effect = requests.exceptions.SSLError("SSL handshake failed")
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is None

    @patch("utils.news._session.get")
    def test_fetch_rss_empty_tags(self, mock_get):
        """Статья с пустыми тегами должна иметь пустые строки."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>Пустые теги</title>
      <guid isPermaLink="true">https://habr.com/1</guid>
      <pubDate>Mon, 28 May 2026 10:00:00 +0000</pubDate>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert result[0]["title"] == "Пустые теги"
        assert result[0]["link"] == "https://habr.com/1"
        assert result[0]["pub_date"] == "Mon, 28 May 2026 10:00:00 +0000"
        assert result[0]["creator"] == ""
        assert result[0]["tags"] == []

    @patch("utils.news._session.get")
    def test_fetch_rss_category_without_text(self, mock_get):
        """Категория без текста должна быть пропущена."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>Статья</title>
      <guid isPermaLink="true">https://habr.com/1</guid>
      <category></category>
      <category>AI</category>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert result[0]["tags"] == ["AI"]

    @patch("utils.news._session.get")
    def test_fetch_rss_atom_missing_author(self, mock_get):
        """Atom feed без автора должен иметь пустого creator."""
        atom_content = """<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <entry>
    <title>Без автора</title>
    <link href="https://habr.com/1" />
    <published>2026-05-28T10:00:00Z</published>
  </entry>
</feed>""".encode()
        mock_response = MagicMock()
        mock_response.content = atom_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/atom"))
        assert result is not None
        assert result[0]["title"] == "Без автора"
        assert result[0]["creator"] == ""

    @patch("utils.news._session.get")
    def test_fetch_rss_atom_missing_link(self, mock_get):
        """Atom feed без link должен иметь пустую ссылку."""
        atom_content = """<?xml version="1.0" encoding="UTF-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
  <entry>
    <title>Без ссылки</title>
    <published>2026-05-28T10:00:00Z</published>
  </entry>
</feed>""".encode()
        mock_response = MagicMock()
        mock_response.content = atom_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/atom"))
        assert result is not None
        assert result[0]["title"] == "Без ссылки"
        assert result[0]["link"] == ""

    @patch("utils.news._session.get")
    def test_fetch_rss_request_exception(self, mock_get):
        """Общий RequestException должен вернуть None."""
        import requests
        mock_get.side_effect = requests.RequestException("Generic error")
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is None

    @patch("utils.news._session.get")
    def test_fetch_rss_guid_fallback_to_link(self, mock_get):
        """Если нет guid isPermaLink, ссылка должна быть пустой."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>Статья</title>
      <link>https://habr.com/alternative</link>
      <guid>https://habr.com/alternative</guid>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert result[0]["link"] == ""

    @patch("utils.news._session.get")
    def test_fetch_rss_single_item(self, mock_get):
        """Один item должен быть распарсен корректно."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>Единственная статья</title>
      <guid isPermaLink="true">https://habr.com/1</guid>
      <pubDate>Mon, 28 May 2026 10:00:00 +0000</pubDate>
      <dc:creator xmlns:dc="http://purl.org/dc/elements/1.1/">Единственный автор</dc:creator>
      <category>ML</category>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert len(result) == 1
        assert result[0]["title"] == "Единственная статья"
        assert result[0]["link"] == "https://habr.com/1"
        assert result[0]["creator"] == "Единственный автор"
        assert result[0]["tags"] == ["ML"]

    @patch("utils.news._session.get")
    def test_fetch_rss_special_characters_in_title(self, mock_get):
        """Заголовки со спецсимволами должны парситься корректно."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>AI &amp; ML: будущее &lt;технологий&gt;</title>
      <guid isPermaLink="true">https://habr.com/1</guid>
      <pubDate>Mon, 28 May 2026 10:00:00 +0000</pubDate>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert "AI" in result[0]["title"]
        assert "ML" in result[0]["title"]

    @patch("utils.news._session.get")
    def test_fetch_rss_date_with_gmt(self, mock_get):
        """Дата с GMT должна парситься корректно."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>Статья</title>
      <guid isPermaLink="true">https://habr.com/1</guid>
      <pubDate>Mon, 28 May 2026 10:00:00 GMT</pubDate>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert result[0]["pub_date"] == "Mon, 28 May 2026 10:00:00 GMT"

    @patch("utils.news._session.get")
    def test_fetch_rss_many_categories(self, mock_get):
        """Множество категорий должны быть собраны."""
        rss_content = """<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0">
  <channel>
    <item>
      <title>Статья</title>
      <guid isPermaLink="true">https://habr.com/1</guid>
      <category>AI</category>
      <category>ML</category>
      <category>Deep Learning</category>
      <category>NLP</category>
      <category>Computer Vision</category>
    </item>
  </channel>
</rss>""".encode()
        mock_response = MagicMock()
        mock_response.content = rss_content
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = asyncio.run(fetch_rss("https://example.com/rss"))
        assert result is not None
        assert result[0]["tags"] == ["AI", "ML", "Deep Learning", "NLP", "Computer Vision"]