import requests
from requests.exceptions import ConnectionError, Timeout, SSLError
from unittest.mock import patch, MagicMock
from utils.cat import fetch_cat


class TestFetchCat:
    """Тесты функции fetch_cat() — получение URL случайного котика."""

    @patch("utils.cat._session.get")
    async def test_fetch_cat_success(self, mock_get) -> None:
        """Успешный ответ с URL должен вернуть строку."""
        mock_response = MagicMock()
        mock_response.json.return_value = [{"url": "https://example.com/cat.jpg"}]
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = await fetch_cat()
        assert result == "https://example.com/cat.jpg"

    @patch("utils.cat._session.get")
    async def test_fetch_cat_empty_array(self, mock_get) -> None:
        """Пустой массив должен вернуть None."""
        mock_response = MagicMock()
        mock_response.json.return_value = []
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = await fetch_cat()
        assert result is None

    @patch("utils.cat._session.get")
    async def test_fetch_cat_http_error(self, mock_get) -> None:
        """HTTP-ошибка (raise_for_status) должна вернуть None."""
        mock_response = MagicMock()
        mock_response.raise_for_status.side_effect = requests.HTTPError("404 Not Found")
        mock_get.return_value = mock_response
        result = await fetch_cat()
        assert result is None

    @patch("utils.cat._session.get")
    async def test_fetch_cat_connection_error(self, mock_get) -> None:
        """ConnectionError должна вернуть None."""
        mock_get.side_effect = ConnectionError("No connection")
        result = await fetch_cat()
        assert result is None

    @patch("utils.cat._session.get")
    async def test_fetch_cat_timeout(self, mock_get) -> None:
        """Timeout должна вернуть None."""
        mock_get.side_effect = Timeout("Request timed out")
        result = await fetch_cat()
        assert result is None

    @patch("utils.cat._session.get")
    async def test_fetch_cat_ssl_error(self, mock_get) -> None:
        """SSLError должна вернуть None."""
        mock_get.side_effect = SSLError("SSL handshake failed")
        result = await fetch_cat()
        assert result is None

    @patch("utils.cat._session.get")
    async def test_fetch_cat_json_parse_error(self, mock_get) -> None:
        """Ошибка парсинга JSON должна вернуть None."""
        mock_response = MagicMock()
        mock_response.json.side_effect = requests.JSONDecodeError(
            "Expecting value", "", 0
        )
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = await fetch_cat()
        assert result is None

    @patch("utils.cat._session.get")
    async def test_fetch_cat_missing_url_key(self, mock_get) -> None:
        """Отсутствие ключа 'url' в ответе должно вернуть None."""
        mock_response = MagicMock()
        mock_response.json.return_value = [{"error": "no image"}]
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = await fetch_cat()
        assert result is None

    @patch("utils.cat._session.get")
    async def test_fetch_cat_request_exception(self, mock_get) -> None:
        """Общий RequestException должен вернуть None."""
        mock_get.side_effect = requests.RequestException("Generic error")
        result = await fetch_cat()
        assert result is None

    @patch("utils.cat._session.get")
    async def test_fetch_cat_url_with_special_chars(self, mock_get) -> None:
        """URL со спецсимволами должен вернуться как есть."""
        mock_response = MagicMock()
        mock_response.json.return_value = [
            {"url": "https://example.com/cat?w=100&h=200"}
        ]
        mock_response.raise_for_status = MagicMock()
        mock_get.return_value = mock_response
        result = await fetch_cat()
        assert result == "https://example.com/cat?w=100&h=200"