# Source code for scrapy.spiders

    """
    Base class for Scrapy spiders

    See documentation in docs/topics/spiders.rst
    """

    from __future__ import annotations

    import logging
    from typing import TYPE_CHECKING, Any, cast

    from scrapy import signals
    from scrapy.http import Request, Response
    from scrapy.utils.trackref import object_ref
    from scrapy.utils.url import url_is_from_spider

    if TYPE_CHECKING:
        from collections.abc import AsyncIterator

        from twisted.internet.defer import Deferred

        # typing.Self requires Python 3.11
        from typing_extensions import Self

        from scrapy.crawler import Crawler
        from scrapy.http.request import CallbackT
        from scrapy.settings import BaseSettings
        from scrapy.utils.log import SpiderLoggerAdapter

    class Spider(object_ref):
        """Base class that any spider must subclass.

        It provides a default :meth:`start` implementation that sends
        requests based on the :attr:`start_urls` class attribute and calls the
        :meth:`parse` method for each response.
        """

        name: str
        custom_settings: dict[str, Any] | None = None

        #: Start URLs. See :meth:`start`.
        start_urls: list[str]

        def __init__(self, name: str | None = None, **kwargs: Any):
            if name is not None:
                self.name: str = name
            elif not getattr(self, "name", None):
                raise ValueError(f"{type(self).__name__} must have a name")
            self.__dict__.update(kwargs)
            if not hasattr(self, "start_urls"):
                self.start_urls: list[str] = []

        @property
        def logger(self) -> SpiderLoggerAdapter:
            # circular import
            from scrapy.utils.log import SpiderLoggerAdapter  # noqa: PLC0415

            logger = logging.getLogger(self.name)
            return SpiderLoggerAdapter(logger, {"spider": self})

        def log(self, message: Any, level: int = logging.DEBUG, **kw: Any) -> None:
            """Log the given message at the given log level

            This helper wraps a log call to the logger within the spider, but you
            can use it directly (e.g. Spider.logger.info('msg')) or use any other
            Python logger too.
            """
            self.logger.log(level, message, **kw)

        @classmethod
        def from_crawler(cls, crawler: Crawler, *args: Any, **kwargs: Any) -> Self:
            spider = cls(*args, **kwargs)
            spider._set_crawler(crawler)
            return spider

        def _set_crawler(self, crawler: Crawler) -> None:
            self.crawler: Crawler = crawler
            self.settings: BaseSettings = crawler.settings
            crawler.signals.connect(self.close, signals.spider_closed)

        async def start(self) -> AsyncIterator[Any]:
            """Yield the initial :class:`~scrapy.Request` objects to send.

            .. versionadded:: 2.13

            For example:

            .. code-block:: python

                from scrapy import Request, Spider

                class MySpider(Spider):
                    name = "myspider"

                    async def start(self):
                        yield Request("https://toscrape.com/")

            The default implementation reads URLs from :attr:`start_urls` and
            yields a request for each with :attr:`~scrapy.Request.dont_filter`
            enabled. It is functionally equivalent to:

            .. code-block:: python

                async def start(self):
                    for url in self.start_urls:
                        yield Request(url, dont_filter=True)

            You can also yield :ref:`items <topics-items>`. For example:

            .. code-block:: python

                async def start(self):
                    yield {"foo": "bar"}

            To write spiders that work on Scrapy versions lower than 2.13,
            define also a synchronous ``start_requests()`` method that returns an
            iterable. For example:

            .. code-block:: python

                def start_requests(self):
                    yield Request("https://toscrape.com/")

            .. seealso:: :ref:`start-requests`
            """
            for url in self.start_urls:
                yield Request(url, dont_filter=True)

        def _parse(self, response: Response, **kwargs: Any) -> Any:
            return self.parse(response, **kwargs)

        if TYPE_CHECKING:
            parse: CallbackT
        else:

            def parse(self, response: Response, **kwargs: Any) -> Any:
                raise NotImplementedError(
                    f"{self.__class__.__name__}.parse callback is not defined"
                )

        @classmethod
        def update_settings(cls, settings: BaseSettings) -> None:
            settings.setdict(cls.custom_settings or {}, priority="spider")

        @classmethod
        def handles_request(cls, request: Request) -> bool:
            return url_is_from_spider(request.url, cls)

        @staticmethod
        def close(spider: Spider, reason: str) -> Deferred[None] | None:
            closed = getattr(spider, "closed", None)
            if callable(closed):
                return cast("Deferred[None] | None", closed(reason))
            return None

        def __repr__(self) -> str:
            return f"<{type(self).__name__} {self.name!r} at 0x{id(self):0x}>"

    # Top-level imports
    from scrapy.spiders.crawl import CrawlSpider, Rule
    from scrapy.spiders.feed import CSVFeedSpider, XMLFeedSpider
    from scrapy.spiders.sitemap import SitemapSpider

    __all__ = [
        "CSVFeedSpider",
        "CrawlSpider",
        "Rule",
        "SitemapSpider",
        "Spider",
        "XMLFeedSpider",
    ]