"""
This module defines the Link object used in Link extractors.

For actual link extractors implementation see scrapy.linkextractors, or
its documentation in: docs/topics/link-extractors.rst
"""


class Link:
    """Link objects represent an extracted link by the LinkExtractor.

    Using the anchor tag sample below to illustrate the parameters::

            <a href="https://example.com/nofollow.html#foo" rel="nofollow">Dont follow this one</a>

    :param url: the absolute url being linked to in the anchor tag.
                From the sample, this is ``https://example.com/nofollow.html``.

    :param text: the text in the anchor tag. From the sample, this is ``Dont follow this one``.

    :param fragment: the part of the url after the hash symbol. From the sample, this is ``foo``.

    :param nofollow: an indication of the presence or absence of a nofollow value in the ``rel`` attribute
                    of the anchor tag.
    """

    __slots__ = ['url', 'text', 'fragment', 'nofollow']

    def __init__(self, url, text='', fragment='', nofollow=False):
        if not isinstance(url, str):
            got = url.__class__.__name__
            raise TypeError(f"Link urls must be str objects, got {got}")
        self.url = url
        self.text = text
        self.fragment = fragment
        self.nofollow = nofollow

    def __eq__(self, other):
        return (
            self.url == other.url
            and self.text == other.text
            and self.fragment == other.fragment
            and self.nofollow == other.nofollow
        )

    def __hash__(self):
        return hash(self.url) ^ hash(self.text) ^ hash(self.fragment) ^ hash(self.nofollow)

    def __repr__(self):
        return (
            f'Link(url={self.url!r}, text={self.text!r}, '
            f'fragment={self.fragment!r}, nofollow={self.nofollow!r})'
        )