# -*- coding: utf-8 -*-

"""
 (c) 2015 - Copyright Red Hat Inc
 Authors:
   Jens Petersen <petersen@redhat.com>
"""


from anitya.lib.backends import BaseBackend, get_versions_by_regex


class StackageBackend(BaseBackend):
    """The custom class for Haskell projects hosted on Stackage.org.
    This backend allows to specify a version_url and a regex that will
    be used to retrieve the version information.
    """

    name = "Stackage"
    examples = [
        "https://www.stackage.org/package/conduit",
        "https://www.stackage.org/package/cabal-install",
    ]

    @classmethod
    def get_version(cls, project):
        """Method called to retrieve the latest version of the projects
        provided, project that relies on the backend of this plugin.
        :arg Project project: a :class:`anitya.db.models.Project` object whose backend
            corresponds to the current plugin.
        :return: the latest version found upstream
        :return type: str
        :raise AnityaPluginException: a
            :class:`anitya.lib.exceptions.AnityaPluginException` exception
            when the version cannot be retrieved correctly
        """
        return cls.get_ordered_versions(project)[-1]

    @classmethod
    def get_version_url(cls, project):
        """Method called to retrieve the url used to check for new version
        of the project provided, project that relies on the backend of this plugin.

        Attributes:
            project (:obj:`anitya.db.models.Project`): Project object whose backend
                corresponds to the current plugin.

        Returns:
            str: url used for version checking
        """
        url = "https://www.stackage.org/package/%(name)s" % {"name": project.name}

        return url

    @classmethod
    def get_versions(cls, project):
        """Method called to retrieve all the versions (that can be found)
        of the projects provided, project that relies on the backend of
        this plugin.
        :arg Project project: a :class:`anitya.db.models.Project` object whose backend
            corresponds to the current plugin.
        :return: a list of all the possible releases found
        :return type: list
        :raise AnityaPluginException: a
            :class:`anitya.lib.exceptions.AnityaPluginException` exception
            when the versions cannot be retrieved correctly
        """
        url = cls.get_version_url(project)

        regex = (
            r"<a href=\"https://hackage.haskell.org/package/%s\"><span class=\"version\">"
            r"([\d.]*).*</span></a>" % project.name
        )

        return get_versions_by_regex(url, regex, project)
