from .reference import Reference

__all__ = ["TagReference", "Tag"]

# typing ------------------------------------------------------------------

from typing import Any, Type, Union, TYPE_CHECKING
from git.types import Commit_ish, PathLike

if TYPE_CHECKING:
    from git.repo import Repo
    from git.objects import Commit
    from git.objects import TagObject
    from git.refs import SymbolicReference


# ------------------------------------------------------------------------------


class TagReference(Reference):

    """Class representing a lightweight tag reference which either points to a commit
    ,a tag object or any other object. In the latter case additional information,
    like the signature or the tag-creator, is available.

    This tag object will always point to a commit object, but may carry additional
    information in a tag object::

     tagref = TagReference.list_items(repo)[0]
     print(tagref.commit.message)
     if tagref.tag is not None:
        print(tagref.tag.message)"""

    __slots__ = ()
    _common_default = "tags"
    _common_path_default = Reference._common_path_default + "/" + _common_default

    @property
    def commit(self) -> "Commit":  # type: ignore[override]  # LazyMixin has unrelated commit method
        """:return: Commit object the tag ref points to

        :raise ValueError: if the tag points to a tree or blob"""
        obj = self.object
        while obj.type != "commit":
            if obj.type == "tag":
                # it is a tag object which carries the commit as an object - we can point to anything
                obj = obj.object
            else:
                raise ValueError(
                    (
                        "Cannot resolve commit as tag %s points to a %s object - "
                        + "use the `.object` property instead to access it"
                    )
                    % (self, obj.type)
                )
        return obj

    @property
    def tag(self) -> Union["TagObject", None]:
        """
        :return: Tag object this tag ref points to or None in case
            we are a light weight tag"""
        obj = self.object
        if obj.type == "tag":
            return obj
        return None

    # make object read-only
    # It should be reasonably hard to adjust an existing tag

    # object = property(Reference._get_object)
    @property
    def object(self) -> Commit_ish:  # type: ignore[override]
        return Reference._get_object(self)

    @classmethod
    def create(
        cls: Type["TagReference"],
        repo: "Repo",
        path: PathLike,
        reference: Union[str, "SymbolicReference"] = "HEAD",
        logmsg: Union[str, None] = None,
        force: bool = False,
        **kwargs: Any,
    ) -> "TagReference":
        """Create a new tag reference.

        :param path:
            The name of the tag, i.e. 1.0 or releases/1.0.
            The prefix refs/tags is implied

        :param ref:
            A reference to the Object you want to tag. The Object can be a commit, tree or
            blob.

        :param logmsg:
            If not None, the message will be used in your tag object. This will also
            create an additional tag object that allows to obtain that information, i.e.::

                tagref.tag.message

        :param message:
            Synonym for :param logmsg:
            Included for backwards compatibility. :param logmsg is used in preference if both given.

        :param force:
            If True, to force creation of a tag even though that tag already exists.

        :param kwargs:
            Additional keyword arguments to be passed to git-tag

        :return: A new TagReference"""
        if "ref" in kwargs and kwargs["ref"]:
            reference = kwargs["ref"]

        if "message" in kwargs and kwargs["message"]:
            kwargs["m"] = kwargs["message"]
            del kwargs["message"]

        if logmsg:
            kwargs["m"] = logmsg

        if force:
            kwargs["f"] = True

        args = (path, reference)

        repo.git.tag(*args, **kwargs)
        return TagReference(repo, "%s/%s" % (cls._common_path_default, path))

    @classmethod
    def delete(cls, repo: "Repo", *tags: "TagReference") -> None:  # type: ignore[override]
        """Delete the given existing tag or tags"""
        repo.git.tag("-d", *tags)


# provide an alias
Tag = TagReference