# Copyright (C) 2008, 2009 Michael Trier (mtrier@gmail.com) and contributors
#
# This module is part of GitPython and is released under the
# 3-Clause BSD License: https://opensource.org/license/bsd-3-clause/

"""Provides an :class:`~git.objects.base.Object`-based type for annotated tags.

This defines the :class:`TagObject` class, which represents annotated tags.
For lightweight tags, see the :mod:`git.refs.tag` module.
"""

__all__ = ["TagObject"]

import sys

from git.compat import defenc
from git.util import Actor, hex_to_bin

from . import base
from .util import get_object_type_by_name, parse_actor_and_date

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

from typing import List, TYPE_CHECKING, Union

if sys.version_info >= (3, 8):
    from typing import Literal
else:
    from typing_extensions import Literal

if TYPE_CHECKING:
    from git.repo import Repo

    from .blob import Blob
    from .commit import Commit
    from .tree import Tree

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


class TagObject(base.Object):
    """Annotated (i.e. non-lightweight) tag carrying additional information about an
    object we are pointing to.

    See :manpage:`gitglossary(7)` on "tag object":
    https://git-scm.com/docs/gitglossary#def_tag_object
    """

    type: Literal["tag"] = "tag"

    __slots__ = (
        "object",
        "tag",
        "tagger",
        "tagged_date",
        "tagger_tz_offset",
        "message",
    )

    def __init__(
        self,
        repo: "Repo",
        binsha: bytes,
        object: Union[None, base.Object] = None,
        tag: Union[None, str] = None,
        tagger: Union[None, Actor] = None,
        tagged_date: Union[int, None] = None,
        tagger_tz_offset: Union[int, None] = None,
        message: Union[str, None] = None,
    ) -> None:  # @ReservedAssignment
        """Initialize a tag object with additional data.

        :param repo:
            Repository this object is located in.

        :param binsha:
            20 byte SHA1.

        :param object:
            :class:`~git.objects.base.Object` instance of object we are pointing to.

        :param tag:
            Name of this tag.

        :param tagger:
            :class:`~git.util.Actor` identifying the tagger.

        :param tagged_date: int_seconds_since_epoch
            The DateTime of the tag creation.
            Use :func:`time.gmtime` to convert it into a different format.

        :param tagger_tz_offset: int_seconds_west_of_utc
            The timezone that the `tagged_date` is in, in a format similar to
            :attr:`time.altzone`.
        """
        super().__init__(repo, binsha)
        if object is not None:
            self.object: Union["Commit", "Blob", "Tree", "TagObject"] = object
        if tag is not None:
            self.tag = tag
        if tagger is not None:
            self.tagger = tagger
        if tagged_date is not None:
            self.tagged_date = tagged_date
        if tagger_tz_offset is not None:
            self.tagger_tz_offset = tagger_tz_offset
        if message is not None:
            self.message = message

    def _set_cache_(self, attr: str) -> None:
        """Cache all our attributes at once."""
        if attr in TagObject.__slots__:
            ostream = self.repo.odb.stream(self.binsha)
            lines: List[str] = ostream.read().decode(defenc, "replace").splitlines()

            _obj, hexsha = lines[0].split(" ")
            _type_token, type_name = lines[1].split(" ")
            object_type = get_object_type_by_name(type_name.encode("ascii"))
            self.object = object_type(self.repo, hex_to_bin(hexsha))

            self.tag = lines[2][4:]  # tag <tag name>

            if len(lines) > 3:
                tagger_info = lines[3]  # tagger <actor> <date>
                (
                    self.tagger,
                    self.tagged_date,
                    self.tagger_tz_offset,
                ) = parse_actor_and_date(tagger_info)

            # Line 4 empty - it could mark the beginning of the next header.
            # In case there really is no message, it would not exist.
            # Otherwise a newline separates header from message.
            if len(lines) > 5:
                self.message = "\n".join(lines[5:])
            else:
                self.message = ""
        # END check our attributes
        else:
            super()._set_cache_(attr)