# SPDX-FileCopyrightText: 2023 Agathe Porte
#
# SPDX-License-Identifier: MIT

import subprocess

from pelican import signals


def git_describe():
    """Check and return git describe --tags value."""
    return subprocess \
        .run(["git", "describe", "--tags"],
             stdout=subprocess.PIPE, check=True) \
        .stdout.decode('utf-8').strip()


def expand_context(generators):
    desc = git_describe()
    for gen in generators:
        gen.context['git_describe'] = desc


def register():
    """Register Pelican signals to dedicated functions."""
    signals.all_generators_finalized.connect(expand_context)