# Copyright (C) 2017  The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information

import os
import shutil
import tempfile

from subprocess import call


def init_git_repo_from_archive(project_name, archive_path,
                               root_temp_dir='/tmp'):
    """Given a path to an archive containing a git repository.

    Uncompress that archive to a temporary location and returns the path.

    If any problem whatsoever is raised, clean up the temporary location.

    Args:
        project_name (str): Project's name
        archive_path (str): Full path to the archive
        root_temp_dir (str): Optional temporary directory mount point
                             (default to /tmp)

    Returns
        A tuple:
        - temporary folder: containing the mounted repository
        - repo_path, path to the mounted repository inside the temporary folder

    Raises
        ValueError in case of failure to run the command to uncompress

    """
    temp_dir = tempfile.mkdtemp(
        suffix='.swh.loader.git', prefix='tmp.', dir=root_temp_dir)

    try:
        # create the repository that will be loaded with the dump
        r = call(['unzip', '-q', '-o', archive_path, '-d', temp_dir])
        if r != 0:
            raise ValueError('Failed to uncompress archive %s' % archive_path)

        repo_path = os.path.join(temp_dir, project_name)
        return temp_dir, repo_path
    except Exception as e:
        shutil.rmtree(temp_dir)
        raise e