#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
#  version.py
#
#  Copyright 2014 Neil Williams <codehelp@debian.org>
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

import subprocess
import os


# pylint: disable=superfluous-parens,too-many-locals


def version_tag():
    """
    Parses the git status to determine if this is a git tag
    or a developer commit and builds a version string combining
    the two. If there is no git directory, relies on this being
    a directory created from the tarball created by setup.py when
    it uses this script and retrieves the original version string
    from that.
    :return: a version string based on the tag and short hash
    """
    tag_name = None
    if os.path.exists("./.git/"):
        tag_list = [
            'git', 'for-each-ref', '--sort=taggerdate', '--format',
            "'%(refname)'", 'refs/tags',
        ]
        hash_list = ['git', 'log', '-n', '1']
        tag_hash_list = ['git', 'rev-list']
        clone_data = subprocess.check_output(hash_list).strip().decode('utf-8')
        commits = clone_data.split('\n')
        clone_hash = commits[0].replace('commit ', '')[:8]
        tag_data = subprocess.check_output(tag_list).strip().decode('utf-8')
        tags = tag_data.split('\n')
        if not set([tag for tag in tags if 'refs/tags/' in tag]):
            return clone_hash
        tag_line = str(tags[len(tags) - 1]).replace('\'', '').strip()
        tag_name = tag_line.split("/")[2]
        tag_hash_list.append(tag_name)
        tag_hash = subprocess.check_output(tag_hash_list).strip().decode('utf-8')
        tags = tag_hash.split('\n')
        tag_hash = tags[0][:8]
        if tag_hash == clone_hash:
            return tag_name
        else:
            # tag, month end and release are now out of sync.
            # use the rev-list count to always ensure that we are building
            # a newer version to cope with date changes at month end.
            # use short git hash for reference.
            dev_stamp = ['git', 'rev-list', '--count', 'HEAD']
            dev_count = subprocess.check_output(dev_stamp).strip().decode('utf-8')
            dev_short = ['git', 'rev-parse', '--short', 'HEAD']
            dev_hash = subprocess.check_output(dev_short).strip().decode('utf-8')
            return "%s+%s.%s" % (tag_name, dev_count, dev_hash)
    if not tag_name and os.path.exists('debian/changelog'):
        deb_version = subprocess.check_output(('dpkg-parsechangelog',
                                               '--show-field',
                                               'Version')).strip().decode(
                                                   'utf-8')
        # example version returned would be '2016.11'
        return deb_version.split('-')[0]


def main():
    print(version_tag())
    return 0


if __name__ == '__main__':
    main()