#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Copyright 2016 OpenMarket Ltd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import subprocess
import os
import logging

logger = logging.getLogger(__name__)


def get_version_string(module):
    try:
        null = open(os.devnull, 'w')
        cwd = os.path.dirname(os.path.abspath(module.__file__))
        try:
            git_branch = subprocess.check_output(
                ['git', 'rev-parse', '--abbrev-ref', 'HEAD'],
                stderr=null,
                cwd=cwd,
            ).strip()
            git_branch = "b=" + git_branch
        except subprocess.CalledProcessError:
            git_branch = ""

        try:
            git_tag = subprocess.check_output(
                ['git', 'describe', '--exact-match'],
                stderr=null,
                cwd=cwd,
            ).strip()
            git_tag = "t=" + git_tag
        except subprocess.CalledProcessError:
            git_tag = ""

        try:
            git_commit = subprocess.check_output(
                ['git', 'rev-parse', '--short', 'HEAD'],
                stderr=null,
                cwd=cwd,
            ).strip()
        except subprocess.CalledProcessError:
            git_commit = ""

        try:
            dirty_string = "-this_is_a_dirty_checkout"
            is_dirty = subprocess.check_output(
                ['git', 'describe', '--dirty=' + dirty_string],
                stderr=null,
                cwd=cwd,
            ).strip().endswith(dirty_string)

            git_dirty = "dirty" if is_dirty else ""
        except subprocess.CalledProcessError:
            git_dirty = ""

        if git_branch or git_tag or git_commit or git_dirty:
            git_version = ",".join(
                s for s in
                (git_branch, git_tag, git_commit, git_dirty,)
                if s
            )

            return (
                "%s (%s)" % (
                    module.__version__, git_version,
                )
            ).encode("ascii")
    except Exception as e:
        logger.info("Failed to check for git repository: %s", e)

    return module.__version__.encode("ascii")
