# Copyright 2010-present Basho Technologies, Inc.
#
# 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.

"""
Gets the current version number.
If in a git repository, it is the current git tag.
Otherwise it is the one contained in the PKG-INFO file.

To use this script, simply import it in your setup.py file
and use the results of get_version() as your package version::

    from version import *

    setup(
        version=get_version()
    )
"""


import re
from os.path import dirname, isdir, join
from subprocess import CalledProcessError, PIPE, Popen

try:
    from subprocess import check_output
except ImportError:
    def check_output(*popenargs, **kwargs):
        """Run command with arguments and return its output as a byte string.

        If the exit code was non-zero it raises a CalledProcessError.  The
        CalledProcessError object will have the return code in the returncode
        attribute and output in the output attribute.

        The arguments are the same as for the Popen constructor.  Example:

        >>> check_output(["ls", "-l", "/dev/null"])
        "crw-rw-rw- 1 root root 1, 3 Oct 18  2007 /dev/null\n"

        The stdout argument is not allowed as it is used internally.
        To capture standard error in the result, use stderr=STDOUT.

        >>> import sys
        >>> check_output(["/bin/sh", "-c",
        ...               "ls -l non_existent_file ; exit 0"],
        ...              stderr=sys.stdout)
        "ls: non_existent_file: No such file or directory\n"
        """
        if "stdout" in kwargs:
            raise ValueError("stdout argument not allowed, it will be "
                             "overridden.")
        process = Popen(stdout=PIPE, *popenargs, **kwargs)
        output, unused_err = process.communicate()
        retcode = process.poll()
        if retcode:
            cmd = kwargs.get("args")
            if cmd is None:
                cmd = popenargs[0]
            raise CalledProcessError(retcode, cmd)
        return output

version_re = re.compile("^Version: (.+)$", re.M)

__all__ = ["get_version"]


def get_version():
    d = dirname(__file__)

    if isdir(join(d, ".git")):
        # Get the version using "git describe".
        cmd = "git describe --tags --match [0-9]*".split()
        try:
            version = check_output(cmd).decode().strip()
        except CalledProcessError:
            print("Unable to get version number from git tags")
            exit(1)

        # PEP 386 compatibility
        if "-" in version:
            version = ".post".join(version.split("-")[:2])

    else:
        # Extract the version from the PKG-INFO file.
        import codecs
        with codecs.open(join(d, "PKG-INFO"), "r", "utf-8") as f:
            version = version_re.search(f.read()).group(1)

    return version


if __name__ == "__main__":
    print(get_version())