# Copyright (C) 2005 by Intevation GmbH

# Author(s):

# Thomas Arendsen Hein <thomas@intevation.de>

#

# This program is free software under the GNU GPL (>=v2)

# Read the file COPYING coming with the software for details.

"""

Mercurial version

"""

import os

import os.path

import re

import time

unknown_version = 'unknown'

def get_version():

    """Return version information if available."""

    try:

        from mercurial.__version__ import version

    except ImportError:

        version = unknown_version

    return version

def write_version(version):

    """Overwrite version file."""

    filename = os.path.join(os.path.dirname(__file__), '__version__.py')

    f = open(filename, 'w')

    f.write("# This file is auto-generated.\n")

    f.write("version = %r\n" % version)

    f.close()

def remember_version():

    """Store version information."""

    f = os.popen("hg identify 2>/dev/null")  # use real hg installation

    ident = f.read()[:-1]

    if not f.close() and ident:

        ids = ident.split(' ', 1)

        version = ids.pop(0)

        if version[-1] == '+':

            version = version[:-1]

            modified = True

        else:

            modified = False

        if version.isalnum() and ids:

            for tag in ids[0].split('/'):

                # is a tag is suitable as a version number?

                if re.match(r'^(\d+\.)+[\w.-]+$', tag):

                    version = tag

                    break

        if modified:

            version += time.strftime('+%Y%m%d')

    else:

        version = unknown_version

    write_version(version)

def forget_version():

    """Remove version information."""

    write_version(unknown_version)