# -*- coding: UTF-8 -*-

# Copyright (c) 2010, Pascal Volk

# See COPYING for distribution information.

"""

    VirtualMailManager.common

    Some common functions

"""

import os

import re

from VirtualMailManager import ENCODING

from VirtualMailManager.constants.ERROR import \

     NOT_EXECUTABLE, NO_SUCH_BINARY, NO_SUCH_DIRECTORY

from VirtualMailManager.errors import VMMError

_ = lambda msg: msg

def expand_path(path):

    """Expands paths, starting with ``.`` or ``~``, to an absolute path."""

    if path.startswith('.'):

        return os.path.abspath(path)

    if path.startswith('~'):

        return os.path.expanduser(path)

    return path

def get_unicode(string):

    """Converts `string` to `unicode`, if necessary."""

    if isinstance(string, unicode):

        return string

    return unicode(string, ENCODING, 'replace')

def is_dir(path):

    """Checks if `path` is a directory.

    Throws a `VMMError` if `path` is not a directory.

    """

    path = expand_path(path)

    if not os.path.isdir(path):

        raise VMMError(_(u"'%s' is not a directory") % get_unicode(path),

                       NO_SUCH_DIRECTORY)

    return path

def exec_ok(binary):

    """Checks if the `binary` exists and if it is executable.

    Throws a `VMMError` if the `binary` isn't a file or is not

    executable.

    """

    binary = expand_path(binary)

    if not os.path.isfile(binary):

        raise VMMError(_(u"'%s' is not a file") % get_unicode(binary),

                       NO_SUCH_BINARY)

    if not os.access(binary, os.X_OK):

        raise VMMError(_(u"File is not executable: '%s'") %

                       get_unicode(binary), NOT_EXECUTABLE)

    return binary

def version_hex(version_string):

    """Convert a Dovecot version, e.g.: '1.2.3' or '2.0.beta4', to an int.

    Returns 0 if the *version_string* has the wrong™ format.

    version_hex('1.2.3') -> 16909296

    hex(version_hex('1.2.3')) -> '0x10203f0'

    """

    version = 0

    version_re = r'^(\d+)\.(\d+)\.(?:(\d+)|(alpha|beta|rc)(\d+))$'

    version_level = dict(alpha=0xA, beta=0xB, rc=0xC)

    version_mo = re.match(version_re, version_string)

    if version_mo:

        major, minor, patch, level, serial = version_mo.groups()

        version += int(major) << 24

        version += int(minor) << 16

        if patch:

            version += int(patch) << 8

        version += version_level.get(level, 0xF) << 4

        if serial:

            version += int(serial)

    return version

del _