"""Convert a NT pathname to a file URL and vice versa."""

def url2pathname(url):
    r"""Convert a URL to a DOS path.

            ///C|/foo/bar/spam.foo

                    becomes

            C:\foo\bar\spam.foo
    """
    import string, urllib
    if not '|' in url:
        # No drive specifier, just convert slashes
        if url[:4] == '////':
            # path is something like ////host/path/on/remote/host
            # convert this to \\host\path\on\remote\host
            # (notice halving of slashes at the start of the path)
            url = url[2:]
        components = string.split(url, '/')
        # make sure not to convert quoted slashes :-)
        return urllib.unquote(string.join(components, '\\'))
    comp = string.split(url, '|')
    if len(comp) != 2 or comp[0][-1] not in string.letters:
        error = 'Bad URL: ' + url
        raise IOError, error
    drive = string.upper(comp[0][-1])
    components = string.split(comp[1], '/')
    path = drive + ':'
    for  comp in components:
        if comp:
            path = path + '\\' + urllib.unquote(comp)
    return path

def pathname2url(p):
    r"""Convert a DOS path name to a file url.

            C:\foo\bar\spam.foo

                    becomes

            ///C|/foo/bar/spam.foo
    """

    import string, urllib
    if not ':' in p:
        # No drive specifier, just convert slashes and quote the name
        if p[:2] == '\\\\':
        # path is something like \\host\path\on\remote\host
        # convert this to ////host/path/on/remote/host
        # (notice doubling of slashes at the start of the path)
            p = '\\\\' + p
        components = string.split(p, '\\')
        return urllib.quote(string.join(components, '/'))
    comp = string.split(p, ':')
    if len(comp) != 2 or len(comp[0]) > 1:
        error = 'Bad path: ' + p
        raise IOError, error

    drive = urllib.quote(string.upper(comp[0]))
    components = string.split(comp[1], '\\')
    path = '///' + drive + '|'
    for comp in components:
        if comp:
            path = path + '/' + urllib.quote(comp)
    return path