"""Macintosh-specific module for conversion between pathnames and URLs.

Do not import directly; use urllib instead."""

import urllib

import os

__all__ = ["url2pathname","pathname2url"]

def url2pathname(pathname):

    """OS-specific conversion from a relative URL of the 'file' scheme

    to a file system path; not recommended for general use."""

    #

    # XXXX The .. handling should be fixed...

    #

    tp = urllib.splittype(pathname)[0]

    if tp and tp != 'file':

        raise RuntimeError, 'Cannot convert non-local URL to pathname'

    # Turn starting /// into /, an empty hostname means current host

    if pathname[:3] == '///':

        pathname = pathname[2:]

    elif pathname[:2] == '//':

        raise RuntimeError, 'Cannot convert non-local URL to pathname'

    components = pathname.split('/')

    # Remove . and embedded ..

    i = 0

    while i < len(components):

        if components[i] == '.':

            del components[i]

        elif components[i] == '..' and i > 0 and \

                                  components[i-1] not in ('', '..'):

            del components[i-1:i+1]

            i = i-1

        elif components[i] == '' and i > 0 and components[i-1] != '':

            del components[i]

        else:

            i = i+1

    if not components[0]:

        # Absolute unix path, don't start with colon

        rv = ':'.join(components[1:])

    else:

        # relative unix path, start with colon. First replace

        # leading .. by empty strings (giving ::file)

        i = 0

        while i < len(components) and components[i] == '..':

            components[i] = ''

            i = i + 1

        rv = ':' + ':'.join(components)

    # and finally unquote slashes and other funny characters

    return urllib.unquote(rv)

def pathname2url(pathname):

    """OS-specific conversion from a file system path to a relative URL

    of the 'file' scheme; not recommended for general use."""

    if '/' in pathname:

        raise RuntimeError, "Cannot convert pathname containing slashes"

    components = pathname.split(':')

    # Remove empty first and/or last component

    if components[0] == '':

        del components[0]

    if components[-1] == '':

        del components[-1]

    # Replace empty string ('::') by .. (will result in '/../' later)

    for i in range(len(components)):

        if components[i] == '':

            components[i] = '..'

    # Truncate names longer than 31 bytes

    components = map(_pncomp2url, components)

    if os.path.isabs(pathname):

        return '/' + '/'.join(components)

    else:

        return '/'.join(components)

def _pncomp2url(component):

    component = urllib.quote(component[:31], safe='')  # We want to quote slashes

    return component

def test():

    for url in ["index.html",

                "bar/index.html",

                "/foo/bar/index.html",

                "/foo/bar/",

                "/"]:

        print '%r -> %r' % (url, url2pathname(url))

    for path in ["drive:",

                 "drive:dir:",

                 "drive:dir:file",

                 "drive:file",

                 "file",

                 ":file",

                 ":dir:",

                 ":dir:file"]:

        print '%r -> %r' % (path, pathname2url(path))

if __name__ == '__main__':

    test()