1"""Macintosh-specific module for conversion between pathnames and URLs.
2
3Do not import directly; use urllib instead."""
4
5import urllib.parse
6import os
7
8__all__ = ["url2pathname","pathname2url"]
9
10def url2pathname(pathname):
11    """OS-specific conversion from a relative URL of the 'file' scheme
12    to a file system path; not recommended for general use."""
13    #
14    # XXXX The .. handling should be fixed...
15    #
16    tp = urllib.parse.splittype(pathname)[0]
17    if tp and tp != 'file':
18        raise RuntimeError('Cannot convert non-local URL to pathname')
19    # Turn starting /// into /, an empty hostname means current host
20    if pathname[:3] == '///':
21        pathname = pathname[2:]
22    elif pathname[:2] == '//':
23        raise RuntimeError('Cannot convert non-local URL to pathname')
24    components = pathname.split('/')
25    # Remove . and embedded ..
26    i = 0
27    while i < len(components):
28        if components[i] == '.':
29            del components[i]
30        elif components[i] == '..' and i > 0 and \
31                                  components[i-1] not in ('', '..'):
32            del components[i-1:i+1]
33            i = i-1
34        elif components[i] == '' and i > 0 and components[i-1] != '':
35            del components[i]
36        else:
37            i = i+1
38    if not components[0]:
39        # Absolute unix path, don't start with colon
40        rv = ':'.join(components[1:])
41    else:
42        # relative unix path, start with colon. First replace
43        # leading .. by empty strings (giving ::file)
44        i = 0
45        while i < len(components) and components[i] == '..':
46            components[i] = ''
47            i = i + 1
48        rv = ':' + ':'.join(components)
49    # and finally unquote slashes and other funny characters
50    return urllib.parse.unquote(rv)
51
52def pathname2url(pathname):
53    """OS-specific conversion from a file system path to a relative URL
54    of the 'file' scheme; not recommended for general use."""
55    if '/' in pathname:
56        raise RuntimeError("Cannot convert pathname containing slashes")
57    components = pathname.split(':')
58    # Remove empty first and/or last component
59    if components[0] == '':
60        del components[0]
61    if components[-1] == '':
62        del components[-1]
63    # Replace empty string ('::') by .. (will result in '/../' later)
64    for i in range(len(components)):
65        if components[i] == '':
66            components[i] = '..'
67    # Truncate names longer than 31 bytes
68    components = map(_pncomp2url, components)
69
70    if os.path.isabs(pathname):
71        return '/' + '/'.join(components)
72    else:
73        return '/'.join(components)
74
75def _pncomp2url(component):
76    # We want to quote slashes
77    return urllib.parse.quote(component[:31], safe='')
78