# works on Windows only
import os
import sys
import codecs
from ctypes import *

winver = sys.getwindowsversion()

if sys.version_info >= (3,):
    unicode = str
    stdout = sys.stdout.buffer
else:
    stdout = sys.stdout
    
def chcp(cp):
    os.system(u"chcp %d > NUL" % cp)

def _take_fst(f):
    def f2(*a, **kw):
        return f(*a, **kw)[0]
    return f2

if sys.version_info >= (3,3):
    cp_enc = _take_fst(codecs.code_page_encode)
    cp_dec = _take_fst(codecs.code_page_decode)
else:
    def cp_dec(cp, bs):
        buf = create_unicode_buffer(len(bs) * 2)
        n = cdll.kernel32.MultiByteToWideChar(
            c_uint(cp),
            c_int32(0),
            c_char_p(bs),
            c_int(len(bs)),
            buf,
            c_int(len(bs) * 2))
        if n <= 0:
            raise ValueError(n)
        return u''.join(buf[0:n])
    def cp_enc(cp, us):
        buf = create_string_buffer(len(us) * 4)
        n = cdll.kernel32.WideCharToMultiByte(
            c_uint(cp),
            c_int32(0),
            c_wchar_p(us),
            c_int(len(us)),
            buf,
            c_int(len(us) * 4),
            c_char_p(None),
            c_char_p(None))
        if n <= 0:
            raise ValueError(n)
        return b''.join(buf[0:n])

def test_cp_dec(cp, bs):
    mbcs = cp_dec(cp, bs)
    pycp = bs.decode(u"cp%d" % cp, u'replace')
    return (mbcs == pycp, mbcs, pycp)

def test_cp_enc(cp, us):
    mbcs = cp_enc(cp, us)
    pycp = us.encode(u"cp%d" % cp, u'replace')
    return (mbcs == pycp, mbcs, pycp)

# Now we add a few encodings that someone else have found strange.
# https://ftfy.readthedocs.io/en/latest/#module-ftfy.bad_codecs.sloppy
known_pages = list(range(1250,1259)) + [437, 874]

# Known-bad per ftfy.
known_bytes = b'\x81\x8D'
dec_results = {cp: test_cp_dec(cp, known_bytes) for cp in known_pages}

known_chars = known_bytes.decode('latin-1')
enc_results = {cp: test_cp_enc(cp, known_chars) for cp in known_pages}

chcp(65001)

def pr65001(s=u'', nl=True):
    global stdout
    stdout.write(str(s).encode(u'utf_8'))
    if nl:
        stdout.write(b'\r\n')

pr65001(u"Results for Py {0} on Windows {1}:".format(
    unicode(tuple(sys.version_info)),
    unicode(tuple(winver))))
for cp in known_pages:
    pr65001(u"cp%d:" % cp, False)
    if not dec_results[cp][0]:
        pr65001(u' dec=(')
        pr65001(u',\n'.join(u'    ' + unicode(repr(s)) for s in dec_results[cp]))
        pr65001(u')', False)
    if not enc_results[cp][0]:
        pr65001(u', enc=(')
        pr65001(u',\n'.join(u'    ' + unicode(repr(s)) for s in enc_results[cp]))
        pr65001(u')', False)
    pr65001(u'')
    pr65001(u'')