Telethon/telethon/extensions/markdown.py

185 lines
7.0 KiB
Python

"""
Simple markdown parser which does not support nesting. Intended primarily
for use within the library, which attempts to handle emojies correctly,
since they seem to count as two characters and it's a bit strange.
"""
import re
from enum import Enum
from ..tl.types import (
MessageEntityBold, MessageEntityItalic, MessageEntityCode,
MessageEntityPre, MessageEntityTextUrl
)
class Mode(Enum):
"""Different modes supported by Telegram's Markdown"""
NONE = 0
BOLD = 1
ITALIC = 2
CODE = 3
PRE = 4
URL = 5
# TODO Special cases, these aren't count as emojies. Alternatives?
# These were determined by generating all emojies with EMOJI_RANGES,
# sending the message through an official application, and cherry-picking
# which ones weren't rendered as emojies (from the beginning one). I am
# not responsible for dropping those characters that did not render with
# my font.
NOT_EMOJIES = {
9733, 9735, 9736, 9737, 9738, 9739, 9740, 9741, 9743, 9744, 9746, 9750,
9751, 9754, 9755, 9756, 9758, 9759, 9761, 9764, 9765, 9767, 9768, 9769,
9771, 9772, 9773, 9776, 9777, 9778, 9779, 9780, 9781, 9782, 9783, 9787,
9788, 9789, 9790, 9791, 9792, 9793, 9794, 9795, 9796, 9797, 9798, 9799,
9812, 9813, 9814, 9815, 9816, 9817, 9818, 9819, 9820, 9821, 9822, 9823,
9825, 9826, 9828, 9831, 9833, 9834, 9835, 9836, 9837, 9838, 9839, 9840,
9841, 9842, 9843, 9844, 9845, 9846, 9847, 9848, 9849, 9850, 9852, 9853,
9854, 9856, 9857, 9858, 9859, 9860, 9861, 9862, 9863, 9864, 9865, 9866,
9867, 9868, 9869, 9870, 9871, 9872, 9873, 9877, 9880, 9882, 9886, 9887,
9890, 9891, 9892, 9893, 9894, 9895, 9896, 9897, 9900, 9901, 9902, 9903,
9907, 9908, 9909, 9910, 9911, 9912, 9920, 9921, 9922, 9923, 9985, 9987,
9988, 9998, 10000, 10001, 10085, 10086, 10087, 127027, 127028, 127029,
127030, 127031, 127032, 127033, 127034, 127035, 127036, 127037, 127038,
127039, 127040, 127041, 127042, 127043, 127044, 127045, 127046, 127047,
127048, 127049, 127050, 127051, 127052, 127053, 127054, 127055, 127056,
127057, 127058, 127059, 127060, 127061, 127062, 127063, 127064, 127065,
127066, 127067, 127068, 127069, 127070, 127071, 127072, 127073, 127074,
127075, 127076, 127077, 127078, 127079, 127080, 127081, 127082, 127083,
127084, 127085, 127086, 127087, 127088, 127089, 127090, 127091, 127092,
127093, 127094, 127095, 127096, 127097, 127098, 127099, 127100, 127101,
127102, 127103, 127104, 127105, 127106, 127107, 127108, 127109, 127110,
127111, 127112, 127113, 127114, 127115, 127116, 127117, 127118, 127119,
127120, 127121, 127122, 127123
}
# using telethon_generator/emoji_ranges.py
EMOJI_RANGES = (
(8596, 8601), (8617, 8618), (8986, 8987), (9193, 9203), (9208, 9210),
(9642, 9643), (9723, 9726), (9728, 9733), (9735, 9746), (9748, 9751),
(9754, 9884), (9886, 9905), (9907, 9953), (9956, 9983), (9985, 9988),
(9992, 10002), (10035, 10036), (10067, 10069), (10083, 10087),
(10133, 10135), (10548, 10549), (11013, 11015), (11035, 11036),
(126976, 127166), (127169, 127183), (127185, 127231), (127245, 127247),
(127340, 127345), (127358, 127359), (127377, 127386), (127405, 127487),
(127489, 127503), (127538, 127546), (127548, 127551), (127561, 128419),
(128421, 128591), (128640, 128767), (128884, 128895), (128981, 129023),
(129036, 129039), (129096, 129103), (129114, 129119), (129160, 129167),
(129198, 129338), (129340, 129342), (129344, 129349), (129351, 129355),
(129357, 129471), (129473, 131069)
)
DEFAULT_DELIMITERS = {
'**': Mode.BOLD,
'__': Mode.ITALIC,
'`': Mode.CODE,
'```': Mode.PRE
}
DEFAULT_URL_RE = re.compile(r'\[(.+?)\]\((.+?)\)')
def is_emoji(char):
"""Returns True if 'char' looks like an emoji"""
char = ord(char)
for start, end in EMOJI_RANGES:
if start <= char <= end:
return char not in NOT_EMOJIES
return False
def emojiness(char):
"""
Returns 2 if the character is an emoji, or 1 otherwise.
This seems to be the length Telegram uses for offsets and lengths.
"""
return 2 if is_emoji(char) else 1
def parse(message, delimiters=None, url_re=None):
"""
Parses the given message and returns the stripped message and a list
of tuples containing (start, end, mode) using the specified delimiters
dictionary (or default if None).
The url_re(gex) must contain two matching groups: the text to be
clickable and the URL itself.
"""
if url_re is None:
url_re = DEFAULT_URL_RE
elif url_re:
if isinstance(url_re, str):
url_re = re.compile(url_re)
if not delimiters:
if delimiters is not None:
return message, []
delimiters = DEFAULT_DELIMITERS
result = []
current = Mode.NONE
offset = 0
i = 0
while i < len(message):
url_match = None
if url_re and current == Mode.NONE:
url_match = url_re.match(message, pos=i)
if url_match:
message = ''.join((
message[:url_match.start()],
url_match.group(1),
message[url_match.end():]
))
emoji_len = sum(emojiness(c) for c in url_match.group(1))
result.append((
offset,
offset + emoji_len,
(Mode.URL, url_match.group(2))
))
i += len(url_match.group(1))
if not url_match:
for d, m in delimiters.items():
if message[i:i + len(d)] == d and current in (Mode.NONE, m):
if message[i + len(d):i + 2 * len(d)] == d:
continue # ignore two consecutive delimiters
message = message[:i] + message[i + len(d):]
if current == Mode.NONE:
result.append(offset)
current = m
else:
result[-1] = (result[-1], offset, current)
current = Mode.NONE
break
if i < len(message):
offset += emojiness(message[i])
i += 1
if result and not isinstance(result[-1], tuple):
result.pop()
return message, result
def parse_tg(message, delimiters=None):
"""Similar to parse(), but returns a list of MessageEntity's"""
message, tuples = parse(message, delimiters=delimiters)
result = []
for start, end, mode in tuples:
extra = None
if isinstance(mode, tuple):
mode, extra = mode
if mode == Mode.BOLD:
result.append(MessageEntityBold(start, end - start))
elif mode == Mode.ITALIC:
result.append(MessageEntityItalic(start, end - start))
elif mode == Mode.CODE:
result.append(MessageEntityCode(start, end - start))
elif mode == Mode.PRE:
result.append(MessageEntityPre(start, end - start, ''))
elif mode == Mode.URL:
result.append(MessageEntityTextUrl(start, end - start, extra))
return message, result