Add support for Telegram

Closes #50

snscrape/modules/telegram.py

@@ -0,0 +1,67 @@
+import bs4
+import datetime
+import logging
+import snscrape.base
+import typing
+import urllib.parse
+
+
+logger = logging.getLogger(__name__)
+
+
+class TelegramPost(typing.NamedTuple, snscrape.base.Item):
+	url: str
+	date: datetime.datetime
+	content: str
+	outlinks: list
+	outlinksss: str
+
+	def __str__(self):
+		return self.url
+
+
+class TelegramChannelScraper(snscrape.base.Scraper):
+	name = 'telegram-channel'
+
+	def __init__(self, name, **kwargs):
+		super().__init__(**kwargs)
+		self._name = name
+
+	def _soup_to_items(self, soup, pageUrl):
+		posts = soup.find_all('div', attrs = {'class': 'tgme_widget_message', 'data-post': True})
+		for post in reversed(posts):
+			date = datetime.datetime.strptime(post.find('div', class_ = 'tgme_widget_message_footer').find('a', class_ = 'tgme_widget_message_date').find('time', datetime = True)['datetime'].replace('-', '', 2).replace(':', ''), '%Y%m%dT%H%M%S%z')
+			message = post.find('div', class_ = 'tgme_widget_message_text')
+			if message:
+				content = message.text
+				outlinks = [urllib.parse.urljoin(pageUrl, link['href']) for link in post.find_all('a') if not link.text.startswith('@') and link['href'].startswith('https://t.me/')]
+				outlinksss = ' '.join(outlinks)
+			else:
+				content = None
+				outlinks = []
+				outlinksss = ''
+			yield TelegramPost(url = f'https://t.me/s/{post["data-post"]}', date = date, content = content, outlinks = outlinks, outlinksss = outlinksss)
+
+	def get_items(self):
+		headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36'}
+
+		nextPageUrl = f'https://t.me/s/{self._name}'
+		while True:
+			r = self._get(nextPageUrl, headers = headers)
+			if r.status_code != 200:
+				logger.error(f'Got status code {r.status_code}')
+				return
+			soup = bs4.BeautifulSoup(r.text, 'lxml')
+			yield from self._soup_to_items(soup, nextPageUrl)
+			pageLink = soup.find('a', attrs = {'class': 'tme_messages_more', 'data-before': True})
+			if not pageLink:
+				break
+			nextPageUrl = urllib.parse.urljoin(nextPageUrl, pageLink['href'])
+
+	@classmethod
+	def setup_parser(cls, subparser):
+		subparser.add_argument('channel', help = 'A channel name')
+
+	@classmethod
+	def from_args(cls, args):
+		return cls(args.channel, retries = args.retries)