pub static ref RE_SPECIAL: Regex = Regex::new(r"([\-_*\[\]()~`>#+|{}\.!])").unwrap();
}

/// Encodes special HTML entities to prevent them interfering with Telegram HTML
pub fn encode (text: &str) -> Cow<'_, str> {
	RE_SPECIAL.replace_all(text, "\\$1")
}

// This one does nothing except making sure only one token exists for each id
pub struct Token {
	running: Arc<Mutex<HashSet<i32>>>,
	my_id: i32,
}

impl Token {
	fn new (running: &Arc<Mutex<HashSet<i32>>>, my_id: i32) -> Option<Token> {
		let running = running.clone();
		smol::block_on(async {
			let mut set = running.lock_arc().await;
			if set.contains(&my_id) {
				None
			} else {
				set.insert(my_id);
				Some(Token {
					running,
					my_id,
				})
			}
		})
	}
}

impl Drop for Token {
	fn drop (&mut self) {
		smol::block_on(async {
			let mut set = self.running.lock_arc().await;
			set.remove(&self.my_id);
		})
	}
}

#[derive(Clone)]
pub struct Core {
	owner_chat: ChatPeerId,
	// max_delay: u16,
	pub tg: Client,
	pub me: Bot,
	pub db: Db,
	running: Arc<Mutex<HashSet<i32>>>,
	http_client: reqwest::Client,
}

pub struct Post {
	uri: String,
	title: String,
	authors: String,

		let http_client = client.build().stack()?;
		let me = tg.execute(GetBot).await.stack()?;
		let core = Core {
			tg,
			me,
			owner_chat,
			db: Db::new(&settings.get_string("pg").stack()?)?,
			running: Arc::new(Mutex::new(HashSet::new())),
			http_client,
			// max_delay: 60,
		};
		let clone = core.clone();
		smol::spawn(Compat::new(async move {
			loop {
				let delay = match &clone.autofetch().await {

		).await.stack()
	}

	pub async fn check (&self, id: i32, real: bool, last_scrape: Option<DateTime<Local>>) -> Result<String> {
		let mut posted: i32 = 0;
		let mut conn = self.db.begin().await.stack()?;






		let token = Token::new(&self.running, id);

		if token.is_none() {

			bail!("check is already running");
		}



		let source = conn.get_source(id, self.owner_chat).await.stack()?;
		conn.set_scrape(id).await.stack()?;
		let destination = ChatPeerId::from(match real {
			true => source.channel_id,
			false => source.owner,
		});
		let mut this_fetch: Option<DateTime<chrono::FixedOffset>> = None;
		let mut posts: BTreeMap<DateTime<chrono::FixedOffset>, Post> = BTreeMap::new();

		let mut builder = self.http_client.get(&source.url);
		if let Some(last_scrape) = last_scrape {
			builder = builder.header(LAST_MODIFIED, last_scrape.to_rfc2822());
		};
		let response = builder.send().await.stack()?;
		{
			let headers = response.headers();
			let expires = headers.get(EXPIRES);
			let cache = headers.get(CACHE_CONTROL);
			if expires.is_some() || cache.is_some() {
				println!("{} {} {:?} {:?} {:?}", Local::now().to_rfc2822(), &source.url, last_scrape, expires, cache);
			}
		}
		let status = response.status();
		let content = response.bytes().await.stack()?;
		match rss::Channel::read_from(&content[..]) {
			Ok(feed) => {
				for item in feed.items() {
					if let Some(link) = item.link() {
						let date = match item.pub_date() {
							Some(feed_date) => DateTime::parse_from_rfc2822(feed_date),
							None => DateTime::parse_from_rfc3339(match item.dublin_core_ext() {
								Some(dates) => &dates.dates()[0],
								None => bail!("Feed item misses posting date."),
							}),
						}.stack()?;
						let uri = link.to_string();
						let title = item.title().unwrap_or("").to_string();
						let authors = item.author().unwrap_or("").to_string();
						let summary = item.content().unwrap_or("").to_string();
						posts.insert(date, Post{
							uri,
							title,
							authors,
							summary,
						});
					}
				};
			},
			Err(err) => match err {
				rss::Error::InvalidStartTag => {
					match atom_syndication::Feed::read_from(&content[..]) {
						Ok(feed) => {
							for item in feed.entries() {
								let date = item.published().unwrap();
								let uri = item.links()[0].href().to_string();
								let title = item.title().to_string();
								let authors = item.authors().iter().map(|x| format!("{} <{:?}>", x.name(), x.email())).collect::<Vec<String>>().join(", ");
								let summary = if let Some(sum) = item.summary() { sum.value.clone() } else { String::new() };
								posts.insert(*date, Post{
									uri,
									title,
									authors,
									summary,
								});
							};
						},
						Err(err) => {
							bail!("Unsupported or mangled content:\n{:?}\n{err}\n{status:#?}\n", &source.url)
						},
					}
				},
				rss::Error::Eof => (),
				_ => bail!("Unsupported or mangled content:\n{:?}\n{err}\n{status:#?}\n", &source.url)
			}
		};
		for (date, post) in posts.iter() {
			let post_url: Cow<str> = match source.url_re {
				Some(ref x) => sedregex::ReplaceCommand::new(x).stack()?.execute(&post.uri),
				None => post.uri.clone().into(),
			};
			if let Some(exists) = conn.exists(&post_url, id).await.stack()? {
				if ! exists {
					if this_fetch.is_none() || *date > this_fetch.unwrap() {
						this_fetch = Some(*date);
					};
					self.send( match &source.iv_hash {
						Some(hash) => format!("<a href=\"https://t.me/iv?url={post_url}&rhash={hash}\"> </a>{post_url}"),
						None => format!("{post_url}"),
					}, Some(destination), Some(ParseMode::Html)).await.stack()?;
					conn.add_post(id, date, &post_url).await.stack()?;
				};
			};
			posted += 1;
		};
		posts.clear();

		Ok(format!("Posted: {posted}"))
	}

	async fn autofetch(&self) -> Result<std::time::Duration> {
		let mut delay = chrono::Duration::minutes(1);
		let now = chrono::Local::now();
		let queue = {