use crate::Cursor;
use std::borrow::Cow;
use html_escape::encode_text;
use lazy_static::lazy_static;
use regex::Regex;
use stacked_errors::{
bail,
Result,
};
lazy_static! {
pub static ref RE_DOMAIN: Regex = Regex::new(r"^[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*$").expect("Invalid domain regex");
pub static ref RE_CLOSING: Regex = Regex::new(r"</[ \t]*(pre|code)[ \t]*>").expect("Invalid cloding tag regex");
}
/// Stores binary attachment data and metadata for Telegram messages.
/// The data is wrapped in a `Cursor<Vec<u8>>` for efficient streaming,
/// while `name` holds the filename or display name of the attachment.
#[derive(Debug)]
pub struct Attachment {
pub data: Cursor<Vec<u8>>,
pub name: String,
}
/// Pass any text here to be validated as not breaking from Telegram preformatted blocks
/// escape all HTML chars afterwards
pub fn validate <'a>(text: &'a str) -> Result<Cow<'a, str>> {
if RE_CLOSING.is_match(text) {
bail!("Telegram closing tag found.");
} else {
Ok(encode_text(text))
}
}