//! Utility functions and types for the application.

use crate::Cursor;

use std::{
	borrow::Cow,
	sync::LazyLock,
};

/// 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
/// Validates text to ensure it doesn't break Telegram's preformatted blocks.
///
/// Escapes HTML special characters to prevent injection.
///
/// # Arguments
/// * `text` - Text to validate and escape.
///
/// # Returns
/// * `Result<Cow<'a, str>>` - Escaped text or error if invalid.
///
/// # Errors
/// Returns an error if the text contains Telegram closing tags (`</pre>`, `</code>`).
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))
	}
}