512369f93e 2026-08-01 arcade: //! Utility functions and types for the application.
512369f93e 2026-08-01 arcade:
f5ed284f8c 2025-06-21 arcade: use crate::Cursor;
f5ed284f8c 2025-06-21 arcade:
997fb1cff4 2026-08-01 arcade: use std::{
997fb1cff4 2026-08-01 arcade: borrow::Cow,
997fb1cff4 2026-08-01 arcade: sync::LazyLock,
997fb1cff4 2026-08-01 arcade: };
85fa6bddaa 2026-01-18 arcade:
85fa6bddaa 2026-01-18 arcade: use html_escape::encode_text;
bf99298edf 2026-07-31 arcade: use regex::{
bf99298edf 2026-07-31 arcade: Regex,
bf99298edf 2026-07-31 arcade: RegexBuilder,
bf99298edf 2026-07-31 arcade: };
0f47e23e21 2026-01-12 arcade: use stacked_errors::{
0f47e23e21 2026-01-12 arcade: bail,
0f47e23e21 2026-01-12 arcade: Result,
0f47e23e21 2026-01-12 arcade: };
0f47e23e21 2026-01-12 arcade:
997fb1cff4 2026-08-01 arcade: pub static RE_DOMAIN: LazyLock<Regex> = LazyLock::new(|| {
997fb1cff4 2026-08-01 arcade: 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")
997fb1cff4 2026-08-01 arcade: });
997fb1cff4 2026-08-01 arcade: pub static RE_CLOSING: LazyLock<Regex> = LazyLock::new(|| {
997fb1cff4 2026-08-01 arcade: RegexBuilder::new(r"</[ \t]*(pre|code)[ \t]*>")
997fb1cff4 2026-08-01 arcade: .case_insensitive(true).build().expect("Invalid closing tag regex")
997fb1cff4 2026-08-01 arcade: });
0f47e23e21 2026-01-12 arcade:
3c858ed7c4 2026-07-31 arcade: /// Stores binary attachment data and metadata for Telegram messages.
3c858ed7c4 2026-07-31 arcade: /// The data is wrapped in a `Cursor<Vec<u8>>` for efficient streaming,
3c858ed7c4 2026-07-31 arcade: /// while `name` holds the filename or display name of the attachment.
f5ed284f8c 2025-06-21 arcade: #[derive(Debug)]
f5ed284f8c 2025-06-21 arcade: pub struct Attachment {
f5ed284f8c 2025-06-21 arcade: pub data: Cursor<Vec<u8>>,
f5ed284f8c 2025-06-21 arcade: pub name: String,
0f47e23e21 2026-01-12 arcade: }
0f47e23e21 2026-01-12 arcade:
512369f93e 2026-08-01 arcade: /// Validates text to ensure it doesn't break Telegram's preformatted blocks.
512369f93e 2026-08-01 arcade: ///
512369f93e 2026-08-01 arcade: /// Escapes HTML special characters to prevent injection.
512369f93e 2026-08-01 arcade: ///
512369f93e 2026-08-01 arcade: /// # Arguments
512369f93e 2026-08-01 arcade: /// * `text` - Text to validate and escape.
512369f93e 2026-08-01 arcade: ///
512369f93e 2026-08-01 arcade: /// # Returns
512369f93e 2026-08-01 arcade: /// * `Result<Cow<'a, str>>` - Escaped text or error if invalid.
512369f93e 2026-08-01 arcade: ///
512369f93e 2026-08-01 arcade: /// # Errors
512369f93e 2026-08-01 arcade: /// Returns an error if the text contains Telegram closing tags (`</pre>`, `</code>`).
3c858ed7c4 2026-07-31 arcade: pub fn validate <'a>(text: &'a str) -> Result<Cow<'a, str>> {
dafeec0481 2026-01-18 arcade: if RE_CLOSING.is_match(text) {
dafeec0481 2026-01-18 arcade: bail!("Telegram closing tag found.");
dafeec0481 2026-01-18 arcade: } else {
85fa6bddaa 2026-01-18 arcade: Ok(encode_text(text))
dafeec0481 2026-01-18 arcade: }
f5ed284f8c 2025-06-21 arcade: }