78b11b0319 2026-08-01 arcade: //! Utility functions and types for the application.
78b11b0319 2026-08-01 arcade:
f5ed284f8c 2025-06-21 arcade: use crate::Cursor;
f5ed284f8c 2025-06-21 arcade:
78b11b0319 2026-08-01 arcade: use std::{
78b11b0319 2026-08-01 arcade: borrow::Cow,
78b11b0319 2026-08-01 arcade: sync::LazyLock,
78b11b0319 2026-08-01 arcade: };
1c10bccb4e 2026-01-18 arcade:
1c10bccb4e 2026-01-18 arcade: use html_escape::encode_text;
f4660639ca 2026-07-31 arcade: use regex::{
f4660639ca 2026-07-31 arcade: Regex,
f4660639ca 2026-07-31 arcade: RegexBuilder,
f4660639ca 2026-07-31 arcade: };
d87e80b9be 2026-01-12 arcade: use stacked_errors::{
d87e80b9be 2026-01-12 arcade: bail,
d87e80b9be 2026-01-12 arcade: Result,
d87e80b9be 2026-01-12 arcade: };
d87e80b9be 2026-01-12 arcade:
78b11b0319 2026-08-01 arcade: pub static RE_DOMAIN: LazyLock<Regex> = LazyLock::new(|| {
78b11b0319 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")
78b11b0319 2026-08-01 arcade: });
78b11b0319 2026-08-01 arcade: pub static RE_CLOSING: LazyLock<Regex> = LazyLock::new(|| {
78b11b0319 2026-08-01 arcade: RegexBuilder::new(r"</[ \t]*(pre|code)[ \t]*>")
78b11b0319 2026-08-01 arcade: .case_insensitive(true).build().expect("Invalid closing tag regex")
78b11b0319 2026-08-01 arcade: });
d87e80b9be 2026-01-12 arcade:
f4660639ca 2026-07-31 arcade: /// Stores binary attachment data and metadata for Telegram messages.
f4660639ca 2026-07-31 arcade: /// The data is wrapped in a `Cursor<Vec<u8>>` for efficient streaming,
f4660639ca 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,
d87e80b9be 2026-01-12 arcade: }
d87e80b9be 2026-01-12 arcade:
78b11b0319 2026-08-01 arcade: /// Validates text to ensure it doesn't break Telegram's preformatted blocks.
78b11b0319 2026-08-01 arcade: ///
78b11b0319 2026-08-01 arcade: /// Escapes HTML special characters to prevent injection.
78b11b0319 2026-08-01 arcade: ///
78b11b0319 2026-08-01 arcade: /// # Arguments
78b11b0319 2026-08-01 arcade: /// * `text` - Text to validate and escape.
78b11b0319 2026-08-01 arcade: ///
78b11b0319 2026-08-01 arcade: /// # Returns
78b11b0319 2026-08-01 arcade: /// * `Result<Cow<'a, str>>` - Escaped text or error if invalid.
78b11b0319 2026-08-01 arcade: ///
78b11b0319 2026-08-01 arcade: /// # Errors
78b11b0319 2026-08-01 arcade: /// Returns an error if the text contains Telegram closing tags (`</pre>`, `</code>`).
f4660639ca 2026-07-31 arcade: pub fn validate <'a>(text: &'a str) -> Result<Cow<'a, str>> {
1c10bccb4e 2026-01-18 arcade: if RE_CLOSING.is_match(text) {
1c10bccb4e 2026-01-18 arcade: bail!("Telegram closing tag found.");
1c10bccb4e 2026-01-18 arcade: } else {
1c10bccb4e 2026-01-18 arcade: Ok(encode_text(text))
1c10bccb4e 2026-01-18 arcade: }
f5ed284f8c 2025-06-21 arcade: }