libmudtelnet-rs 2.0.10

//! Event types emitted by the Telnet parser.
//!
//! The parser transforms incoming bytes into a small set of structured events
//! that are easy to handle in your application loop:
//!
//! - [`TelnetEvents::DataReceive`]: Application data from the server. Any
//!   doubled IAC bytes are already unescaped. The payload is a zero‑copy
//!   `bytes::Bytes` slice referencing the parser’s buffer at parse time.
//! - [`TelnetEvents::DataSend`]: Bytes your app must send to the socket as‑is.
//!   These are already fully encoded (negotiation frames, escaped IAC, etc.).
//! - [`TelnetEvents::Negotiation`]: A WILL/WONT/DO/DONT triplet.
//! - [`TelnetEvents::Subnegotiation`]: `IAC SB <option> <data> IAC SE` payload.
//!   Inside `<data>`, embedded IAC bytes have been escaped on send and are
//!   presented as‑is on receive.
//! - [`TelnetEvents::IAC`]: A two‑byte IAC command such as GA/EOR/NOP.
//! - [`TelnetEvents::DecompressImmediate`]: MCCP2/3 boundary signal. Decompress
//!   this payload immediately and feed the result back into `Parser::receive`.
//!
//! Converting back to bytes
//! ```
//! use libmudtelnet_rs::events::{TelnetEvents, TelnetIAC};
//! use libmudtelnet_rs::telnet::op_command::{IAC, NOP};
//! let ev = TelnetEvents::IAC(TelnetIAC::new(NOP));
//! let bytes = ev.to_bytes();
//! assert_eq!(&bytes[..], [IAC, NOP]);
//! ```

use alloc::vec::Vec;

use bytes::{BufMut, Bytes, BytesMut};

use crate::telnet::op_command::{IAC, SB, SE};
use crate::Parser;

/// A struct representing a 2‑byte `IAC <command>` sequence.
#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
pub struct TelnetIAC {
  pub command: u8,
}

impl TelnetIAC {
  #[must_use]
  pub fn new(command: u8) -> Self {
    Self { command }
  }

  /// Consume the sequence struct and return the encoded bytes.
  #[must_use]
  pub fn to_bytes(self) -> Bytes {
    Bytes::copy_from_slice(&[IAC, self.command])
  }

  #[must_use]
  #[deprecated(since = "0.2.1", note = "Use `to_bytes` instead.")]
  pub fn into_bytes(self) -> Bytes {
    self.to_bytes()
  }
}

/// A struct representing a 3‑byte `IAC <command> <option>` negotiation.
#[derive(Clone, Copy, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
#[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
pub struct TelnetNegotiation {
  pub command: u8,
  pub option: u8,
}

impl TelnetNegotiation {
  #[must_use]
  pub fn new(command: u8, option: u8) -> Self {
    Self { command, option }
  }

  /// Consume the sequence struct and return the encoded bytes.
  #[must_use]
  pub fn to_bytes(self) -> Bytes {
    Bytes::copy_from_slice(&[IAC, self.command, self.option])
  }

  #[must_use]
  #[deprecated(since = "0.2.1", note = "Use `to_bytes` instead.")]
  pub fn into_bytes(self) -> Bytes {
    self.to_bytes()
  }
}

/// A struct representing `IAC SB <option> <data> IAC SE`.
#[derive(Clone, Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct TelnetSubnegotiation {
  pub option: u8,
  pub buffer: Bytes,
}

#[cfg(feature = "arbitrary")]
impl<'a> arbitrary::Arbitrary<'a> for TelnetSubnegotiation {
  fn arbitrary(u: &mut arbitrary::Unstructured<'a>) -> arbitrary::Result<Self> {
    let option = u.arbitrary()?;
    let buffer: Vec<u8> = u.arbitrary()?;
    Ok(Self {
      option,
      buffer: Bytes::from(buffer),
    })
  }
}

impl TelnetSubnegotiation {
  pub fn new(option: u8, buffer: Bytes) -> Self {
    Self { option, buffer }
  }

  #[must_use]
  pub fn to_bytes(self) -> Bytes {
    let head = [IAC, SB, self.option];
    let parsed = &Parser::escape_iac(self.buffer)[..];
    let tail = [IAC, SE];
    let mut buf = BytesMut::with_capacity(head.len() + parsed.len() + tail.len());
    buf.put(&head[..]);
    buf.put(parsed);
    buf.put(&tail[..]);
    buf.freeze()
  }

  #[must_use]
  #[deprecated(since = "0.2.1", note = "Use `to_bytes` instead.")]
  pub fn into_bytes(self) -> Bytes {
    self.to_bytes()
  }
}

/// The set of events produced by the parser.
#[derive(Clone, Debug, Eq, PartialEq)]
#[non_exhaustive]
pub enum TelnetEvents {
  /// A 2‑byte IAC command sequence (e.g., GA/EOR/NOP).
  IAC(TelnetIAC),
  /// A WILL/WONT/DO/DONT negotiation (`IAC <cmd> <opt>`).
  Negotiation(TelnetNegotiation),
  /// A subnegotiation payload (`IAC SB <opt> <data> IAC SE`).
  Subnegotiation(TelnetSubnegotiation),
  /// Application data received from the remote end.
  DataReceive(Bytes),
  /// Fully encoded data to send to the remote end.
  DataSend(Bytes),
  /// MCCP2/3 boundary. Decompress this data before feeding back into the parser.
  DecompressImmediate(Bytes),
}

impl From<TelnetIAC> for TelnetEvents {
  fn from(iac: TelnetIAC) -> Self {
    TelnetEvents::IAC(iac)
  }
}

impl From<TelnetNegotiation> for TelnetEvents {
  fn from(neg: TelnetNegotiation) -> Self {
    TelnetEvents::Negotiation(neg)
  }
}

impl From<TelnetSubnegotiation> for TelnetEvents {
  fn from(sub: TelnetSubnegotiation) -> Self {
    TelnetEvents::Subnegotiation(sub)
  }
}

impl TelnetEvents {
  /// Helper method to generate a `TelnetEvents::DataSend`.
  #[deprecated(since = "0.2.1", note = "Construct enum variant directly or use into.")]
  pub fn build_send(buffer: Bytes) -> Self {
    TelnetEvents::DataSend(buffer)
  }

  /// Helper method to generate a `TelnetEvents::DataReceive`.
  #[deprecated(since = "0.2.1", note = "Construct enum variant directly or use into.")]
  pub fn build_receive(buffer: Bytes) -> Self {
    TelnetEvents::DataReceive(buffer)
  }

  /// Helper method to generate a `TelnetEvents::IAC`.
  #[must_use]
  #[deprecated(since = "0.2.1", note = "Construct enum variant directly or use into.")]
  pub fn build_iac(command: u8) -> TelnetEvents {
    TelnetEvents::IAC(TelnetIAC::new(command))
  }

  /// Helper method to generate a `TelnetEvents::Negotiation`.
  #[must_use]
  #[deprecated(since = "0.2.1", note = "Construct enum variant directly or use into.")]
  pub fn build_negotiation(command: u8, option: u8) -> Self {
    TelnetEvents::Negotiation(TelnetNegotiation::new(command, option))
  }

  /// Helper method to generate a `TelnetEvents::Subnegotiation`.
  #[deprecated(since = "0.2.1", note = "Construct enum variant directly or use into.")]
  pub fn build_subnegotiation(option: u8, buffer: Bytes) -> Self {
    TelnetEvents::Subnegotiation(TelnetSubnegotiation::new(option, buffer))
  }

  #[must_use]
  pub fn to_bytes(self) -> Bytes {
    match self {
      TelnetEvents::IAC(iac) => iac.to_bytes(),
      TelnetEvents::Negotiation(neg) => neg.to_bytes(),
      TelnetEvents::Subnegotiation(sub) => sub.to_bytes(),
      TelnetEvents::DataReceive(data)
      | TelnetEvents::DataSend(data)
      | TelnetEvents::DecompressImmediate(data) => data,
    }
  }
}

/*
TODO(@cpu): remove/retool this stuff in breaking release.
*/
#[allow(clippy::from_over_into)]
impl Into<Bytes> for TelnetIAC {
  fn into(self) -> Bytes {
    self.to_bytes()
  }
}

#[allow(clippy::from_over_into)]
impl Into<Vec<u8>> for TelnetIAC {
  fn into(self) -> Vec<u8> {
    self.to_bytes().into()
  }
}

#[allow(clippy::from_over_into)]
impl Into<Bytes> for TelnetNegotiation {
  fn into(self) -> Bytes {
    self.to_bytes()
  }
}

#[allow(clippy::from_over_into)]
impl Into<Vec<u8>> for TelnetNegotiation {
  fn into(self) -> Vec<u8> {
    self.to_bytes().into()
  }
}

#[allow(clippy::from_over_into)]
impl Into<Bytes> for TelnetSubnegotiation {
  fn into(self) -> Bytes {
    self.to_bytes()
  }
}

#[allow(clippy::from_over_into)]
impl Into<Vec<u8>> for TelnetSubnegotiation {
  fn into(self) -> Vec<u8> {
    self.to_bytes().into()
  }
}