monocoque-rs-core 0.1.1

/// Monocoque Error Types
///
/// Comprehensive error handling for all Monocoque operations.
use std::io;
use thiserror::Error;

/// Main error type for Monocoque operations
#[derive(Error, Debug)]
pub enum MonocoqueError {
    /// IO error during socket operations
    #[error("IO error: {0}")]
    Io(#[from] io::Error),

    /// Protocol error during ZMTP handshake or framing
    #[error("Protocol error: {0}")]
    Protocol(String),

    /// Handshake timeout
    #[error("Handshake timeout after {0:?}")]
    HandshakeTimeout(std::time::Duration),

    /// Invalid greeting received
    #[error("Invalid greeting: {0}")]
    InvalidGreeting(String),

    /// Invalid frame format
    #[error("Invalid frame: {0}")]
    InvalidFrame(String),

    /// Socket closed
    #[error("Socket closed")]
    SocketClosed,

    /// Channel send error
    #[error("Channel send error")]
    ChannelSend,

    /// Channel receive error
    #[error("Channel receive error")]
    ChannelRecv,

    /// Peer disconnected
    #[error("Peer disconnected: {0}")]
    PeerDisconnected(String),

    /// Invalid routing ID
    #[error("Invalid routing ID")]
    InvalidRoutingId,

    /// Message too large
    #[error("Message too large: {size} bytes (max: {max})")]
    MessageTooLarge { size: usize, max: usize },

    /// Subscription error
    #[error("Subscription error: {0}")]
    Subscription(String),
}

/// Result type alias for Monocoque operations
pub type Result<T> = std::result::Result<T, MonocoqueError>;

/// Extension trait for adding context to results
pub trait ResultExt<T> {
    /// Add context to an error
    fn context(self, context: impl Into<String>) -> Result<T>;

    /// Add context via a closure (lazy evaluation)
    fn with_context<F>(self, f: F) -> Result<T>
    where
        F: FnOnce() -> String;
}

impl<T> ResultExt<T> for Result<T> {
    fn context(self, context: impl Into<String>) -> Self {
        self.map_err(|e| {
            let ctx = context.into();
            match e {
                MonocoqueError::Io(io_err) => {
                    MonocoqueError::Io(io::Error::new(io_err.kind(), format!("{ctx}: {io_err}")))
                }
                MonocoqueError::Protocol(msg) => MonocoqueError::Protocol(format!("{ctx}: {msg}")),
                other => other,
            }
        })
    }

    fn with_context<F>(self, f: F) -> Self
    where
        F: FnOnce() -> String,
    {
        self.map_err(|e| {
            let ctx = f();
            match e {
                MonocoqueError::Io(io_err) => {
                    MonocoqueError::Io(io::Error::new(io_err.kind(), format!("{ctx}: {io_err}")))
                }
                MonocoqueError::Protocol(msg) => MonocoqueError::Protocol(format!("{ctx}: {msg}")),
                other => other,
            }
        })
    }
}

impl MonocoqueError {
    /// Create a protocol error with a message
    pub fn protocol(msg: impl Into<String>) -> Self {
        Self::Protocol(msg.into())
    }

    /// Create an invalid greeting error
    pub fn invalid_greeting(msg: impl Into<String>) -> Self {
        Self::InvalidGreeting(msg.into())
    }

    /// Create an invalid frame error
    pub fn invalid_frame(msg: impl Into<String>) -> Self {
        Self::InvalidFrame(msg.into())
    }

    /// Create a peer disconnected error
    pub fn peer_disconnected(peer_id: impl Into<String>) -> Self {
        Self::PeerDisconnected(peer_id.into())
    }

    /// Check if this error is recoverable
    #[must_use]
    pub fn is_recoverable(&self) -> bool {
        match self {
            Self::Io(e) => matches!(
                e.kind(),
                io::ErrorKind::Interrupted | io::ErrorKind::WouldBlock | io::ErrorKind::TimedOut
            ),
            Self::HandshakeTimeout(_) | Self::ChannelSend | Self::ChannelRecv => false,
            _ => false,
        }
    }

    /// Check if this is a connection error
    #[must_use]
    pub const fn is_connection_error(&self) -> bool {
        matches!(
            self,
            Self::SocketClosed | Self::PeerDisconnected(_) | Self::HandshakeTimeout(_)
        )
    }
}