//! Error types for MCP Gateway
use std::io;
use thiserror::Error;
/// Result type alias for MCP Gateway
pub type Result<T> = std::result::Result<T, Error>;
/// MCP Gateway errors
#[derive(Error, Debug)]
pub enum Error {
/// Configuration error
#[error("Configuration error: {0}")]
Config(String),
/// Backend not found
#[error("Backend not found: {0}")]
BackendNotFound(String),
/// Backend unavailable (circuit open)
#[error("Backend unavailable: {0}")]
BackendUnavailable(String),
/// Backend timeout
#[error("Backend timeout: {0}")]
BackendTimeout(String),
/// Transport error
#[error("Transport error: {0}")]
Transport(String),
/// Protocol error
#[error("Protocol error: {0}")]
Protocol(String),
/// JSON-RPC error
#[error("JSON-RPC error {code}: {message}")]
JsonRpc {
/// Error code
code: i32,
/// Error message
message: String,
/// Optional data
data: Option<serde_json::Value>,
},
/// IO error
#[error("IO error: {0}")]
Io(#[from] io::Error),
/// JSON error
#[error("JSON error: {0}")]
Json(#[from] serde_json::Error),
/// HTTP error
#[error("HTTP error: {0}")]
Http(#[from] reqwest::Error),
/// Server shutdown
#[error("Server shutdown")]
Shutdown,
/// Internal error
#[error("Internal error: {0}")]
Internal(String),
}
impl Error {
/// Create a JSON-RPC error
pub fn json_rpc(code: i32, message: impl Into<String>) -> Self {
Self::JsonRpc {
code,
message: message.into(),
data: None,
}
}
/// Convert to JSON-RPC error code
#[must_use]
pub fn to_rpc_code(&self) -> i32 {
match self {
Self::JsonRpc { code, .. } => *code,
Self::Json(_) => -32700, // Parse error
Self::Protocol(_) => -32600, // Invalid request
Self::BackendNotFound(_) => -32001,
Self::BackendUnavailable(_) => -32000,
Self::BackendTimeout(_) => -32000,
Self::Transport(_) => -32000,
_ => -32603, // Internal error
}
}
}
/// Standard JSON-RPC error codes
pub mod rpc_codes {
/// Parse error - Invalid JSON
pub const PARSE_ERROR: i32 = -32700;
/// Invalid Request - Not a valid Request object
pub const INVALID_REQUEST: i32 = -32600;
/// Method not found
pub const METHOD_NOT_FOUND: i32 = -32601;
/// Invalid params
pub const INVALID_PARAMS: i32 = -32602;
/// Internal error
pub const INTERNAL_ERROR: i32 = -32603;
/// Server error range start
pub const SERVER_ERROR_START: i32 = -32000;
/// Server error range end
pub const SERVER_ERROR_END: i32 = -32099;
}
