/// Errors from the API layer (HTTP, JSON, SSE, auth).
pub enum ApiError {
 Http str
 Json str
 Api(uint, str, bool)
 Sse str
 Auth str
 RetriesExhausted uint
}

fn api_error_to_string(err ApiError) str {
 is err {
 ApiError.Http(msg) -> return f"Http: $msg",
 ApiError.Json(msg) -> return f"Json: $msg",
 ApiError.Api(status msg retry) -> return f"Api($status): $msg",
 ApiError.Sse(msg) -> return f"Sse: $msg",
 ApiError.Auth(msg) -> return f"Auth: $msg",
 ApiError.RetriesExhausted(n) -> return f"RetriesExhausted($n)"
 }
 return "Unknown ApiError"
}

/// Errors from tool execution.
pub enum ToolError {
 ExecutionFailed str
 InvalidInput str
 PermissionDenied str
}

pub fn tool_error_to_string(err ToolError) str {
 is err {
 ToolError.ExecutionFailed(msg) -> return f"ExecutionFailed: $msg",
 ToolError.InvalidInput(msg) -> return f"InvalidInput: $msg",
 ToolError.PermissionDenied(msg) -> return f"PermissionDenied: $msg"
 }
 return "Unknown ToolError"
}

/// Errors from the agent runtime.
pub enum RuntimeError {
 Api str
 MaxIterations uint
 EmptyResponse
}

fn runtime_error_to_string(err RuntimeError) str {
 is err {
 RuntimeError.Api(msg) -> return f"Api: $msg",
 RuntimeError.MaxIterations(n) -> return f"MaxIterations($n)",
 RuntimeError.EmptyResponse -> return "EmptyResponse"
 }
 return "Unknown RuntimeError"
}