klieo-core 0.4.0

//! Pre/post-LLM guardrail dispatch shared by the blocking and
//! streaming drivers.

use crate::error::Error;
use crate::guardrail::{Guardrail, GuardrailOutcome};
use crate::llm::{ChatRequest, ChatResponse};
use std::sync::Arc;
use tracing::debug;

/// Run every guardrail's `pre_llm` hook against the outgoing request.
///
/// Iterates in registration order; the first non-`Pass` outcome
/// short-circuits with [`Error::Refused`] or [`Error::Handoff`]. An
/// empty slice is the zero-cost no-op default.
pub(crate) async fn check_pre_llm(
    guardrails: &[Arc<dyn Guardrail>],
    req: &ChatRequest,
) -> Result<(), Error> {
    for g in guardrails {
        match g.pre_llm(req).await {
            GuardrailOutcome::Pass => {}
            GuardrailOutcome::Refuse { reason } => {
                debug!(guardrail = g.name(), %reason, "pre-LLM guardrail refused");
                return Err(Error::Refused { reason });
            }
            GuardrailOutcome::Handoff { agent, reason } => {
                debug!(guardrail = g.name(), %agent, %reason, "pre-LLM guardrail handoff");
                return Err(Error::Handoff { agent, reason });
            }
        }
    }
    Ok(())
}

/// Run every guardrail's `post_llm` hook against the request +
/// response pair. Short-circuit semantics match [`check_pre_llm`].
pub(crate) async fn check_post_llm(
    guardrails: &[Arc<dyn Guardrail>],
    req: &ChatRequest,
    resp: &ChatResponse,
) -> Result<(), Error> {
    for g in guardrails {
        match g.post_llm(req, resp).await {
            GuardrailOutcome::Pass => {}
            GuardrailOutcome::Refuse { reason } => {
                debug!(guardrail = g.name(), %reason, "post-LLM guardrail refused");
                return Err(Error::Refused { reason });
            }
            GuardrailOutcome::Handoff { agent, reason } => {
                debug!(guardrail = g.name(), %agent, %reason, "post-LLM guardrail handoff");
                return Err(Error::Handoff { agent, reason });
            }
        }
    }
    Ok(())
}