Function wrap_py_llm_request_intercept_fn

crates/python/src/py_callable.rs:647–715

Wrap a Python callable for unified LLM request intercepts. The Python function receives ``(name: str, request: LlmRequest, annotated: AnnotatedLLMRequest | None)`` and must return ``(LlmRequest, AnnotatedLLMRequest | None)``.

(py_fn: Py<PyAny>)

/// The Python function receives ``(name: str, request: LlmRequest, annotated: AnnotatedLLMRequest | None)``
/// and must return ``(LlmRequest, AnnotatedLLMRequest | None)``.
pub fn wrap_py_llm_request_intercept_fn(py_fn: Py<PyAny>) -> LlmRequestInterceptFn {
    Arc::new(
        move |name: &str,
              request: LlmRequest,
              annotated: Option<AnnotatedLLMRequest>|
              -> FlowResult<(LlmRequest, Option<AnnotatedLLMRequest>)> {
            Python::attach(|py| {
                let py_req = PyLLMRequest {
                    inner: request.clone(),
                };
                let py_ann: Py<PyAny> = match annotated {
                    Some(ann) => {
                        let wrapper = PyAnnotatedLLMRequest { inner: ann };
                        wrapper
                            .into_pyobject(py)
                            .map_err(|e| {
                                FlowError::Internal(format!(
                                    "Failed to convert AnnotatedLLMRequest to Python: {e}"
                                ))
                            })?
                            .into_any()
                            .unbind()
                    }
                    None => py.None(),
                };
                let result = py_fn.call1(py, (name, py_req, py_ann)).map_err(|e| {
                    FlowError::Internal(format!("LLM request intercept callable failed: {e}"))
                })?;

                // Extract the tuple (LlmRequest, AnnotatedLLMRequest | None)
                let tuple = result.bind(py);
                let new_req: PyLLMRequest = tuple
                    .get_item(0)
                    .map_err(|e| {
                        FlowError::Internal(format!(
                            "LLM request intercept result[0] extraction failed: {e}"
                        ))
                    })?
                    .extract()
                    .map_err(|e| {
                        FlowError::Internal(format!(
                            "LLM request intercept result[0] is not LlmRequest: {e}"
                        ))
                    })?;
                let ann_item = tuple.get_item(1).map_err(|e| {
                    FlowError::Internal(format!(
                        "LLM request intercept result[1] extraction failed: {e}"
                    ))
                })?;
                let new_ann = if ann_item.is_none() {
                    None
                } else {
                    Some(
                        ann_item
                            .extract::<PyAnnotatedLLMRequest>()
                            .map_err(|e| {
                                FlowError::Internal(format!(
                                    "LLM request intercept result[1] is not AnnotatedLLMRequest: {e}"