-- Customer-managed quality floor for runtime Few-shot retrieval.
-- Lower cosine distance is more similar.  The value is data, not application code.
MERGE INTO sg_game_scope_policy t
USING (
  SELECT 'QA_VECTOR_MAX_COSINE_DISTANCE' AS policy_key,
         0.650000 AS number_value,
         'Maximum cosine distance accepted for a runtime approved Few-shot example.' AS description
    FROM dual
) s
ON (t.policy_key = s.policy_key)
WHEN MATCHED THEN UPDATE SET
  t.number_value = s.number_value,
  t.description = s.description,
  t.active_yn = 'Y',
  t.updated_at = SYSTIMESTAMP
WHEN NOT MATCHED THEN INSERT (
  policy_key, number_value, text_value, description, active_yn
) VALUES (
  s.policy_key, s.number_value, NULL, s.description, 'Y'
);
/

CREATE OR REPLACE FUNCTION sg_qa_vector_search(
  p_question    IN CLOB,
  p_top_k       IN PLS_INTEGER DEFAULT 3,
  p_target_type IN VARCHAR2 DEFAULT 'ANY'
) RETURN SYS_REFCURSOR AUTHID DEFINER
IS
  v_query_vector VECTOR;
  v_results SYS_REFCURSOR;
  v_target_type VARCHAR2(16) := UPPER(TRIM(NVL(p_target_type, 'ANY')));
  v_max_cosine_distance NUMBER;
BEGIN
  IF p_question IS NULL THEN
    RAISE_APPLICATION_ERROR(-20003, 'question is required.');
  END IF;
  IF p_top_k IS NULL OR p_top_k < 1 OR p_top_k > 20 THEN
    RAISE_APPLICATION_ERROR(-20004, 'top_k must be between 1 and 20.');
  END IF;
  IF v_target_type NOT IN ('NONE', 'SINGLE', 'MULTI', 'ALL', 'ANY') THEN
    RAISE_APPLICATION_ERROR(-20005, 'invalid target type.');
  END IF;

  SELECT number_value
    INTO v_max_cosine_distance
    FROM sg_game_scope_policy
   WHERE policy_key = 'QA_VECTOR_MAX_COSINE_DISTANCE'
     AND active_yn = 'Y'
     AND number_value IS NOT NULL;

  v_query_vector := DBMS_VECTOR.UTL_TO_EMBEDDING(
    p_question, JSON(sg_qa_vector_params('search_query'))
  );

  OPEN v_results FOR
    SELECT example_id, question, answer_sql, answer_text, embedding_model,
           reference_kind, target_type, object_role, source_case_id, source_type,
           cosine_distance
      FROM (
        SELECT example_id, question, answer_sql, answer_text, embedding_model,
               reference_kind, target_type, object_role, source_case_id, source_type,
               VECTOR_DISTANCE(embedding, v_query_vector, COSINE) AS cosine_distance
         FROM sg_qa_vector_example
         WHERE reference_status = 'APPROVED'
           -- A generated structural pattern is review material, not a runtime
           -- Few-shot. Runtime examples must have human verification and an
           -- executable SQL body rather than unresolved logical placeholders.
           AND inspection_status = 'VERIFIED'
           AND answer_sql IS NOT NULL
           AND NOT REGEXP_LIKE(answer_sql, '<[A-Z][A-Z0-9_]*>', 'i')
           AND (target_type = 'ANY' OR v_target_type = 'ANY' OR target_type = v_target_type)
      )
     WHERE cosine_distance <= v_max_cosine_distance
     ORDER BY cosine_distance, example_id
     FETCH FIRST p_top_k ROWS ONLY;
  RETURN v_results;
END;
/

COMMENT ON TABLE sg_game_scope_policy IS
  'Customer-managed game scope and runtime retrieval policy values; changing a value requires no application deployment.';
/