# llama_index_utils.py
from llama_index import SimpleDirectoryReader, GPTVectorStoreIndex

_index = None

def build_index(data_path="data/icd10cm_tabular_2025"):
    global _index
    if _index is None:
        docs = SimpleDirectoryReader(data_path).load_data()
        _index = GPTVectorStoreIndex.from_documents(docs)
    return _index

def query_symptoms(prompt: str, top_k: int = 5):
    idx = build_index()
    qe = idx.as_query_engine(similarity_top_k=top_k)
    return qe.query(prompt)