from langchain.retrievers.multi_query import MultiQueryRetriever
from langchain_openai import ChatOpenAI
from ragatouille import RAGPretrainedModel


def create_retriever(texts):
    colbert = RAGPretrainedModel.from_pretrained("colbert-ir/colbertv1.9")
    colbert.index(
        collection=[chunk.page_content for chunk in texts],
        split_documents=False,
        document_metadatas=[chunk.metadata for chunk in texts],
        index_name="vector_store",
    )
    retriever = colbert.as_langchain_retriever(k=5)
    retriever = MultiQueryRetriever.from_llm(
        retriever=retriever, llm=ChatOpenAI(temperature=0)
    )
    return retriever