from langchain.chat_models import ChatOpenAI
from langchain.vectorstores.pinecone import Pinecone
import openai
from langchain.chains import RetrievalQA
import os
OPENAI_API_KEY = os.environ.get("OPENAI_API_KEY")
def get_chain(vectorstore: Pinecone):
    openai.api_key = OPENAI_API_KEY
    llm = ChatOpenAI(temperature=0, model_name="gpt-3.5-turbo")
    qa_chain = RetrievalQA.from_chain_type(llm=llm, chain_type="stuff", retriever=vectorstore.as_retriever(),return_source_documents=True)
    return qa_chain