langchain_backend/main.py

import os
from langchain_backend.utils import create_prompt_llm_chain, create_retriever, getPDF
from langchain.chains import create_retrieval_chain

os.environ.get("OPENAI_API_KEY")

def get_llm_answer(system_prompt, user_prompt, pdf_url, model):
  print('model: ', model)
  pages = None
  if pdf_url:
    pages = getPDF(pdf_url)
  else:
    pages = getPDF()
  retriever = create_retriever(pages)
  rag_chain = None
  if model:
    rag_chain = create_retrieval_chain(retriever, create_prompt_llm_chain(system_prompt, model))
  else:
    rag_chain = create_retrieval_chain(retriever, create_prompt_llm_chain(system_prompt))
  results = rag_chain.invoke({"input": user_prompt})
  return results