import os
from datetime import datetime

from langchain import OpenAI
from langchain.chains import load_chain
from langchain.chains.question_answering import load_qa_chain
from langchain.embeddings import OpenAIEmbeddings
from langchain.llms import OpenAIChat

from config.config import MAX_TOKENS, TOOLS_DEFAULT_LIST


def set_openai_api_key(api_key, use_gpt4):
    """Set the api key and return chain.
    If no api_key, then None is returned.
    """
    if api_key and api_key.startswith("sk-") and len(api_key) > 50:
        os.environ["OPENAI_API_KEY"] = api_key
        print("\n\n ++++++++++++++ Setting OpenAI API key ++++++++++++++ \n\n")
        print(str(datetime.now()) + ": Before OpenAI, OPENAI_API_KEY length: " + str(
            len(os.environ["OPENAI_API_KEY"])))

        if use_gpt4:
            llm = OpenAIChat(temperature=0, max_tokens=MAX_TOKENS, model_name="gpt-4")
            print("Trying to use llm OpenAIChat with gpt-4")
        else:
            print("Trying to use llm OpenAI with text-davinci-003")
            llm = OpenAI(temperature=0, max_tokens=MAX_TOKENS, model_name="text-davinci-003")

        print(str(datetime.now()) + ": After OpenAI, OPENAI_API_KEY length: " + str(
            len(os.environ["OPENAI_API_KEY"])))
        chain, express_chain, memory = load_chain(TOOLS_DEFAULT_LIST, llm)

        # Pertains to question answering functionality
        embeddings = OpenAIEmbeddings()

        if use_gpt4:
            qa_chain = load_qa_chain(OpenAIChat(temperature=0, model_name="gpt-4"), chain_type="stuff")
            print("Trying to use qa_chain OpenAIChat with gpt-4")
        else:
            print("Trying to use qa_chain OpenAI with text-davinci-003")
            qa_chain = OpenAI(temperature=0, max_tokens=MAX_TOKENS, model_name="text-davinci-003")

        print(str(datetime.now()) + ": After load_chain, OPENAI_API_KEY length: " + str(
            len(os.environ["OPENAI_API_KEY"])))
        os.environ["OPENAI_API_KEY"] = ""
        return chain, express_chain, llm, embeddings, qa_chain, memory, use_gpt4
    return None, None, None, None, None, None, None