app.py

### Import Section ###
import chainlit as cl
import os
from dotenv import load_dotenv
from langchain_openai import ChatOpenAI
from langchain_core.runnables.config import RunnableConfig
from utilities.all_utilities import process_file
from utilities.prompts import get_opening_content

################
# General code
################

load_dotenv()
openai_api_key = os.getenv("OPENAI_API_KEY")

# ChatOpenAI Templates

@cl.action_callback("icelandic")
async def on_action(action):
    cl.user_session.set("language", "icelandic")
    await cl.Message(content=f"Changing to {action.name}").send()
    # Optionally remove the action button from the chatbot user interface
    # await action.remove()

@cl.action_callback("english")
async def on_action(action):
    cl.user_session.set("language", "english")
    await cl.Message(content=f"Changing to {action.name}").send()
    # Optionally remove the action button from the chatbot user interface
    # await action.remove()

#############################################
### On Chat Start (Session Start) Section ###
#############################################
@cl.on_chat_start
async def on_chat_start():

    actions = [
        cl.Action(name="icelandic", value="icelandic", description="Switch to Icelandic"),
        cl.Action(name="english", value="english", description="Switch to English")
    ]


    await cl.Message(content="Languages", actions=actions).send()
 
    await cl.Message(content=get_opening_content()).send()

    prompt_cache_input = await cl.AskActionMessage(
        content="Do you want to use Prompt Cache?",
        actions=[
            cl.Action(name="yes", value="yes", label="✅ Yes"),
            cl.Action(name="no", value="no", label="❌ No"),
        ],
    ).send()
    prompt_cache = prompt_cache_input.get("value")
    files = None
    # Wait for the user to upload a file
    while not files:
        files = await cl.AskFileMessage(
            content="Please upload a .pdf file to begin processing!",
            accept=["application/pdf"],
            max_size_mb=20,
            timeout=180,
        ).send()

    file = files[0]

    msg = cl.Message(
        content=f"Processing `{file.name}`...", disable_human_feedback=True
    )
    await msg.send()
    response = process_file(file, prompt_cache)
    rag_chain = response["chain"]
    retriever = response["retriever"]

    msg.content = f"Processing `{file.name}` is complete."
    await msg.update()
    msg.content = f"You can now ask questions about `{file.name}`."
    await msg.update()
    cl.user_session.set("chain", rag_chain)
    cl.user_session.set("retriever", retriever)

##########################
### On Message Section ###
##########################
@cl.on_message
async def main(message: cl.Message):
    # Ensure that message.content is not None or empty
    chain = cl.user_session.get("chain")
    language = cl.user_session.get("language", "english")
    msg = cl.Message(content="")
    question = message.content

    async for chunk in chain.astream(
        {"question": question, "language": language},
        config=RunnableConfig(callbacks=[cl.LangchainCallbackHandler()]),
    ):
        await msg.stream_token(chunk.content)

    await msg.send()