"""Entry point to Streamlit UI.

Ref: https://docs.streamlit.io/get-started/tutorials/create-a-multipage-app
"""

from pathlib import Path
from typing import Dict

import streamlit as st


def welcome_message() -> Dict[str, str]:
    return {
        "role": "assistant",
        "content": "Welcome to My Notion Companion.",
    }


def main():

    st.set_page_config(
        page_title="My Notion Companion",
        page_icon="🤖",
    )

    st.title("My Notion Companion 🤖")
    st.caption(
        "A conversational RAG that helps to chat with my (mostly Chinese-based) Notion Databases."
    )
    st.caption(
        "Powered by: [🦜🔗](https://www.langchain.com/), [🤗](https://huggingface.co/), [LlamaCpp](https://github.com/ggerganov/llama.cpp), [Streamlit](https://streamlit.io/)."
    )

    # Initialize chat history
    if "messages" not in st.session_state:
        st.session_state.messages = [welcome_message()]

    # Display chat messages from history on app rerun
    for message in st.session_state.messages:
        with st.chat_message(message["role"]):
            st.markdown(message["content"])

    # Two buttons to control history/memory
    def start_over():
        st.session_state.messages = [
            {"role": "assistant", "content": "Okay, let's start over."}
        ]

    st.sidebar.button(
        "Start All Over Again", on_click=start_over, use_container_width=True
    )

    def clear_chat_history():
        st.session_state.messages = [
            {
                "role": "assistant",
                "content": "Retrieved documents are still in my memory. What else you want to know?",
            }
        ]

    st.sidebar.button(
        "Keep Retrieved Docs but Clear Chat History",
        on_click=clear_chat_history,
        use_container_width=True,
    )

    # Accept user input
    if prompt := st.chat_input("Any questiones?"):

        # Add user message to chat history
        st.session_state.messages.append({"role": "user", "content": prompt})

        # Display user message in chat message container
        with st.chat_message("user"):
            st.markdown(prompt)

        # Display assistant response in chat message container
        with st.chat_message("assistant"):
            # response = st.session_state.t.invoke()
            response = """##### NOTES: \n\nThis is only a mock UI hosted on Hugging Face because of limited computing resources available as a freemium user. 
            Please check the video demo (side bar) and see how this the companion works as a standalone offline webapp.\n\nAlternatively, 
            please visit the [GitHub page](https://github.com/fyang0507/my-notion-companion/tree/main) and follow the quickstart guide to build your own!
            """
            st.write(response)
            st.session_state.messages.append({"role": "assistant", "content": response})

if __name__ == "__main__":
    main()