import streamlit as st
from rag_chain import get_rag_chain

st.set_page_config(page_title="Cricket Chat", page_icon="🏏")
st.title("YouTube Video Chatbot")

video_id = st.text_input("Enter YouTube video ID (e.g. Gfr50f6ZBvo)")

if video_id and st.session_state.get("current_video") != video_id:
    with st.spinner("Processing transcript..."):
        try:
            st.session_state.chain = get_rag_chain(video_id)
            st.session_state.current_video = video_id
            st.session_state.messages = []
            st.success("Ready! Ask away.")
        except ValueError as e:
            st.error(str(e))
            st.stop()

if "messages" not in st.session_state:
    st.session_state.messages = []

for msg in st.session_state.messages:
    with st.chat_message(msg["role"]):
        st.markdown(msg["content"])

if "chain" in st.session_state:
    if prompt := st.chat_input("Ask about the video..."):
        st.session_state.messages.append({"role": "user", "content": prompt})
        with st.chat_message("user"):
            st.markdown(prompt)

        with st.chat_message("assistant"):
            with st.spinner("Thinking..."):
                response = st.session_state.chain.invoke(prompt)
            st.markdown(response)
            st.session_state.messages.append({"role": "assistant", "content": response})