src/app.py

import streamlit as st
from streamlit.components.v1 import html

from langchain_ollama.chat_models import ChatOllama
from langchain_ollama.embeddings import OllamaEmbeddings
from langchain.schema import HumanMessage, SystemMessage, BaseMessage, AIMessage
from langchain_core.prompts import MessagesPlaceholder, ChatPromptTemplate

st.set_page_config(layout="wide")

st.set_page_config(page_title="Agentic", page_icon=":robot_face:")
st.header(":red[CineGuide] the AI Agent\n  ", divider='rainbow')

@st.cache_resource
def get_chat_model():
    return ChatOllama(model="deepseek-r1:8b")

@st.cache_resource
def get_embedding_model():
    return OllamaEmbeddings(model='nomic-embed-text:latest')

if "chat_model" not in st.session_state:
    st.session_state.chat_model = get_chat_model()
if "embedding_model" not in st.session_state:
    st.session_state.embedding_model = get_embedding_model()
if "messages" not in st.session_state:
    st.session_state.messages = []

system_message = SystemMessage(
    content="""
You are “CineGuide,” a friendly and intelligent AI assistant specializing in personalized film and TV show recommendations.

Before performing any recommendations, searches, or actions:
- Check if the user's profile includes:
    1. Name (optional but good for personalization)
    2. Location (for local theaters and premieres)
    3. Preference: Movies, TV shows, or both
    4. Favorite genres
    5. Preferred time period (classics, recent releases, specific decades)
- If any of these are missing, ask in a conversational way, one at a time, without overwhelming the user.
- If the user has not yet mentioned whether they prefer movies or TV shows, their favorite genres, or the period they enjoy most, naturally discover this before proceeding.

Your mission:
- Build and update a dynamic user profile purely from conversation.
- Recommend both classic and new releases tailored to their tastes.
- Use available tools to:
    - Search movies and shows with filters (genre, release year, rating, etc.).
    - Find local theaters or events where these are premiering.
    - Identify OTT platforms where suggested content is available.
- Provide short summaries and available viewing options for each recommendation.
- Ask follow-up questions to refine recommendations (e.g., “Do you feel like watching a drama or a comedy tonight?”).

Tone & style:
- Be conversational and engaging.
- Keep recommendations relevant.
- Avoid asking for unnecessary personal data unless it clearly improves suggestions.
"""
)


col1,col2 =st.columns([0.3,0.7])

st.markdown("""
                <style>
                .stMainBlockContainer{
                    padding: 4rem;
                }
                .stColumn:nth-child(1) {
                    padding: 2rem;
                    width: 100%;
                    background-color: #06080c;
                }
                .stColumn:nth-child(2)>div {
                    overflow-y: scroll;
                    height: 70vh;
                }
                </style>
            """, unsafe_allow_html=True)

with col1:
    st.markdown("<h4 style='text-align:right'>User Information</h4>", unsafe_allow_html=True)
    st.text_input('Name',placeholder="")
    st.text_input('Location',placeholder="")
    st.multiselect('Preferred Language', options=['English', 'Hindi'])
    st.multiselect("Preferred Genres", options=['Action', 'Comedy', 'Drama', 'Horror', 'Romance', 'Sci-Fi', 'Thriller', 'Documentary'])
    st.text_area('Preferred Plots', placeholder="")
    with st.expander("Liked Movies", expanded=True):
        pass
    with st.expander("Liked TV Shows", expanded=True):
        pass

with col2:
    for msg in st.session_state.messages:
        if isinstance(msg, HumanMessage):
            st.chat_message("user").write(msg.content)
        
        if isinstance(msg, AIMessage):
            st.chat_message("assistant").write(msg.content)

    user_input = st.chat_input("Type your message here...")
    st.markdown("""
    <style>
    .stChatInput {
        position: fixed;
        bottom: 4rem;
        left: 32%;
        width: 65%;
        z-index: 999;
    }
    </style>
    """, unsafe_allow_html=True)

    
    scroll_js = """
    <script>
    function scrollToBottom(){
        const el = window.parent.document.querySelector(".stColumn:nth-child(2) > div");
        if (el) {
            el.scrollTop = el.scrollHeight;
        }
    }
    setInterval(scrollToBottom, 500);
    </script>
    """

    html(scroll_js, height=0, width=0, scrolling=False)

    if user_input:
        user_msg = HumanMessage(content=user_input)
        st.chat_message("user").write(user_input)
        st.session_state.messages.append(user_msg)

        prompt = ChatPromptTemplate.from_messages(
            [system_message, MessagesPlaceholder(variable_name="messages")]
        )
        formatted_prompt = prompt.invoke({"messages": st.session_state.messages})

        response = st.session_state.chat_model.stream(formatted_prompt)

        thinking = False
        thinking_available = False
        thinking_data = ""

        assistant_response_text = ""
        def stream_saver(response):
            for chunk in response:
                global assistant_response_text, thinking, thinking_data, thinking_available
                text = chunk.content

                if text == "<think>":
                    if not thinking:
                        thinking = True
                        thinking_available = True
                if text == "</think>":
                    if thinking:
                        thinking = False
                        continue
                
                if not thinking:
                    assistant_response_text += text
                else:
                    thinking_data += text

                yield text

        for chunk in stream_saver(response):
            if chunk == "<think>":
                status = st.status("Thinking...", expanded=True) if thinking_available else None
                thinking_placeholder = status.empty() if thinking_available else None
                thinking_text_accumulated = ""
            if thinking:
                if chunk == "<think>":
                    status.update(label="Thinking...", state="running", expanded=True)
                else:
                    thinking_text_accumulated += chunk
                    thinking_placeholder.markdown(thinking_text_accumulated)
            else:
                if thinking_available:
                    status.update(label="Thinking complete.", state="complete", expanded=False)
                break
        if not thinking:
            assistant_message_container = st.chat_message("assistant")
            assistant_message_container.write_stream(stream_saver(response))

        st.session_state.messages.append(AIMessage(content=assistant_response_text))