app.py

import streamlit as st
from graph import EssayWriter, RouteQuery, GraphState
from crew import *
import os
import base64

#st.title("Multi-Agent Essay Writing Assistant")
st.set_page_config(page_title="Multi-Agent Essay Writing Assistant", page_icon="🤖🤖🤖✍️", layout = "centered")

# Ensure session state variables are initialized properly
if "messages" not in st.session_state:
    st.session_state["messages"] = [{"role": "assistant", "content": "Hello! How can I assist you today?"}]

if "app" not in st.session_state:
    st.session_state["app"] = None

if "chat_active" not in st.session_state:
    st.session_state["chat_active"] = True

# Sidebar with essay settings and user-defined length
with st.sidebar:
    st.subheader("About:")
    st.info(
        "\n\n* This app uses the 'gpt-4o-mini-2024-07-18' model."
        "\n\n* Writing essays may take some time, approximately 1-2 minutes."
    )

    # API Key Retrieval
    openai_key = st.secrets.get("OPENAI_API_KEY", "")

    st.divider()

    # User-defined essay length selection
    st.subheader("📝 Configure Essay Settings:")
    essay_length = st.number_input(
        "Select Essay Length (words):",
        min_value=150,
        max_value=400,
        value=250,
        step=50
    )

    st.divider()

    # Reference section
    st.subheader("📖 References:")
    st.markdown(
        "[1. Multi-Agent System with CrewAI and LangChain](https://discuss.streamlit.io/t/new-project-i-have-build-a-multi-agent-system-with-crewai-and-langchain/84002)",
        unsafe_allow_html=True
    )

# Initialize agents function
def initialize_agents():
    if not openai_key:
        st.error("⚠️ OpenAI API key is missing! Please provide a valid key through Hugging Face Secrets.")
        st.session_state["chat_active"] = True
        return None

    os.environ["OPENAI_API_KEY"] = openai_key
    try:
        if st.session_state["app"] is not None:
            return st.session_state["app"]  # Prevent re-initialization
        
        essay_writer = EssayWriter().graph
        st.session_state["chat_active"] = False

        # Success message
        #st.success("✅ Agents successfully initialized!")
        return essay_writer
    except Exception as e:
        st.error(f"❌ Error initializing agents: {e}")
        st.session_state["chat_active"] = True
        return None

# Automatically initialize agents on app load
if st.session_state["app"] is None:
    st.session_state["app"] = initialize_agents()

if st.session_state["app"] is None:
    st.error("⚠️ Failed to initialize agents. Please check your API key and restart the app.")

app = st.session_state["app"]

# Function to invoke the agent and generate a response
def generate_response(topic, length):
    if not app:
        st.error("⚠️ Agents are not initialized. Please check the system or restart the app.")
        return {"response": "Error: Agents not initialized."}

    return app.invoke(input={"topic": topic, "length": length})

# Display chat messages from the session
if "messages" in st.session_state:
    for message in st.session_state["messages"]:
        with st.chat_message(message["role"]):
            st.markdown(message["content"], unsafe_allow_html=True)

# Handle user input
if topic := st.chat_input(placeholder="📝 Ask a question or provide an essay topic...", disabled=st.session_state["chat_active"]):
    st.chat_message("user").markdown(topic)
    st.session_state["messages"].append({"role": "user", "content": topic})

    with st.spinner("⏳ Generating your essay..."):
        response = generate_response(topic, essay_length)  

    # Handle the assistant's response
    with st.chat_message("assistant"):
        if "essay" in response:  # Display essay preview and download link
            st.markdown(f"### 📝 Essay Preview ({essay_length} words)")
            st.markdown(f"#### {response['essay']['header']}")
            st.markdown(response["essay"]["entry"])
            for para in response["essay"]["paragraphs"]:
                st.markdown(f"**{para['sub_header']}**")
                st.markdown(para["paragraph"])
            st.markdown("**🖊️ Conclusion:**")
            st.markdown(response["essay"]["conclusion"])

            # Provide download link for the PDF
            with open(response["pdf_name"], "rb") as pdf_file:
                b64 = base64.b64encode(pdf_file.read()).decode()
                href = f"<a href='data:application/octet-stream;base64,{b64}' download='{response['pdf_name']}'>📄 Click here to download the PDF</a>"
                st.markdown(href, unsafe_allow_html=True)

            # Save the assistant's message to session state
            st.session_state["messages"].append(
                {"role": "assistant", "content": f"Here is your {essay_length}-word essay preview and the download link."}
            )
        else:  # For other responses (e.g., general answers)
            st.markdown(response["response"])
            st.session_state["messages"].append({"role": "assistant", "content": response["response"]})

# Acknowledgment Section
st.markdown(
    """
    <div style="text-align: center; font-size: 14px; color: #555; padding-top: 250px; margin-top: 250px;">
        <strong>Acknowledgment:</strong> This app is based on Mesut Duman's work: 
        <a href="https://github.com/mesutdmn/Autonomous-Multi-Agent-Systems-with-CrewAI-Essay-Writer/tree/main" 
           target="_blank" style="color: #007BFF; text-decoration: none;">
           CrewAI Essay Writer
        </a>
    </div>
    """,
    unsafe_allow_html=True,
    )