app.py

import os
import streamlit as st
from huggingface_hub import InferenceClient
from dotenv import load_dotenv

# 1. Load your HF token from .env
load_dotenv()

# 2. Instantiate the Hugging Face Inference client once
client = InferenceClient(
    provider="auto",
    api_key=os.environ["HUGGINGFACEHUB_API_TOKEN"]
)

# 3. Streamlit page config
st.set_page_config(page_title="Educational Chatbot", layout="wide")
st.title("🎓 Educational Chatbot")

# 4. Initialize chat history in session state
if "history" not in st.session_state:
    # history is a list of (sender, message) tuples
    st.session_state.history = []

def build_messages():
    """
    Convert session_state.history into the list of {"role", "content"} dicts
    that the Hugging Face chat API expects.
    """
    msgs = []
    for sender, text in st.session_state.history:
        role = "user" if sender == "You" else "assistant"
        msgs.append({"role": role, "content": text})
    return msgs

# 5. Render the existing chat as chat bubbles
for sender, text in st.session_state.history:
    if sender == "You":
        st.chat_message("user").write(text)
    else:
        st.chat_message("assistant").write(text)

# 6. Get new user input
user_input = st.chat_input("Ask me anything…")

if user_input:
    # 7. Immediately record & display the user message
    st.session_state.history.append(("You", user_input))
    st.chat_message("user").write(user_input)

    # 8. Show a placeholder for the assistant response
    placeholder = st.chat_message("assistant")
    placeholder.write("⏳ Thinking...")

    # 9. Build the full message history to send
    full_messages = build_messages()

    # 10. Call the HF Inference API with the full conversation
    try:
        completion = client.chat.completions.create(
            model="deepseek-ai/DeepSeek-R1",
            messages=full_messages,
        )
        reply = completion.choices[0].message["content"]
    except Exception as e:
        reply = f"❌ API Error: {e}"

    # 11. Update the placeholder and session history
    placeholder.write(reply)
    st.session_state.history.append(("Bot", reply))