app.py

import os
import streamlit as st
st.set_page_config(page_title="Medical Assistant AI", page_icon="🩺")

from langchain_huggingface import HuggingFaceEndpoint, ChatHuggingFace
from langchain_core.messages import SystemMessage, HumanMessage, AIMessage

# ✅ Load Hugging Face token securely
hf_token = os.getenv("hf")
os.environ["HUGGINGFACEHUB_API_TOKEN"] = hf_token

# ✅ Custom CSS styling
st.markdown("""
    <style>
    body {
        background-image: url('https://images.unsplash.com/photo-1588776814546-bb1a479f4c25');
        background-size: cover;
        background-attachment: fixed;
    }
    .main {
        background-color: rgba(255, 255, 255, 0.9);
        padding: 2rem;
        border-radius: 20px;
    }
    .stTextInput>div>div>input {
        background-color: #ffffffcc;
        padding: 12px;
        border-radius: 8px;
        border: 1px solid #ccc;
    }
    .chat-bubble-user {
        background-color: #DCF8C6;
        padding: 10px 15px;
        margin: 10px 0;
        border-radius: 10px;
        max-width: 80%;
        margin-left: auto;
        text-align: right;
    }
    .chat-bubble-ai {
        background-color: #F1F0F0;
        padding: 10px 15px;
        margin: 10px 0;
        border-radius: 10px;
        max-width: 80%;
        text-align: left;
    }
    </style>
""", unsafe_allow_html=True)

# ✅ Initialize model
llama_endpoint = HuggingFaceEndpoint(
    repo_id="meta-llama/Llama-3.1-8B-Instruct",
    provider="novita",
    temperature=0.8,
    max_new_tokens=256,
    task="conversational"
)

llama_model = ChatHuggingFace(
    llm=llama_endpoint,
    repo_id="meta-llama/Llama-3.1-8B-Instruct",
    provider="novita",
    temperature=0.8,
    max_new_tokens=256,
    task="conversational"
)

# ✅ Streamlit Interface

st.markdown('<div class="main">', unsafe_allow_html=True)
st.title("🩺 Medical Assistant (LLaMA 3.1)")
st.markdown("Ask your medical queries below and get AI-powered advice.")

# ✅ Conversation memory
if "messages" not in st.session_state:
    st.session_state.messages = [
        SystemMessage(content="You are a highly experienced and qualified medical assistant with 10 years of experience in a busy family practice clinic. You are known for your professionalism, empathy, attention to detail, and ability to anticipate the needs of both patients and the doctor.")
    ]

# ✅ Input Box
user_input = st.text_input("💬 You:", placeholder="E.g. What is paracetamol?", key="input")

# ✅ Handle Input
if user_input:
    st.session_state.messages.append(HumanMessage(content=user_input))
    with st.spinner("💡 Thinking..."):
        response = llama_model.invoke(st.session_state.messages)
    st.session_state.messages.append(AIMessage(content=response.content))

# ✅ Display Chat History
for msg in st.session_state.messages[1:]:
    if isinstance(msg, HumanMessage):
        st.markdown(f'<div class="chat-bubble-user">🧑‍⚕️ {msg.content}</div>', unsafe_allow_html=True)
    elif isinstance(msg, AIMessage):
        st.markdown(f'<div class="chat-bubble-ai">🤖 {msg.content}</div>', unsafe_allow_html=True)

st.markdown('</div>', unsafe_allow_html=True)