import streamlit as st
import os
from langchain_huggingface import HuggingFaceEndpoint, ChatHuggingFace
from langchain_core.messages import HumanMessage, SystemMessage

# Set environment variables for Hugging Face token
hf = os.getenv('Data_science')
os.environ['HUGGINGFACEHUB_API_TOKEN'] = hf
os.environ['HF_TOKEN'] = hf

# Page config
st.set_page_config(page_title="🧠 Deep Learning Mentor Chat", page_icon="🔬", layout="centered")

# Inject Custom CSS Styling
st.markdown("""
    <style>
    .main {
        background: linear-gradient(135deg, #1d2671 0%, #c33764 100%);
        padding: 2rem;
        font-family: 'Segoe UI', sans-serif;
    }
    h1, h2, h3, h4, h5, h6, p, label, .css-10trblm, .css-q8sbsg {
        color: #ffffff !important;
        text-align: center;
    }
    .stTextInput>div>div>input {
        background-color: rgba(255, 255, 255, 0.1);
        color: white;
        border: 1px solid rgba(255, 255, 255, 0.5);
        border-radius: 8px;
        padding: 0.6em;
    }
    .stTextInput>div>div>input::placeholder {
        color: rgba(255, 255, 255, 0.6);
    }
    .stButton>button {
        background: rgba(255, 255, 255, 0.15);
        border: 2px solid rgba(255, 255, 255, 0.4);
        color: white;
        font-size: 18px;
        font-weight: bold;
        padding: 0.8em 1.2em;
        border-radius: 12px;
        width: 100%;
        transition: all 0.3s ease;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
    }
    .stButton>button:hover {
        background: rgba(255, 255, 255, 0.3);
        border-color: white;
        color: white;
    }
    .stSidebar > div:first-child {
        background: #2c3e50;
        padding: 1rem;
        border-radius: 0 15px 15px 0;
    }
    .stSidebar h1, .stSidebar h2, .stSidebar h3, .stSidebar label, .stSidebar p {
        color: white !important;
    }
    hr {
        border: 1px solid rgba(255, 255, 255, 0.3);
        margin: 2em 0;
    }
    </style>
""", unsafe_allow_html=True)

# --- Title ---
st.title("🧠 Deep Learning Mentor Chat")
st.markdown("### 💡 Ask questions on neural networks, architectures, optimization, and more!")

# --- Sidebar: Experience Level ---
st.sidebar.title("🧑‍🏫 Mentor Preferences")
exp = st.sidebar.selectbox("🎓 Choose your experience level:", ['Beginner', 'Intermediate', 'Expert'])

# --- Load Deep Learning Model ---
mentor_llm = HuggingFaceEndpoint(
    repo_id='Qwen/Qwen3-32B',
    provider='sambanova',
    temperature=0.7,
    max_new_tokens=150,
    task='conversational'
)

deep_mentor = ChatHuggingFace(
    llm=mentor_llm,
    repo_id='Qwen/Qwen3-32B',
    provider='sambanova',
    temperature=0.7,
    max_new_tokens=150,
    task='conversational'
)

# --- Session State Initialization ---
PAGE_KEY = "deep_learning_chat_history"
if PAGE_KEY not in st.session_state:
    st.session_state[PAGE_KEY] = []

# --- Chat Input Form ---
with st.form(key="chat_form"):
    user_input = st.text_input("🧠 Ask your Deep Learning question:", placeholder="e.g. What is the vanishing gradient problem?")
    submit = st.form_submit_button("🚀 Send")

# --- Handle Submission ---
if submit and user_input:
    system_prompt = (
        f"You are a deep learning mentor with {exp.lower()} level expertise. "
        f"Answer only deep learning-related questions in a friendly, concise manner. "
        f"Keep answers under 150 words. Politely decline non-DL topics."
    )
    messages = [SystemMessage(content=system_prompt), HumanMessage(content=user_input)]
    result = deep_mentor.invoke(messages)
    st.session_state[PAGE_KEY].append((user_input, result.content))

# --- Display Chat History ---
st.subheader("📜 Chat History")
for user, bot in st.session_state[PAGE_KEY]:
    st.markdown(f"**🧑 You:** {user}")
    st.markdown(f"**🤖 Mentor:** {bot}")
    st.markdown("---")