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('HF_TOKEN')
os.environ['HUGGINGFACEHUB_API_TOKEN'] = hf
os.environ['HF_TOKEN'] = hf

# Page config
st.set_page_config(page_title="Deep Learning Mentor Chat", layout="centered")
st.markdown("""
    <style>
    body {
        background-color: #1e1e2f;
        font-family: 'Segoe UI', sans-serif;
    }

    .main {
        background: linear-gradient(to right,#3e32a8, #80ffe0);
        padding: 2rem;
        border-radius: 12px;
    }

    h1, h2, h3, p, label {
        color: white !important;
        text-align: center;
    }

    .stTextInput>div>div>input {
        border: 1px solid #ddd;
        border-radius: 10px;
        padding: 0.5rem;
        font-size: 16px;
        width: 100%;
    }

    .stButton>button {
        background-color: #6a00ff;
        color: white;
        padding: 0.6rem 1.2rem;
        font-size: 16px;
        font-weight: 600;
        border: None;
        border-radius: 10px;
        transition: all 0.3s ease;
    }

    .stButton>button:hover {
        background-color: #5300e8;
        color: white;
        border-color: #fff;
    }

    .chat-box {
        background-color: #ffffff15;
        border-radius: 12px;
        padding: 1rem;
        margin-bottom: 1rem;
        color: white;
        line-height: 1.6;
    }

    .user-msg {
        color: #e0e0e0;
        font-weight: 600;
    }

    .bot-msg {
        color: #ffffff;
        margin-top: 0.3rem;
    }

    .chat-container {
        display: flex;
        flex-direction: column;
        gap: 0.5rem;
        margin-top: 2rem;
    }

    .chat-bubble-user {
        background-color: #ffffff25;
        padding: 0.75rem 1rem;
        border-radius: 1rem;
        margin-bottom: 0.5rem;
        color: #fff;
        font-weight: 500;
        text-align: left;
        width: fit-content;
        max-width: 90%;
        align-self: flex-end;
    }

    .chat-bubble-bot {
        background-color: #ffffff15;
        padding: 0.75rem 1rem;
        border-radius: 1rem;
        margin-bottom: 0.5rem;
        color: #fff;
        text-align: left;
        width: fit-content;
        max-width: 90%;
        align-self: flex-start;
    }

    hr {
        border: 0;
        height: 1px;
        background: #ffffff30;
        margin: 1.5rem 0;
    }
    </style>
""", unsafe_allow_html=True)

st.markdown("<h1>🤖 Deep Learning Mentor Chat</h1>", unsafe_allow_html=True)
st.markdown("<p>Learn Deep Learning with personalized AI mentorship</p>", unsafe_allow_html=True)

# Sidebar for experience level
st.sidebar.title("🎓 Select Your Level")
exp = st.sidebar.selectbox("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)

# Session key for conversation
PAGE_KEY = "deep_learning_chat_history"
if PAGE_KEY not in st.session_state:
    st.session_state[PAGE_KEY] = []

# Chat input form
st.markdown("<hr>", unsafe_allow_html=True)
with st.form(key="chat_form"):
    user_input = st.text_input("💬 Ask your deep learning question:")
    submit = st.form_submit_button("Send")

# Handle chat submission
if submit and user_input:
    system_prompt = f"""You are a knowledgeable Deep Learning mentor with {exp} years of practical experience. Your communication style is friendly, supportive, and focused. Please adhere to the following strict instructions:

    1. Only respond to queries that are specifically about deep learning programming — this includes related libraries, tools, and frameworks.
    2. If a question is outside the scope of deep learning, respond exactly with: "I specialize only in deep learning programming. This appears to be a non-deep learning topic."
    3. Do not offer help or advice on non-deep learning subjects.
    4. Aim for clarity and practical relevance in your explanations, keeping them beginner-friendly when needed.
    5. Reinforce learning through relevant code snippets and applied examples.
    6. For more advanced discussions, assume the learner has a working knowledge of deep learning fundamentals."""

    messages = [SystemMessage(content=system_prompt), HumanMessage(content=user_input)]
    result = deep_mentor.invoke(messages)
    st.session_state[PAGE_KEY].append((user_input, result.content))

# Chat history display with bubble styling
if st.session_state[PAGE_KEY]:
    st.markdown('<div class="chat-container">', unsafe_allow_html=True)
    for user, bot in st.session_state[PAGE_KEY]:
        st.markdown(f'<div class="chat-user">👤 <strong>You:</strong> {user}</div>', unsafe_allow_html=True)
        st.markdown(f'<div class="chat-bot">🧑‍🏫 <strong>Mentor:</strong> {bot}</div>', unsafe_allow_html=True)
    st.markdown('</div>', unsafe_allow_html=True)