import streamlit as st
import requests
import os
import re

GROQ_API_KEY = os.getenv("EngGlass_GroqAPI")
GROQ_API_URL = "https://api.groq.com/openai/v1/chat/completions"

if not GROQ_API_KEY:
    st.error("❌ API key not found. Please set 'EngGlass_GroqAPI' in Hugging Face repository secrets.")
    st.stop()

def generate_prompt(term):
    return f"""
You are engGlass, a friendly, knowledgeable AI tutor who specializes in explaining engineering terms in simple, structured, and accurate language. Your goal is to help beginners and non-specialists understand technical concepts clearly. Use real-world analogies where appropriate. Avoid jargon unless absolutely necessary—and if you must use a technical term, define it in plain English.

Explain the engineering term: {term}

Respond in the following structure:

1. **Definition:** One-sentence definition in plain English.  
2. **Brief Explanation:** 2–3 short paragraphs elaborating the concept.  
3. **Formula(s) (if any):** Include key formulas (use LaTeX format, like this: $$E = mc^2$$) and explain them simply.  
4. **Real-World Analogy:** A simple analogy that helps understand the concept.  
5. **Real-World Application:** A practical example of where this concept is applied.
"""

def get_explanation_from_groq(prompt):
    headers = {
        "Authorization": f"Bearer {GROQ_API_KEY}",
        "Content-Type": "application/json"
    }

    payload = {
        "model": "llama-3.3-70b-versatile",
        "messages": [
            {"role": "system", "content": "You are engGlass, a helpful AI tutor."},
            {"role": "user", "content": prompt}
        ],
        "temperature": 0.5,
        "max_tokens": 1024
    }

    response = requests.post(GROQ_API_URL, headers=headers, json=payload)
    if response.status_code != 200:
        st.error(f"❌ Groq API returned {response.status_code}: {response.text}")
        st.stop()
    return response.json()["choices"][0]["message"]["content"]

def extract_latex(text):
    return re.findall(r"\$\$(.+?)\$\$", text, re.DOTALL)

def render_explanation(term, explanation):
    latex_formulas = extract_latex(explanation)
    text_without_latex = re.sub(r"\$\$(.+?)\$\$", "", explanation, flags=re.DOTALL)

    # Layout: Two columns
    col1, col2 = st.columns([2, 1])

    with col1:
        st.markdown(text_without_latex.strip())
        if latex_formulas:
            st.markdown("### 🧮 Formula(s):")
            for formula in latex_formulas:
                st.latex(formula.strip())

    with col2:
        st.markdown("### 🖼️ Illustration")
        # Image placeholder — you can plug in your own API or static images
        st.image("https://placehold.co/300x200?text=Diagram+of+" + term.replace(" ", "+"))

    st.download_button(
        label="📥 Download Explanation",
        data=explanation,
        file_name=f"{term.strip().replace(' ', '_')}_explanation.txt",
        mime="text/plain"
    )

# Streamlit UI
st.set_page_config(page_title="engGlass - Engineering Terms Explained", layout="centered")
st.title("📘 engGlass")
st.markdown("### 🔍 Learn Engineering Visually\nUnderstand technical terms with clarity, context, and illustrations.")

user_input = st.text_input("Enter an engineering term:", placeholder="e.g., Fluid Dynamics")

if st.button("Explain") and user_input.strip():
    with st.spinner("Generating explanation and illustration..."):
        try:
            prompt = generate_prompt(user_input.strip())
            output = get_explanation_from_groq(prompt)
            render_explanation(user_input.strip(), output)
        except Exception as e:
            st.error(f"❌ Error: {str(e)}")

st.markdown("---")
st.caption("Built with ❤️ using Groq + Streamlit")