import streamlit as st
import requests
import json
import os

# CONFIG
# For Hugging Face Spaces (Same container)
BACKEND_URL = "http://127.0.0.1:8000/analyze"

st.set_page_config(page_title="Smart ATS", page_icon="🎯", layout="wide")

# CUSTOM CSS
st.markdown("""
<style>
    .metric-card {
        background-color: #f0f2f6;
        padding: 20px;
        border-radius: 10px;
        border-left: 5px solid #4CAF50;
    }
    .skill-tag {
        display: inline-block;
        padding: 5px 10px;
        margin: 2px;
        border-radius: 12px;
        font-size: 12px;
        font-weight: bold;
    }
    .match { background-color: #d4edda; color: #155724; border: 1px solid #c3e6cb; }
    .missing { background-color: #f8d7da; color: #721c24; border: 1px solid #f5c6cb; }
</style>
""", unsafe_allow_html=True)

st.title("🎯 AI Smart Resume Screen")
st.markdown("Compare resumes against job descriptions to find the perfect fit.")

# LAYOUT: Two columns for input
col1, col2 = st.columns([1, 1])

with col1:
    st.subheader("1. Job Description (Optional)")
    jd_input = st.text_area("Paste the Job Description here...", height=200, 
                           placeholder="e.g. Seeking a Senior Python Developer with AWS experience...")

with col2:
    st.subheader("2. Candidate Resume")
    uploaded_file = st.file_uploader("Upload PDF", type="pdf")

# ACTION
if st.button("Analyze Fit", type="primary"):
    if not uploaded_file:
        st.warning("Please upload a resume first.")
    else:
        with st.spinner("Analyzing candidate against requirements..."):
            try:
                # Prepare Payload
                files = {"file": (uploaded_file.name, uploaded_file.getvalue(), "application/pdf")}
                data = {"job_description": jd_input} if jd_input else {}
                
                response = requests.post(BACKEND_URL, files=files, data=data, timeout=60)
                
                if response.status_code == 200:
                    result = response.json()
                    
                    if "error" in result:
                        st.error(result["error"])
                    else:
                        # --- DASHBOARD UI ---
                        candidate = result.get("candidate", {})
                        analysis = result.get("match_analysis", {})
                        
                        # 1. Header (Candidate Info)
                        st.divider()
                        c1, c2, c3, c4 = st.columns(4)
                        c1.markdown(f"**Name:** {candidate.get('name', 'N/A')}")
                        c2.markdown(f"**Email:** {candidate.get('email', 'N/A')}")
                        c3.markdown(f"**Phone:** {candidate.get('phone', 'N/A')}")
                        
                        # 2. Score Section (Only if JD provided)
                        if jd_input:
                            score = analysis.get("score", 0)
                            verdict = analysis.get("verdict", "N/A")
                            
                            # Color coding the score
                            score_color = "green" if score >= 80 else "orange" if score >= 50 else "red"
                            
                            st.markdown(f"""
                            <div class="metric-card">
                                <h3 style="margin:0">Match Score: <span style="color:{score_color}">{score}%</span></h3>
                                <p style="margin:0"><strong>Verdict:</strong> {verdict}</p>
                                <p style="margin-top:10px"><em>"{analysis.get('reasoning', '')}"</em></p>
                            </div>
                            """, unsafe_allow_html=True)
                            
                            st.markdown("### 🧩 Skill Gap Analysis")
                            k1, k2 = st.columns(2)
                            
                            with k1:
                                st.success("✅ Matching Skills")
                                matches = analysis.get("matching_skills", [])
                                if matches:
                                    html = "".join([f'<span class="skill-tag match">{s}</span>' for s in matches])
                                    st.markdown(html, unsafe_allow_html=True)
                                else:
                                    st.write("No direct skill matches found.")

                            with k2:
                                st.error("⚠️ Missing / To Improve")
                                missing = analysis.get("missing_skills", [])
                                if missing:
                                    html = "".join([f'<span class="skill-tag missing">{s}</span>' for s in missing])
                                    st.markdown(html, unsafe_allow_html=True)
                                else:
                                    st.write("No major skills missing!")
                                    
                        else:
                            # Standard Extraction View (No JD)
                            st.info("💡 Paste a Job Description on the left to see a Match Score!")
                            st.markdown("### 🛠 Skills Detected")
                            st.write(", ".join(candidate.get("skills", [])))

                        with st.expander("View Raw JSON Data"):
                            st.json(result)

                else:
                    st.error(f"Server Error: {response.text}")
                    
            except Exception as e:
                st.error(f"Connection Error: {e}")