import streamlit as st
import requests
from bs4 import BeautifulSoup
import pandas as pd
import re
from urllib.parse import urljoin

HEADERS = {"User-Agent": "Mozilla/5.0"}


# -------------------------------
# FETCH PAGE
# -------------------------------
def fetch_page(url):
    try:
        response = requests.get(url, headers=HEADERS, timeout=10)
        return BeautifulSoup(response.text, "html.parser")
    except:
        return None


# -------------------------------
# EXTRACT FROM BLOCKS (MAIN LOGIC)
# -------------------------------
def extract_from_blocks(soup):
    blocks = soup.find_all(["p", "div", "li"])
    data = []

    for block in blocks:
        text = block.get_text(" ", strip=True)

        # Email detection
        email_match = re.search(
            r"[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}", text
        )

        if email_match:
            email = email_match.group()

            # Name guess
            words = text.split()
            name = " ".join(words[:3]) if len(words) >= 3 else "Unknown"

            # Phone
            phone_match = re.search(r"\+?\d[\d\s\-]{8,15}", text)
            phone = phone_match.group() if phone_match else "Not Available"

            data.append([name, email, phone])

    return data


# -------------------------------
# TRY TO FIND PROFILE LINKS
# -------------------------------
def get_profile_links(soup, base_url):
    links = set()

    for a in soup.find_all("a", href=True):
        href = a["href"]
        full = urljoin(base_url, href)

        keywords = ["faculty", "profile", "staff", "person", "people"]
        if any(k in full.lower() for k in keywords):
            links.add(full)

    return list(links)


# -------------------------------
# EXTRACT FROM PROFILE PAGE
# -------------------------------
def extract_from_profile(url):
    soup = fetch_page(url)
    if not soup:
        return None

    text = soup.get_text(" ", strip=True)

    # Name
    name = "Not Available"
    for tag in ["h1", "h2", "h3"]:
        t = soup.find(tag)
        if t:
            val = t.get_text(strip=True)
            if 2 < len(val) < 80:
                name = val
                break

    # Email
    email_match = re.search(
        r"[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}", text
    )
    email = email_match.group() if email_match else "Not Available"

    # Phone
    phone_match = re.search(r"\+?\d[\d\s\-]{8,15}", text)
    phone = phone_match.group() if phone_match else "Not Available"

    return [name, email, phone]


# -------------------------------
# MAIN SCRAPER FUNCTION
# -------------------------------
def scrape(url):
    soup = fetch_page(url)
    if not soup:
        return None, "❌ Failed to load page"

    # Method 1: Direct extraction
    data = extract_from_blocks(soup)

    # Method 2: Profile-based extraction (fallback)
    if not data:
        links = get_profile_links(soup, url)

        for link in links[:20]:  # limit for speed
            result = extract_from_profile(link)
            if result:
                data.append(result)

    if not data:
        return None, "❌ No data found (site may block scraping or use JavaScript)"

    df = pd.DataFrame(data, columns=["Name", "Email", "Phone"])
    df = df.drop_duplicates()

    return df, f"✅ Found {len(df)} records"


# -------------------------------
# STREAMLIT UI
# -------------------------------
st.set_page_config(page_title="Faculty Scraper", layout="wide")

st.title("🎓 Universal Faculty Scraper")
st.markdown("Paste a college faculty page URL and extract emails, names, and phone numbers.")

url = st.text_input("🔗 Enter Faculty Page URL")

if st.button("🚀 Scrape"):
    if not url:
        st.warning("Please enter a URL")
    else:
        with st.spinner("Scraping in progress..."):
            df, msg = scrape(url)

        if df is not None:
            st.success(msg)

            st.dataframe(df, use_container_width=True)

            csv = df.to_csv(index=False).encode("utf-8")

            st.download_button(
                label="📥 Download CSV",
                data=csv,
                file_name="faculty_data.csv",
                mime="text/csv",
            )
        else:
            st.error(msg)