import streamlit as st
import pandas as pd
import re
import time

from selenium import webdriver
from selenium.webdriver.chrome.options import Options
from bs4 import BeautifulSoup

st.set_page_config(page_title="Faculty Scraper", layout="wide")
st.title("🎓 Universal Faculty Scraper (Clean + Smart)")

EMAIL_REGEX = r"[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}"

# -------- DRIVER --------
def get_driver():
    options = Options()
    options.binary_location = "/usr/bin/chromium"

    options.add_argument("--headless")
    options.add_argument("--no-sandbox")
    options.add_argument("--disable-dev-shm-usage")

    driver = webdriver.Chrome(options=options)
    return driver


# -------- NAME CLEANING --------
def name_from_email(email):
    name_part = email.split("@")[0]

    # Replace separators
    name_part = re.sub(r"[._]", " ", name_part)

    # Split camel case
    name_part = re.sub(r'([a-z])([A-Z])', r'\1 \2', name_part)

    # Remove numbers
    name_part = re.sub(r'\d+', '', name_part)

    words = name_part.split()

    return " ".join([w.capitalize() for w in words if len(w) > 1])


# -------- PHONE CLEANING --------
def clean_phone(text):
    phones = re.findall(r"\+?\d[\d\s\-]{8,15}", text)

    for p in phones:
        p_clean = p.replace(" ", "")

        # Reject year-like values
        if re.search(r"\d{4}-\d{2}", p_clean):
            continue

        digits = re.sub(r"\D", "", p_clean)

        # Accept only realistic phone lengths
        if 10 <= len(digits) <= 13:
            return p_clean

    return "Not Available"


# -------- MAIN SCRAPER --------
def scrape_faculty(url):
    driver = get_driver()
    driver.get(url)

    time.sleep(5)

    soup = BeautifulSoup(driver.page_source, "html.parser")
    driver.quit()

    data = []

    blocks = soup.find_all(["tr", "div", "li", "section"])

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

        if len(text) < 20:
            continue

        # -------- EMAIL --------
        email_match = re.search(EMAIL_REGEX, text)
        if not email_match:
            mail = block.find("a", href=re.compile("mailto:", re.I))
            if mail:
                email = mail.get("href").replace("mailto:", "").strip()
            else:
                continue
        else:
            email = email_match.group()

        # -------- NAME --------
        name = None

        # Try headings
        h = block.find(["h1", "h2", "h3", "h4", "strong", "b"])
        if h:
            name = h.get_text(strip=True)

        # Fallback
        if not name or len(name) < 3:
            name = name_from_email(email)

        # -------- PHONE --------
        phone = clean_phone(text)

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

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

    # -------- REMOVE DUPLICATES --------
    df = df.drop_duplicates(subset=["Email"])

    return df


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

if st.button("🚀 Scrape Data"):
    if not url:
        st.warning("Please enter a URL")
    else:
        with st.spinner("Scraping intelligently..."):
            df = scrape_faculty(url)

        if not df.empty:
            st.success("✅ Data Extracted Successfully")

            st.dataframe(df, use_container_width=True)

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

            st.download_button(
                "📥 Download CSV",
                csv,
                "faculty_data.csv",
                "text/csv"
            )
        else:
            st.error("❌ No data found")