import requests
from bs4 import BeautifulSoup
from urllib.parse import urlparse, urljoin
import gradio as gr

def seo_check(url):
    report = []
    suggestions = []

    # Ensure HTTPS
    if not url.startswith("http"):
        url = "https://" + url

    try:
        response = requests.get(url, timeout=10)
        response.raise_for_status()
        html = response.text
    except Exception as e:
        return f"❌ Error accessing URL: {e}", ""

    soup = BeautifulSoup(html, "html.parser")

    # Title Tag
    title = soup.title.string.strip() if soup.title else ""
    if not title:
        report.append("❌ Missing <title> tag.")
        suggestions.append("Add a <title> tag that describes your page in 50–60 characters.")
    elif len(title) > 70:
        report.append("⚠️ Title is too long.")
        suggestions.append("Keep title under 70 characters.")

    # Meta Description
    desc_tag = soup.find("meta", attrs={"name": "description"})
    desc = desc_tag["content"].strip() if desc_tag and desc_tag.get("content") else ""
    if not desc:
        report.append("❌ Missing meta description.")
        suggestions.append("Add a <meta name='description'> summarizing the page.")
    elif len(desc) > 160:
        report.append("⚠️ Meta description is too long.")
        suggestions.append("Keep meta descriptions under 160 characters.")

    # Canonical Tag
    canonical = soup.find("link", rel="canonical")
    if not canonical:
        report.append("❌ Missing canonical link.")
        suggestions.append("Add a <link rel='canonical'> to avoid duplicate content.")

    # H1 Tag
    h1_tags = soup.find_all("h1")
    if len(h1_tags) != 1:
        report.append(f"⚠️ Found {len(h1_tags)} <h1> tags.")
        suggestions.append("Use exactly one <h1> tag for SEO clarity.")

    # Mobile viewport
    viewport = soup.find("meta", attrs={"name": "viewport"})
    if not viewport:
        report.append("⚠️ No viewport meta tag.")
        suggestions.append("Add a viewport meta tag for mobile responsiveness.")

    # HTTPS check
    if not url.startswith("https://"):
        report.append("⚠️ URL is not secure (no HTTPS).")
        suggestions.append("Install SSL and redirect HTTP to HTTPS.")

    # Robots.txt and sitemap.xml
    parsed = urlparse(url)
    base = f"{parsed.scheme}://{parsed.netloc}"
    robots_url = urljoin(base, "/robots.txt")
    sitemap_url = urljoin(base, "/sitemap.xml")
    try:
        r1 = requests.get(robots_url)
        if r1.status_code != 200:
            report.append("❌ robots.txt not found.")
            suggestions.append("Create a robots.txt to guide search bots.")
    except:
        report.append("❌ Could not access robots.txt.")

    try:
        r2 = requests.get(sitemap_url)
        if r2.status_code != 200:
            report.append("❌ sitemap.xml not found.")
            suggestions.append("Add sitemap.xml for better crawling.")
    except:
        report.append("❌ Could not access sitemap.xml.")

    # Open Graph Tags
    og_title = soup.find("meta", property="og:title")
    if not og_title:
        report.append("⚠️ Missing Open Graph (og:title).")
        suggestions.append("Add OG tags to improve sharing on social media.")

    # Image alt text
    images = soup.find_all("img")
    alt_missing = [img for img in images if not img.get("alt")]
    if alt_missing:
        report.append(f"⚠️ {len(alt_missing)} images missing alt text.")
        suggestions.append("Add descriptive alt attributes to all images.")

    # Internal and external links
    links = soup.find_all("a", href=True)
    internal = 0
    external = 0
    for link in links:
        href = link['href']
        if parsed.netloc in href:
            internal += 1
        elif href.startswith("http"):
            external += 1
    report.append(f"ℹ️ Internal Links: {internal} | External Links: {external}")
    suggestions.append("Ensure most important links are internal. Check broken links.")

    # Keyword density (basic)
    body_text = soup.get_text().lower()
    words = body_text.split()
    word_count = len(words)
    keyword = parsed.netloc.replace("www.", "").split(".")[0]
    keyword_freq = words.count(keyword)
    density = (keyword_freq / word_count) * 100 if word_count else 0
    report.append(f"ℹ️ Keyword '{keyword}' appears {keyword_freq} times ({density:.2f}% density)")
    if density < 0.5:
        suggestions.append("Consider using your main keyword more often (target 1–2%).")

    return "\n".join(report), "\n".join(suggestions)

# Gradio UI
gr.Interface(
    fn=seo_check,
    inputs=gr.Textbox(label="Enter Website URL"),
    outputs=[
        gr.Textbox(label="SEO Report", lines=15),
        gr.Textbox(label="Suggestions & Fixes", lines=15)
    ],
    title="SEO Website Checker",
    description="Analyze your website's SEO like Sitechecker.pro & SEOSiteCheckup, with clear solutions!"
).launch()