import gradio as gr
import requests
from bs4 import BeautifulSoup
from urllib.parse import urlparse
import re
import matplotlib.pyplot as plt

def fetch_html(url):
    try:
        headers = {'User-Agent': 'Mozilla/5.0'}
        response = requests.get(url, timeout=10, headers=headers)
        response.raise_for_status()
        return response.text, ""
    except Exception as e:
        return None, f"❌ Error fetching the URL: {e}"

def seo_check(url):
    html, error = fetch_html(url)
    if error:
        return error, "", "", "", "", None

    soup = BeautifulSoup(html, 'html.parser')
    parsed = urlparse(url)

    checks = []

    def add_check(name, result, details, suggestion=""):
        checks.append((name, result, details.strip(), suggestion.strip()))

    # SEO Tests
    title = soup.title.string.strip() if soup.title and soup.title.string else ""
    add_check("Title Tag", "Passed" if title else "Failed",
              f"Found: {title}" if title else "Title tag missing.",
              "" if title else "Add a <title> tag with relevant keywords.")

    meta_desc = soup.find("meta", attrs={"name": "description"})
    meta_text = meta_desc.get("content", "").strip() if meta_desc else ""
    add_check("Meta Description", "Passed" if meta_text else "Warning",
              f"Found: {meta_text}" if meta_text else "No meta description found.",
              "Add a concise meta description (150-160 characters)." if not meta_text else "")

    h1 = soup.find("h1")
    h1_text = h1.get_text(strip=True) if h1 else ""
    add_check("H1 Tag", "Passed" if h1_text else "Failed",
              f"Found: {h1_text}" if h1_text else "No <h1> tag found.",
              "Include one <h1> tag per page.")

    h2_tags = soup.find_all("h2")
    add_check("H2 Tags", "Passed" if h2_tags else "Warning",
              f"Found {len(h2_tags)} <h2> tags." if h2_tags else "No <h2> tags found.",
              "Use <h2> tags to structure subheadings.")

    canonical = soup.find("link", rel="canonical")
    add_check("Canonical Tag", "Passed" if canonical else "Warning",
              f"Found: {canonical['href']}" if canonical and canonical.has_attr('href') else "No canonical tag found.",
              "Add a canonical tag to prevent duplicate content issues.")

    add_check("HTTPS", "Passed" if parsed.scheme == "https" else "Failed",
              f"URL uses {'HTTPS' if parsed.scheme == 'https' else 'HTTP'}.",
              "Use HTTPS for secure connections.")

    robots_url = f"{parsed.scheme}://{parsed.netloc}/robots.txt"
    try:
        robots_response = requests.get(robots_url, timeout=5)
        add_check("robots.txt", "Passed" if robots_response.status_code == 200 else "Warning",
                  "robots.txt is accessible." if robots_response.status_code == 200 else "robots.txt not found.",
                  "Create a robots.txt file to manage crawler access.")
    except:
        add_check("robots.txt", "Warning", "robots.txt could not be fetched.", "Ensure it's accessible.")

    sitemap_url = f"{parsed.scheme}://{parsed.netloc}/sitemap.xml"
    try:
        sitemap_response = requests.get(sitemap_url, timeout=5)
        add_check("sitemap.xml", "Passed" if sitemap_response.status_code == 200 else "Warning",
                  "sitemap.xml is accessible." if sitemap_response.status_code == 200 else "sitemap.xml not found.",
                  "Add a sitemap.xml to help search engines index your pages.")
    except:
        add_check("sitemap.xml", "Warning", "Could not access sitemap.xml.", "Ensure it's publicly accessible.")

    favicon = soup.find("link", rel=re.compile("icon", re.I))
    add_check("Favicon", "Passed" if favicon else "Warning",
              "Favicon found." if favicon else "No favicon detected.",
              "Add a favicon for branding and user experience.")

    charset = soup.find("meta", attrs={"charset": True})
    add_check("Charset", "Passed" if charset else "Warning",
              f"Found: {charset['charset']}" if charset else "No charset declared.",
              "Add a <meta charset='UTF-8'> to define character encoding.")

    lang_attr = soup.html.get("lang", "") if soup.html else ""
    add_check("Language Attribute", "Passed" if lang_attr else "Warning",
              f"Found: lang='{lang_attr}'" if lang_attr else "No lang attribute found in <html>.",
              "Set <html lang='en'> for proper language targeting.")

    viewport = soup.find("meta", attrs={"name": "viewport"})
    add_check("Mobile Viewport", "Passed" if viewport else "Warning",
              "Viewport tag present." if viewport else "No viewport meta tag found.",
              "Add <meta name='viewport' content='width=device-width, initial-scale=1.0'>.")

    ga_code = "google-analytics.com" in html or "gtag(" in html
    add_check("Google Analytics", "Passed" if ga_code else "Warning",
              "Google Analytics script detected." if ga_code else "No GA script found.",
              "Install GA script to track visitors.")

    og_tags = soup.find("meta", property="og:title")
    add_check("Open Graph Tags", "Passed" if og_tags else "Warning",
              "OG tags found." if og_tags else "No OG tags present.",
              "Add Open Graph meta tags to enhance social sharing.")

    twitter_card = soup.find("meta", attrs={"name": "twitter:card"})
    add_check("Twitter Card", "Passed" if twitter_card else "Warning",
              "Twitter Card tag present." if twitter_card else "No Twitter Card meta tag found.",
              "Add Twitter Card tags to improve tweet previews.")

    images = soup.find_all("img")
    alt_missing = sum(1 for img in images if not img.get("alt"))
    add_check("Image ALT Texts", "Passed" if alt_missing == 0 else "Warning",
              f"{len(images)} images found, {alt_missing} missing alt text.",
              "Add descriptive alt attributes to all images.")

    inline_styles = bool(soup.find(style=True))
    add_check("Inline Styles", "Warning" if inline_styles else "Passed",
              "Inline styles detected." if inline_styles else "No inline styles found.",
              "Move inline styles to external CSS.")

    font_tags = soup.find_all("font")
    add_check("Deprecated <font> Tags", "Warning" if font_tags else "Passed",
              f"Found {len(font_tags)} <font> tags." if font_tags else "No deprecated tags.",
              "Avoid deprecated tags like <font>, use CSS instead.")

    strong_tags = soup.find_all("strong") + soup.find_all("em")
    add_check("Semantic Emphasis Tags", "Passed" if strong_tags else "Warning",
              f"Found {len(strong_tags)} <strong>/<em> tags." if strong_tags else "No emphasis tags.",
              "Use <strong> and <em> to highlight important content.")

    noindex = soup.find("meta", attrs={"name": "robots", "content": re.compile("noindex", re.I)})
    add_check("Noindex Tag", "Warning" if noindex else "Passed",
              "Page marked noindex." if noindex else "No noindex tag found.",
              "Remove noindex to allow search indexing (if intentional).")

    ext_scripts = soup.find_all("script", src=True)
    ext_styles = soup.find_all("link", rel="stylesheet")
    add_check("External JS/CSS", "Passed" if len(ext_scripts) + len(ext_styles) <= 10 else "Warning",
              f"Found {len(ext_scripts)} JS and {len(ext_styles)} CSS includes.",
              "Reduce number of external scripts/styles for better performance.")

    social_links = [a['href'] for a in soup.find_all('a', href=True) if any(x in a['href'] for x in ['facebook', 'twitter', 'linkedin'])]
    add_check("Social Media Links", "Passed" if social_links else "Warning",
              f"Found links: {', '.join(social_links)}" if social_links else "No social media links found.",
              "Add links to your social profiles to build trust.")

    page_size = len(html.encode('utf-8'))
    add_check("Page Size", "Passed" if page_size < 250000 else "Warning",
              f"Page size: {page_size / 1024:.2f} KB.",
              "Keep HTML under 250KB for faster load times.")

    broken_links = []
    for a in soup.find_all('a', href=True):
        href = a['href']
        if href.startswith("http"):
            try:
                r = requests.head(href, timeout=5)
                if r.status_code >= 400:
                    broken_links.append(href)
            except:
                broken_links.append(href)

    add_check("Broken Links", "Passed" if not broken_links else "Failed",
              f"Broken links: {broken_links}" if broken_links else "No broken links found.",
              "Fix or remove broken links.")

    # Score Calculation
    total = len(checks)
    passed = sum(1 for _, r, _, _ in checks if r == "Passed")
    warning = sum(1 for _, r, _, _ in checks if r == "Warning")
    failed = sum(1 for _, r, _, _ in checks if r == "Failed")
    score = int((passed / total) * 100)

    report = ""
    for name, result, details, suggestion in checks:
        icon = {"Passed": "✅", "Warning": "⚠️", "Failed": "❌"}[result]
        report += f"{icon} {name} — {result}\n{details}\n"
        if suggestion:
            report += f"💡 {suggestion}\n"
        report += "\n"

    # Generate graph
    fig, ax = plt.subplots()
    ax.bar(["Passed", "Warnings", "Failed"], [passed, warning, failed], color=["green", "orange", "red"])
    ax.set_title(f"SEO Test Summary (Score: {score}/100)")
    ax.set_ylabel("Number of Checks")
    fig.tight_layout()

    return f"✅ SEO Score: {score}/100", f"{passed}", f"{warning}", f"{failed}", fig, report.strip()

# Gradio Interface
interface = gr.Interface(
    fn=seo_check,
    inputs=gr.Textbox(label="Enter Website URL"),
    outputs=[
        gr.Textbox(label="SEO Score"),
        gr.Textbox(label="Passed Tests"),
        gr.Textbox(label="Warnings"),
        gr.Textbox(label="Failed Tests"),
        gr.Plot(label="SEO Score Graph"),
        gr.Textbox(label="Detailed Report", lines=60, max_lines=100, show_copy_button=True),
    ],
    title="🔍 Advanced SEO Checker",
    description="Checks 25 SEO parameters and gives detailed results, solutions, and a score graph. Built with ❤️ using Gradio."
)

if __name__ == "__main__":
    interface.launch()