class ImageAnalyzer:
    def analyze_site(self, site_data):
        """
        Analyzes the crawled site data for missing ALT text.
        :param site_data: Dict { page_url: [image_dicts] }
        :return: Dict containing summary and detailed report.
        """
        total_images = 0
        total_missing_alt = 0
        pages_report = []

        for page_url, images in site_data.items():
            missing_images = []
            for img in images:
                total_images += 1
                alt_text = img.get('alt')
                
                # Check for strictly missing alt text (None or empty string)
                if not alt_text or alt_text.strip() == "":
                    # Double check if 'alt' attribute existed but was empty vs didn't exist?
                    # The crawler uses .get('alt', '') so it's '' if missing.
                    # User asked for "missing alt text".
                    # We will count empty string as missing alt text for SEO purposes.
                    missing_images.append(img['src'])
                    total_missing_alt += 1
            
            pages_report.append({
                "page_url": page_url,
                "missing_alt_count": len(missing_images),
                "images_without_alt": list(set(missing_images))
            })

        return {
            "summary": {
                "total_pages_scanned": len(site_data),
                "total_images_found": total_images,
                "total_images_missing_alt": total_missing_alt
            },
            "details": pages_report
        }