<?php
/**
 * Plugin Name: Loksifu Security and Performance
 * Description: Security headers, WP version removal, image lazy loading
 * Version: 1.0
 */

// Security headers
add_action('send_headers', 'loksifu_sec_headers');
function loksifu_sec_headers() {
    header('Strict-Transport-Security: max-age=31536000; includeSubDomains');
    header('X-Content-Type-Options: nosniff');
    header('X-Frame-Options: SAMEORIGIN');
    header('Referrer-Policy: strict-origin-when-cross-origin');
    header('X-XSS-Protection: 1; mode=block');
}

// Cache-Control for static assets
add_action('send_headers', 'loksifu_cache_headers');
function loksifu_cache_headers() {
    header('Cache-Control: public, max-age=3600');
}

// Remove WordPress version generator tag
remove_action('wp_head', 'wp_generator');

// Force lazy loading on images that don't have it
add_filter('wp_content_img_tag', 'loksifu_img_lazy', 10, 3);
function loksifu_img_lazy($img, $context, $attachment_id) {
    if (strpos($img, 'loading=') === false) {
        $img = str_replace('<img ', '<img loading="lazy" ', $img);
    }
    return $img;
}

// Also add lazy loading to post thumbnails
add_filter('post_thumbnail_html', 'loksifu_thumb_lazy', 10);
function loksifu_thumb_lazy($html) {
    if (strpos($html, 'loading=') === false) {
        $html = str_replace('<img ', '<img loading="lazy" ', $html);
    }
    return $html;
}
<?php
/**
 * Plugin Name: Loksifu SEO and Optimization
 * Description: SEO meta tags, OG tags, schema, and performance tweaks
 * Version: 1.0
 */

// Remove jQuery Migrate
add_action('wp_default_scripts', function($scripts) {
    if (!is_admin() && isset($scripts->registered['jquery'])) {
        $script = $scripts->registered['jquery'];
        if ($script->deps) {
            $script->deps = array_diff($script->deps, ['jquery-migrate']);
        }
    }
});

// Meta description
add_action('wp_head', 'loksifu_meta_desc', 1);
function loksifu_meta_desc() {
    if (is_front_page() || is_home()) {
        $desc = "駱法丹風水命理，香港專業風水玄學服務。提供種生基、家居風水、陰宅風水、辦公室風水、起名改名、六壬神功、和合、嬰靈超渡、擇日、紫微斗數及生肖運程等服務。";
    } elseif (is_single() || is_page()) {
        $excerpt = get_the_excerpt();
        $desc = $excerpt ? wp_strip_all_tags($excerpt) : wp_trim_words(wp_strip_all_tags(get_the_content()), 30);
    } elseif (is_category()) {
        $desc = single_cat_title('', false) . " - 駱法丹風水命理相關文章合集。";
    } else {
        $desc = "駱法丹風水命理，香港專業風水玄學服務。";
    }
    $desc = mb_substr($desc, 0, 160);
    if ($desc) {
        echo '<meta name="description" content="' . esc_attr($desc) . '">' . "
";
    }
}

// Open Graph tags
add_action('wp_head', 'loksifu_og', 2);
function loksifu_og() {
    echo '<meta property="og:locale" content="zh_HK">' . "
";
    echo '<meta property="og:site_name" content="駱法丹風水山堂">' . "
";
    if (is_front_page() || is_home()) {
        echo '<meta property="og:type" content="website">' . "
";
        echo '<meta property="og:title" content="駱法丹風水命理 | 香港專業風水玄學服務">' . "
";
        echo '<meta property="og:description" content="駱法丹風水命理，香港專業風水玄學服務。提供種生基、家居風水、陰宅風水、辦公室風水、起名改名等服務。">' . "
";
        echo '<meta property="og:url" content="' . esc_url(home_url('/')) . '">' . "
";
    } elseif (is_single() || is_page()) {
        echo '<meta property="og:type" content="article">' . "
";
        echo '<meta property="og:title" content="' . esc_attr(get_the_title()) . '">' . "
";
        echo '<meta property="og:url" content="' . esc_url(get_permalink()) . '">' . "
";
        if (has_post_thumbnail()) {
            echo '<meta property="og:image" content="' . esc_url(get_the_post_thumbnail_url(null, 'full')) . '">' . "
";
        }
    }
}

// Twitter cards
add_action('wp_head', 'loksifu_twitter', 3);
function loksifu_twitter() {
    echo '<meta name="twitter:card" content="summary_large_image">' . "
";
}

// Canonical URL
add_action('wp_head', 'loksifu_canonical', 4);
function loksifu_canonical() {
    if (is_front_page() || is_home()) {
        echo '<link rel="canonical" href="' . esc_url(home_url('/')) . '">' . "
";
    } elseif (is_single() || is_page()) {
        echo '<link rel="canonical" href="' . esc_url(get_permalink()) . '">' . "
";
    }
}

// JSON-LD structured data
add_action('wp_head', 'loksifu_schema', 5);
function loksifu_schema() {
    if (is_front_page() || is_home()) {
        $data = array(
            '@context' => 'https://schema.org',
            '@type' => 'ProfessionalService',
            'name' => "駱法丹風水山堂",
            'description' => "香港專業風水玄學服務，提供種生基、家居風水、陰宅風水、辦公室風水、起名改名、六壬神功等服務。",
            'url' => home_url('/'),
            'address' => array(
                '@type' => 'PostalAddress',
                'addressCountry' => 'HK'
            )
        );
        echo '<script type="application/ld+json">' . json_encode($data, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES) . '</script>' . "
";
    }
}

// BreadcrumbList for single posts
add_action('wp_head', 'loksifu_breadcrumb', 6);
function loksifu_breadcrumb() {
    if (is_single()) {
        global $post;
        $cat = get_the_category($post->ID);
        $items = array(
            array('@type' => 'ListItem', 'position' => 1, 'name' => "首頁", 'item' => home_url('/'))
        );
        if (!empty($cat)) {
            $items[] = array('@type' => 'ListItem', 'position' => 2, 'name' => $cat[0]->name, 'item' => get_category_link($cat[0]->term_id));
        }
        $items[] = array('@type' => 'ListItem', 'position' => count($items) + 1, 'name' => get_the_title());
        $schema = array('@context' => 'https://schema.org', '@type' => 'BreadcrumbList', 'itemListElement' => $items);
        echo '<script type="application/ld+json">' . json_encode($schema, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES) . '</script>' . "
";
    }
}

// Homepage title filter
add_filter('pre_get_document_title', 'loksifu_title', 20);
function loksifu_title($title) {
    if (is_front_page() || is_home()) {
        return "駱法丹風水命理 | 香港專業風水玄學服務";
    }
    return $title;
}

// H1 fix - add screen-reader-text H1 for homepage when custom logo hides it
add_action('wp_head', 'loksifu_h1_fix', 0);
function loksifu_h1_fix() {
    if ((is_front_page() || is_home())) {
        echo '<h1 class="screen-reader-text">駱法丹風水命理 | 香港專業風水玄學服務</h1>' . "
";
    }
}


// Auto alt text via output buffering
add_action('template_redirect', 'loksifu_alt_buffer_start');
function loksifu_alt_buffer_start() {
    ob_start('loksifu_alt_buffer_callback');
}
function loksifu_alt_buffer_callback() {
     = esc_attr(get_bloginfo('name'));
     = preg_replace('/ alt=""/', ' alt="' .  . '"', );
    return ;
}
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /www/wwwroot/www.loksifu.cn/wp-content/plugins/loksifu-seo/loksifu-seo.php:1) in <b>/www/wwwroot/www.loksifu.cn/wp-includes/pluggable.php</b> on line <b>1535</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /www/wwwroot/www.loksifu.cn/wp-content/plugins/loksifu-seo/loksifu-seo.php:1) in <b>/www/wwwroot/www.loksifu.cn/wp-includes/pluggable.php</b> on line <b>1538</b><br />