functions.php

<?php
/**
 * Functions.php contains all the core functions for your theme to work properly.
 *
 * @package dangopress
 */

/*
 * Global variables
 */

// Set the content width based on the theme's design and stylesheet.
if (!isset($content_width)) {
    $content_width = 640;
}

// Theme version
$dangopress_version = '0.5.0';

/*
 * Include the functions
 */

// Theme options
require_once('theme-options.php');

/*
 * Utility functions used in the theme
 */

// Define a debug log function (DEBUG use only)
if (!function_exists('write_log')) {
    function write_log($log) {
        if (true === WP_DEBUG) {
            if (is_array($log) || is_object($log)) {
                error_log(print_r($log, true));
            } else {
                error_log($log);
            }
        }
    }
}

/*
 * Get theme url prefix for styles or scripts
 */
function get_url_prefix()
{
    $options = get_option('dangopress_options');

    if (!empty($options['cdn_prefix']))
        return $options['cdn_prefix'];
    else
        return get_template_directory_uri();
}

/*
 * Show humanable time delta
 */
function show_human_time_diff($gmt_time)
{
    $from_timestamp = strtotime("$gmt_time" . ' UTC');
    $to_timestamp = current_time('timestamp', 1);

    if ($to_timestamp - $from_timestamp > 2592000) { // One month ago
        return date_i18n('Y-m-d G:i:s', $from_timestamp, true);
    } else {
        $diff = human_time_diff($from_timestamp, $to_timestamp);
        return preg_replace('/(\d+)/', "$1 ", "{$diff}前");
    }
}

/*
 * Theme core functions
 */

/**
 * Sets up theme defaults and registers support for various WordPress features.
 */
function dangopress_setup_theme()
{
    // Add theme support
    add_theme_support('automatic-feed-links');
    add_theme_support('custom-background');
    add_theme_support('post-thumbnails');
    add_theme_support('title-tag');

    // Enable page excerpt support
    add_post_type_support('page', 'excerpt');

    // Register WordPress menu
    register_nav_menus(array('primary' => 'Primary Navigation'));
}
add_action('after_setup_theme', 'dangopress_setup_theme');

/*
 * Prune the theme to remove un-needed functions
 */
function dangopress_prune_theme() {
    remove_action('wp_head', 'feed_links', 2);
    remove_action('wp_head', 'feed_links_extra', 3);
    remove_action('wp_head', 'rsd_link');
    remove_action('wp_head', 'wlwmanifest_link');
    remove_action('wp_head', 'index_rel_link');
    remove_action('wp_head', 'parent_post_rel_link', 10, 0);
    remove_action('wp_head', 'start_post_rel_link', 10, 0);
    remove_action('wp_head', 'adjacent_posts_rel_link_wp_head', 10, 0);
    remove_action('wp_head', 'locale_stylesheet');
    remove_action('wp_head', 'noindex', 1);
    remove_action('wp_head', 'rel_canonical');
    remove_action('wp_head', 'wp_generator');
    remove_action('wp_head', 'wp_shortlink_wp_head', 10, 0);
    remove_action('wp_head', 'print_emoji_detection_script', 7);
    remove_action('wp_head', 'wp_resource_hints', 2);
    remove_action('wp_print_styles', 'print_emoji_styles');
    remove_action('xmlrpc_rsd_apis', 'rest_output_rsd');
    remove_action('wp_head', 'rest_output_link_wp_head', 10);
    remove_action('template_redirect', 'rest_output_link_header', 11);
    remove_action('wp_head', 'wp_oembed_add_discovery_links');
    remove_action('rest_api_init', 'wp_oembed_register_route');

    add_filter('xmlrpc_enabled', '__return_false');
    add_filter('show_admin_bar', '__return_false');
    add_filter('max_srcset_image_width', '__return_false');
    add_filter('json_enabled', '__return_false');
    add_filter('json_jsonp_enabled', '__return_false');
    add_filter('rest_enabled', '__return_false');
    add_filter('rest_jsonp_enabled', '__return_false');

    add_filter( 'yarpp_enqueue_related_style', '__return_false' );
    add_filter( 'yarpp_enqueue_thumbnails_style', '__return_false' );

    remove_filter('the_content', 'wptexturize');
    remove_filter('the_excerpt', 'wptexturize');
    remove_filter('the_title', 'wptexturize');
    remove_filter('comment_text', 'wptexturize');
    remove_filter('rest_pre_serve_request', '_oembed_rest_pre_serve_request', 10, 4);
    remove_filter('oembed_dataparse', 'wp_filter_oembed_result', 10 );
    remove_filter('oembed_response_data',   'get_oembed_response_data_rich',  10, 4);
    remove_action('wp_head', 'wp_oembed_add_discovery_links');
    remove_action('wp_head', 'wp_oembed_add_host_js');
}
add_action('init', 'dangopress_prune_theme');

/*
 * Add the defer attribute to the specified script
 */
 function dangopress_defer_scripts($tag, $handle, $src) {
     $defer_scripts = array(
         'prettify-js',
         'dangopress-script'
     );

     if (in_array($handle, $defer_scripts)) {
         return str_replace(' src', ' defer="defer" src', $tag);
     } else {
         return $tag;
     }
 }
 add_filter('script_loader_tag', 'dangopress_defer_scripts', 10, 3);

/*
 * Load css and javascript
 */
function dangopress_load_scripts()
{
    $options = get_option('dangopress_options');
    $url_prefix = get_url_prefix();

    wp_dequeue_style('wp-block-library');
    wp_dequeue_style('classic-theme-styles');
    wp_dequeue_style('global-styles');

    // Remove yarpp widget styles
    //wp_dequeue_style('yarppWidgetCss');

    wp_enqueue_style('dangopress-style', "$url_prefix/static/theme.css", array(), null);
    wp_enqueue_script('prettify-js', "$url_prefix/static/prettify.js", array(), null, true);
    wp_enqueue_script('dangopress-script', "$url_prefix/static/theme.js", array(), null, true);
}
add_action('wp_enqueue_scripts', 'dangopress_load_scripts');

/*
 * Generate the meta description.
 */
function dangopress_get_description() {
    $description = '';

    if (is_home() || is_front_page()) {
        $options = get_option('dangopress_options');
        $description = $options['home_meta_descripton'];
    } elseif (is_singular() && !is_attachment()) {
        global $post;
        $description = ($post->post_excerpt != '') ? $post->post_excerpt : $post->post_content;
    } elseif (is_category()) {
        $description = category_description();
    } elseif (is_tag()) {
        $description = tag_description();
    }

    if ($description != '') {
        $description = preg_replace('#\[[^\]]+\]#', '', $description);
        $description = wp_html_excerpt(wp_strip_all_tags($description, true), 200);
    }

    return $description;
}

/*
 * Add necessary code into head part.
 */
function dangopress_wp_head() {
    $description = dangopress_get_description();

    if ($description != '') {
        echo '<meta name="description" content="' . $description . '" />';
    }

    global $paged;

    if ($paged > 1 || is_author() || is_tag() || is_search() || is_date() || is_attachment() || is_page_template("page-archives.php")) {
        echo '<meta name="robots" content="noindex,follow" />';
    }

    $options = get_option('dangopress_options');

    if (!empty($options['google_webid'])) {
?>

<script async src="https://www.googletagmanager.com/gtag/js?id=<?php echo $options['google_webid']; ?>"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());
  gtag('config', '<?php echo $options['google_webid']; ?>');
</script>

<?php
    }
}
add_action('wp_head', 'dangopress_wp_head');

/*
 * Customize WordPress title
 */
function dangopress_get_title()
{
    $blog_name = get_bloginfo('name');
    $sep = '-';

    if (is_single() || is_page()) { // singular page
        $title = sprintf('%1$s %2$s %3$s', single_post_title('', false), $sep, $blog_name);
    } else if (is_category()) { // category page
        $title = sprintf('%1$s %2$s %3$s', single_cat_title('', false), $sep, $blog_name);
    } else if(is_tag()) { // tag page
        $title = sprintf('%1$s %2$s %3$s', single_tag_title('', false), $sep, $blog_name);
    } else { // other page, like home page or front page
        $site_description = get_bloginfo('description');

        if ($site_description) {
            $title = "$blog_name $sep $site_description";
        } else {
            $title = "$blog_name";
        }
    }

    return $title;
}
add_filter('pre_get_document_title', 'dangopress_get_title');

/*
 * Add rel="nofollow" to read more link
 */
function dangopress_nofollow_link($link)
{
    return str_replace('<a', '<a rel="nofollow"', $link);
}
add_filter('the_content_more_link', 'dangopress_nofollow_link');

/*
 * Disable self ping
 */
function dangopress_disable_self_ping(&$links)
{
    $home = home_url();

    foreach ($links as $l => $link) {
        if (0 === strpos($link, $home)) {
            unset($links[$l]);
        }
    }
}
add_action('pre_ping', 'dangopress_disable_self_ping');

/*
 * Exclude the sticky posts from the main loop in the home page
 */
function dangopress_exclude_sticky_posts($query)
{
    /* Only for main loop in home page */
    if (!$query->is_home() || !$query->is_main_query())
        return;

    // ignore sticky posts, don't show them in the start
    $query->set('ignore_sticky_posts', 1);
}
add_action('pre_get_posts', 'dangopress_exclude_sticky_posts');

if (is_admin()) {
    /*
     * Wrap the post image in div container
     */
    function dangopress_wrap_post_image($html, $id, $caption, $title, $align, $url, $size, $alt)
    {
        return '<div class="post-image">'.$html.'</div>';
    }
    add_filter('image_send_to_editor', 'dangopress_wrap_post_image', 10, 8);
}

/*
 * Escape special characters in pre.prettyprint into their HTML entities
 */
 function dangopress_esc_callback($matches)
 {
     $tag_open = $matches[1];
     $content = $matches[2];
     $tag_close = $matches[3];

     //$content = htmlspecialchars($content, ENT_NOQUOTES, get_bloginfo('charset'));
     $content = esc_html($content);
     $tag_open = preg_replace('/<pre>[\n\s]*<code>/', '<pre class="prettyprint"><code>', $tag_open);

     return $tag_open . $content . $tag_close;
}

function dangopress_esc_html($content)
{
    $patterns = array(
        '/(<pre\s+[^>]*?class\s*?=\s*?[",\'].*?prettyprint.*?[",\'].*?>)(.*?)(<\/pre>)/sim',
        '/(<pre>[\n\s]*<code>)(.*?)(<\/code>[\n\s]*<\/pre>)/sim',
    );

    return preg_replace_callback($patterns, 'dangopress_esc_callback', $content);
}
add_filter('the_content', 'dangopress_esc_html', 10);
add_filter('comment_text', 'dangopress_esc_html', 10);

/*
 * Retrieve paginated link for archive post pages
 */
function dangopress_paginate_links()
{
    global $wp_query;

    $total = $wp_query->max_num_pages;
    $big = 999999999; // need an unlikely integer

    if ($total < 2)
        return;

    $output = paginate_links(array(
        'base' => str_replace($big, '%#%', esc_url(get_pagenum_link($big))),
        'format' => '%#%',
        'current' => max(1, get_query_var('paged')),
        'total' => $total,
        'prev_text' => '<i class="icon-arrow-circle-left"></i>',
        'next_text' => '<i class="icon-arrow-circle-right"></i>',
    ));

    echo '<div id="pagenavi">' . $output . '</div>';
}

/*
 * Display comment lists
 */
function dangopress_comments_callback($comment, $args, $depth) {
    $GLOBALS['comment'] = $comment;

    global $commentcount;

    /* Initialize the comment count */
    if (!$commentcount) {
        $page = intval(get_query_var('cpage')) - 1;

        if ($page > 0) {
            $cpp = get_option('comments_per_page');
            $commentcount = $cpp * $page;
        } else {
            $commentcount = 0;
        }
    }

    $comment_id = $comment->comment_ID; ?>

    <li <?php comment_class(); ?> id="li-comment-<?php echo $comment_id; ?>">
        <div id="comment-<?php echo $comment_id; ?>" class="comment-body <?php if ($comment->comment_approved == '0') echo 'pending-comment'; ?>">
            <div class="comment-avatar">
                <?php echo get_avatar($comment, $depth==1 ? 48: 32, '', "$comment->comment_author's avatar"); ?>
            </div>
            <div class="comment-meta">
                <span class="comment-author<?php echo user_can($comment->user_id, 'administrator') ? ' postauthor': ''?>"><?php comment_author_link(); ?></span>
                <span class="comment-date">发表于 <?php echo show_human_time_diff($comment->comment_date_gmt); ?></span>
                <span class="comment-reply">
                <?php
                    $link = get_comment_reply_link(array_merge($args, array(
                        'reply_text' => '回复',
                        'depth' => $depth,
                        'max_depth' => $args['max_depth']
                    )));

                    // remove ?replytocom parameter in the comment reply link
                    echo preg_replace('/href=\'(.*(\?|&)replytocom=(\d+)#respond)/', 'href=\'#respond', $link);

                    if ($depth == 1) { // Show the floor number
                         printf(' #%1$s', ++$commentcount);
                    }
                ?>

                </span>

            </div>

            <div class="comment-text"><?php comment_text(); ?></div>
        </div>
<?php
}

/*
 * Add at user before comment text
 */
function dangopress_add_at_author($comment_text, $comment)
{
    if ($comment->comment_parent) { // Show reply to somebody
        $parent = get_comment($comment->comment_parent);
        $parent_href = htmlspecialchars(get_comment_link($comment->comment_parent));

        $parent_author = $parent->comment_author;
        $parent_title = mb_strimwidth(strip_tags($parent->comment_content), 0, 100, '...');

        $parent_link = "<a href=\"$parent_href\" title=\"$parent_title\">@$parent_author</a>";
        $comment_text = '<span class="at-author">' . $parent_link . ':</span>' . $comment_text;
    }

    return $comment_text;
}
add_filter('comment_text', 'dangopress_add_at_author', 10, 2);

/*
 * Send an email when recieved a reply
 */
function dangopress_email_nodify($comment_id)
{
    global $wpdb;

    $admin_email = get_bloginfo('admin_email');

    $comment = get_comment($comment_id);
    $comment_author_email = trim($comment->comment_author_email);

    $parent_id = $comment->comment_parent ? $comment->comment_parent : '';

    /*
     * Add comment_mail_notify column when first run
     */
    if ($wpdb->query("Describe $wpdb->comments comment_mail_notify") == '')
        $wpdb->query("ALTER TABLE $wpdb->comments ADD COLUMN comment_mail_notify TINYINT NOT NULL DEFAULT 0;");

    /*
     * Set notify value to 1 if the checkbox is checked in the comment form
     */
    if (isset($_POST['comment_mail_notify']))
        $wpdb->query("UPDATE $wpdb->comments SET comment_mail_notify='1' WHERE comment_ID='$comment_id'");

    $notify = $parent_id ? get_comment($parent_id)->comment_mail_notify : '0';
    $spam_confirmed = $comment->comment_approved;

    /*
     * Don't send email if:
     * 1. the comment is a spam
     * 2. the notify checkbox isn't checked
     */
    if ($notify != '1' || $spam_confirmed == 'spam')
        return;

    // Prepare the email
    $sender = 'no-reply@' . preg_replace('#^www.#', '', strtolower($_SERVER['SERVER_NAME']));

    $to = trim(get_comment($parent_id)->comment_author_email);
    $subject = '您在 [' . get_option('blogname') . '] 的留言有了回复';

    $from = 'From: "' . get_option('blogname') . '" <' . $sender . '>';
    $headers = "$from\nContent-Type: text/html; charset=" . get_option('blog_charset') . "\n";

    $message .= '<div style="background-color:#eef2fa;border:1px solid #d8e3e8;padding:0 15px;">';
    $message .= '<p style="color:#000">您好, <strong>' . trim(get_comment($parent_id)->comment_author) . '</strong>:</p>';
    $message .= '<p style="color:#000">您曾在《' . get_the_title($comment->comment_post_ID) . '》的留言: </p>';
    $message .= '<blockquote style="background:#fafafa;border-left:1px solid #ddd;padding:10px;margin:15px 0;">';
    $message .= trim(get_comment($parent_id)->comment_content) . '</blockquote>';
    $message .= '<p style="color:#000">收到来自 <strong>' . trim($comment->comment_author) . '</strong> 给您的回复:</p>';
    $message .= '<blockquote style="background:#fafafa;border-left:1px solid #ddd;padding:10px;margin:15px 0;">';
    $message .= trim($comment->comment_content) . '</blockquote>';
    $message .= '<p style="color:#000">您可以点击以下链接（或者复制链接到地址栏访问）查看回复的完整内容:</p>';
    $message .= '<blockquote style="background:#fafafa;border-left:1px solid #ddd;padding:10px;margin:15px 0;">';
    $message .= get_comment_link($comment) . '</blockquote>';
    $message .= '<p style="color:#000">欢迎再次光临 <a href="' . home_url() . '">' . get_bloginfo('name') . '</a></p>';
    $message .= '<p style="color:#888;">友情提醒: 此邮件由系统自动发送，请勿回复。</p></div>';

    wp_mail($to, $subject, $message, $headers);
}
add_action('comment_post', 'dangopress_email_nodify');

/*
 * Show breadcrumb by Dimox
 * URL: http://dimox.net/wordpress-breadcrumbs-without-a-plugin/
 * Version: 2017.21.01
 * License: MIT
 */
function dangopress_breadcrumb()
{
    /* === OPTIONS === */
    $text['home']     = '首页'; // text for the 'Home' link
    $text['category'] = '%s'; // text for a category page
    $text['search']   = '"%s" 的搜索结果'; // text for a search results page
    $text['tag']      = '含标签 "%s" 的文章'; // text for a tag page
    $text['404']      = '页面未找到'; // text for the 404 page

    $prefix         = '<i class="icon-windows"></i>'; // Prefix the breadcrumb
    $wrap_before    = '<div id="breadcrumbs" itemscope itemtype="http://schema.org/BreadcrumbList">'; // the opening wrapper tag
    $wrap_after     = '</div><!-- .breadcrumbs -->'; // the closing wrapper tag
    $sep            = '<i class="icon-caret-right"></i>'; // separator between crumbs
    $sep_before     = '<span class="sep">'; // tag before separator
    $sep_after      = '</span>'; // tag after separator
    $before         = '<h1 class="current-crumb">'; // tag before the current crumb
    $after          = '</h1>'; // tag after the current crumb
    /* === END OF OPTIONS === */

    global $post;
    $home_url       = home_url('/');

    $link_before    = '<span itemprop="itemListElement" itemscope itemtype="http://schema.org/ListItem">';
    $link_after     = '</span>';
    $link_attr      = ' itemprop="item"';
    $link_in_before = '<span itemprop="name">';
    $link_in_after  = '</span>';
    $link           = $link_before . '<a href="%1$s"' . $link_attr . '>' . $link_in_before . '%2$s' . $link_in_after . '</a><meta itemprop="position" content="%3$d" />' . $link_after;
    $link2          = $link_before . '<a%1$s' . $link_attr . '>' . $link_in_before . '%2$s' . $link_in_after . '</a><meta itemprop="position" content="%3$d" />' . $link_after;

    $frontpage_id   = get_option('page_on_front');
    $parent_id      = ($post) ? $post->post_parent : '';
    $sep            = ' ' . $sep_before . $sep . $sep_after . ' ';

    if (is_home() || is_front_page()) {
        return;
    }
    
    $home_link = sprintf($link2, ' rel="nofollow" class="home" href="' . $home_url . '"', $text['home'], 1);
    echo $wrap_before . $prefix . $home_link . $sep;

    if (is_category()) {
        $cat = get_category(get_query_var('cat'), false);
        
        if ($cat->parent != 0) {
            $cats = get_category_parents($cat->parent, TRUE, $sep);
            $cats = preg_replace("#^(.+)$sep$#", "$1", $cats);
            $cats = preg_replace_callback(
                '#<a([^>]+)>([^<]+)<\/a>#',
                function($m) use($link2) {
                    static $id = 1;
                    return sprintf($link2, $m[1], $m[2], ++$id);
                },
                $cats);
            echo $cats . $sep;
        }

        echo $before . sprintf($text['category'], single_cat_title('', false)) . $after;
    } elseif (is_tag()) {
        echo $before . sprintf($text['tag'], single_tag_title('', false)) . $after;
    } elseif (is_search()) {
            echo $before . sprintf($text['search'], get_search_query()) . $after;
    } elseif (is_day()) {
        echo sprintf($link, get_year_link(get_the_time('Y')), get_the_time('Y'), 2) . $sep;
        echo sprintf($link, get_month_link(get_the_time('Y'), get_the_time('m')), get_the_time('m'), 3) . $sep;
        echo $before . get_the_time('d') . $after;
    } elseif (is_month()) {
        echo sprintf($link, get_year_link(get_the_time('Y')), get_the_time('Y'), 2) . $sep;
        echo $before . get_the_time('m') . $after;
    } elseif (is_year()) {
        echo $before . get_the_time('Y') . $after;
    } elseif (is_single() && !is_attachment()) {
        if (get_post_type() != 'post') {
            $post_type = get_post_type_object(get_post_type());
            $slug = $post_type->rewrite;
            printf($link, $home_url . $slug['slug'] . '/', $post_type->labels->singular_name, 2) . $sep;
            echo $before . get_the_title() . $after;
        } else {
            $cat = get_the_category();
            $cats = get_category_parents($cat[0], TRUE, $sep);

            $cats = preg_replace_callback(
                '#<a([^>]+)>([^<]+)<\/a>#',
                function($m) use($link2) {
                    static $id = 1;
                    return sprintf($link2, $m[1], $m[2], ++$id);
                },
                $cats);
            echo $cats . $before . get_the_title() . $after;
        }
    } elseif (is_attachment()) {
        $parent = get_post($parent_id);
        $cat = get_the_category($parent->ID);
        $cat = $cat[0];
        
        $id = 1;
        if ($cat) {
            $cats = get_category_parents($cat, TRUE, $sep);
            $cats = preg_replace_callback(
                '#<a([^>]+)>([^<]+)<\/a>#',
                function($m) use($link2, &$id) {
                    static $id = 1;
                    return sprintf($link2, $m[1], $m[2], ++$id);
                },
                $cats);
            echo $cats;
        }
        printf($link, get_permalink($parent), $parent->post_title, ++$id);
        echo $sep . $before . get_the_title() . $after;
    } elseif (is_page()) {
        echo $before . get_the_title() . $after;
    } elseif (!is_single() && !is_page() && get_post_type() != 'post' && !is_404()) {
        $post_type = get_post_type_object(get_post_type());
        echo $before . $post_type->label . $after;
    } elseif (has_post_format() && !is_singular()) {
        echo get_post_format_string( get_post_format());
    } elseif (is_404()) {
        echo $before . $text['404'] . $after;
    } 
    
    echo $wrap_after;
}

/*
 * Add additional button in the WordPress editor
 */
function dangopress_add_quicktags()
{
    /* Check whether the quicktags.js is registered */
    if (!wp_script_is('quicktags'))
        return;
?>

    <script type="text/javascript">
    QTags.addButton('eg_h3', 'h3', '<h3>', '</h3>', '', '三级标题', 101);
    QTags.addButton('eg_h4', 'h4', '<h4>', '</h4>', '', '四级标题', 102);
    QTags.addButton('eg_pre', 'pre', '<pre>', '</pre>', '', '', 111);
    QTags.addButton('eg_prettify', 'prettify', '<pre class="prettyprint">', '</pre>', '', '代码高亮', 112);
    </script>

<?php
}
add_action('admin_print_footer_scripts', 'dangopress_add_quicktags');

/*
 * Disable google fonts
 */
function dangopress_disable_google_fonts($translations, $text, $context, $domain )
{
    $google_fonts_contexts = array(
        'Open Sans font: on or off',
        'Lato font: on or off',
        'Source Sans Pro font: on or off',
        'Bitter font: on or off');

    if ($text == 'on' && in_array($context, $google_fonts_contexts)) {
        $translations = 'off';
    }

    return $translations;
}
add_filter('gettext_with_context', 'dangopress_disable_google_fonts', 15, 4);

/*
 * Embed gists with a URL in post article
 */
function dangopress_embed_gist($matches, $attr, $url, $rawattr)
{
    $embed = sprintf(
        '<script src="https://gist.github.com/%1$s.js%2$s"></script>',
        esc_attr($matches[1]),
        esc_attr($matches[2])
    );

    return apply_filters('dangopress_embed_gist', $embed, $matches, $attr, $url, $rawattr);
}

wp_embed_register_handler(
    'gist',
    '#https?://gist\.github\.com(?:/[a-z0-9-]+)?/([a-z0-9]+)(\?file=.*)?#i',
    'dangopress_embed_gist'
);

/*
 * Use another avatar service
 */
function dangopress_replace_avatar($avatar) {
    return str_replace(
        array(
            "secure.gravatar.com/avatar",
            "0.gravatar.com/avatar",
            "1.gravatar.com/avatar",
            "2.gravatar.com/avatar"
        ), "cravatar.cn/avatar", $avatar);
}
add_filter('get_avatar', 'dangopress_replace_avatar');

/*
 * Show dynamic copyright information
 */
function dangopress_show_copyright() {
    global $wpdb;

    $copyright_dates = $wpdb->get_results("
        SELECT
        YEAR(min(post_date_gmt)) AS firstdate,
        YEAR(curdate()) AS lastdate
        FROM
        $wpdb->posts
        WHERE
        post_status = 'publish'
    ");

    if ($copyright_dates) {
        $copyright = "&copy; " . $copyright_dates[0]->firstdate;

        if ($copyright_dates[0]->firstdate != $copyright_dates[0]->lastdate) {
            $copyright .= '-' . $copyright_dates[0]->lastdate;
        }
    } else {
        $copyright = "&copy; " . date('Y');
    }

    $copyright .= ' ' . get_bloginfo('name') . ' 版权所有';

    $options = get_option('dangopress_options');
    $beian_str = $options['beian_str'];

    if ($beian_str != '') {
        $copyright .= ' <a href="https://beian.miit.gov.cn/" target="_blank">' . $beian_str . '</a>';
    }

    $copyright = '<span class="copyright">' . $copyright . '</span>';
    echo $copyright;
}

/*
 * Show sitexmap link
 */
function dangopress_show_sitemap() {
   $options = get_option('dangopress_options');
   $sitemap = $options['sitemap_xml'];

   if (empty($sitemap)) {
       return;
   }

   echo '<span class="sitemap">';

   if (is_home()) {
       echo '<a href="' . home_url() . '/' . $sitemap . '">站点地图<i class="icon-sitemap"></i>';
   } else {
       echo '<a rel="nofollow" href="' . home_url() . '/' . $sitemap . '">站点地图<i class="icon-sitemap"></i>';
   }

   echo '</a></span>';
}
?>