// 从文本域解析图片URL，返回指定数量的不同随机图片URL
private function get_random_img_urls( $count = 1 ) {
    $raw = get_option( self::OPTION_IMG_URLS, '' );
    if ( empty( $raw ) ) return array();

    $lines = explode( "\n", $raw );
    $urls  = array();
    foreach ( $lines as $line ) {
        $url = trim( $line );
        if ( ! empty( $url ) ) {
            $urls[] = $url;
        }
    }
    
    if ( empty( $urls ) ) return array();
    
    // 打乱数组顺序，保证随机性
    shuffle( $urls );
    
    // 如果需要的数量大于可用数量，循环补充
    $result = array();
    $urlCount = count( $urls );
    for ( $i = 0; $i < $count; $i++ ) {
        $result[] = $urls[ $i % $urlCount ];
    }
    
    return $result;
}

// 单张随机图兼容方法（保留原有调用）
private function get_random_img_url() {
    $urls = $this->get_random_img_urls( 1 );
    return $urls ? $urls[0] : '';
}

private function process_post( $post_id, $source ) {
    $post = get_post( $post_id );
    if ( ! $post || 'publish' !== $post->post_status ) return;

    $content = (string)$post->post_content;
    $images  = $this->extract_image_urls( $content );

    // 文章无图片 → 中间插入图片（原有逻辑不变）
    if ( empty( $images ) ) {
        $new_img_url = $this->get_random_img_url();
        if ( empty( $new_img_url ) ) {
            $this->insert_log( array(
                'post_id'        => $post_id,
                'post_title'     => get_the_title( $post_id ),
                'status'         => 'failed',
                'reason'         => '未配置可用图片地址，无法新增图片',
                'image_count'    => 0,
                'broken_count'   => 0,
                'replaced_count' => 0,
                'old_urls'       => array(),
                'new_urls'       => array(),
                'run_source'     => $source
            ) );
            return;
        }

        $img_tag = '<p><img src="' . esc_url( $new_img_url ) . '" alt=""></p>';
        $content_len = mb_strlen( $content );
        $mid_pos     = (int)( $content_len / 2 );
        $new_content = mb_substr( $content, 0, $mid_pos ) . $img_tag . mb_substr( $content, $mid_pos );

        $updated = wp_update_post( array(
            'ID'           => $post_id,
            'post_content' => $new_content
        ), true );

        if ( is_wp_error( $updated ) ) {
            $this->insert_log( array(
                'post_id'        => $post_id,
                'post_title'     => get_the_title( $post_id ),
                'status'         => 'failed',
                'reason'         => '新增图片失败：' . $updated->get_error_message(),
                'image_count'    => 0,
                'broken_count'   => 0,
                'replaced_count' => 1,
                'old_urls'       => array(),
                'new_urls'       => array( $new_img_url ),
                'run_source'     => $source
            ) );
            return;
        }

        clean_post_cache( $post_id );
        $this->insert_log( array(
            'post_id'        => $post_id,
            'post_title'     => get_the_title( $post_id ),
            'status'         => 'add_image',
            'reason'         => '文章无图片，已在内容中间插入图片',
            'image_count'    => 1,
            'broken_count'   => 0,
            'replaced_count' => 1,
            'old_urls'       => array(),
            'new_urls'       => array( $new_img_url ),
            'run_source'     => $source
        ) );
        return;
    }

    // 检测失效图片（原有逻辑不变）
    $broken_urls = array();
    $reasons     = array();
    foreach ( $images as $url ) {
        $check = $this->is_image_url_valid( $url );
        if ( ! $check['valid'] ) {
            $broken_urls[] = $url;
            $reasons[]     = $url . ' => ' . $check['reason'];
        }
    }
    $broken_urls = array_values( array_unique( $broken_urls ) );

    if ( empty( $broken_urls ) ) {
        $this->insert_log( array(
            'post_id'        => $post_id,
            'post_title'     => get_the_title( $post_id ),
            'status'         => 'no_need',
            'reason'         => '所有图片均可正常访问',
            'image_count'    => count( $images ),
            'broken_count'   => 0,
            'replaced_count' => 0,
            'old_urls'       => array(),
            'new_urls'       => array(),
            'run_source'     => $source
        ) );
        return;
    }

    // 替换失效图片（核心修改部分）
    $new_content    = $content;
    $replace_map    = array();
    $replaced_count = 0;
    $failed_reason  = '';
    
    // 获取与失效图片数量匹配的随机备用图
    $rand_imgs = $this->get_random_img_urls( count( $broken_urls ) );

    if ( empty( $rand_imgs ) ) {
        $failed_reason = '未配置可用图片地址，无法替换';
    } else {
        // 为每个失效URL分配不同的备用图
        foreach ( $broken_urls as $index => $bad_url ) {
            $new_img = $rand_imgs[ $index ];
            if ( false !== strpos( $new_content, $bad_url ) ) {
                $new_content = str_replace( $bad_url, $new_img, $new_content );
                $replace_map[ $bad_url ] = $new_img;
                $replaced_count++;
            }
        }
    }

    if ( $failed_reason ) {
        $this->insert_log( array(
            'post_id'        => $post_id,
            'post_title'     => get_the_title( $post_id ),
            'status'         => 'failed',
            'reason'         => $failed_reason . '；失效明细：' . implode( '；', $reasons ),
            'image_count'    => count( $images ),
            'broken_count'   => count( $broken_urls ),
            'replaced_count' => $replaced_count,
            'old_urls'       => $broken_urls,
            'new_urls'       => $replace_map,
            'run_source'     => $source
        ) );
        return;
    }

    if ( $new_content === $content || $replaced_count <= 0 ) {
        $this->insert_log( array(
            'post_id'        => $post_id,
            'post_title'     => get_the_title( $post_id ),
            'status'         => 'failed',
            'reason'         => '检测到失效图片，但未能完成替换；失效明细：' . implode( '；', $reasons ),
            'image_count'    => count( $images ),
            'broken_count'   => count( $broken_urls ),
            'replaced_count' => 0,
            'old_urls'       => $broken_urls,
            'new_urls'       => $replace_map,
            'run_source'     => $source
        ) );
        return;
    }

    $updated = wp_update_post( array(
        'ID'           => $post_id,
        'post_content' => $new_content
    ), true );

    if ( is_wp_error( $updated ) ) {
        $this->insert_log( array(
            'post_id'        => $post_id,
            'post_title'     => get_the_title( $post_id ),
            'status'         => 'failed',
            'reason'         => '文章更新失败：' . $updated->get_error_message(),
            'image_count'    => count( $images ),
            'broken_count'   => count( $broken_urls ),
            'replaced_count' => 0,
            'old_urls'       => $broken_urls,
            'new_urls'       => $replace_map,
            'run_source'     => $source
        ) );
        return;
    }

    clean_post_cache( $post_id );
    $this->insert_log( array(
        'post_id'        => $post_id,
        'post_title'     => get_the_title( $post_id ),
        'status'         => 'success',
        'reason'         => '已替换失效图片；失效明细：' . implode( '；', $reasons ),
        'image_count'    => count( $images ),
        'broken_count'   => count( $broken_urls ),
        'replaced_count' => $replaced_count,
        'old_urls'       => $broken_urls,
        'new_urls'       => $replace_map,
        'run_source'     => $source
    ) );
}<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /www/wwwroot/www.dongwubaike.cn/fanhao/wp-content/plugins/img-batch-replace/wp-image-health-repair-bulk-v2.php:1) in <b>/www/wwwroot/www.dongwubaike.cn/fanhao/wp-includes/rest-api/class-wp-rest-server.php</b> on line <b>1902</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /www/wwwroot/www.dongwubaike.cn/fanhao/wp-content/plugins/img-batch-replace/wp-image-health-repair-bulk-v2.php:1) in <b>/www/wwwroot/www.dongwubaike.cn/fanhao/wp-includes/rest-api/class-wp-rest-server.php</b> on line <b>1902</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /www/wwwroot/www.dongwubaike.cn/fanhao/wp-content/plugins/img-batch-replace/wp-image-health-repair-bulk-v2.php:1) in <b>/www/wwwroot/www.dongwubaike.cn/fanhao/wp-includes/rest-api/class-wp-rest-server.php</b> on line <b>1902</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /www/wwwroot/www.dongwubaike.cn/fanhao/wp-content/plugins/img-batch-replace/wp-image-health-repair-bulk-v2.php:1) in <b>/www/wwwroot/www.dongwubaike.cn/fanhao/wp-includes/rest-api/class-wp-rest-server.php</b> on line <b>1902</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /www/wwwroot/www.dongwubaike.cn/fanhao/wp-content/plugins/img-batch-replace/wp-image-health-repair-bulk-v2.php:1) in <b>/www/wwwroot/www.dongwubaike.cn/fanhao/wp-includes/rest-api/class-wp-rest-server.php</b> on line <b>1902</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /www/wwwroot/www.dongwubaike.cn/fanhao/wp-content/plugins/img-batch-replace/wp-image-health-repair-bulk-v2.php:1) in <b>/www/wwwroot/www.dongwubaike.cn/fanhao/wp-includes/rest-api/class-wp-rest-server.php</b> on line <b>1902</b><br />
<br />
<b>Warning</b>:  Cannot modify header information - headers already sent by (output started at /www/wwwroot/www.dongwubaike.cn/fanhao/wp-content/plugins/img-batch-replace/wp-image-health-repair-bulk-v2.php:1) in <b>/www/wwwroot/www.dongwubaike.cn/fanhao/wp-includes/rest-api/class-wp-rest-server.php</b> on line <b>1902</b><br />
{"version":"1.0","provider_name":"\u756a\u5267\u767e\u79d1","provider_url":"https:\/\/www.dongwubaike.cn\/fanhao","author_name":"\u79d1\u5965\u7f51","author_url":"https:\/\/www.dongwubaike.cn\/fanhao\/author\/1518014142","title":"\u30102016\u5e74\u3011\u9ad8\u5343\u7a57\u94c3\uff08\u9ad8\u5343\u7a42\u3059\u305a\uff09\u4e2a\u4eba\u4f5c\u54c1\u6587\u7ae0\u56fe\u7247\u5c01\u9762\u4ee5\u53ca\u756a\u53f7 \u5ef6\u7eed\u66f4\u65b0","type":"rich","width":600,"height":338,"html":"<blockquote class=\"wp-embedded-content\" data-secret=\"BH5pqjNNw3\"><a href=\"https:\/\/www.dongwubaike.cn\/fanhao\/134738.html\">\u30102016\u5e74\u3011\u9ad8\u5343\u7a57\u94c3\uff08\u9ad8\u5343\u7a42\u3059\u305a\uff09\u4e2a\u4eba\u4f5c\u54c1\u6587\u7ae0\u56fe\u7247\u5c01\u9762\u4ee5\u53ca\u756a\u53f7 \u5ef6\u7eed\u66f4\u65b0<\/a><\/blockquote><iframe sandbox=\"allow-scripts\" security=\"restricted\" src=\"https:\/\/www.dongwubaike.cn\/fanhao\/134738.html\/embed#?secret=BH5pqjNNw3\" width=\"600\" height=\"338\" title=\"\u300a \u30102016\u5e74\u3011\u9ad8\u5343\u7a57\u94c3\uff08\u9ad8\u5343\u7a42\u3059\u305a\uff09\u4e2a\u4eba\u4f5c\u54c1\u6587\u7ae0\u56fe\u7247\u5c01\u9762\u4ee5\u53ca\u756a\u53f7 \u5ef6\u7eed\u66f4\u65b0 \u300b\u2014\u756a\u5267\u767e\u79d1\" data-secret=\"BH5pqjNNw3\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" class=\"wp-embedded-content\"><\/iframe><script type=\"text\/javascript\">\n\/* <![CDATA[ *\/\n\/*! This file is auto-generated *\/\n!function(d,l){\"use strict\";l.querySelector&&d.addEventListener&&\"undefined\"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!\/[^a-zA-Z0-9]\/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret=\"'+t.secret+'\"]'),o=l.querySelectorAll('blockquote[data-secret=\"'+t.secret+'\"]'),c=new RegExp(\"^https?:$\",\"i\"),i=0;i<o.length;i++)o[i].style.display=\"none\";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute(\"style\"),\"height\"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):\"link\"===t.message&&(r=new URL(s.getAttribute(\"src\")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener(\"message\",d.wp.receiveEmbedMessage,!1),l.addEventListener(\"DOMContentLoaded\",function(){for(var e,t,s=l.querySelectorAll(\"iframe.wp-embedded-content\"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute(\"data-secret\"))||(t=Math.random().toString(36).substring(2,12),e.src+=\"#?secret=\"+t,e.setAttribute(\"data-secret\",t)),e.contentWindow.postMessage({message:\"ready\",secret:t},\"*\")},!1)))}(window,document);\n\/\/# sourceURL=https:\/\/www.dongwubaike.cn\/fanhao\/wp-includes\/js\/wp-embed.min.js\n\/* ]]> *\/\n<\/script>\n"}