// 插入内容到文章中
add_filter('the_content', 'cci_insert_content');
function cci_insert_content($content) {
    if (is_single()) {
        $options = get_option('cci_options');

        // 获取当前时间
        $current_time = current_time('Y-m-d H:i:s');

        // 获取绝对时间
        $start_time = isset($options['cci_start_time']) ? $options['cci_start_time'] : '';
        $end_time = isset($options['cci_end_time']) ? $options['cci_end_time'] : '';
        
        // 获取相对时间
        $relative_time_value = isset($options['cci_relative_time']) ? (int)$options['cci_relative_time'] : 0;
        $relative_time_unit = isset($options['cci_relative_time_unit']) ? $options['cci_relative_time_unit'] : 'days'; 
        
        // 计算相对时间的生效时间
        $effective_start_time = new DateTime($current_time);
        if ($relative_time_value > 0) {
            switch ($relative_time_unit) {
                case 'minutes':
                    $effective_start_time->modify("+$relative_time_value minutes");
                    break;
                case 'hours':
                    $effective_start_time->modify("+$relative_time_value hours");
                    break;
                case 'days':
                    $effective_start_time->modify("+$relative_time_value days");
                    break;
                case 'weeks':
                    $effective_start_time->modify("+$relative_time_value weeks");
                    break;
                case 'months':
                    $effective_start_time->modify("+$relative_time_value months");
                    break;
            }
            $start_time = $effective_start_time->format('Y-m-d H:i:s');
        }

        // 输出调试信息
        error_log("当前时间: $current_time");
        error_log("生效时间: $start_time");
        error_log("结束时间: $end_time");

        // 检查时间有效性
        if ($current_time < $start_time || ($end_time !== '' && $current_time > $end_time)) {
            error_log("时间不在有效范围内。");
            return $content; // 如果时间不在范围内，直接返回内容
        }

        // 在文章顶部插入内容（如果启用）
        if (isset($options['top_content_enabled']) && $options['top_content_enabled']) {
            $content = $options['cci_top_content'] . $content;
        }

        // 在指定段落后插入中部内容
        if (isset($options['cci_ad_after_paragraph']) && intval($options['cci_ad_after_paragraph']) > 0) {
            $ad_after_paragraph = intval($options['cci_ad_after_paragraph']);
            $paragraphs = explode('</p>', $content);
            if (count($paragraphs) > $ad_after_paragraph) {
                array_splice($paragraphs, $ad_after_paragraph, 0, [$options['cci_middle_content']]);
                $content = implode('</p>', $paragraphs);
            }
        }

        // 检查内部推荐文章的时间限制
        $recommended_posts = cci_insert_recommended_posts($options);
        if (!empty($recommended_posts)) {
            $content .= $recommended_posts;
        } else {
            error_log("没有找到推荐文章。");
        }

        // 检查外部推荐文章的时间
        if ($current_time >= $options['cci_external_start_time'] && $current_time <= $options['cci_external_end_time']) {
            $content .= cci_insert_external_links($options);
        }

        // 在底部插入内容（如果启用）
        if (isset($options['bottom_content_enabled']) && $options['bottom_content_enabled']) {
            $content .= $options['cci_bottom_content'];
        }
    }
    return $content;
}

// 内部推荐文章插入逻辑
function cci_insert_recommended_posts($options) {
    $current_post_id = get_the_ID();
    $post_ids = isset($options['cci_recommend_post_ids']) ? $options['cci_recommend_post_ids'] : '';
    $post_ids_array = array_unique(array_map('trim', explode(',', $post_ids)));

    // 输出推荐文章 ID
    error_log("推荐文章 ID: " . implode(', ', $post_ids_array));

    // 从推荐文章ID中排除当前文章ID
    $post_ids_array = array_diff($post_ids_array, [$current_post_id]);

    if (!empty($post_ids_array)) {
        $recommended_posts = new WP_Query([
            'post__in' => $post_ids_array,
            'orderby' => 'post__in',
            'posts_per_page' => -1,
        ]);

        if ($recommended_posts->have_posts()) {
            $title_font_size = isset($options['cci_title_font_size']) ? esc_attr($options['cci_title_font_size']) : '16px';
            $title_color = isset($options['cci_title_color']) ? esc_attr($options['cci_title_color']) : '#000000';
            $output = '<div style="margin-top: 20px;">
                        <h3 style="font-size: ' . $title_font_size . '; color: ' . $title_color . ';">' . esc_html($options['cci_recommend_title']) . '</h3>
                        <ul style="list-style-type: none; padding: 0;">';

            while ($recommended_posts->have_posts()) {
                $recommended_posts->the_post();
                $output .= '<li><a href="' . get_permalink() . '" style="text-decoration: none; color: inherit;">' . get_the_title() . '</a></li>';
            }
            $output .= '</ul></div>';
            wp_reset_postdata();
            return $output;
        } else {
            error_log("推荐文章查询没有结果。");
        }
    } else {
        error_log("内部推荐文章 ID 为空或无效。");
    }
    return '';
}<br />
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