#mu-plugins/functions.php

#注册专属业务文档 CPT (sc_doc) 并开启修订支持
add_action( 'init', function() {
    register_post_type( 'sc_doc', array(
        'labels' => array( 'name' => '业务文书', 'singular_name' => '文书' ),
        'public' => true,
        'has_archive' => false,
        'supports' => array( 'title', 'editor', 'author', 'revisions' ), // 核心：开启 revisions
        'show_in_rest' => true,
    ) );
} );

#从母版起草文书与版本历史 API（免进后台） 通过 REST API 让前端页面直接完成“起草、版本列表获取、版本对比
add_action( 'rest_api_init', function () {
    // 1. 从母版克隆新草案
    register_rest_route( 'shipchain/v1', '/doc/fork', array(
        'methods'  => 'POST',
        'callback' => 'sc_fork_template_to_doc',
        'permission_callback' => function() { return is_user_logged_in(); }
    ) );

    // 2. 获取文档的所有历史修订版本
    register_rest_route( 'shipchain/v1', '/doc/(?P<id>\d+)/revisions', array(
        'methods'  => 'GET',
        'callback' => 'sc_get_doc_revisions',
        'permission_callback' => function() { return is_user_logged_in(); }
    ) );

    // 3. 对比任意两个版本的文本差异 (Diff)
    register_rest_route( 'shipchain/v1', '/doc/diff', array(
        'methods'  => 'GET',
        'callback' => 'sc_compare_doc_revisions',
        'permission_callback' => function() { return is_user_logged_in(); }
    ) );
} );

// 1. 克隆实现
function sc_fork_template_to_doc( WP_REST_Request $request ) {
    $template_id = intval( $request->get_param('template_id') );
    $template = get_post( $template_id );
    if ( ! $template ) {
        return new WP_Error( 'not_found', '模板不存在', array( 'status' => 404 ) );
    }

    $current_user_id = get_current_user_id();
    $new_doc_id = wp_insert_post( array(
        'post_title'   => $template->post_title . ' - 草案 (' . date('m-d H:i') . ')',
        'post_content' => $template->post_content,
        'post_status'  => 'draft',
        'post_type'    => 'sc_doc',
        'post_author'  => $current_user_id,
    ) );

    // 记录来源母版
    update_post_meta( $new_doc_id, '_source_template_id', $template_id );

    return rest_ensure_response( array(
        'status'  => 'success',
        'doc_id'  => $new_doc_id,
        'title'   => get_the_title( $new_doc_id ),
        'content' => $template->post_content
    ) );
}

// 2. 版本清单实现
function sc_get_doc_revisions( WP_REST_Request $request ) {
    $doc_id = intval( $request['id'] );
    $doc = get_post( $doc_id );
    if ( ! $doc || ( $doc->post_author != get_current_user_id() && ! current_user_can('edit_others_posts') ) ) {
        return new WP_Error( 'forbidden', '无权调阅此文书版本', array( 'status' => 403 ) );
    }

    $revisions = wp_get_post_revisions( $doc_id );
    $history = array();

    foreach ( $revisions as $rev ) {
        $history[] = array(
            'revision_id' => $rev->ID,
            'time'        => $rev->post_modified,
            'author_name' => get_the_author_meta( 'display_name', $rev->post_author ),
            'char_count'  => mb_strlen( strip_tags( $rev->post_content ) )
        );
    }

    return rest_ensure_response( array( 'doc_id' => $doc_id, 'history' => $history ) );
}

// 3. 版本 Diff 差异对比实现 (利用 WP 原生差异比对器)
function sc_compare_doc_revisions( WP_REST_Request $request ) {
    require_once ABSPATH . 'wp-admin/includes/diff.php';

    $rev_from_id = intval( $request->get_param('from') );
    $rev_to_id   = intval( $request->get_param('to') );

    $rev_from = get_post( $rev_from_id );
    $rev_to   = get_post( $rev_to_id );

    if ( ! $rev_from || ! $rev_to ) {
        return new WP_Error( 'not_found', '对比版本不存在', array( 'status' => 404 ) );
    }

    // 原生渲染红绿增删对比 HTML 表格
    $diff_table = wp_text_diff( $rev_from->post_content, $rev_to->post_content, array(
        'title'        => '文书版本差异分析',
        'title_left'   => '早期版本 (' . $rev_from->post_modified . ')',
        'title_right'  => '目标版本 (' . $rev_to->post_modified . ')'
    ) );

    return rest_ensure_response( array(
        'diff_html' => $diff_table ?: '<div class="text-center text-muted p-4">两个版本内容一致，无变动差异。</div>'
    ) );
}