/*
 * Copyright 2022-2025 兮玥(190785909@qq.com)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.chestnut.common.utils.sql;

import com.chestnut.common.exception.UtilException;
import com.chestnut.common.utils.StringUtils;

/**
 * sql操作工具类
 *
 * @author 兮玥
 * @email 190785909@qq.com
 */
public class SqlUtil
{
    /**
     * 定义常用的 sql关键字
     */
    public static String SQL_REGEX = "select |insert |delete |update |drop |count |exec |chr |mid |master |truncate |char |and |declare ";

    /**
     * 仅支持字母、数字、下划线、空格、逗号、小数点（支持多个字段排序）
     */
    public static String SQL_PATTERN = "[a-zA-Z0-9_\\ \\,\\.]+";

    /**
     * 检查字符，防止注入绕过
     */
    public static String escapeOrderBySql(String value)
    {
        if (StringUtils.isNotEmpty(value) && !isValidOrderBySql(value))
        {
            throw new UtilException("参数不符合规范，不能进行查询");
        }
        return value;
    }

    /**
     * 验证 order by 语法是否符合规范
     */
    public static boolean isValidOrderBySql(String value)
    {
        return value.matches(SQL_PATTERN);
    }

    /**
     * SQL关键字检查
     */
    public static void filterKeyword(String value)
    {
        if (StringUtils.isEmpty(value))
        {
            return;
        }
        String[] sqlKeywords = StringUtils.split(SQL_REGEX, "\\|");
        for (String sqlKeyword : sqlKeywords)
        {
            if (StringUtils.indexOfIgnoreCase(value, sqlKeyword) > -1)
            {
                throw new UtilException("参数存在SQL注入风险");
            }
        }
    }
}
