using System;

namespace NetCore.Common
{
    /// <summary>
    /// 关键词算法,有白名单算法
    /// </summary>
    public class KeyWordHelper
    {
        /// <summary>
        /// 是否违规
        /// </summary>
        /// <param name="content"></param>
        /// <param name="keyword"></param>
        /// <returns></returns>
        public static bool IsViolation(string content, string keyword)
        {
            bool result = false;
            try
            {
                string newcontent = content.ToString();
                string word = "";
                string[] whitewords = { };
                if (keyword.IndexOf("{") == -1)
                {
                    word = keyword;
                }
                else
                {
                    var xa = keyword.IndexOf("{");
                    word = keyword.Substring(0, xa);
                    whitewords = keyword.Substring(xa).Replace("{", "").Replace("}", "").Split(",");
                }
                if (content.Contains(word))
                {
                    if (whitewords.Length == 0)//没有白名单直接返回true
                    {
                        return true;
                    }
                    int whitcount = 0;//白名单数量，要等于出现关键词的次数，才能算是全部在白名单中
                    int wordcount = 0;
                    while (newcontent.IndexOf(word) > -1)
                    {
                        wordcount++;
                        int i = newcontent.IndexOf(word);//关键词位置
                        bool needreplace = true;
                        foreach (var item in whitewords)
                        {
                            int mx = item.IndexOf(word);//关键词在白名单位置
                            if (mx == -1)
                                continue;//不在此白名单中
                            int worindex = newcontent.IndexOf(item);//白名单所在位置
                            if (worindex == i - mx)
                            {
                                needreplace = false;
                                whitcount++;
                                newcontent = newcontent.Substring(0, worindex) + newcontent.Substring(worindex + item.Length);//把白名单替换掉
                                break;
                            }
                        }
                        if (needreplace == true)
                            newcontent = newcontent.Substring(0, i) + newcontent.Substring(i + word.Length);//把白名单替换掉
                    }
                    if (whitcount == wordcount)
                    {
                        result = false;
                    }
                    else
                    {
                        result = true;
                    }

                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());

            }
            return result;
        }
    }
}