using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.IO;
using System.Text;

namespace Sog.Service
{
    public class DirtyService : Singleton<DirtyService>
    {
        private Dictionary<string, int> m_dirtyDict = new Dictionary<string, int>();

        public void InitFromFile(string filename)
        {
            if (!File.Exists(filename))
            {
                TraceLog.Error("DirtyService.InitFromFile file {0} not exists", filename);
                return;
            }

            //这样支持reload
            m_dirtyDict.Clear();

            string[] allline = File.ReadAllLines(filename);

            foreach(var line in allline)
            {
                if(string.IsNullOrEmpty(line))
                {
                    continue;
                }

                if (string.IsNullOrWhiteSpace(line))
                {
                    continue;
                }

                if(line.Length < 2)
                {
                    continue;
                }

                string lowLine = line.ToLower();

                if (m_dirtyDict.ContainsKey(lowLine))
                {
                    continue;
                }

                //转成小写
                m_dirtyDict.Add(lowLine, 1);
            }
        }

        // true表示有字符被替换
        public bool ReplaceDirtyText(string content, out string outcontent)
        {
            outcontent = content;

            string lowContent = content.ToLower();
            char[] charArray = null;

            //bool bReplace = false;

            foreach (var dirty in m_dirtyDict.Keys)
            {
                //可能包含同一个脏词多次，所以要遍历
                int index = lowContent.IndexOf(dirty);
                while(index >= 0)
                {
                    if(charArray == null)
                    {
                        charArray = content.ToArray();
                    }

                    for (int i = 0; i < dirty.Length; i++)
                    {
                        charArray[index + i] = '*';
                    }

                    index = lowContent.IndexOf(dirty, index + dirty.Length);
                }
            }

            if(charArray == null)
            {
                return false;
            }

            StringBuilder builder = new StringBuilder(charArray.Length);
            builder.Append(charArray);

            outcontent = builder.ToString();

            return true;


                
        }
    }
}