using Newtonsoft.Json;

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Runtime.InteropServices.ComTypes;

using System.Text;

using NSmartProxy.Data;

using NSmartProxy.Infrastructure;

using Snappy.Sharp;

namespace NSmartProxy

{

public static class StringUtil

{

/// <summary>

/// 整型转双字节

/// </summary>

/// <param name="number"></param>

/// <returns></returns>

public static byte[] IntTo2Bytes(int number)

{

byte[] bytes = new byte[2];

bytes[0] = (byte)(number / 256);

bytes[1] = (byte)(number % 256);

return bytes;

}

/// <summary>

/// 客户端首次连接服务端时，需要发送标记以便服务端归类

/// </summary>

/// <param name="clientID"></param>

/// <param name="appid"></param>

/// <returns></returns>

public static byte[] ClientIDAppIdToBytes(int clientID, int appid)

{

byte[] bytes = new byte[3];

byte[] clientbytes = IntTo2Bytes(clientID);

bytes[0] = clientbytes[0];

bytes[1] = clientbytes[1];

bytes[2] = (byte)appid;

return bytes;

}

/// <summary>

/// 双字节转整型

/// </summary>

/// <param name="hByte"></param>

/// <param name="lByte"></param>

/// <returns></returns>

public static int DoubleBytesToInt(byte hByte, byte lByte)

{

return (hByte << 8) + lByte;

}

public static int DoubleBytesToInt(byte[] bytes)

{

return (bytes[0] << 8) + bytes[1];

}

public static string ToASCIIString(this byte[] bytes)

{

return System.Text.Encoding.ASCII.GetString(bytes);

}

public static byte[] ToASCIIBytes(this string str)

{

return System.Text.Encoding.ASCII.GetBytes(str);

}

/// <summary>

/// comma

/// </summary>

/// <param name="sb"></param>

/// <returns></returns>

public static StringBuilder C(this StringBuilder sb)

{

return sb.Append(",");

}

/// <summary>

/// delcomma

/// </summary>

/// <param name="sb"></param>

/// <returns></returns>

public static StringBuilder D(this StringBuilder sb)

{

return sb.Remove(sb.Length - 1, 1);

}

public static dynamic ToDynamic(this string jsonString)

{

return JsonConvert.DeserializeObject(jsonString);

}

public static T ToObject<T>(this string jsonString)

{

return JsonConvert.DeserializeObject<T>(jsonString);

}

public static TokenClaims ConvertStringToTokenClaims(string token)

{

try

{

token = EncryptHelper.AES_Decrypt(token);

string[] tokenarr = token.Split('|');

TokenClaims tkClaims = new TokenClaims();

tkClaims.UserKey = tokenarr[0];

try

{

tkClaims.LastTime = DateTime.Parse(tokenarr[1]);

}

catch

{

tkClaims.LastTime = new DateTime(2500, 1, 1);

}

return tkClaims;

}

catch (Exception ex)

{

throw new Exception("token格式不正确" + ex.ToString());

}

}

//From https://stackoverflow.com/questions/4619735/how-to-read-last-n-lines-of-log-file

///<summary>Returns the end of a text reader.</summary>

///<param name="reader">The reader to read from.</param>

///<param name="lineCount">The number of lines to return.</param>

///<returns>The last lneCount lines from the reader.</returns>

public static string[] Tail(this TextReader reader, int lineCount)

{

var buffer = new List<string>(lineCount);

string line;

for (int i = 0; i < lineCount; i++)

{

line = reader.ReadLine();

if (line == null) return buffer.ToArray();

buffer.Add(line);

}

int lastLine = lineCount - 1; //The index of the last line read from the buffer. Everything > this index was read earlier than everything <= this indes

while (null != (line = reader.ReadLine()))

{

lastLine++;

if (lastLine == lineCount) lastLine = 0;

buffer[lastLine] = line;

}

if (lastLine == lineCount - 1) return buffer.ToArray();

var retVal = new string[lineCount];

buffer.CopyTo(lastLine + 1, retVal, 0, lineCount - lastLine - 1);

buffer.CopyTo(0, retVal, lineCount - lastLine - 1, lastLine + 1);

return retVal;

}

/// <summary>

/// 在一个byte数组中查找另外一个byte数组的位置

/// </summary>

/// <param name="haystack"></param>

/// <param name="needle"></param>

/// <returns></returns>

public static int SearchBytesFromBytes(byte[] haystack, byte[] needle)

{

for (int i = 0; i <= haystack.Length - needle.Length; i++)

{

if (Match(haystack, needle, i))

{

return i;

}

}

return -1;

}

public static bool Match(byte[] haystack, byte[] needle, int start)

{

if (needle.Length + start > haystack.Length)

{

return false;

}

else

{

for (int i = 0; i < needle.Length; i++)

{

if (needle[i] != haystack[i + start])

{

return false;

}

}

return true;

}

}

/// <summary>

/// 判断字符串是否是无小数点纯数字

/// </summary>

/// <param name="str"></param>

/// <returns></returns>

public static bool IsNum(this string str)

{

for (int i = 0; i < str.Length; i++)

{

if (str[i] < '0' || str[i] > '9')

return false;

}

return true;

}

/// <summary>

/// 使用snappy算法解压缩

/// </summary>

/// <param name="compressed"></param>

/// <param name="offset"></param>

/// <param name="length"></param>

/// <returns></returns>

public static byte[] DecompressInSnappy(byte[] compressed, int offset, int length)

{

SnappyDecompressor sd = new SnappyDecompressor();

try

{

return sd.Decompress(compressed, offset, length);

}

catch (Exception ex)

{

_ = ex;

//啥情況？

return null;

}

}

/// <summary>

/// 使用snappy算法压缩

/// </summary>

/// <param name="uncompressed"></param>

/// <param name="offset"></param>

/// <param name="uncompressedLength"></param>

/// <returns></returns>

public static CompressedBytes CompressInSnappy(byte[] uncompressed, int offset, int uncompressedLength)

{

SnappyCompressor sc = new SnappyCompressor();

//var bytes = Encoding.ASCII.GetBytes("HelloWor134ertegsdfgsfdgsdfgsdfgsfdgsdfgsdfgsdfgsdfgdsfgsdfgdsfgdfgdsfgld");

byte[] outBytes = new byte[sc.MaxCompressedLength(uncompressed.Length)];

int actualLength = sc.Compress(uncompressed, 0, uncompressedLength, outBytes);

return new CompressedBytes() { ContentBytes = outBytes, Length = actualLength };

}

/// <summary>

/// 压缩专用对象

/// </summary>

public class CompressedBytes

{

public int Length;

public byte[] ContentBytes;

}

}

}