using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace TinaX.IO
{
    public static class XFile
    {
        /// <summary>
        /// Get MD5
        /// </summary>
        /// <param name="fileName"></param>
        /// <param name="shortMd5">if true, return 16 bit md5</param>
        /// <returns></returns>
        public static string GetMD5(string fileName, bool shortMd5 = false)
        {
            try
            {
                FileStream file = new FileStream(fileName, System.IO.FileMode.Open);
                MD5 md5 = new MD5CryptoServiceProvider();
                byte[] retVal = md5.ComputeHash(file);
                file.Close();
                StringBuilder sb = new StringBuilder();
                for (int i = 0; i < retVal.Length; i++)
                {
                    sb.Append(retVal[i].ToString("x2"));
                }
                md5.Dispose();
                return shortMd5 ? sb.ToString().Substring(8, 16) : sb.ToString();
            }
            catch (Exception ex)
            {
                throw new Exception("GetMD5() fail,error:" + ex.Message);
            }
        }
        
        public static void DeleteIfExists(string path)
        {
            if (File.Exists(path))
                File.Delete(path);
        }
    
    }
}