using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Security.Cryptography;
//using MySql.Data.MySqlClient;
using System.Data;
using System.Text.RegularExpressions;

namespace AntiVirus
{
    class Program
    {
        static void Main(string[] args)
        {
            //string connectionString = "datasource=localhost;port=3306;username=root;password=ece426";
            //MySqlConnection connection = new MySqlConnection(connectionString);
            //MySqlDataAdapter myDataAdapter = new MySqlDataAdapter();
            //myDataAdapter.SelectCommand = new MySqlCommand("SELECT * FROM virusdb.sha256;", connection);
            //MySqlCommandBuilder cb = new MySqlCommandBuilder(myDataAdapter);
            DataSet ds = new DataSet();
            //myDataAdapter.Fill(ds);
            //connection.Open();
            Console.WriteLine("Connected to mySQL.");
            foreach (var file in Directory.EnumerateFiles(@"C:\\Users\Nick\\Desktop\\ECE426L\\AntiVirus\\VirusTextFiles\\"))
            {

                int i = 0;
                FileStream stream = File.OpenRead(file);
                string md5result = GetMd5Hash(stream);
                string sha256result = GetSha256Hash(stream,file);

                string answer = " ";
                foreach (DataRow row in ds.Tables[0].Rows)
                {
                    //string x = (row["hash"].ToString());
                    Regex regex = new Regex(@row["hash"].ToString());
                    Match match1 = regex.Match(md5result);
                    Match match2 = regex.Match(sha256result);
                    if(match1.Success || match2.Success)
                    {
                        Console.WriteLine("There is a virus.");
                    }
                }
                if (answer == "yes")
                {
                    stream.Close();
                    File.Delete(file);
                }
                Console.WriteLine("Scanning completed.");
                Console.WriteLine();
                i++;
            }
            //connection.Close();
            Console.ReadLine();
            //StreamReader ReadFile = new StreamReader(Value);
        }
        static string GetSha256Hash(FileStream filename, string file)
        {
            var sha = new SHA256Managed();
            byte[] SHAchecksum = sha.ComputeHash(filename);
            Console.WriteLine("Scanning " + Path.GetFileName(file) + "...");
            byte[] content = File.ReadAllBytes(file);
            StringBuilder sb = new StringBuilder();
            foreach (byte b in content)
                sb.Append(b.ToString("X2"));
            string hexString = sb.ToString();
            //Console.WriteLine("Displaying the hex values of the file..");
            //Console.WriteLine(hexString);
            Console.WriteLine("Hashing the string with SHA-256..");
            Console.WriteLine(BitConverter.ToString(SHAchecksum).Replace("-", String.Empty));
            return BitConverter.ToString(SHAchecksum).Replace("-", String.Empty);
        }
        static string GetMd5Hash(FileStream filename)
        {
            using (var md5 = MD5.Create())
            {
                var hash = md5.ComputeHash(filename);
                return BitConverter.ToString(hash).Replace("-", "").ToLowerInvariant();
            }
        }

    }
}