using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace HashFiles
{
    class Program
    {
        static string Paths = System.IO.Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location);

        static void Main(string[] args)
        {
            CreateFile();
            Console.WriteLine("Attempting to Hash your Files!");
            string filepath = Paths + "/files/";
            Console.WriteLine("Path: "+filepath);
            string[] localfilelist = Directory.GetFiles(filepath, "*", SearchOption.AllDirectories);
            string[] localfilenames = new string[localfilelist.Length];
            string[] md5 = new string[localfilelist.Length];
            for (int i = 0;i<localfilelist.Length;i++)
            {
                md5[i] = CalculateMD5(localfilelist[i]);
                Console.WriteLine("Hashing "+localfilelist[i]+" Hash: "+md5[i]);
            }
            for (int i = 0; i < localfilenames.Length; i++)
            {
                localfilenames[i] = localfilelist[i].Replace(filepath, "");
            }
            using (StreamWriter sw = new StreamWriter("manifest.txt", true))
            {
                for (int i = 0; i < localfilelist.Length; i++)
                {
                    string[] split = Regex.Split(localfilelist[i], "/files/");

                    sw.WriteLine(split[1]+"="+localfilenames[i]+"="+md5[i]);
                }
                sw.Close();

                Console.WriteLine("Finished");
                Console.ReadLine();
            }
        }

        public static void CreateFile()
        {
            if (!File.Exists("manifest.txt"))
            {
                File.Create("manifest.txt");
            }
        }

        public static  string CalculateMD5(string filename) //calculate MD5s the same way HashMyFiles does it
        {
            using (var md5 = MD5.Create())
            {
                using (var stream = File.OpenRead(filename))
                {
                    var hash = md5.ComputeHash(stream);
                    return BitConverter.ToString(hash).Replace("-", "").ToLowerInvariant();
                }
            }
        }
    }
}