using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Data;
using System.Threading;


namespace Merge
{
    public class Program
    {
        static void Main(string[] args)//////TESTAR  TESTAR TESTAR TAMANHO MAXIMO!!!!!!!!!!!!!!!!!!!!!!!
        {
            FileHandling obj = new FileHandling();
            int opcao;
            do
            {
                Console.WriteLine("1 - Dividir");
                Console.WriteLine("2 - Juntar");
                opcao = int.Parse(Console.ReadLine());
                Console.WriteLine("Digite o caminho do arquivo");
                String arquivo = Console.ReadLine();
                if (opcao == 1)
                {
                    Console.WriteLine("Digite o tamanho de cada pedaco");
                    int tamanhoDoPedaco = int.Parse(Console.ReadLine());
                    obj.SplitUp(arquivo, tamanhoDoPedaco);
                }
                else if (opcao == 2)
                {
                    obj.MargeUp(arquivo);
                }
            } while (opcao != 1 && opcao != 2);
        }
    }


    //Operacao principal de arquivo eh feita aqui
    public class FileHandling
    {
        string caminho = string.Empty;
        int sliceLen = 512;  //512 bytes cada fatia
        int counter = 0;
        int limitesuperior = 0;
        float temp;

        public void SplitUp(string filename, int fileSizeInBytes)
        {
            byte[] buffer = new byte[sliceLen];
            //string curFileName;
            caminho = filename;
            caminho = caminho.Replace("\\", "\\\\");
            if (fileSizeInBytes < 1)
            {
                Console.WriteLine("You can't put less than 1 Byte");
                return;
            }
            else
                sliceLen = fileSizeInBytes;

            if (filename.Length < 1)
                return;

            counter = 0;

            BinaryReader br = new BinaryReader(new FileStream(caminho, FileMode.Open));
            //Verifica se a fatia eh maior que o tamanho do aquivo
            if (br.BaseStream.Length < sliceLen)
                sliceLen = (int)br.BaseStream.Length;

            //Comeca a partir
            for (int iteracao = 1; iteracao <= 5; iteracao++)
            {
                limitesuperior += (((int)br.BaseStream.Length / sliceLen) / 5 );
                if (iteracao == 5)
                {
                    temp = (float)br.BaseStream.Length / sliceLen;
                    if ((float)(br.BaseStream.Length % sliceLen) != 0) temp = (int)temp + 1;
                    temp = temp % 5;

                    limitesuperior = limitesuperior + (int)temp;
                    //Console.WriteLine("aaaaaaaaaaaaaaa: " + temp);
                    //Console.WriteLine("limite: " + limitesuperior);
                    //Console.WriteLine("tmanho: " + ((br.BaseStream.Length )));
                    //Console.WriteLine("pedaço: " + ((sliceLen)));
                }
                Worker workerObject = new Worker(counter, sliceLen, br, limitesuperior, filename);
                Thread workerThread = new Thread(workerObject.DoWork);
                workerThread.Start();
                //Console.WriteLine("limite superior: " + limitesuperior);
                counter = counter + ((int)br.BaseStream.Length / (sliceLen* 5));
            }
        }

        public void MargeUp(string firstFileName)
        {
            if (firstFileName.Length < 1)
                return;

            string endPart = firstFileName;
            string orgFile = "";

            orgFile = endPart.Substring(0, endPart.LastIndexOf("."));
            endPart = endPart.Substring(endPart.LastIndexOf(".") + 1);

            if (endPart == "E")//Se so houver um pedaco
            {
                orgFile = orgFile.Substring(0, orgFile.LastIndexOf("."));
                endPart = "0";
            }

            if (File.Exists(orgFile))
            {
                Console.WriteLine("Arquivo ja existe, quer deletar e fazer um novo?");
                Console.WriteLine("1 - Sim");
                Console.WriteLine("2 - Nao");
                int opcao = int.Parse(Console.ReadLine());
                do
                {
                    if (opcao == 1) File.Delete(orgFile);
                    else if (opcao == 2)
                    {
                        Console.WriteLine("Arquivo nao foi juntado. Operacao cancelada pelo usuario");
                        return;
                    }
                } while (opcao != 1 && opcao != 2);
            }

            //Junta a partir daqui
            BinaryWriter bw = new BinaryWriter(File.Open(orgFile, FileMode.Append));
            string nextFileName = "";
            byte[] buffer = new byte[bw.BaseStream.Length];


            int counter = int.Parse(endPart);
            while (true)
            {
                nextFileName = orgFile + "." + counter.ToString();
                if (File.Exists(nextFileName + ".E"))
                {
                    //Ultima fatia
                    buffer = File.ReadAllBytes(nextFileName + ".E");
                    bw.Write(buffer);
                    break;
                }
                else
                {
                    buffer = File.ReadAllBytes(nextFileName);
                    bw.Write(buffer);
                }
                counter++;
            }
            bw.Close();
            Console.WriteLine("File assembled successfully");
        }
    }

    public class Worker
    {
        int counter;
        int sliceLen;
        BinaryReader br;
        int limitesuperior;
        string filename;


        public Worker(int counter, int sliceLen, BinaryReader br, int limitesuperior, string filename)
        {
            this.counter = counter;
            this.sliceLen = sliceLen;
            this.br = br;
            this.limitesuperior = limitesuperior;
            this.filename = filename;
        }

        // This method will be called when the thread is started.
        public void DoWork()
        {
            byte[] buffer = new byte[sliceLen];
            string curFileName;
            while (counter != limitesuperior)
            {
                //Console.WriteLine(counter);
                if (br.BaseStream.Length > sliceLen * (counter + 1))
                {
                    br.BaseStream.Read(buffer, 0, sliceLen);
                    curFileName = filename + "." + counter.ToString();
                }

                else
                {
                    Console.WriteLine("Pego papai");
                    int remainLen = (int)br.BaseStream.Length - (sliceLen * counter);
                    Console.WriteLine();
                    buffer = new byte[remainLen];
                    br.BaseStream.Read(buffer, 0, remainLen);
                    curFileName = filename + "." + counter.ToString() + ".E";
                }

                if (File.Exists(curFileName)) File.Delete(curFileName);

                File.WriteAllBytes(curFileName, buffer);
                counter++;
            }

            //br.Close();
            Console.WriteLine("File splitted successfully");
            Console.Read();
        }
    }
}