// Code/decode symbols from cp1251 by their codes

//#include "stdafx.h"
#include <iostream>
#include <cstdio>
//#include <Windows.h>
#include <fstream>
#include <cstring>

#define ADDSIZE 10 // memory alloc defined

using namespace std;

int main(int argc, char* argv[])
{
    short int start_ans;
    if(argc == 2)
        start_ans = 1;

    cout << "Hello there! This program can CODE/DECODE text\n";
    do
    {
        cout << "\nWhat do you want to do?\n\n"
            << " [1] Open file with text\n [2] Write text here\n\n"
            << "Your answer will be: ";
        cin >> start_ans;
    } while (start_ans != 1 && start_ans != 2);

    if (start_ans == 1)
    {
        // File name

        /*char f_name[90];
        cout << "\nEnter file full path\nor name: ";
        fflush(stdin);
        //gets(f_name); // dangerous
        while((fgets(f_name, sizeof(f_name)-1, stdin)) != NULL) { // fgets() will be safer
            f_name[strlen(f_name)-1] = '\0';
            fflush(stdin);
        } */

        // Open file

        ifstream f0_stream(argv[1], ios::in | ios::binary);
        if (!f0_stream)
        {
            cout << "\nError in opening...\n\n";
            //system("pause");
            return 1;
        }
        else
            cout << "\nFile successfully opened!\n\n";

        // Search chars number in file

        register short int chs_in_file = 0;
        char test;
        while (f0_stream.get(test)) chs_in_file++;
        cout  << "chars: " << chs_in_file << "\n\n";

        // Rewind f_srteam:

        f0_stream.close();
        ifstream f_stream(argv[1], ios::in | ios::binary);
        if (!f_stream)
            return 1;

        // Allocate memory
        cout << "chs_in_file + " << ADDSIZE << ": " << chs_in_file + ADDSIZE;
        char *ptr_file_buf = new char [chs_in_file + ADDSIZE];
        /*if (!*ptr_file_buf)
        {
            cout << "\nError in memory allocating...\n\n";
            //system("pause");
            return 1;
        } */

        // Copy information in buffer & preview

        //system("pause");
        cout << "\n''" << argv[1] << "'' preview:\n\n";
        register short int i = 0;
        while (f_stream.get(*ptr_file_buf))
        {
            cout << endl << ++i << endl; // Number of char we working on
            if (i <= 100) cout << *ptr_file_buf;
            //ptr_file_buf++; // Do not use, iteration already in while();
        }
        *ptr_file_buf = '\0';

        if (i > 100) cout << "\n\n... [etc.]\n\n";
        delete [] ptr_file_buf; //                                                      !!! HERE IS A TRABL

    }

    //system("pause");
    return 0;
}