/*
    This source code does not compile on Turbo C++. If you are working on that
    compiler, please, use the translate button selecting the option Dynamic array in C.
*/
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <string>
#include <vector>
#include <algorithm>
#ifdef __linux__
    #include <termios.h>
    #include <unistd.h>
    #define CLEAR_SCREEN "clear"
    int _getch ();
#else
    #include <conio.h>
    #define CLEAR_SCREEN "cls"
#endif
using namespace std;

class Book {
public:
    string ISBN;
    string title;
    string author;
    string publisher;
    int number_of_pages;
    int year;

    Book() {}
    ~Book() {}

    bool operator==(const Book &book) const
    {
        return this==&book || this->ISBN==book.ISBN;
    }

    bool operator!=(const Book &book) const
    {
        return this!=&book && this->ISBN!=book.ISBN;
    }

    bool operator<(const Book &book) const
    {
        return this->ISBN<book.ISBN;
    }

    Book& operator=(const Book &book)
    {
        if (this!=&book)
        {
            this->ISBN = book.ISBN;
            this->title = book.title;
            this->author = book.author;
            this->publisher = book.publisher;
            this->number_of_pages = book.number_of_pages;
            this->year = book.year;
        }
        return *this;
    }

    static void print (Book &book, int *counter);
    static void print_on_file (Book &book, ostream *file_stream);
};

void   pause_screen (const char *message);
string read_str (const char *message);
int    read_integer (const char *message);
bool   read_field (istream &file_stream, char *field, char delimiter);

const char *path = "books.tsv";

int main ()
{
    vector<Book> books;
    vector<Book>::iterator i;
    Book *datum, book;
    int counter=0, main_option, suboption;
    char field[255];
    ifstream file_stream (path);
    if (file_stream!=NULL)
    {
        while (read_field (file_stream, field, '\t'))
        {
            book.ISBN = field;
            read_field (file_stream, field, '\t');
            book.title = field;
            read_field (file_stream, field, '\t');
            book.author = field;
            read_field (file_stream, field, '\t');
            book.publisher = field;
            read_field (file_stream, field, '\t');
            book.number_of_pages = atoi (field);
            read_field (file_stream, field, '\n');
            book.year = atoi (field);
            books.push_back (book);
        }
        file_stream.close();
    }
    do {
        cout << endl;
        system (CLEAR_SCREEN);
        cout << "MENU" << endl;
        cout << "1.- Insertions" << endl;
        cout << "2.- Queries" << endl;
        cout << "3.- Updates" << endl;
        cout << "4.- Deletions" << endl;
        cout << "5.- Sort records" << endl;
        cout << "6.- List records" << endl;
        cout << "7.- Exit" << endl;
        cout << "Select an option: ";
        do
            main_option = _getch ();
        while (main_option<'1' || main_option>'7');
        cout << (char)main_option << endl << endl;
        if (books.empty() && main_option!='1' && main_option!='7')
        {
            pause_screen ("There are not records.\n");
            continue;
        }
        if (main_option<'5')
        {
            book.ISBN = read_str ("Enter the ISBN of the book");
            i = find (books.begin(), books.end(), book);
            datum = i != books.end() ? &books[i - books.begin()] : NULL;
            if (datum!=NULL)
            {
                cout << endl;
                Book::print (*datum, &counter);
            }
        }
        if (main_option=='1' && datum!=NULL)
            cout << "The record already exists." << endl;
        else if (main_option>='2' && main_option<='4' && datum==NULL)
            cout << endl << "Record not found." << endl;
        else switch (main_option)
        {
            case '1':
                book.title = read_str ("Enter the title");
                book.author = read_str ("Enter the author");
                book.publisher = read_str ("Enter the publisher");
                book.number_of_pages = read_integer ("Enter the number of pages");
                book.year = read_integer ("Enter the year");
                books.push_back (book);
                cout << endl << "Record added correctly." << endl;
                break;
            case '3':
                cout << "Menu of fields updating" << endl;
                cout << "1.- title" << endl;
                cout << "2.- author" << endl;
                cout << "3.- publisher" << endl;
                cout << "4.- number of pages" << endl;
                cout << "5.- year" << endl;
                do {
                    suboption = read_integer ("Select a field number to be updated");
                    if (suboption<1 || suboption>5)
                        printf ("Incorrect option.\n");
                } while (suboption<1 || suboption>5);
                switch (suboption)
                {
                    case 1:
                        datum->title = read_str ("Enter the new title");
                        break;
                    case 2:
                        datum->author = read_str ("Enter the new author");
                        break;
                    case 3:
                        datum->publisher = read_str ("Enter the new publisher");
                        break;
                    case 4:
                        datum->number_of_pages = read_integer ("Enter the new number of pages");
                        break;
                    case 5:
                        datum->year = read_integer ("Enter the new year");
                        break;
                }
                cout << endl << "Record updated correctly." << endl;
                break;
            case '4':
                books.erase (find (books.begin(), books.end(), *datum));
                cout << "Record removed correctly." << endl;
                break;
            case '5':
                sort (books.begin(), books.end());
                cout << "Records sorted correctly." << endl;
                break;
            case '6':
                counter = 0;
                for (i=books.begin(); i!=books.end(); i++)
                    Book::print (*i, &counter);
                cout << "Total of records: " << counter << "." << endl;
                break;
        }
        if (main_option!='7')
            pause_screen ("");
    } while (main_option!='7');
    ofstream output_stream (path);
    if (output_stream!=NULL)
    {
        for (i=books.begin(); i!=books.end(); i++)
            Book::print_on_file (*i, &output_stream);
        output_stream.close();
    }
    return EXIT_SUCCESS;
}

void Book::print (Book &book, int *counter)
{
    cout << "ISBN           : " << book.ISBN.c_str() << endl;
    cout << "title          : " << book.title.c_str() << endl;
    cout << "author         : " << book.author.c_str() << endl;
    cout << "publisher      : " << book.publisher.c_str() << endl;
    cout << "number of pages: " << book.number_of_pages << endl;
    cout << "year           : " << book.year << endl;
    cout << endl;
    (*counter)++;
}

void Book::print_on_file (Book &book, ostream *file_stream)
{
    *file_stream << book.ISBN.c_str() << "\t";
    *file_stream << book.title.c_str() << "\t";
    *file_stream << book.author.c_str() << "\t";
    *file_stream << book.publisher.c_str() << "\t";
    *file_stream << book.number_of_pages << "\t";
    *file_stream << book.year << endl;
}

string read_str (const char *message)
{
    char string_var[255];
    cout << message << ": ";
    cin.get (string_var, sizeof (string_var), '\n');
    cin.get();
    string str(string_var);
    return str;
}

int read_integer (const char *message)
{
    int integer_var;
    cout << message << ": ";
    cin >> integer_var;
    cin.get();
    return integer_var;
}

bool read_field (istream &file_stream, char *str, char delimiter)
{
    file_stream.get (str, 255, delimiter);
    file_stream.get();
    return !file_stream.eof();
}

void pause_screen (const char *message)
{
    cout << message << endl << "Press any key to continue . . . ";
    _getch ();
}

#ifdef __linux__

int _getch ()
{
    int ch;
    struct termios oldt, newt;
    tcgetattr (STDIN_FILENO, &oldt);
    newt = oldt;
    newt.c_lflag &= ~(ICANON | ECHO);
    tcsetattr (STDIN_FILENO, TCSANOW, &newt);
    ch = getchar();
    tcsetattr (STDIN_FILENO, TCSANOW, &oldt);
    return ch;
}

#endif