#include <iostream>
#include <math.h>
#include <string>
#include <regex>
using namespace std;
void CheckIfCodeValid8(char BarCodeAdd8[]);
void CheckIfCodeValid13(char BarCodeAdd13[]);
bool isnum(string s);
const short Size1 = 8;
const short Size2 = 13;
long S = 0;
int ControlNumber = 0;
int main()
{
    int Choice;
    char BarCodeAdd[18];
    while (1)
    {
        cout << "Menu" << endl;
        cout << "Wybierz rodzaj kodu kreskowego" << endl;
        cout << "\t1. EAN-8."
            << "\n\t2. EAN-13."
            << "\n\t9 By zakonczyc program"<<endl;
        cin >> Choice;
        switch (Choice)
        {
        case 1:
            cout << "Wprowadz swoj kod" << endl;
            cin >> BarCodeAdd;
            try
            {
                CheckIfCodeValid8(BarCodeAdd);
            }
            catch (string w)
            {
                cout << "Exception: " << w;
            }

            cout << endl;
            break;
        case 2:
            cout << "Wprowadz swoj kod" << endl;
            cin >> BarCodeAdd;
            try
            {
                CheckIfCodeValid13(BarCodeAdd);
            }
            catch (string e)
            {
                cout << "Exception: " << e;
            }
            cout << endl;
            break;
        case 9:
            exit(1);
        default:
            break;
        }
    }
    return 0;
}
void CheckIfCodeValid8( char BarCodeAdd8[])
{
        S = 0;
        int BarCode8[Size1];
        string BarCodeCheck(BarCodeAdd8);
        if (isnum(BarCodeCheck))
        {
            if (BarCodeCheck.length() < 13)
            {
                for (int i = 0; i < Size1; i++)
                {
                    BarCode8[i] = BarCodeAdd8[i] - '0';
                }
                for (int i = 1; i < Size1; i++)
                {
                    S += ((2 - pow(-1, i)) * BarCode8[i - 1]);
                }
                ControlNumber = 10 - (S % 10);
                if (ControlNumber == BarCode8[Size1 - 1])
                {
                    cout << "\n Valid bar code:" << endl;
                    for (int i = 0; i < Size1; i++)
                    {
                        cout << BarCode8[i];
                    }
                }
                else
                {
                    cout << "\n Invalid bar code";
                    cout << "\n Valid Barcode is: " << endl;
                    BarCode8[Size1 - 1] = ControlNumber;
                    for (int i = 0; i < 8; i++)
                    {
                        cout << BarCode8[i];
                    }
                }
            }
            else
            {
                string Excp = "Your barcode shouldn't be longer than 13 numbers";
                throw Excp;
            }
        }
        else
        {
            string Excp = "Your barcode should include only numbers";
            throw Excp;
        }

}
void CheckIfCodeValid13(char BarCodeAdd13[])
{
    S = 0;
    int BarCode[Size2];
    string BarCodeCheck(BarCodeAdd13);
    if (isnum(BarCodeCheck)) {
        if (BarCodeCheck.length() < 18)
        {
            for (int j = 0; j < Size2; j++)
            {
                BarCode[j] = BarCodeAdd13[j] - '0';
            }
            for (int i = 1; i < Size2 - 1; i++)
            {
                S += ((2 - pow(-1, i)) * BarCode[i]);
            }
            ControlNumber = 10 - (S % 10);
            cout << ControlNumber << endl;
            if (ControlNumber == BarCode[Size2 - 1])
            {
                cout << "\n Valid bar code:" << endl;
                for (int i = 0; i < Size2; i++)
                {
                    cout << BarCode[i];
                }
            }
            else
            {
                cout << "\n Invalid bar code";
                cout << "\n Valid Barcode is: " << endl;
                BarCode[Size2 - 1] = ControlNumber;

                for (int i = 0; i < Size2; i++)
                {
                    cout << BarCode[i];
                }
            }
        }
        else
        {
            string Excp = "Your barcode shouldn't be longer than 18 numbers";
            throw Excp;
        }
    }
    else {
        string Excp = "Your barcode should include only numbers";
        throw Excp;
    }


}
bool isnum(string s) {

    regex e("[-+]?([0-9]*\.[0-9]+|[0-9]+)");

    if (regex_match(s, e))
        return true;

    return false;
}