#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
using namespace std;


struct inventorydata
{
char description[15];
int quantityonhand;
float wholesalecost;
float retailcost;
char dateadded[15];
};

int main()
{
    inventorydata record;
    char menu='Y';
    int number, recordnum=0, whichrecord, count=0;

    fstream inventory("inventorydata.dat", ios::in | ios::out | ios::binary | ios::beg);
    if (!inventory.good()) return -10000;

    while(menu == 'y'||menu == 'Y')
    {
        cout << "chose an option by typing the correct number: " << endl;
        cout << "add record: 1" << endl;
        cout << "display a record: 2" << endl;
        cout << "change record: 3" << endl;
        cin >> number;
        cout << endl;

        if (number == 1)
        {
            count+=1;

            inventorydata record = {"",0,0.0,0.0,""};

            cout << "Enter data\n";
            cout << "Description: \n";
            cin.ignore();
            cin.getline(record.description, 15);
            cout << "Quantity on hand: \n";
            cin >> record.quantityonhand;
                while (record.quantityonhand < 0){
                cout <<"Error cannot be negative\n";
                cin >> record.quantityonhand;}
            cout << "Wholesale cost: \n";
            cin >> record.wholesalecost;
                while (record.wholesalecost < 0){
                cout <<"Error cannot be negative\n";
                cin >> record.wholesalecost;}
            cout << "Retail cost: \n";
            cin >> record.retailcost;
                while (record.retailcost < 0){
                cout <<"Error cannot be negative\n";
                cin >> record.retailcost;}
            cout << "Date added: \n";
            cin >> record.dateadded;
                while (record.dateadded < 0){
                cout <<"Error a date cannot be negative.. \n";
                cin >> record.dateadded;}

            inventory.seekp(recordnum * sizeof(record), ios::beg);
            inventory.write(reinterpret_cast<char *>(&record), sizeof(record));

            recordnum += 1;

            cout << "do something else? y for yes.\n";
            cin >> menu;
        }
        else if(number == 2)
        {
            cout << "which record would you like to display?\n";
            cin >> whichrecord;
            while (whichrecord > count)
            {
                cout << "error: record not added\n";
                cin >> whichrecord;
            }
            whichrecord -=1;

            /*fstream inventory("inventorydata.dat", ios::in | ios::out | ios::binary);
            if (!inventory.good()) return -10000;*/
            inventory.seekg(whichrecord * sizeof(record), ios::beg);
            inventory.read(reinterpret_cast<char *>(&record), sizeof(record));

            cout << "Description: ";
            cout << record.description << "\n";
            cout << "Quantity on hand: ";
            cout << record.quantityonhand << "\n";
            cout << "Wholesale cost: ";
            cout << record.wholesalecost << "\n";
            cout << "Retail cost: ";
            cout << record.retailcost << "\n";
            cout << "Date added: ";
            cout << record.dateadded << "\n";
            //inventory.close();

            cout << "do something else? y for yes.\n";
            cin >> menu;
        }
        else if(number == 3)
        {

            cout << "which record would you like to edit?\n";
            cin >> whichrecord;
            while (whichrecord > count)
            {
                cout << "error: record not added\n";
                cin >> whichrecord;
            }
            whichrecord -=1;

            /*fstream inventory("inventorydata.dat", ios::in | ios::out | ios::binary);
            if (!inventory.good()) return -10000;*/
            inventory.seekg(whichrecord * sizeof(record), ios::beg);
            inventory.read(reinterpret_cast<char *>(&record), sizeof(record));

            cout << "Enter data\n";
            cout << "Description: \n";
            cin.ignore();
            cin.getline(record.description, 15);
            cout << "Quantity on hand: \n";
            cin >> record.quantityonhand;
            while (record.quantityonhand < 0){
            cout <<"Error cannot be negative\n";
            cin >> record.quantityonhand;}
            cout << "Wholesale cost: \n";
            cin >> record.wholesalecost;
            while (record.wholesalecost < 0){
            cout <<"Error cannot be negative\n";
            cin >> record.wholesalecost;}
            cout << "Retail cost: \n";
            cin >> record.retailcost;
            while (record.retailcost < 0){
            cout <<"Error cannot be negative\n";
            cin >> record.retailcost;}
            cout << "Date added: \n";
            cin >> record.dateadded;
            while (record.dateadded < 0){
            cout <<"Error a date cannot be negative.. \n";
            cin >> record.dateadded;}

            inventory.seekp(whichrecord * sizeof(record), ios::beg);
            inventory.write(reinterpret_cast<char *>(&record), sizeof(record));


            cout << "do something else? y for yes.\n";
            cin >> menu;

        }
    }
    inventory.close();
    return 0;
}