#define _CRT_SECURE_NO_WARNINGS
#include<iostream>
#include<conio.h>
#include<cctype>
#include<stdlib.h>
#include<cstring>
#include<fstream>
#include<iomanip>
#include<type_traits>
#include<Windows.h>
#include<stdio.h>
#include<string.h>
using namespace std;
struct Factory
{
    char name[50];
    char ownership[50];
    char area[50];
    char workers[50];
    Factory* next;
};
bool MyAudit(const char* string)
{
    const char* temp = "0123456789-+.";
    unsigned int number = 0;

    for (int i = 0; i < strlen(string); i++)   //strlen(string) -- функція що повертає розмір рядка 'string'
    {
        if ((i > 0) && (string[i] == '+' || string[i] == '-')) //шукаємо '+' або '-' в рядку 'string'
        {
            return false;
        }
        if (string[i] == '.') //шукаємо крапку 
        {
            number++;
            if (number > 1) //перевіряємо чи не більше однієї крапки в рядку
            {
                return false;
            }
        }
        if (strchr(temp, string[i]) == 0) //ми перевіряємо наш рядок 'string' на цифри і на "+-."
        {
            return false;
        }
    }
    return true;
}
int IsEmpty(Factory** first) //перевірка пустоти черги
{
    if (first == NULL)
    {
        return 1;
    }        
    else
    {
        return 0;
    }
        
}
void AddNew(Factory** last, Factory** first)
{    
    if (first = NULL)
    {
        *first = new(Factory);
        last = first;       
        cout << "Enter the factory name: ";
        cin >> (*first)->name;
        cout << "The types of property: N - national, P - private, C - cooperative";
        cout << "\nEnter the type of property: ";
        cin >> (*first)->ownership;
        cout << "Enter the area of land(hectares): ";
        cin >> (*first)->area;
        while (MyAudit((*first)->area) != true)
        {
            cout << "\nError! Enter a correct value: ";
            cin >> (*first)->area;
        }
        cout << "Enter the number of workers: ";
        cin >> (*first)->workers;
        while (MyAudit((*first)->workers) != true)
        {
            cout << "\nError! Enter a correct value: ";
            cin >> (*first)->workers;
        }
        (*first)->next = 0;
    }
    else
    {        
        Factory* temp = new(Factory);
        temp->next = 0;
        cout << "Enter the factory name: ";
        cin >> temp->name;
        cout << "The types of property: N - national, P - private, C - cooperative";
        cout << "\nEnter the type of property: ";
        cin >> temp->ownership;
        cout << "Enter the area of land(hectares): ";
        cin >> temp->area;
        while (MyAudit(temp->area) != true)
        {
            cout << "\nError! Enter a correct value: ";
            cin >> temp->area;
        }
        cout << "Enter the number of workers: ";
        cin >> temp->workers;
        while (MyAudit(temp->workers) != true)
        {
            cout << "\nError! Enter a correct value: ";
            cin >> temp->workers;
        }       
        (*last) = temp;
    }
}
void Show(Factory* first)
{
    Factory* tmp = first->next;
    while (tmp != NULL)
    {        
        cout << "\n" << tmp->name;
        cout << "\n" << tmp->ownership;
        cout << "\n" << tmp->area;
        cout << "\n" << tmp->workers;
        tmp = tmp->next;        
    }    
    _getch();
}
void main()
{
    Factory* first = NULL;
    Factory* last = NULL;   
    int size = 0;
    bool index = false;
    while (index != true)
    {
        cout << "\t Menu: \n";
        cout << "1.View the list of factorys\n";
        cout << "2.Add a new factory\n";
        cout << "3.Exit\n";
        cout << "---------------\n";
        cout << "Enter the number" << endl;
        int menu;
        cin >> menu;
        system("cls");
        switch (menu)
        {
        case 1:
        {
            if (IsEmpty(&first) == 1)
            {
               cout << "Database is empty";
            }                
            else
            {                
                Show(first);                
            }            
            system("cls");
            break;
        }
        case 2:
        {
            AddNew(&last, &first);
            size++;
            system("cls");
            break;
        }
        case 3:
        {
            index = true;
            break;
        }
        default:
        {
            cout << "A non-existent menu item is selected\n";
        }
        }
    }
}