#include<iostream.h>
#include<ctype.h>

const double s_cost = 5.00; // dollars
const double m_cost = 7.00;
const double l_cost = 9.00;
const double t_cost =  .75;

const double    tax =  .10; // percent

void   take_order(int pizzas);
int    get_num_pizzas();
char   get_pizza_size(int count);
int    get_num_toppings(int count);
int    check_order(int small, int medium, int large, int toppings);
void   print_receipt(int small, int medium, int large, int toppings);
double calc_tax(double total);

/*
 *   Take a series of orders.
 *   For each order, determine number of pizzas and call take_order to handle order.
 *   Repeat until user enters zero for number of pizzas.
 */
void main()
{
  int orders, pizzas;
  
  cout << "Welcome to Pizza Yurt!" << endl;

  orders = 1;

  do
  {
    cout << "This is order " << orders << endl;
    
    pizzas = get_num_pizzas();  // check
    if (pizzas == 0)
        break;
            
    take_order(pizzas);
    orders++;
  } while (1);
  
  cout << "Thank you for working at Pizza Yurt!" << endl;
  
}

/*
 *   Take a single order. For each order, determine number of pizzas.
 *   For each pizza, determine size and number of toppings.
 *   Call check_order to print a summary of the order and verify.
 *   Repeat until order is correct, then print receipt.
 */
void take_order(int pizzas)
{
  int  small, medium, large;
  int  toppings;

  char size;
  
  int  count;                   // keep track of pizza number
  int  done     = 0;            // flag to test for correct order

  while ( ! done )              // until order is correct
  { 
    small = medium = large = toppings = 0;
    count = 1;
    do                          // for each pizza
    {
        size = get_pizza_size(count);
    
        if (size == 's')
            small++;
        else if (size == 'm')
            medium++;
        else                    // size must be large
            large++;

		// get toppings
        toppings = toppings + get_num_toppings(count);

		// increase number of pizzas entered for this order
        count = count + 1;

    } while (count <= pizzas);
    
    // check_order prints summary and returns "true" only if order is OK
    done = check_order(small, medium, large, toppings);
 
  } 
  
  // print_recept calculates the total with tax
  print_receipt(small, medium, large, toppings);
}

/* 
 *  Check the user input to obtain a non-negative number of pizzas for an order. 
 *  Returns 0 if user wants to quit.
 *  Does NOT check for non-numerical entries.
 */
int get_num_pizzas()
{
    int pizzas;
    
    do
    {   cout << "How many pizzas would you like ? ";
        cin >> pizzas;
        
        if (pizzas < 0)
            cout << "Please enter a positive number, or 0 to quit." << endl;
            
    } while (pizzas < 0);
    
    return pizzas;
}


/*
 *   Check user input to obtain a pizza size of 's', 'm' or 'l'
 *   Uses the ctype.h function tolower to take care of uppercase input
 *   Only returns one of the 3 legal chars.
 */
char get_pizza_size(int number)
{
    char size;
    
    do
    {   
        cout << "What size pizza would you like (S, M, L) for pizza ";
        cout << number;
        cout << " ? ";          
        
        cin >> size;
        size = tolower(size);           
        
        if (size != 's' && size !='m' && size !='l')
            cout << "You may choose from S, M, or L." << endl;
        else
            return size;
    } while (1);
}

/*
 *   Check the user input to obtain a non-negative number of toppings for a pizza.
 *   Returns 0 if user wants no toppings.
 *   Does NOT check for non-numerical entries.
 */
int get_num_toppings(int number)
{
    int toppings;
    
    do
    {
        cout << "How many toppings would you like on pizza ";
        cout << number;  
        cout << " ? ";          
        
        cin >> toppings;
        
        if (toppings < 0)
            cout << "Please enter a positive number, or 0 for none." << endl;
        
    } while (toppings < 0);
    
    return toppings;
}

/* 
 *   Prints number of small, medium, and large pizzas ordered.
 *   Prints total number of toppings ordered.
 */
int check_order(int small, int medium, int large, int toppings)
{
    char ok;
    
    cout << "Your order is:" << endl;
    
    if (small > 0)
        cout << small << " small pizzas" << endl;

    if (medium > 0)
        cout << medium << " medium pizzas" << endl;
        
    if (large > 0)
        cout << large << " large pizzas" << endl;
        
    if (toppings == 0)
        cout << "no toppings" << endl;
    if (toppings > 0)
        cout << toppings << " toppings" << endl;
        
    do
    {
        cout << "Is this correct ? ";
        cin >> ok;
        
        if (ok == 'y' || ok =='Y')
            return 1;
        
        if (ok == 'n' || ok =='N')
            return 0;
            
    } while (1);
}

/* 
 *   Prints number of small, medium, and large pizzas ordered.
 *   Prints total number of toppings ordered.
 *   If quantity of a given item is 0, nothing is printed for that item.
 *   For each item, calculates and displays subtotal and total order cost.
 *   Uses calc_tax() to display tax and total cost.
 */
void print_receipt(int small, int medium, int large, int toppings)
{
    double total = 0;
    double sub, tax;

    // format cout for "money style" floating point numbers
    cout.setf(ios::fixed);
    cout.setf(ios::showpoint);
    cout.precision(2);
    
    if (small > 0)
    {
        cout << small << " small pizzas  $ ";
        sub = small * s_cost;
        cout << sub << endl;
        total = total + sub;
    }
    
    if (medium > 0)
    {
        cout << medium << " medium pizzas $ "; 
        sub = medium * m_cost;
        cout << sub << endl;
        total = total + sub;
    }
        
    if (large > 0)
    {
        cout << large << " large pizzas  $ ";
        sub = large * l_cost;
        cout << sub << endl;
        total = total + sub;
    }   
    
    if (toppings > 0)
    {
        cout << toppings << " toppings      $ ";
        sub = toppings * t_cost;
        cout << sub << endl;
        total = total + sub;
    }
    
    cout << endl << "  subtotal      $ " << total;
    
    tax = calc_tax(total);  
    cout << endl << "       tax      $ " << tax << endl;
    
    total = total + tax;
    cout << endl << "  TOTAL         $ " << total << endl;
    
    // could return total here...   
}

/* 
 *   Calculates tax using global constant tax, returns tax only.
 */
double calc_tax(double total)
{
  return (total * tax);
}

/* SAMPLE RUN

Welcome to Pizza Yurt!
This is order 1
How many pizzas would you like ? 3
What size pizza would you like (S, M, L) for pizza 1 ? s
How many toppings would you like on pizza 1 ? 1
What size pizza would you like (S, M, L) for pizza 2 ? m
How many toppings would you like on pizza 2 ? 2
What size pizza would you like (S, M, L) for pizza 3 ? l
How many toppings would you like on pizza 3 ? 3
Your order is:
1 small pizzas
1 medium pizzas
1 large pizzas
6 toppings
Is this correct ? y
1 small pizzas  $ 5.00
1 medium pizzas $ 7.00
1 large pizzas  $ 9.00
6 toppings      $ 4.50

  subtotal      $ 25.50
       tax      $ 2.55

  TOTAL         $ 28.05
This is order 2
How many pizzas would you like ? 1
What size pizza would you like (S, M, L) for pizza 1 ? s
How many toppings would you like on pizza 1 ? 3
Your order is:
1 small pizzas
3 toppings
Is this correct ? y
1 small pizzas  $ 5.00
3 toppings      $ 2.25

  subtotal      $ 7.25
       tax      $ 0.73

  TOTAL         $ 7.97
This is order 3
How many pizzas would you like ? 0
Thank you for working at Pizza Yurt!
*/