// Kyleigh Brown, Deena Dayal, Shawntraree Lucas, Rodney Sampson II
// Dr. Lawrence
// CIS 346 - Theory of Programming Languages
// Cash Register Project

// Design a CashRegister class that can be used with an InventoryItem class.
// The CashRegister class should perform the following:
//      1.  Ask the user for the item and quantity being purchased.
//      2.  Get the item’s cost from the InventoryItem object. 
//          Inventory Items should have a name, cost, and quantity available.
//      3.  Add a 30% profit to the cost to get the item’s unit price.
//      4.  Multiply the unit price times the quantity being purchased
//          to get the purchase subtotal.
//      5.  Compute a 6% sales tax on the subtotal to get the purchase total.
//      6.  Repeat until user has entered all desired items.
//      7.  Display the items purchased,  subtotal, tax, and total on the screen.
//      8.  Subtract the quantity being purchased from the onHand variable of the
//          InventoryItem class object.

// Implement both classes in a complete program. Feel free to modify the
// InventoryItem class in any way necessary.

// Input Validation: Do not accept a negative value for the
// quantity of items being purchased.

#include <iostream>
#include <string>
#include <iomanip>

using namespace std;

class InventoryItem {
    private:
        // Variables for the name of item, quantity and cost
        string name;
        int quantity;
        double cost;

    public:
        // Constructors for InventoryItem
        InventoryItem(string name = "", int quantity = 0, double cost = 0){
            //set the variables to their new names
            this->name = name;
            this->quantity = quantity;
            this->cost = cost;
        }
        
        // Getter for name
        string getName() const {
            return this->name;
        }

        // Getter for the quantity
        int getQuantity() const {
            return this->quantity;
        }

        //Getter for the cost
        double getCost() const {
            return this->cost;
        }

        // Setter for the name
        void setName(string name) {
            this->name = name;
        }

        // Setter for the quantity
        void setQuantity(int quantity) {
            this->quantity = quantity;
        }

        // Setter for the cost
        void setCost(double cost) {
            this->cost = cost;
        }
};

class CashRegister {
    private:
        // Variables for the subtotal, tax & total
        double subTotal;
        double tax;
        double total;
  
    public:
        // Defualt constructor
        CashRegister() {
            this->subTotal = 0.0;
            this->tax = 0.0;
            this->total = 0.0;
        }

        // Function for the user to make their purchase
        void makePurchase(InventoryItem available[]) {
            //variable to store their choice of item and quantity
            int itemChoice, itemQuantity;
            //ask user for their item choice
            cout << "Enter item number: ";
            //take their input of choice
            cin >> itemChoice;
            //subtract 1 from the selected item
            itemChoice--; 
            //display the selected item
            cout << "The item you selected is: ";
            //display the selected item
            cout << available[itemChoice].getName();
            //ask user for the quantity
            cout << "\nEnter the quantity: ";
            //take quantity as input
            cin >> itemQuantity;

            //if the input of quantity is less than 0
            while (itemQuantity < 0){
                //prompt user for new quantity
                cout << "\nNo negative inputs. Please enter a new quantity: ";
                //take the new input as the new quantity
                cin >> itemQuantity;
            }
    
            //if the user asks for more items than available
            while(itemQuantity > available[itemChoice].getQuantity()) {
                //tell the user how many items they have available
                cout << "\nThere are only " << available[itemChoice].getQuantity() << " available.\n";
                //ask the user to input a new item quantity
                cout << "Please enter a new quantity: ";
                //take the user's new input
                cin >> itemQuantity;
            }

            //calculate the subtotal with the cost of the item and the quantity
            calcSubTotal(available[itemChoice].getCost(), itemQuantity);
            //calculate the tax with the subtotal
            calcTax(subTotal);
            //calculate the final total
            calcTotal();

            //set the new quantity to the original quantity minus the user's quantity input
            available[itemChoice].setQuantity(available[itemChoice].getQuantity() - itemQuantity);
        }

        //function to calculate subtotal with cost and quantity
        void calcSubTotal(double cost, int itemQuantity) {
            //multiply the cost by 1.3
            double unitCost = 1.3 * cost;
            //subtotal is cost times quantity
            subTotal = unitCost * itemQuantity;
        }

        //function to calculate tax with subtotal
        void calcTax(double subTotal) {
            //tax is subtotal times 6%
            tax = 0.06 * subTotal;
        }

        //function to calculate total
        void calcTotal() {
            //total is subtotal plus tax
            total = subTotal + tax;
        }

        //getter for subtotal
        double getSubTotal() const {
            //return the subtotal
            return subTotal;
        }

        //getter for tax
        double getTax() const {
            //return the tax
            return tax;
        }

        //getter for total
        double getTotal() const {
            //return the total
            return total;
        }
};

//function to show available items
void display(InventoryItem items[]){
  //print values to make a table
  cout << "\n\t\t\tItem\t\t\t\t\t   Quantity\t\t\t\t  Price\n";
  cout << "--------------------------------------------------------------------\n";

  //iterate 5 times to print out each grocery item
  for(int i = 0; i < 5; i++){
    //print out the item #
    cout << "Item #" << i+1 << "\t\t";
    //print out the item name
    cout << items[i].getName() << "\t\t\t\t\t\t";
    //print out the item quantity
    cout << items[i].getQuantity() << "\t\t\t\t\t\t";
    //print out the item cost
    cout << items[i].getCost() << endl;
  }
}

int main() {
  //set 5 items to the array of items for purchase
  //set their names, quantities & prices
  InventoryItem items[5] = {
    //20 milks for $3.68 each
    InventoryItem("Milk", 20, 2.99),
    //30 eggs for $1.72 each
    InventoryItem("Eggs", 30, 1.69),
    //25 breads for $1.41 each
    InventoryItem("Bread", 25, 1.99),
    //15 cheeses for $2.04 each
    InventoryItem("Cheese", 15, 2.59),
    //35 waters for $4.38 each
    InventoryItem("Water", 35, 3.99)
  };
  
  int choice;
  CashRegister cashRegister;

  cout << "CASH REGISTER";

  // use a do while loop to display a menu for user to purchase items
  do {
    // ask the user if they would like to shop (1) or quit (0)
    cout << "\n\n1) Start shopping!";
    cout << "\n0) Stop shopping";
    cout << "\nEnter your number choice: ";
    // take the user's input
    cin >> choice;

    // switch case with the user's choice
    switch(choice) {
      case 1:
        // display the available items
        display(items);
        cout << endl;
        // use the items to make a purchase
        cashRegister.makePurchase(items);
        // display information about the totals to 2 decimals
        cout << "\nSubtotal: $";
        printf("%.2f", cashRegister.getSubTotal());
        cout << "\nSales tax: $";
        printf("%.2f", cashRegister.getTax());
        cout << "\nTotal: $";
        printf("%.2f", cashRegister.getTotal());
        break;
      case 2:
        break;
    }
  } while(choice != 0);
}