/*  Chetan Grewal
    Lab 4
    Description:

*/

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

// Sets up struct
struct drinkInfo{
    string name;
    double price;
    int quantity;
};

//Money calculation function
void moneyCalc(double &due, double &total);

int main(){

    drinkInfo drinks[5]; // Makes array for the struct
    int choice = 0; // Drink option user selects
    double due;
    double totalPaid = 0;
    // Set values of all the drinks
    drinks[0] = {"Cola", .75, 5};
    drinks[1] = {"Root Beer", .75, 20};
    drinks[2] = {"Lemon-Lime", .75, 20};
    drinks[3] = {"Grape Soda", .80, 20};
    drinks[4] = {"Cream Soda", .80, 20};

    // Loop runs as long as option 6 isn't selected
    while(choice !=6){
        cout << "\n\n";
        for(int i=0; i<5; i++){ //Display Options
            cout << (i+1) << ") " << drinks[i].name << "\t$";
            cout << fixed << setprecision(2) << drinks[i].price << "\t";
            cout << drinks[i].quantity << "\n";
        }
        cout << "6) ";
        cout << "Leave the drink machine\n";

        // Ask user to choose drink or quit
        cout << "\nPlease choice an option: ";
        cin >> choice;
        // Display error if invald choice
        while(choice <1 || choice > 6){
            cout << "\nError, please enter a valid choice: ";
            cin >> choice;
        }

        // Switch executes similar program for various drinks
        switch(choice){
            case 1 :
                // Displays error if the drink quantity is 0
                if(drinks[0].quantity == 0){
                    cout << drinks[0].name << " is out of stock\n\n";
                    break; // Breaks out to let user pick different drink
                }
                due = drinks[0].price; // Sets drink price to a variable
                moneyCalc(due, totalPaid); // Money calculation program
                totalPaid += due; // Adds money earned to total
                drinks[0].quantity -= 1; // Takes 1 drink out of total avaible
                break; // Breaks out of switch when done
            // Code works the same, but for different drink for cases 2-5
            case 2:
                if(drinks[1].quantity == 0){
                    cout << drinks[1].name << " is out of stock\n\n";
                    break;
                }
                due = drinks[1].price;
                moneyCalc(due, totalPaid);
                totalPaid += due;
                drinks[1].quantity -= 1;
                break;
            case 3:
                if(drinks[2].quantity == 0){
                    cout << drinks[2].name << " is out of stock\n\n";
                    break;
                }
                due = drinks[2].price;
                moneyCalc(due, totalPaid);
                totalPaid += due;
                drinks[2].quantity -= 1;
                break;
            case 4:
                if(drinks[3].quantity == 0){
                    cout << drinks[3].name << " is out of stock\n\n";
                    break;
                }
                due = drinks[3].price;
                moneyCalc(due, totalPaid);
                totalPaid += due;
                drinks[3].quantity -= 1;
                break;
            case 5:
                if(drinks[4].quantity == 0){
                    cout << drinks[4].name << " is out of stock\n\n";
                    break;
                }
                due = drinks[4].price;
                moneyCalc(due, totalPaid);
                totalPaid += due;
                drinks[4].quantity -= 1;
                break;
            // Breaks out of switch to exit
            case 6:
                break;
        }
    }
    // Display total earned
    cout << "Total money earned this session: " << totalPaid;
    cout << "\n\n";
    return 0;
}

void moneyCalc(double &due, double &total){
    bool paid = 0;
    double payment;
    double change;
    while(paid==0){
        if(due==0){
            paid = 1;
        }
        // Ask user for money
        cout << "\nThe drink costs $" << due << ".";
        cout << "\nPlease insert money for drink: ";
        cin >> payment;
        // Display error if wrong amount entered
        while(payment < 0 || payment > 1){
            cout << "\nError, enter amount between $0.00 and $1.00: ";
            cin >> payment;
        }
        // If payment is over the amount due
        // user recieves change
        if(payment > due){
            change = payment - due;
            cout << "\nYour change is " << change;
            due = 0;
        // If the payment is exact, no change recieved
        } else{
            due -= payment;
        }
    }
}