#include <iostream>
#include <iomanip>

void showBalance(double balance);
double deposit();
double withdraw(double balance);

int main()
{
    double balance = 0;
    int choice = 0;

    do{
        std::cout << "******************\\n";
        std::cout << "Enter your choice:\\n";
        std::cout << "******************\\n";
        std::cout << "1. Show Balance\\n";
        std::cout << "2. Deposit Money\\n";
        std::cout << "3. Withdraw Money\\n";
        std::cout << "4. Exit\\n";
        std::cin >> choice;

        std::cin.clear(); 
        fflush(stdin);

        switch(choice){
            case 1: showBalance(balance);
                    break;
            case 2: balance += deposit();
                    showBalance(balance);
                    break;
            case 3: balance -= withdraw(balance);
                    showBalance(balance);
                    break;
            case 4: std::cout << "Thanks for visiting!\\n";
                    break;
            default:std::cout << "Invalid choice\\n";
        }
    }while(choice != 4);

    return 0;
}
void showBalance(double balance){
    
    std::cout << "Your balance is: $"<< std::setprecision(2) << std::fixed << balance << '\\n';
}
double deposit(){
    
    double amount = 0;

    std::cout << "Enter amount to be deposited: ";
    std::cin >> amount;

    if(amount > 0){
        return amount;
    }
    else{
        std::cout << "That's not a valid amount:\\n";
        return 0;
    }
}
double withdraw(double balance){

    double amount = 0;

    std::cout << "Enter amount to be withdrawn: ";
    std::cin >> amount;

    if(amount > balance){
        std::cout << "insufficient funds\\n";
        return 0;
    }
    else if(amount < 0){
        std::cout << "That's not a valid amount\\n";
        return 0;
    }
    else{
        return amount;
    }
}