// page 141 logical operations and or not
// page 142 if statments
// page 139 relationals > < >= <= != ==

// = assigns a value
// == in equality to tests a value  page 139
// ===  in quality to tests a value strictly to the type. In.Net Core and C# this would be the equivalent of ReferenceEquals(var1,var2) method

// do while
// 2 control variables
// we are using the do/while to test if the userAge is an int
int userAge;
bool isValidInput = false;


do
{
    
    Console.WriteLine("Enter your age: ");
#pragma warning disable CS8600
    string input = Console.ReadLine(); // warning
                                       //inherited from ReadLine() not string input;
                                       // if return true userAge
                                       // if return false input
#pragma warning restore CS8600
    if (int.TryParse(input, out userAge))
    {
        isValidInput = true;
        Console.WriteLine($"You entered: {userAge}"); // template variable in the view. Ignore type str + int

    } // if
    else
    {
        Console.WriteLine("Invalid entry. Please enter a valid number between 1 and 120.");
    } // else

} // do
while ( !isValidInput );

int age = userAge;

// Method 1 using Convert
// int age = Convert.ToInt32(userAge);


// age < 18 nothing
// age >= 18 and < 21 vote
// age >= 21 and < 65 vote and drink
// age 65 or > vote, drink retire
// if age < 18 lambda exp with no false
// if (age < 18)

if (age > 0 & age < 18) {
    Console.WriteLine("You can not vote, drink or retire");
}
else if (age >= 18 & age < 21)
{
    Console.WriteLine("You can vote, but not drink or retire");
}
else if (age >= 21 & age < 65)
{
    Console.WriteLine("You can vote and drink but not retire");
}
else if (age >= 65 & age < 120)
{
    Console.WriteLine("You can vote, drink and   retire");
}

else
{
    Console.WriteLine("Invalid entry");
}

// switch page 145
Console.WriteLine("Enter customer type (C,R,W): ");
string userInput = Console.ReadLine(); // string input
Console.WriteLine("You entered: " + userInput);

string customertype = userInput; // control

switch (customertype) // condition
                      // operations or expressions
{
    // cases do NOT have to be sorted for usability, but a best practice for readability
    // Big 3 for Best Practices
    // readability framework resource(pu/memory)
    case "C":
        Console.WriteLine("Customer");
        break;
    case "R": 
        Console.WriteLine("Retailer");
        break;
    case "W":
        Console.WriteLine("Wholesaler");
        break;
    // default No Match
    default:
        Console.WriteLine("No Customer Type Defined");
        break;

} // switch