use std::io;

fn main() {
    let mut wack  = String::new();

    f_to_c();

     println!("Do you want to hear the singing? (y/n): ");

    io::stdin()
        .read_line(&mut wack)
        .expect("ay yo that ain't it chief");
    let choice: &str = wack.trim();
    let mut done = false;
    while done == false{

        if choice == "y" || choice == "n"{
            if choice == "y"{
                done = true;
                sing_goddamn_it();
            }
            else{
                done = true;
            }
        }
        else{
            println!("man try again...or I'll slap your balls");
        }
    }

    println!("{}",fibbonacci(-10));
}

fn f_to_c() {

    let mut s = String::new();

    println!("Type a float to be a fahrenheit: ");

    io::stdin()
        .read_line(&mut s)
        .expect("Failed to read number, or number was formatted as an integer. Try putting a .0 at the end of the number...");

    let x: f32 = s.trim().parse().unwrap();
    let y = (x - 32.0)*(5.0/9.0);

    println!("Fahrenheit: {} to Celsius: {}",x, y);
}

fn sing_goddamn_it() {
    let sents = ["a partridge in a pear tree", "2 turtle-doves", "3 French hens", "4 calling birds", "5 golden rings", "6 geese a-laying",
    "7 swans a-swimming", "8 maids a-milking", "9 ladies dancing", "10 lords a-leaping", "11 pipers piping", "12 drummers drumming"];
    let mut days = 1;

    for _number in 1..13{
        println!("On the {} day of christmas, my true love sent to me", days);
        for number2 in (0..0+days).rev(){
            println!("{}", sents[number2]);
        }
        days += 1;
    }

}

fn fibbonacci(n: i32) -> i32{
    if n < 0
    {
        panic!("{} is a negative number, mucho no bueno...", n);
    }else if n == 0{
        panic!("equals zero, error");
    }else if n == 1{
        return 1;
    }

    let mut sum = 0;
    let mut temp = 0;
    let mut temp2 = 1;

    for _i in 1..n {
        sum = temp + temp2;
        temp = temp2;
        temp2 = sum;
    }
    sum
}