treehouse.rs

use std::io::stdin;

fn what_is_your_name() -> String {
    println!("Hello! What's your name?");

    let mut your_name = String::new();
    stdin()
        .read_line(&mut your_name)
        .expect("You forgot to enter something!!!");
    your_name
        .trim()
        .to_lowercase()
}

#[derive(Debug)]
enum VisitorAction {
    Accept,
    AcceptWithNote { note: String },
    Refuse,
    Probation,
}

#[derive(Debug)]
struct Visitor {
    name: String,
    action: VisitorAction,
    age: i8,
}

impl Visitor {
    fn new(name: &str, action: VisitorAction, age: i8) -> Self {
        Self {
            name: name.to_lowercase(),
            action,
            age
        }
    }

    fn greet(&self) {
        match &self.action {
            VisitorAction::Accept => println!("Welcome to the treehouse, {}!", self.name),
            VisitorAction::AcceptWithNote { note} => {
                println!("{}", note);
                if self.age < 21 {
                    println!("Do not serve alcohol to {}.", self.name);
                }
            }
            VisitorAction::Probation => println!("{} is now a probationary member", self.name),
            VisitorAction::Refuse => println!("Do not let {} in!!!", self.name),
        }
    }
}

fn find_visitor<'a>(name: &String, visitor_list: &'a Vec<Visitor>) -> Option<&'a Visitor> {
    let maybe_visitor = visitor_list
        .iter()
        .find(|visitor| &visitor.name == name);

    maybe_visitor
}

fn main() {
    let mut visitor_list = vec![
        Visitor::new("bert", VisitorAction::Accept, 45),
        Visitor::new("steve", VisitorAction::AcceptWithNote {
            note: String::from("Lactose-free milk is in the fridge.")
        }, 15),
        Visitor::new("fred", VisitorAction::Refuse, 30),
    ];

    loop {
        let name = what_is_your_name();

        let maybe_visitor = find_visitor(&name, &visitor_list);

        match maybe_visitor {
            Some(visitor) => visitor.greet(),
            None => {
                if !name.is_empty() {
                    println!("{} is not on the list; adding new visitor!", name);
                    visitor_list.push(Visitor::new(&name, VisitorAction::Probation, 0));
                } else {
                    println!("Goodbye!!!");
                    break;
                }
            }
        }
    }

    println!("The final visitor list is:");
    println!("{:#?}", visitor_list);
}