#[derive(Debug)]
struct Person {
    mood: Mood,
}

#[derive(Debug)]
enum Mood {
    Happy { duration: std::time::Duration },
    Sad { seriousness: u8, reason: String },
}

impl Person {
    fn feed_cake(&mut self, how_much_cake: u8) {
        self.mood = match self.mood {
            mood @ Mood::Happy { .. } => {
                eprintln!("I can't get any happier.");
                mood
            }
            Mood::Sad {
                seriousness,
                reason,
            } => {
                if how_much_cake > seriousness {
                    Mood::Happy {
                        duration: std::time::Duration::from_secs(90),
                    }
                } else {
                    Mood::Sad {
                        seriousness: seriousness - how_much_cake,
                        reason: reason,
                    }
                }
            }
        }
    }
}

fn main() {
    let mut dude = Person {
        mood: Mood::Sad {
            seriousness: 6,
            reason: "ran out of cake".to_owned(),
        },
    };
    eprintln!("{:?}", dude);
    dude.feed_cake(4);
    eprintln!("{:?}", dude);
    dude.feed_cake(4);
    eprintln!("{:?}", dude);
}