99bottles.rs

99bottles.rs

impl Bottles {
    pub fn song(&self) -> String {
        self.verses(99, 0)
    }

    pub fn verse(&self, n: i32) -> String {
        format!("{} {} of beer on the wall, {} {} of beer.\n{}",
            self.start(n),
            self.pluralization(n),
            self.start(n).to_lowercase(),
            self.pluralization(n),
            self.beer_chore(n)
        )
    }

    pub fn verses(&self, from: i32, to: i32) -> String {
        (to..=from).rev().map(|n| self.verse(n)).collect::<Vec<String>>().join("\n")
    }

    fn pluralization(&self, n: i32) -> &'static str {
        if n == 1 {
            "bottle"
        } else {
            "bottles"
        }
    }

    fn pronoun(&self, n: i32) -> &'static str {
        if n == 1 {
            "it"
        } else {
            "one"
        }
    }

    fn remaining(&self, n: i32) -> i32 {
        n - 1
    }

    fn start(&self, n: i32) -> String {
        if n == 0 {
            "No more".to_string()
        } else {
            n.to_string()
        }
    }

    fn beer_chore(&self, n: i32) -> String {
        if n == 0 {
            "Go to the store and buy some more, 99 bottles of beer on the wall.\n".to_string()
        } else {
            format!("Take {} down and pass it around, {} {} of beer on the wall.\n",
                self.pronoun(n),
                if self.remaining(n) == 0 { "no more".to_string() } else { self.remaining(n).to_string() },
                self.pluralization(n - 1)
            )
        }
    }
}

fn main() {
    let bottles = Bottles;
    println!("{}", bottles.song());
}