use crate::position::Position;

pub struct Monster {
    life: usize,
    position: Position,
}

impl Monster {
    #[cfg(test)]
    pub fn new(life: usize) -> Self {
        Monster {
            life,
            position: Position::new(0, 0, 0),
        }
    }
    pub fn new_with_position(life: usize, position: Position) -> Self {
        Monster {
            life,
            position,
        }
    }
    #[cfg(test)]
    pub fn get_life(&self) -> usize { self.life }
    pub fn is_dead(&self) -> bool { self.life <= 0 }
    pub fn decrease_life(&mut self, by: usize) {
        self.life = self.life.saturating_sub(by);
    }
    #[cfg(test)]
    pub fn get_position(&mut self) -> &mut Position {
        &mut self.position
    }
    pub fn get_immutable_position(&self) -> &Position {
        &self.position
    }
}

#[test]
fn monsters_can_move() {
    let mut m = Monster::new(2);
    assert_eq!(m.get_position(), &Position::new(0, 0, 0));
    m.get_position().change(1, 2);
    assert_eq!(m.get_position(), &Position::new(0, 1, 2));
    m.get_position().change(2, 1);
    assert_eq!(m.get_position(), &Position::new(0, 3, 3));
    m.get_position().set(1, 2, 3);
    m.get_position().change(2, 1);
    assert_eq!(m.get_position(), &Position::new(1, 4, 4));
}

#[test]
fn monsters_can_die() {
    let mut m = Monster::new(2);
    assert_eq!(m.get_life(), 2);
    assert_eq!(m.is_dead(), false);
    m.decrease_life(1);
    assert_eq!(m.get_life(), 1);
    m.decrease_life(2);
    assert_eq!(m.get_life(), 0);
    assert_eq!(m.is_dead(), true);
}