use crate::node::Node;
use rand::random_range;

const PICK_STOP_PROBABILITY: u8 = 2;

pub struct NodeModifier<'a> {
    picked_node: &'a mut Node,
}

impl<'a> NodeModifier<'a> {
    pub fn from_random(root: &'a mut Node) -> NodeModifier<'a> {
        let mut selected = root;
        while random_range(0..PICK_STOP_PROBABILITY) == PICK_STOP_PROBABILITY - 1 {
            let len = selected.children.len();
            selected = &mut selected.children[random_range(0..len)];
        }
        NodeModifier {
            picked_node: selected,
        }
    }
    pub fn from_node(node: &'a mut Node) -> NodeModifier<'a> {
        NodeModifier { picked_node: node }
    }
}