// https://www.youtube.com/watch?v=HwupNf9iCJk

use std::{
    sync::{Arc, RwLock},
    thread,
};

#[derive(Debug)]
struct Node {
    // RwLock similar to RefCell but thread safe,
    // can also use Mutex and then .lock() it instead of calling .read() or .write()
    str_val: RwLock<String>,
    adjacent: Vec<Arc<Node>>,
}

fn add_urgency(node: Arc<Node>) {
    {
        node.str_val.write().unwrap().push('!');
    }
    for adj in node.adjacent.iter() {
        add_urgency(adj.clone());
    }
}

fn main() {
    let a = Arc::new(Node {
        str_val: RwLock::new(String::from("aaa")),
        adjacent: vec![],
    });

    let b = Arc::new(Node {
        str_val: RwLock::new(String::from("bbb")),
        adjacent: vec![a.clone()],
    });

    let c = Arc::new(Node {
        str_val: RwLock::new(String::from("ccc")),
        adjacent: vec![a.clone()],
    });

    dbg!(a.clone());
    dbg!(b.clone());
    dbg!(c.clone());
    let t1_b = b.clone();
    let _t1 = thread::spawn(move || add_urgency(t1_b)).join();
    dbg!(c.clone());
    let t2_c = c.clone();
    let _t2 = thread::spawn(move || add_urgency(t2_c)).join();
    dbg!(c.clone());
}