//! Random play simulation policy
//!
//! Actions are chosen at random

use crate::state::GameState;
use crate::tree::node::{Node, RewardVal};
use rand::prelude::IndexedRandom;
use std::collections::HashMap;

pub fn simulate<S: GameState>(node: &Node<S>) -> HashMap<S::Player, RewardVal> {
    let mut state: S = node.state.clone();
    while !state.is_terminal() {
        let legal_actions = state.get_legal_actions();
        let action = legal_actions.choose(&mut rand::rng()).unwrap();
        state = state.state_after_action(&action);
    }
    state.rewards_for_players()
}