use std::{
    borrow::BorrowMut,
    cell::RefCell,
    rc::Rc,
    time::{Duration, Instant},
};

type TaskStatus = Rc<RefCell<bool>>;

#[allow(dead_code)]
fn delay_task(delay_time: usize) -> (impl FnMut() -> (), TaskStatus) {
    // 记录当前时间
    let start_time = Instant::now();
    let status = Rc::new(RefCell::new(false));
    let mut _status = status.clone();
    return (
        move || {
            if !(*_status.borrow())
                && (Instant::now() - start_time > Duration::from_secs(delay_time as u64))
            {
                println!("已经经过了至少: {:?}秒", delay_time);
                _status.borrow_mut().replace(true);
            }
        },
        status.clone(),
    );
}
const TIME_PIECE: usize = 500;
pub struct Task<F, T>
where
    F: FnMut() -> T,
{
    task_poll_fn: F,
    task_status: TaskStatus,
}
impl<F, T> Task<F, T>
where
    F: FnMut() -> T,
{
    pub fn new(mut task_init_fn: impl FnMut() -> (F, TaskStatus)) -> Task<F, T> {
        let (task_poll_fn, task_status) = task_init_fn();
        Task {
            task_poll_fn,
            task_status,
        }
    }

    pub fn run(&mut self) {
        if !(*self.task_status.borrow()) {
            (self.task_poll_fn)();
        }
    }
}

fn event_loop<F, T>(task_list: &mut Vec<Task<F, T>>)
where
    F: FnMut() -> T,
{
    loop{
        let mut is_all_done = true;
        for task in task_list.iter_mut() {
            if !(*task.task_status.borrow()) {
                is_all_done = false;
                task.run();
                break;
            }
        }
        if is_all_done {
            break;
        }
        std::thread::sleep(Duration::from_millis(TIME_PIECE as u64));
    }
    println!("事件循环退出!");
}

fn main() {
    let mut task_list = vec![];
    let delay_seconds_time: usize = 5;
    task_list.push(Task::new(move || {
        return delay_task(delay_seconds_time);
    }));
    task_list.push(Task::new(move || {
        return delay_task(delay_seconds_time * 2);
    }));
    event_loop(&mut task_list);
    println!("退出主线程！");
}