use std::path::Path;

use notify::{Config, Event, RecommendedWatcher, RecursiveMode, Watcher};
use tokio::sync::mpsc::channel;
use tracing::{error, info, instrument};

use crate::Besult;

pub type FileWatcher = RecommendedWatcher;

pub mod prelude {
    pub use super::{file_watcher, FileWatcher};
}

pub fn file_watcher<P, F>(dir: P, cb: F) -> Besult<FileWatcher>
where
    P: AsRef<Path>,
    F: Fn(Event) -> () + std::marker::Send + 'static,
{
    let (tx, mut rx) = channel(1);
    let mut watcher = RecommendedWatcher::new(
        move |res| match res {
            Ok(e) => futures::executor::block_on(async {
                tx.send(e).await.unwrap();
            }),
            Err(e) => error!("Error from file_watcher: {e}"),
        },
        Config::default(),
    )?;

    info!("Watching directory '{}'", dir.as_ref().display());

    tokio::spawn(async move {
        while let Some(ev) = rx.recv().await {
            cb(ev)
        }
    });

    watcher.watch(dir.as_ref(), RecursiveMode::Recursive)?;

    Ok(watcher)
}