use std::{
	error::Error,
	fs::File,
	sync::Arc,
};

use tokio::sync::oneshot;

use ptth::relay;
use ptth::relay::RelayState;

#[tokio::main]
async fn main () -> Result <(), Box <dyn Error>> {
	use std::io::Read;
	
	let config_file = {
		let config_file_path = "config/ptth_relay.toml";
		
		let mut f = File::open (config_file_path).unwrap_or_else (|_| panic! ("Can't open {:?}", config_file_path));
		let mut buffer = vec! [0u8; 4096];
		let bytes_read = f.read (&mut buffer).unwrap_or_else (|_| panic! ("Can't read {:?}", config_file_path));
		buffer.truncate (bytes_read);
		
		let config_s = String::from_utf8 (buffer).unwrap_or_else (|_| panic! ("Can't parse {:?} as UTF-8", config_file_path));
		toml::from_str (&config_s).unwrap_or_else (|_| panic! ("Can't parse {:?} as TOML", config_file_path))
	};
	
	eprintln! ("ptth_relay Git version: {:?}", ptth::git_version::GIT_VERSION);
	
	let rx = {
		let (tx, rx) = oneshot::channel::<()> ();
		
		// I have to put the tx into a Cell here so that if Ctrl-C gets
		// called multiple times, we won't send multiple shutdowns to the
		// oneshot channel. (Which would be a compile error)
		
		let tx = Some (tx);
		let tx = std::cell::Cell::new (tx);
		
		ctrlc::set_handler (move ||{
			let tx = tx.replace (None);
			
			if let Some (tx) = tx {
				tx.send (()).unwrap ();
			}
		}).expect ("Error setting Ctrl-C handler");
		
		rx
	};
	
	relay::run_relay (
		Arc::new (RelayState::from (&config_file)),
		Some (rx)
	).await
}