/* Polydoro - Pomodoro widget for polybar and friends
 * Copyright (C) 2025  Vidhu Kant Sharma <vidhukant@vidhukant.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

use std::sync::mpsc::Receiver;
use std::thread;
use std::time::Duration;
use std::os::unix::net::{UnixStream,UnixListener};
use bincode::{encode_into_std_write,config};

use crate::daemon::pomo::Pomo;
use crate::daemon::command::Command;

pub fn start_clock(rx: Receiver<Command>) -> thread::JoinHandle<()> {  
    thread::spawn(move || {
        let mut p = Pomo::new();

        // check if a socket already exists (only one daemon allowed!)
        let sock = "/tmp/polydorod.sock";
        if std::fs::metadata(sock).is_ok() {
            eprintln!("socket {} already exists, is another daemon running?", sock);
            std::process::exit(1);
        }
        
        // all OK, create a sock
        let listener = UnixListener::bind(sock).expect("failed to bind socket /tmp/polydorod.sock");
        listener.set_nonblocking(true).unwrap();

        // all of the connected listeners
        let mut listeners: Vec<UnixStream> = Vec::new();

        loop {
            // if new listener is connected
            match listener.accept() {
                Ok((stream, _addr)) => {
                    listeners.push(stream);
                }
                Err(ref e) if e.kind() == std::io::ErrorKind::WouldBlock => {} // no new client
                Err(e) => eprintln!("error while adding new listener: {}", e),
            }

            // listen to commands 
            while let Ok(cmd) = rx.try_recv() {
                match cmd {
                    Command::Run => p.run(),
                    Command::Pause => p.pause(),
                    Command::Toggle => p.toggle(), 
                    Command::Skip => p.end_cycle(), 
                    Command::SoftReset => p.soft_reset(),
                    Command::HardReset => p.hard_reset(),
                    Command::Reset => p.reset(),
                }
            }

            p.tick();

            // send p struct to the listeners listening to polydorod.sock
            listeners.retain_mut(|l| {
                if let Err(_) = encode_into_std_write(&p, l, config::standard()) {
                    false // drop this listener, seems to be disconnected
                } else {
                    true
                }
            });

            thread::sleep(Duration::from_secs(1));
        }
    })
}