#[macro_use]
extern crate anyhow;

mod bar;
mod blocks_cache;
mod button_manager;
mod color;
mod config;
mod event_loop;
mod i3bar_protocol;
mod icon;
mod output;
mod pointer_btn;
mod protocol;
mod shared_state;
mod state;
mod status_cmd;
mod text;
mod tray;
mod utils;
mod wm_info_provider;

use std::env;
use std::io::{self, ErrorKind, Read};
use std::os::fd::{AsRawFd, RawFd};
use std::path::PathBuf;

use anyhow::Context;
use clap::Parser;
use daemonize::Daemonize;
use signal_hook::consts::*;
use wayrs_client::{Connection, IoMode};

use config::{Config, ConfigWatcher};
use event_loop::{Action, Callback, EventLoop};
use state::State;

#[derive(Parser)]
#[command(author, version, about, long_about = None)]
struct Cli {
    #[arg(short, long, value_name = "FILE", help = "The path to a config file")]
    config: Option<PathBuf>,
    #[arg(long, help = "Keep the bar attached to the current terminal")]
    foreground: bool,
}

fn status_callback(fd: RawFd) -> Callback {
    Box::new(move |ctx| {
        if ctx.state.status_cmd_fd() != Some(fd) {
            return Ok(Action::Unregister);
        }
        match ctx
            .state
            .shared_state
            .status_cmd
            .as_mut()
            .unwrap()
            .receive_blocks()
        {
            Ok(None) => Ok(Action::Keep),
            Ok(Some(blocks)) => {
                ctx.state.set_blocks(ctx.conn, blocks);
                Ok(Action::Keep)
            }
            Err(e) => {
                let _ = ctx
                    .state
                    .shared_state
                    .status_cmd
                    .take()
                    .unwrap()
                    .child
                    .kill();
                ctx.state.set_error(ctx.conn, "status", e);
                Ok(Action::Unregister)
            }
        }
    })
}

fn main() -> anyhow::Result<()> {
    let args = Cli::parse();
    let config_path = Config::path(args.config.as_deref());
    if !args.foreground {
        let working_directory = env::current_dir().context("failed to read working directory")?;
        Daemonize::new()
            .working_directory(working_directory)
            .start()
            .context("failed to start in the background")?;
    }
    let (mut sig_read, sig_write) = io::pipe()?;
    signal_hook::low_level::pipe::register(SIGUSR1, sig_write)?;

    let mut conn = Connection::connect()?;
    conn.blocking_roundtrip()?;

    let mut el = EventLoop::new();
    let mut state = State::new(&mut conn, &mut el, config_path.as_deref());
    conn.flush(IoMode::Blocking)?;

    el.add_on_idle(|ctx| {
        ctx.conn.flush(IoMode::Blocking)?;
        Ok(event_loop::Action::Keep)
    });

    el.register_with_fd(sig_read.as_raw_fd(), move |ctx| {
        sig_read.read_exact(&mut [0u8]).unwrap();
        ctx.state.toggle_visibility(ctx.conn);
        Ok(event_loop::Action::Keep)
    });

    el.register_with_fd(conn.as_raw_fd(), |ctx| {
        match ctx.conn.recv_events(IoMode::NonBlocking) {
            Ok(()) => ctx.conn.dispatch_events(ctx.state),
            Err(e) if e.kind() == ErrorKind::WouldBlock => (),
            Err(e) => bail!(e),
        }
        Ok(event_loop::Action::Keep)
    });

    if let Some(fd) = state.status_cmd_fd() {
        el.register_with_fd(fd, status_callback(fd));
    }

    if let Some(config_path) = config_path {
        let mut watcher = ConfigWatcher::new(&config_path)
            .with_context(|| format!("failed to watch {}", config_path.display()))?;
        let watcher_fd = watcher.fd();
        el.register_with_fd(watcher_fd, move |ctx| {
            if !watcher.changed()? {
                return Ok(Action::Keep);
            }
            match ctx.state.reload_config(ctx.conn, &config_path) {
                Ok(Some(fd)) => Ok(Action::KeepAndRegister(fd, status_callback(fd))),
                Ok(None) => Ok(Action::Keep),
                Err(error) => {
                    ctx.state.set_error(ctx.conn, "config", error);
                    Ok(Action::Keep)
                }
            }
        });
    }

    el.run(&mut conn, &mut state)?;
    unreachable!();
}