use xcb;
use x11;
use comm;
use comm::Channel;
use config::Config;
use std::thread;
use std::time::Duration;

pub fn wait_for<F>(f: F) -> xcb::Window where F: Fn() -> xcb::Window {
    loop {
        let w = f();
        if w == 0 {
            thread::sleep(Duration::from_millis(100));
        }
        else {
            return w;
        }
    }
}

pub fn wm(tx: &Channel, _config: &Config) {
    if let Some(conn) = x11::Connection::new() {
        let screen = conn.default_screen();
        let mut last_win = screen.get_active_window();
        comm::send(tx, "title", conn.get_window_name(last_win).as_ref());

        let stalonetray = wait_for(|| screen.search_by_class("stalonetray"));
        let panel = wait_for(|| screen.search_by_name("__panel_top"));
        let width = xcb::get_geometry(&conn, stalonetray).get_reply().unwrap().width();

        xcb::configure_window(&conn, stalonetray, &[
            (xcb::CONFIG_WINDOW_X as u16, (screen.width - width) as u32),
            (xcb::CONFIG_WINDOW_SIBLING as u16, panel),
            (xcb::CONFIG_WINDOW_STACK_MODE as u16, xcb::STACK_MODE_ABOVE)
        ]);
        xcb::change_window_attributes(&conn, stalonetray, &[(xcb::CW_EVENT_MASK, xcb::EVENT_MASK_STRUCTURE_NOTIFY)]);
        conn.watch(screen.root, true);
        conn.watch(last_win, true);
        conn.flush();

        conn.event_loop(&mut |event: &xcb::GenericEvent| {
            match event.response_type() {
                xcb::PROPERTY_NOTIFY => {
                    let prop_event: &xcb::PropertyNotifyEvent = xcb::cast_event(event);
                    if prop_event.atom() == conn.atom(x11::_NET_ACTIVE_WINDOW) {
                        let new_win = screen.get_active_window();
                        conn.watch(last_win, false);
                        conn.watch(new_win, true);
                        conn.flush();
                        last_win = new_win;
                        comm::send(tx, "title", conn.get_window_name(last_win).as_ref());
                    }
                    else if prop_event.atom() == conn.atom(x11::_NET_WM_NAME) {
                        comm::send(tx, "title", conn.get_window_name(last_win).as_ref());
                    }
                },
                xcb::CONFIGURE_NOTIFY => {
                    let event: &xcb::ConfigureNotifyEvent = unsafe { xcb::cast_event(&event) };
                    let spacer = format!("%{{O{}}}", event.width()+5);
                    comm::send(tx, "spacer", spacer.as_ref());
                },
                _ => ()
            }
        });
    } else {
        println!("Could not connect to X!");
    }
}