use atoms::InternedAtoms;
use clients::ClientList;
use cursors::Cursors;
use error::*;
use xcb::{
    x::{self, ChangeWindowAttributes, PropertyNotifyEvent, Window},
    Connection, Event, Extension,
};

mod atoms;
mod clients;
mod cursors;
mod error;
mod focus;
mod keys;

fn main() -> Result<()> {
    // todo: cli stuff
    let display_name = ":1";

    cleanup_process_children();

    let (conn, screen_num) =
        Connection::connect_with_extensions(Some(display_name), &[], &[Extension::Xinerama])?;

    let mut wm = WM::new(&conn, screen_num)?;
    wm.event_loop()?;

    Ok(())
}

struct WM<'a> {
    conn: &'a Connection,
    screen_num: i32,

    root: Window,
    clients: ClientList,

    cursors: Cursors,
    atoms: InternedAtoms,
}

impl WM<'_> {
    fn new<'a>(conn: &'a Connection, screen_num: i32) -> Result<WM<'a>> {
        // Fetch root window
        let setup = conn.get_setup();
        let screen = setup
            .roots()
            .nth(screen_num as usize)
            .ok_or(Error::NoSuchScreen)?;

        // Check no other WM is running
        conn.check_request(conn.send_request_checked(&ChangeWindowAttributes {
            window: screen.root(),
            value_list: &[
                x::Cw::BackPixel(screen.white_pixel()),
                x::Cw::EventMask(x::EventMask::SUBSTRUCTURE_REDIRECT),
            ],
        }))
        .map_err(|_| Error::OtherWMRunning)?;

        Ok(WM {
            atoms: InternedAtoms::new_with(conn)?,
            cursors: Cursors::new_with(conn)?,
            clients: Default::default(),
            conn,
            screen_num,
            root: screen.root(),
        })
    }

    fn setup_root(&self) -> Result<()> {
        // TODO: set wm properties
        self.conn
            .check_request(self.conn.send_request_checked(&ChangeWindowAttributes {
                window: self.root,
                value_list: &[
                    x::Cw::EventMask(
                        x::EventMask::SUBSTRUCTURE_REDIRECT
                            | x::EventMask::SUBSTRUCTURE_NOTIFY
                            | x::EventMask::BUTTON_PRESS
                            | x::EventMask::POINTER_MOTION
                            | x::EventMask::ENTER_WINDOW
                            | x::EventMask::LEAVE_WINDOW
                            | x::EventMask::STRUCTURE_NOTIFY
                            | x::EventMask::PROPERTY_CHANGE,
                    ),
                    x::Cw::Cursor(self.cursors.normal),
                ],
            }))?;

        // TODO: grab keys

        // TODO: reset focus

        Ok(())
    }

    fn event_loop(&mut self) -> Result<()> {
        self.update_geometry()?;
        self.setup_root()?;

        loop {
            match self.conn.wait_for_event()? {
                // todo: keybinding related stuff
                Event::X(x::Event::KeyPress(e)) => self.handle_key_press(e)?,
                Event::X(x::Event::MappingNotify(e)) => self.handle_mapping_notify(e)?,

                // todo: windows coming and going
                Event::X(x::Event::ConfigureRequest(e)) => self.handle_configure_request(e)?,
                Event::X(x::Event::ConfigureNotify(e)) => self.handle_configure_notify(e)?,
                Event::X(x::Event::DestroyNotify(e)) => self.handle_destroy_notify(e)?,
                Event::X(x::Event::MapRequest(e)) => self.handle_map_request(e)?,
                Event::X(x::Event::UnmapNotify(e)) => self.handle_unmap_notify(e)?,

                // todo: focus stuff
                Event::X(x::Event::EnterNotify(e)) => self.handle_enter_notify(e)?,
                Event::X(x::Event::FocusIn(e)) => self.handle_focus_in(e)?,
                Event::X(x::Event::MotionNotify(e)) => self.handle_motion_notify(e)?,

                // todo: other
                Event::X(x::Event::PropertyNotify(e)) => self.handle_property_notify(e)?,
                _ => {}
            };
        }
    }

    fn handle_property_notify(&self, e: PropertyNotifyEvent) -> Result<()> {
        todo!()
    }
}

fn cleanup_process_children() {
    // todo: dont transform children into zombies when they terminate
    // todo: cleanup zombies
}

impl<'a> std::fmt::Debug for WM<'a> {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("WM")
            .field("screen_num", &self.screen_num)
            .field("root", &self.root)
            .field("clients", &self.clients)
            .field("atoms", &self.atoms)
            .finish()
    }
}