mod imp {
    use crate::model::Song;
    use crate::{mpris, mpv};
    use adw::prelude::*;
    use adw::subclass::prelude::*;
    use glib::subclass::InitializingObject;
    use glib::JoinHandle;
    use gtk::{gdk, gio, glib};
    use std::cell::{Cell, RefCell};
    use std::rc::Rc;
    use tracing::{event, span, Level};
    use zbus::object_server::InterfaceRef;

    #[derive(gtk::CompositeTemplate, glib::Properties)]
    #[template(resource = "/eu/callcc/audrey/window.ui")]
    #[properties(wrapper_type = super::Window)]
    pub struct Window {
        #[template_child]
        pub(super) playbar: TemplateChild<crate::ui::Playbar>,

        #[template_child]
        pub(super) play_queue: TemplateChild<crate::ui::PlayQueue>,

        #[property(get, set, default = false)]
        can_click_shuffle_all: Cell<bool>,

        #[property(get, set, nullable)]
        playing_cover_art: RefCell<Option<gdk::Paintable>>,

        #[property(type = Option<Song>, get = Self::song, nullable)]
        _song: (),

        pub(super) setup: crate::ui::Setup,

        pub(super) api: RefCell<Option<Rc<crate::subsonic::Client>>>,

        pub(super) mpv: mpv::Handle,
        #[property(get)]
        playlist_model: gio::ListStore,

        #[property(type = i64, get = Self::volume, set = Self::set_volume, minimum = 0, maximum = 100)]
        _volume: (),
        #[property(type = bool, get = Self::mute, set = Self::set_mute)]
        _mute: (),
        #[property(type = bool, get = Self::pause, set = Self::set_pause)]
        _pause: (),
        #[property(type = i64, get = Self::playlist_pos)]
        _playlist_pos: (),
        #[property(type = f64, get = Self::time_pos)]
        _time_pos: (),
        #[property(type = f64, get = Self::duration)]
        _duration: (), // as reported by mpv, compare with song.duration
        #[property(type = bool, get = Self::idle_active)]
        _idle_active: (),
        #[property(type = i64, get = Self::playlist_count)]
        _playlist_count: (),

        pub(super) queued_seek: Cell<Option<f64>>,

        pub(crate) initial_setup_handle: RefCell<Option<JoinHandle<()>>>,
        mpv_event_loop_handle: RefCell<Option<JoinHandle<()>>>, // really !, not ()
        zbus_executor_loop_handle: RefCell<Option<JoinHandle<()>>>, // same

        loading_cover_handle: RefCell<Option<JoinHandle<()>>>,

        buffering_timeout: Cell<Option<glib::SourceId>>,
        time_pos_notify_timeout: Cell<Option<glib::SourceId>>,

        mpris_player: RefCell<Option<InterfaceRef<mpris::Player>>>,
    }

    impl Default for Window {
        fn default() -> Self {
            let mpv = mpv::Handle::new();
            mpv.set_property("audio-client-name", "audrey").unwrap();
            mpv.set_property("user-agent", crate::USER_AGENT).unwrap();
            mpv.set_property("vid", false).unwrap();
            mpv.set_property("prefetch-playlist", true).unwrap();

            mpv.observe_property(0, "volume").unwrap();
            mpv.observe_property(1, "mute").unwrap();
            mpv.observe_property(2, "pause").unwrap();
            mpv.observe_property(3, "playlist-pos").unwrap();
            mpv.observe_property(4, "idle-active").unwrap();
            mpv.observe_property(6, "playlist-count").unwrap();
            mpv.observe_property(7, "duration").unwrap();
            mpv.observe_property(8, "path").unwrap();

            // "Useful to drain property changes before a new file is loaded."
            mpv.add_hook(0, "on_before_start_file", 0).unwrap();

            Self {
                playbar: Default::default(),
                play_queue: Default::default(),
                can_click_shuffle_all: Cell::new(false),
                playing_cover_art: Default::default(),
                _song: (),
                setup: Default::default(),
                api: Default::default(),
                mpv,
                playlist_model: gio::ListStore::new::<Song>(),

                _volume: (),
                _mute: (),
                _pause: (),
                _playlist_pos: (),
                _time_pos: (),
                _duration: (),
                _idle_active: (),
                _playlist_count: (),

                queued_seek: Default::default(),

                initial_setup_handle: Default::default(),
                mpv_event_loop_handle: Default::default(),
                zbus_executor_loop_handle: Default::default(),

                loading_cover_handle: Default::default(),

                buffering_timeout: Default::default(),
                time_pos_notify_timeout: Default::default(),

                mpris_player: Default::default(),
            }
        }
    }

    #[glib::object_subclass]
    impl ObjectSubclass for Window {
        const NAME: &'static str = "AudreyUiWindow";
        type Type = super::Window;
        type ParentType = adw::ApplicationWindow;

        fn class_init(klass: &mut Self::Class) {
            klass.bind_template();
            klass.bind_template_callbacks();
        }

        fn instance_init(obj: &InitializingObject<Self>) {
            obj.init_template();
        }
    }

    #[glib::derived_properties]
    impl ObjectImpl for Window {
        fn constructed(&self) {
            self.parent_constructed();

            // update time-pos every 100 ms
            let window = self.obj().downgrade();
            self.time_pos_notify_timeout
                .replace(Some(glib::timeout_add_local(
                    std::time::Duration::from_millis(100),
                    move || match window.upgrade() {
                        None => glib::ControlFlow::Break,
                        Some(window) => {
                            if !window.idle_active() && !window.pause() {
                                window.notify("time-pos");
                            }
                            glib::ControlFlow::Continue
                        }
                    },
                )));

            let window = self.obj().downgrade();
            let mpv_event_loop_handle = glib::spawn_future_local(async move {
                loop {
                    let window = window.upgrade().unwrap();
                    let listener = window.imp().mpv.wakeup_listener();

                    // only send property change notifications after the event queue is drained
                    let freeze_notify = window.freeze_notify();

                    while let Some(event) = window.imp().mpv.wait_event(0.0) {
                        use crate::mpv::Event;

                        match event {
                            Event::PropertyChange(event) => window.imp().on_property_change(event),
                            Event::StartFile(_) => window.imp().on_start_file(),
                            Event::Hook(event) => window.imp().on_hook(event),
                            Event::LogMessage(event) => window.imp().on_log_message(event),
                            Event::Seek => window.imp().on_seek(),
                            Event::PlaybackRestart => window.imp().on_playback_restart(),
                            Event::EndFile(event) => window.imp().on_end_file(event),

                            Event::Unknown(_) => {
                                // either deprecated or future, ignore
                            }

                            Event::AudioReconfig => {
                                // "This is relatively uninteresting, because there is no such thing as audio output embedding."
                                // ^ ignore
                            }

                            _ => event!(Level::DEBUG, "unhandled {event:?}"),
                        }
                    }

                    // send property change notifications now
                    drop(freeze_notify);
                    drop(window);
                    listener.await;
                }
            });
            self.mpv_event_loop_handle
                .replace(Some(mpv_event_loop_handle));

            // set up mpris
            let window = self.obj().clone();
            let zbus_executor_loop_handle = glib::spawn_future_local(async move {
                let conn = zbus::connection::Builder::session()
                    .expect("could not connect to the session bus")
                    .internal_executor(false)
                    .build()
                    .await
                    .expect("could not build connection to the session bus");

                futures::join!(
                    glib::clone!(
                        #[strong]
                        conn,
                        async move {
                            crate::Mpris::setup(conn.object_server(), &window)
                                .await
                                .expect("could not serve mpris");

                            window.imp().mpris_player.replace(Some(
                                mpris::Player::new(conn.object_server(), &window)
                                    .await
                                    .expect("could not serve mpris player"),
                            ));

                            // always set up handlers before requesting service name
                            conn.request_name("org.mpris.MediaPlayer2.audrey")
                                .await
                                .expect("could not register name in session bus");
                        }
                    ),
                    async {
                        loop {
                            conn.executor().tick().await;
                        }
                    }
                );
            });
            self.zbus_executor_loop_handle
                .replace(Some(zbus_executor_loop_handle));
        }
    }

    impl WidgetImpl for Window {}

    impl WindowImpl for Window {}

    impl ApplicationWindowImpl for Window {}

    impl AdwApplicationWindowImpl for Window {}

    #[gtk::template_callbacks]
    impl Window {
        #[template_callback]
        fn show_playbar_cover_art(&self, stack_child: Option<&str>) -> bool {
            stack_child != Some("play-queue")
        }

        #[template_callback]
        async fn shuffle_all(&self) {
            self.obj().set_can_click_shuffle_all(false);

            self.mpv.command(["stop"]).unwrap();
            self.playlist_model.remove_all();
            self.set_pause(false);

            let api = {
                let api = self.api.borrow();
                Rc::clone(api.as_ref().unwrap())
            };
            for song in api.get_random_songs(10).await.unwrap().into_iter() {
                let song = Song::from_child(&api, &song, true);
                self.mpv
                    .command(["loadfile", &song.stream_url(), "append-play"])
                    .unwrap();
                self.playlist_model.append(&song);
            }
            self.obj().set_can_click_shuffle_all(true);
        }

        #[template_callback]
        fn show_setup_dialog(&self) {
            self.setup.present(Some(self.obj().as_ref()));
        }

        fn volume(&self) -> i64 {
            self.mpv
                .get_property::<i64>("volume")
                .unwrap()
                .try_into()
                .unwrap()
        }

        fn set_volume(&self, volume: i64) {
            self.mpv.set_property("volume", volume as i64).unwrap();
        }

        fn mute(&self) -> bool {
            self.mpv.get_property("mute").unwrap()
        }

        fn set_mute(&self, mute: bool) {
            self.mpv.set_property("mute", mute).unwrap();
        }

        fn pause(&self) -> bool {
            self.mpv.get_property("pause").unwrap()
        }

        fn set_pause(&self, pause: bool) {
            self.mpv.set_property("pause", pause).unwrap();
        }

        fn playlist_pos(&self) -> i64 {
            self.mpv
                .get_property("playlist-pos")
                .unwrap()
        }

        fn time_pos(&self) -> f64 {
            if let Some(queued_seek) = self.queued_seek.get() {
                // counterfeit time-pos while the seek is ongoing
                queued_seek
            } else {
                match self.mpv.get_property("time-pos") {
                    Ok(time_pos) => Ok(time_pos),
                    Err(err) if err.is_property_unavailable() => Ok(0.0), //placeholder
                    Err(err) => Err(err),
                }
                .unwrap()
            }
        }

        fn duration(&self) -> f64 {
            let duration = match self.mpv.get_property::<f64>("duration") {
                Ok(duration) => Ok(Some(duration)),
                Err(err) if err.is_property_unavailable() => {
                    Ok(self.song().as_ref().map(|song| song.duration() as f64))
                }
                Err(err) => Err(err),
            }
            .unwrap();

            {
                let left = duration.map(|f| f as i64);
                let right = self.song().as_ref().map(crate::model::Song::duration);
                if left != right {
                    event!(
                        Level::WARN,
                        "mpv duration {left:?} doesn not match subsonic duration {right:?}"
                    );
                }
            }

            duration.unwrap_or(0.0) // placeholder
        }

        fn idle_active(&self) -> bool {
            self.mpv.get_property("idle-active").unwrap()
        }

        fn playlist_count(&self) -> i64 {
            self.mpv
                .get_property::<i64>("playlist-count")
                .unwrap()
                .try_into()
                .unwrap()
        }

        fn song(&self) -> Option<Song> {
            match self.obj().playlist_pos().try_into() {
                Ok(playlist_pos) => Some(
                    self.obj()
                        .playlist_model()
                        .item(playlist_pos)
                        .unwrap()
                        .dynamic_cast()
                        .unwrap(),
                ),
                Err(_) => None,
            }
        }

        fn buffering_start(&self) {
            let started_buffering = std::time::Instant::now();
            let window = self.obj().downgrade();
            self.buffering_timeout
                .replace(Some(glib::timeout_add_local(
                    std::time::Duration::from_millis(100),
                    move || {
                        match window.upgrade() {
                            None => glib::ControlFlow::Break,
                            Some(window) => {
                                // 3 second period from gnome hig
                                if started_buffering.elapsed() > std::time::Duration::from_secs(3) {
                                    window.imp().playbar.set_show_pulse_bar(true);
                                    window.imp().playbar.pulse_bar().pulse();
                                }
                                glib::ControlFlow::Continue
                            }
                        }
                    },
                )))
                .map(|source| source.remove());
        }

        fn buffering_end(&self) {
            self.buffering_timeout.take().map(|source| source.remove());
            self.playbar.set_show_pulse_bar(false);
        }

        fn on_property_change(&self, event: crate::mpv::event::PropertyEvent) {
            match event.reply_userdata {
                0 => {
                    assert_eq!(event.name, "volume");
                    self.obj().notify("volume");
                }

                1 => {
                    assert_eq!(event.name, "mute");
                    self.obj().notify("mute");
                }

                2 => {
                    assert_eq!(event.name, "pause");
                    self.obj().notify("pause");
                }

                3 => {
                    assert_eq!(event.name, "playlist-pos");
                    self.obj().notify("playlist-pos");
                }

                4 => {
                    assert_eq!(event.name, "idle-active");
                    self.obj().notify("idle-active");
                }

                6 => {
                    assert_eq!(event.name, "playlist-count");
                    self.obj().notify("playlist-count");
                }

                7 => {
                    assert_eq!(event.name, "duration");
                    self.obj().notify("duration");
                }

                8 => {
                    assert_eq!(event.name, "path");
                    // sanity check
                    match self.mpv.get_property::<String>("path") {
                        Ok(path) => {
                            assert_eq!(path, self.obj().song().unwrap().stream_url())
                        }
                        Err(err) if err.is_property_unavailable() => {}
                        Err(err) => Err(err).unwrap(),
                    }
                }

                _ => unreachable!(),
            }
        }

        fn on_start_file(&self) {
            event!(Level::INFO, "start file event");
            self.obj().notify("song");
            self.buffering_start();

            let window = self.obj().clone();
            let song_id = window.song().unwrap().id();
            self.loading_cover_handle
                .replace(Some(glib::spawn_future_local(async move {
                    let api = window.imp().api.borrow().as_ref().unwrap().clone();
                    let bytes = api
                        .cover_art(&song_id, None) // full size
                        .await
                        .expect("could not load cover art for song {song_id}");

                    match window.song() {
                        Some(song) if song.id() == song_id => {
                            let texture = gdk::Texture::from_bytes(&glib::Bytes::from_owned(bytes))
                                .expect("could not create texture from cover art for {song_id}");
                            window.set_playing_cover_art(Some(texture));
                        }
                        _ => {
                            event!(
                                Level::WARN,
                                "was too late to fetch cover for song {song_id}"
                            )
                        }
                    }
                })))
                .map(|handle| handle.abort());

            // make sure this is reported as 0
            self.obj().notify("time-pos");
        }

        fn on_hook(&self, event: crate::mpv::event::HookEvent) {
            match event.reply_userdata {
                0 => {
                    assert_eq!(&event.name, "on_before_start_file");
                    event!(Level::DEBUG, "on_before_start_file triggered");
                    // just use this as a barrier
                    self.mpv.continue_hook(event.id).unwrap();
                }

                _ => unreachable!(),
            }
        }

        fn on_log_message(&self, event: crate::mpv::event::LogMessageEvent) {
            let span = span!(Level::DEBUG, "mpv_log", prefix = event.prefix);
            let _guard = span.enter();
            match event.log_level {
                // level has to be 'static so this sux
                l if l <= 20 => {
                    event!(target: "mpv_event", Level::ERROR, "{}", event.text.trim())
                }
                l if l <= 30 => {
                    event!(target: "mpv_event", Level::WARN, "{}", event.text.trim())
                }
                l if l <= 40 => {
                    event!(target: "mpv_event", Level::INFO, "{}", event.text.trim())
                }
                l if l <= 60 => {
                    event!(target: "mpv_event", Level::DEBUG, "{}", event.text.trim())
                }
                l if l <= 70 => {
                    event!(target: "mpv_event", Level::TRACE, "{}", event.text.trim())
                }
                // should be unused
                _ => event!(
                    target: "mpv_erroneus_event",
                    Level::DEBUG,
                    log_level = event.log_level,
                    "{}",
                    event.text.trim(),
                ),
            };
        }

        fn on_seek(&self) {
            event!(Level::INFO, "seek event");
            self.buffering_start();
        }

        fn on_playback_restart(&self) {
            event!(Level::INFO, "playback restart event");
            self.buffering_end();
            self.obj().notify("time-pos");

            if let Some(queued_seek) = self.queued_seek.take() {
                // a seek was tried before and failed, try again now
                event!(Level::INFO, "performing queued seek to {queued_seek}");
                self.obj().seek(queued_seek);
            }
        }

        fn on_end_file(&self, event: crate::mpv::event::EndFileEvent) {
            event!(Level::INFO, "end file event: {event:?}");
            self.obj().notify("song");
            self.buffering_end();

            if let Err(err) = event.reason {
                event!(Level::ERROR, "end file error: {err}");
            }

            // cancel queued seek always
            self.queued_seek.set(None);

            self.obj().set_playing_cover_art(None::<gdk::Texture>);

            // make sure the seekbar looks full
            self.obj().notify("time-pos");
        }
    }

    impl Drop for Window {
        fn drop(&mut self) {
            event!(Level::DEBUG, "dropping AudreyUiWindow");

            self.mpv_event_loop_handle.take().unwrap().abort();
            self.zbus_executor_loop_handle.take().unwrap().abort();

            self.time_pos_notify_timeout
                .take()
                .map(|source| source.remove());
            self.buffering_timeout.take().map(|source| source.remove());
        }
    }
}

use adw::prelude::*;
use adw::subclass::prelude::*;
use gtk::{gio, glib};
use std::rc::Rc;
use tracing::{event, Level};

glib::wrapper! {
    pub struct Window(ObjectSubclass<imp::Window>)
        @extends adw::ApplicationWindow, gtk::ApplicationWindow, gtk::Window, gtk::Widget,
        @implements gio::ActionGroup, gio::ActionMap, gtk::Accessible, gtk::Buildable, gtk::ConstraintTarget, gtk::Native, gtk::Root, gtk::ShortcutManager;
}

impl Window {
    pub fn new(app: &impl IsA<gtk::Application>) -> Self {
        let window: Self = glib::Object::builder().property("application", app).build();

        window.imp().setup.set_window(&window);
        let initial_setup_handle = {
            let setup = window.imp().setup.clone();
            glib::spawn_future_local(async move { setup.load().await })
        };
        window
            .imp()
            .initial_setup_handle
            .replace(Some(initial_setup_handle));

        window
    }

    pub fn playbin(&self) -> ! {
        todo!()
    }

    pub fn playlist_play_index(&self, index: Option<i64>) {
        match index.as_ref() {
            Some(index) => self
                .imp()
                .mpv
                .command(["playlist-play-index", &index.to_string()])
                .unwrap(),
            None => self
                .imp()
                .mpv
                .command(["playlist-play-index", "none"])
                .unwrap(),
        };
    }

    pub fn playlist_remove(&self, index: i64) {
        self.imp()
            .mpv
            .command(["playlist-remove", &index.to_string()])
            .unwrap();
        self.playlist_model().remove(index as u32);
    }

    pub fn setup_connected(&self, api: crate::subsonic::Client) {
        self.imp().api.replace(Some(Rc::new(api)));
        self.set_can_click_shuffle_all(true);
    }

    pub fn playlist_next(&self) {
        self.imp().mpv.command(["playlist-next"]).unwrap();
    }

    pub fn playlist_prev(&self) {
        self.imp().mpv.command(["playlist-prev"]).unwrap();
    }

    pub fn seek(&self, new_position: f64) {
        match self
            .imp()
            .mpv
            .command(["seek", &new_position.to_string(), "absolute", "exact"])
        {
            Ok(()) => {}
            Err(err) => {
                event!(Level::INFO, "queuing seek to {new_position}: {err}");
                self.imp().queued_seek.set(Some(new_position));
                self.notify("time-pos");
            }
        }
    }

    pub fn playlist_move(&self, from: u32, to: u32) {
        // NOTE: for mpv, to refers to the "gap" right before i
        // so playlist-move i 0 makes a track the first
        // playlist-move i 1 makes a track the second
        // and playlist-move i playlist-count makes a track the last
        // (so if to is the position of another track, from is left behind to)
        self.imp()
            .mpv
            .command(["playlist-move", &from.to_string(), &to.to_string()])
            .unwrap();

        if from < to {
            // F1234T -> 1234FT
            let mut spliced = Vec::with_capacity((to - from) as usize);
            for i in from + 1..to {
                spliced.push(self.playlist_model().item(i).unwrap());
            }
            spliced.push(self.playlist_model().item(from).unwrap());

            self.playlist_model()
                .splice(from, spliced.len() as u32, &spliced);
        } else if to < from {
            // T1234F -> FT1234
            let mut spliced = Vec::with_capacity((from - to + 1) as usize);
            spliced.push(self.playlist_model().item(from).unwrap());
            spliced.push(self.playlist_model().item(to).unwrap());
            for i in to + 1..from {
                spliced.push(self.playlist_model().item(i).unwrap());
            }

            self.playlist_model()
                .splice(to, spliced.len() as u32, &spliced);
        }
    }
}