use std::{
    cell::{Cell, OnceCell, RefCell},
    sync::Arc,
};

use fragile::Fragile;
use gstreamer_play::gst;
use gtk::{
    gio,
    glib::{self, clone, subclass::Signal, Properties},
    prelude::*,
    subclass::prelude::*,
};
use mpris_player::{Metadata, MprisPlayer, PlaybackStatus};
use once_cell::sync::Lazy;

use crate::{
    config,
    db::models::{Recording, Track},
    library::MusicusLibrary,
    playlist_item::PlaylistItem,
    program::Program,
};

mod imp {
    use super::*;

    #[derive(Properties, Debug, Default)]
    #[properties(wrapper_type = super::MusicusPlayer)]
    pub struct MusicusPlayer {
        #[property(get, set)]
        pub library: RefCell<Option<MusicusLibrary>>,
        #[property(get, set)]
        pub active: Cell<bool>,
        #[property(get, set)]
        pub playing: Cell<bool>,
        #[property(get, set = Self::set_program)]
        pub program: RefCell<Option<Program>>,
        #[property(get, construct_only)]
        pub playlist: OnceCell<gio::ListStore>,
        #[property(get, set = Self::set_current_index)]
        pub current_index: Cell<u32>,
        #[property(get, set)]
        pub duration_ms: Cell<u64>,
        #[property(get, set)]
        pub position_ms: Cell<u64>,

        pub play: OnceCell<gstreamer_play::Play>,
        pub play_signal_adapter: OnceCell<gstreamer_play::PlaySignalAdapter>,
        pub mpris: OnceCell<Arc<MprisPlayer>>,
    }

    impl MusicusPlayer {
        pub fn set_program(&self, program: &Program) {
            self.program.replace(Some(program.to_owned()));

            if !self.obj().active() {
                self.obj().set_active(true);
                self.obj().generate_items(program);
                self.obj().set_current_index(0);
                self.obj().play();
            }
        }

        pub fn set_current_index(&self, index: u32) {
            let playlist = self.playlist.get().unwrap();

            if let Some(item) = playlist.item(index) {
                if let Some(old_item) = playlist.item(self.current_index.get()) {
                    old_item
                        .downcast::<PlaylistItem>()
                        .unwrap()
                        .set_is_playing(false);
                }

                let item = item.downcast::<PlaylistItem>().unwrap();
                self.mpris.get().unwrap().set_metadata(Metadata {
                    artist: Some(vec![item.make_title()]),
                    title: item.make_subtitle(),
                    ..Default::default()
                });

                let uri = glib::filename_to_uri(item.path(), None)
                    .expect("track path should be parsable as an URI");

                let play = self.play.get().unwrap();
                play.set_uri(Some(&uri));
                if self.playing.get() {
                    play.play();
                }

                self.current_index.set(index);
                item.set_is_playing(true);

                self.library
                    .borrow()
                    .as_ref()
                    .unwrap()
                    .track_played(&item.track_id())
                    .unwrap();
            }
        }
    }

    #[glib::object_subclass]
    impl ObjectSubclass for MusicusPlayer {
        const NAME: &'static str = "MusicusPlayer";
        type Type = super::MusicusPlayer;
    }

    #[glib::derived_properties]
    impl ObjectImpl for MusicusPlayer {
        fn signals() -> &'static [Signal] {
            static SIGNALS: Lazy<Vec<Signal>> =
                Lazy::new(|| vec![Signal::builder("raise").build()]);

            SIGNALS.as_ref()
        }

        fn constructed(&self) {
            self.parent_constructed();

            let play = gstreamer_play::Play::new(None::<gstreamer_play::PlayVideoRenderer>);

            let mpris = MprisPlayer::new(
                config::APP_ID.to_owned(),
                config::NAME.to_owned(),
                config::APP_ID.to_owned(),
            );

            mpris.set_can_raise(true);
            mpris.set_can_play(true);
            mpris.set_can_pause(true);
            mpris.set_can_go_previous(true);
            mpris.set_can_go_next(true);
            mpris.set_can_seek(false);
            mpris.set_can_set_fullscreen(false);

            let obj = self.obj();
            mpris.connect_raise(clone!(@weak obj => move || obj.emit_by_name::<()>("raise", &[])));
            mpris.connect_play(clone!(@weak obj => move || obj.play()));
            mpris.connect_pause(clone!(@weak obj => move || obj.pause()));
            mpris.connect_play_pause(clone!(@weak obj => move || obj.play_pause()));
            mpris.connect_previous(clone!(@weak obj => move || obj.previous()));
            mpris.connect_next(clone!(@weak obj => move || obj.next()));

            self.mpris.set(mpris).expect("mpris should not be set");

            let mut config = play.config();
            config.set_position_update_interval(250);
            play.set_config(config).unwrap();
            play.set_video_track_enabled(false);

            let play_signal_adapter = gstreamer_play::PlaySignalAdapter::new(&play);

            let obj = Fragile::new(self.obj().to_owned());
            play_signal_adapter.connect_end_of_stream(move |_| {
                obj.get().next();
            });

            let obj = Fragile::new(self.obj().to_owned());
            play_signal_adapter.connect_position_updated(move |_, position| {
                if let Some(position) = position {
                    let obj = obj.get();
                    obj.imp().position_ms.set(position.mseconds());
                    obj.notify_position_ms();
                }
            });

            let obj = Fragile::new(self.obj().to_owned());
            play_signal_adapter.connect_duration_changed(move |_, duration| {
                if let Some(duration) = duration {
                    let obj = obj.get();
                    let imp = obj.imp();

                    imp.position_ms.set(0);
                    obj.notify_position_ms();

                    imp.duration_ms.set(duration.mseconds());
                    obj.notify_duration_ms();
                }
            });

            self.play.set(play).unwrap();
            self.play_signal_adapter.set(play_signal_adapter).unwrap();
        }
    }
}

glib::wrapper! {
    pub struct MusicusPlayer(ObjectSubclass<imp::MusicusPlayer>);
}

impl MusicusPlayer {
    pub fn new() -> Self {
        glib::Object::builder()
            .property("active", false)
            .property("playing", false)
            .property("playlist", gio::ListStore::new::<PlaylistItem>())
            .property("current-index", 0u32)
            .property("position-ms", 0u64)
            .property("duration-ms", 60_000u64)
            .build()
    }

    pub fn connect_raise<F: Fn(&Self) + 'static>(&self, f: F) -> glib::SignalHandlerId {
        self.connect_local("raise", true, move |values| {
            let obj = values[0].get::<Self>().unwrap();
            f(&obj);
            None
        })
    }

    pub fn play_recording(&self, recording: &Recording) {
        let tracks = &recording.tracks;

        if tracks.is_empty() {
            log::warn!("Ignoring recording without tracks being added to the playlist.");
            return;
        }

        let title = format!(
            "{}: {}",
            recording.work.composers_string(),
            recording.work.name.get(),
        );

        let performances = recording.performers_string();

        let mut items = Vec::new();

        if tracks.len() == 1 {
            items.push(PlaylistItem::new(
                true,
                &title,
                Some(&performances),
                None,
                &tracks[0].path,
                &tracks[0].track_id,
            ));
        } else {
            let mut tracks = tracks.into_iter();
            let first_track = tracks.next().unwrap();

            let track_title = |track: &Track, number: usize| -> String {
                let title = track
                    .works
                    .iter()
                    .map(|w| w.name.get().to_string())
                    .collect::<Vec<String>>()
                    .join(", ");

                if title.is_empty() {
                    format!("Track {number}")
                } else {
                    title
                }
            };

            items.push(PlaylistItem::new(
                true,
                &title,
                Some(&performances),
                Some(&track_title(&first_track, 1)),
                &first_track.path,
                &first_track.track_id,
            ));

            for (index, track) in tracks.enumerate() {
                items.push(PlaylistItem::new(
                    false,
                    &title,
                    Some(&performances),
                    // track number = track index + 1 (first track) + 1 (zero based)
                    Some(&track_title(&track, index + 2)),
                    &track.path,
                    &track.track_id,
                ));
            }
        }

        self.append(items);
    }

    pub fn append(&self, tracks: Vec<PlaylistItem>) {
        let playlist = self.playlist();

        for track in tracks {
            playlist.append(&track);
        }

        if !self.active() && playlist.n_items() > 0 {
            self.set_active(true);
            self.set_current_index(0);
            self.play();
        }
    }

    pub fn play_pause(&self) {
        if self.playing() {
            self.pause();
        } else {
            self.play();
        }
    }

    pub fn play(&self) {
        let imp = self.imp();
        imp.play.get().unwrap().play();
        self.set_playing(true);
        imp.mpris
            .get()
            .unwrap()
            .set_playback_status(PlaybackStatus::Playing);
    }

    pub fn pause(&self) {
        let imp = self.imp();
        imp.play.get().unwrap().pause();
        self.set_playing(false);
        imp.mpris
            .get()
            .unwrap()
            .set_playback_status(PlaybackStatus::Paused);
    }

    pub fn seek_to(&self, time_ms: u64) {
        let imp = self.imp();
        imp.play
            .get()
            .unwrap()
            .seek(gst::ClockTime::from_mseconds(time_ms));
    }

    pub fn current_item(&self) -> Option<PlaylistItem> {
        let imp = self.imp();
        imp.playlist
            .get()
            .unwrap()
            .item(imp.current_index.get())
            .and_downcast::<PlaylistItem>()
    }

    pub fn next(&self) {
        if self.current_index() < self.playlist().n_items() - 1 {
            self.set_current_index(self.current_index() + 1);
        } else if let Some(program) = self.program() {
            self.generate_items(&program);
            self.set_current_index(self.current_index() + 1);
        }
    }

    pub fn previous(&self) {
        if self.current_index() > 0 {
            self.set_current_index(self.current_index() - 1);
        }
    }

    fn generate_items(&self, program: &Program) {
        if let Some(library) = self.library() {
            // TODO: if program.play_full_recordings() {
            let recording = library.generate_recording(program).unwrap();
            self.play_recording(&recording);
        }
    }
}

impl Default for MusicusPlayer {
    fn default() -> Self {
        Self::new()
    }
}