use crate::*;
pub(crate) use std::fmt::Write;
pub(crate) use ::tengri::tui::ratatui::prelude::Position;

#[tengri_proc::view(TuiOut)]
impl App {
    pub fn view_nil (&self) -> impl Content<TuiOut> + use<'_> {
        "nil"
    }
    pub fn view_history (&self) -> impl Content<TuiOut> {
        Fixed::y(1, Fill::x(Align::w(FieldH(self.color,
            format!("History ({})", self.history.len()),
                self.history.last().map(|last|Fill::x(Align::w(format!("{:?}", last.0))))))))
    }
    pub fn view_status_h2 (&self) -> impl Content<TuiOut> + use<'_> {
        self.update_clock();
        let theme   = self.color;
        let playing = self.clock().is_rolling();
        Fixed::y(2, Stack::east(move|add: &mut dyn FnMut(&dyn Render<TuiOut>)|{
            add(&Fixed::x(5, Tui::bg(if playing { Rgb(0, 128, 0) } else { Rgb(128, 64, 0) },
                Either::new(false, // TODO
                    Thunk::new(move||Fixed::x(9, Either::new(playing,
                        Tui::fg(Rgb(0, 255, 0),   " PLAYING "),
                        Tui::fg(Rgb(255, 128, 0), " STOPPED ")))
                    ),
                    Thunk::new(move||Fixed::x(5, Either::new(playing,
                        Tui::fg(Rgb(0, 255, 0),   Bsp::s(" 🭍🭑🬽 ", " 🭞🭜🭘 ",)),
                        Tui::fg(Rgb(255, 128, 0), Bsp::s(" ▗▄▖ ", " ▝▀▘ ",))))
                    )
                )
            )));
            add(&" ");
            {
                let cache = self.view_cache.read().unwrap();
                add(&Fixed::x(15, Align::w(Bsp::s(
                    FieldH(theme, "Beat", cache.beat.view.clone()),
                    FieldH(theme, "Time", cache.time.view.clone()),
                ))));
                add(&Fixed::x(13, Align::w(Bsp::s(
                    Fill::x(Align::w(FieldH(theme, "BPM", cache.bpm.view.clone()))),
                    Fill::x(Align::w(FieldH(theme, "SR ", cache.sr.view.clone()))),
                ))));
                add(&Fixed::x(12, Align::w(Bsp::s(
                    Fill::x(Align::w(FieldH(theme, "Buf", cache.buf.view.clone()))),
                    Fill::x(Align::w(FieldH(theme, "Lat", cache.lat.view.clone()))),
                ))));
                add(&Bsp::s(
                    Fill::x(Align::w(FieldH(theme, "Selected", Align::w(self.selection().describe(
                        self.tracks(),
                        self.scenes()
                    ))))),
                    Fill::x(Align::w(FieldH(theme, format!("History ({})", self.history.len()),
                        self.history.last().map(|last|Fill::x(Align::w(format!("{:?}", last.0)))))))
                ));
                //if let Some(last) = self.history.last() {
                    //add(&FieldV(theme, format!("History ({})", self.history.len()),
                        //Fill::x(Align::w(format!("{:?}", last.0)))));
                //}
            }
        }))
    }
    pub fn view_status_v (&self) -> impl Content<TuiOut> + use<'_> {
        self.update_clock();
        let cache   = self.view_cache.read().unwrap();
        let theme   = self.color;
        let playing = self.clock().is_rolling();
        Tui::bg(theme.darker.rgb, Fixed::xy(20, 5, Outer(true, Style::default().fg(Tui::g(96))).enclose(
            col!(
                Fill::x(Align::w(Bsp::e(
                    Align::w(Tui::bg(if playing { Rgb(0, 128, 0) } else { Rgb(128, 64, 0) },
                        Either::new(false, // TODO
                            Thunk::new(move||Fixed::x(9, Either::new(playing,
                                Tui::fg(Rgb(0, 255, 0),   " PLAYING "),
                                Tui::fg(Rgb(255, 128, 0), " STOPPED ")))
                            ),
                            Thunk::new(move||Fixed::x(5, Either::new(playing,
                                Tui::fg(Rgb(0, 255, 0),   Bsp::s(" 🭍🭑🬽 ", " 🭞🭜🭘 ",)),
                                Tui::fg(Rgb(255, 128, 0), Bsp::s(" ▗▄▖ ", " ▝▀▘ ",))))
                            )
                        )
                    )),
                    Bsp::s(
                        FieldH(theme, "Beat", cache.beat.view.clone()),
                        FieldH(theme, "Time", cache.time.view.clone()),
                    ),
                ))),
                Fill::x(Align::w(FieldH(theme, "BPM", cache.bpm.view.clone()))),
                Fill::x(Align::w(FieldH(theme, "SR ", cache.sr.view.clone()))),
                Fill::x(Align::w(FieldH(theme, "Buf", Bsp::e(cache.buf.view.clone(), Bsp::e(" = ", cache.lat.view.clone()))))),
            ))))
    }
    pub fn view_status (&self) -> impl Content<TuiOut> + use<'_> {
        self.update_clock();
        let cache = self.view_cache.read().unwrap();
        view_status(Some(self.project.selection.describe(self.tracks(), self.scenes())),
            cache.sr.view.clone(), cache.buf.view.clone(), cache.lat.view.clone())
    }
    pub fn view_transport (&self) -> impl Content<TuiOut> + use<'_> {
        self.update_clock();
        let cache = self.view_cache.read().unwrap();
        view_transport(self.project.clock.is_rolling(),
            cache.bpm.view.clone(), cache.beat.view.clone(), cache.time.view.clone())
    }
    pub fn view_editor (&self) -> impl Content<TuiOut> + use<'_> {
        let bg = self.editor()
            .and_then(|editor|editor.clip().clone())
            .map(|clip|clip.read().unwrap().color.darker)
            .unwrap_or(self.color.darker);
        Fill::xy(Tui::bg(bg.rgb, self.editor()))
    }
    pub fn view_editor_status (&self) -> impl Content<TuiOut> + use<'_> {
        self.editor().map(|e|Fixed::x(20, Outer(true, Style::default().fg(Tui::g(96))).enclose(
            Fill::y(Align::n(Bsp::s(e.clip_status(), e.edit_status()))))))
    }
    pub fn view_midi_ins_status (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.view_midi_ins_status(self.color)
    }
    pub fn view_midi_outs_status (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.view_midi_outs_status(self.color)
    }
    pub fn view_audio_ins_status (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.view_audio_ins_status(self.color)
    }
    pub fn view_audio_outs_status (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.view_audio_outs_status(self.color)
    }
    pub fn view_scenes (&self) -> impl Content<TuiOut> + use<'_> {
        Bsp::e(
            Fixed::x(20, Align::nw(self.project.view_scenes_names())),
            self.project.view_scenes_clips(),
        )
    }
    pub fn view_scenes_names (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.view_scenes_names()
    }
    pub fn view_scenes_clips (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.view_scenes_clips()
    }
    pub fn view_tracks_inputs <'a> (&'a self) -> impl Content<TuiOut> + use<'a> {
        Fixed::y(1 + self.project.midi_ins.len() as u16,
            self.project.view_inputs(self.color))
    }
    pub fn view_tracks_outputs <'a> (&'a self) -> impl Content<TuiOut> + use<'a> {
        self.project.view_outputs(self.color)
    }
    pub fn view_tracks_devices <'a> (&'a self) -> impl Content<TuiOut> + use<'a> {
        Fixed::y(4, self.project.view_track_devices(self.color))
    }
    pub fn view_tracks_names <'a> (&'a self) -> impl Content<TuiOut> + use<'a> {
        Fixed::y(2, self.project.view_track_names(self.color))
    }
    pub fn view_pool (&self) -> impl Content<TuiOut> + use<'_> {
        Fixed::x(20, Bsp::s(
            Fill::x(Align::w(FieldH(self.color, "Clip pool:", ""))),
            Fill::y(Align::n(Tui::bg(Rgb(0, 0, 0), Outer(true, Style::default().fg(Tui::g(96)))
                .enclose(PoolView(&self.pool)))))))
    }
    pub fn view_samples_keys (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.sampler().map(|s|s.view_list(true, self.editor().unwrap()))
    }
    pub fn view_samples_grid (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.sampler().map(|s|s.view_grid())
    }
    pub fn view_sample_viewer (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.sampler().map(|s|s.view_sample(self.editor().unwrap().get_note_pos()))
    }
    pub fn view_sample_info (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.sampler().map(|s|s.view_sample_info(self.editor().unwrap().get_note_pos()))
    }
    pub fn view_sample_status (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.sampler().map(|s|Outer(true, Style::default().fg(Tui::g(96))).enclose(
            Fill::y(Align::n(s.view_sample_status(self.editor().unwrap().get_note_pos())))))
    }
    pub fn view_meters_input (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.sampler().map(|s|s.view_meters_input())
    }
    pub fn view_meters_output (&self) -> impl Content<TuiOut> + use<'_> {
        self.project.sampler().map(|s|s.view_meters_output())
    }
    pub fn view_dialog (&self) -> impl Content<TuiOut> + use<'_> {
        self.dialog.as_ref().map(|dialog|Bsp::b("",
            Fixed::xy(70, 23, Tui::fg_bg(Rgb(255,255,255), Rgb(16,16,16), Bsp::b(
                Repeat(" "), Outer(true, Style::default().fg(Tui::g(96)))
                    .enclose(dialog))))))
    }
}

impl ScenesView for App {
    fn h_scenes (&self) -> u16 {
        (self.height() as u16).saturating_sub(20)
    }
    fn w_side (&self) -> u16 {
        20
    }
    fn w_mid (&self) -> u16 {
        (self.width() as u16).saturating_sub(self.w_side())
    }
}

/// Clear a pre-allocated buffer, then write into it.
#[macro_export] macro_rules! rewrite {
    ($buf:ident, $($rest:tt)*) => { |$buf,_,_|{ $buf.clear(); write!($buf, $($rest)*) } }
}

#[derive(Debug, Default)] pub(crate) struct ViewMemo<T, U> {
    pub(crate) value: T,
    pub(crate) view: Arc<RwLock<U>>
}

impl<T: PartialEq, U> ViewMemo<T, U> {
    fn new (value: T, view: U) -> Self {
        Self { value, view: Arc::new(view.into()) }
    }
    pub(crate) fn update <R> (
        &mut self,
        newval: T,
        render: impl Fn(&mut U, &T, &T)->R
    ) -> Option<R> {
        if newval != self.value {
            let result = render(&mut*self.view.write().unwrap(), &newval, &self.value);
            self.value = newval;
            return Some(result);
        }
        None
    }
}

#[derive(Debug)] pub struct ViewCache {
    pub(crate) sr:   ViewMemo<Option<(bool, f64)>, String>,
    pub(crate) buf:  ViewMemo<Option<f64>, String>,
    pub(crate) lat:  ViewMemo<Option<f64>, String>,
    pub(crate) bpm:  ViewMemo<Option<f64>, String>,
    pub(crate) beat: ViewMemo<Option<f64>, String>,
    pub(crate) time: ViewMemo<Option<f64>, String>,
    pub(crate) scns: ViewMemo<Option<(usize, usize)>, String>,
    pub(crate) trks: ViewMemo<Option<(usize, usize)>, String>,
    pub(crate) stop: Arc<str>,
    pub(crate) edit: Arc<str>,
}

impl Default for ViewCache {
    fn default () -> Self {
        let mut beat = String::with_capacity(16);
        write!(beat, "{}", Self::BEAT_EMPTY);
        let mut time = String::with_capacity(16);
        write!(time, "{}", Self::TIME_EMPTY);
        let mut bpm  = String::with_capacity(16);
        write!(bpm,  "{}", Self::BPM_EMPTY);
        Self {
            beat: ViewMemo::new(None, beat),
            time: ViewMemo::new(None, time),
            bpm:  ViewMemo::new(None, bpm),
            sr:   ViewMemo::new(None, String::with_capacity(16)),
            buf:  ViewMemo::new(None, String::with_capacity(16)),
            lat:  ViewMemo::new(None, String::with_capacity(16)),
            scns: ViewMemo::new(None, String::with_capacity(16)),
            trks: ViewMemo::new(None, String::with_capacity(16)),
            stop: "⏹".into(),
            edit: "edit".into(),
        }
    }
}

impl ViewCache {
    pub const BEAT_EMPTY: &'static str = "-.-.--";
    pub const TIME_EMPTY: &'static str = "-.---s";
    pub const BPM_EMPTY:  &'static str = "---.---";

    pub fn track_counter (cache: &Arc<RwLock<Self>>, track: usize, tracks: usize)
        -> Arc<RwLock<String>>
    {
        let data = (track, tracks);
        cache.write().unwrap().trks.update(Some(data), rewrite!(buf, "{}/{}", data.0, data.1));
        cache.read().unwrap().trks.view.clone()
    }

    pub fn scene_add (cache: &Arc<RwLock<Self>>, scene: usize, scenes: usize, is_editing: bool)
        -> impl Content<TuiOut>
    {
        let data = (scene, scenes);
        cache.write().unwrap().scns.update(Some(data), rewrite!(buf, "({}/{})", data.0, data.1));
        button_3("S", "add scene", cache.read().unwrap().scns.view.clone(), is_editing)
    }

    pub fn update_clock (cache: &Arc<RwLock<Self>>, clock: &Clock, compact: bool) {
        let rate  = clock.timebase.sr.get();
        let chunk = clock.chunk.load(Relaxed) as f64;
        let lat   = chunk / rate * 1000.;
        let delta = |start: &Moment|clock.global.usec.get() - start.usec.get();
        let mut cache = cache.write().unwrap();
        cache.buf.update(Some(chunk), rewrite!(buf, "{chunk}"));
        cache.lat.update(Some(lat),   rewrite!(buf, "{lat:.1}ms"));
        cache.sr.update(Some((compact, rate)), |buf,_,_|{
            buf.clear();
            if compact {
                write!(buf, "{:.1}kHz", rate / 1000.)
            } else {
                write!(buf, "{:.0}Hz", rate)
            }
        });
        if let Some(now) = clock.started.read().unwrap().as_ref().map(delta) {
            let pulse = clock.timebase.usecs_to_pulse(now);
            let time  = now/1000000.;
            let bpm   = clock.timebase.bpm.get();
            cache.beat.update(Some(pulse), |buf, _, _|{
                buf.clear();
                clock.timebase.format_beats_1_to(buf, pulse)
            });
            cache.time.update(Some(time), rewrite!(buf, "{:.3}s", time));
            cache.bpm.update(Some(bpm),   rewrite!(buf, "{:.3}",  bpm));
        } else {
            cache.beat.update(None, rewrite!(buf, "{}", ViewCache::BEAT_EMPTY));
            cache.time.update(None, rewrite!(buf, "{}", ViewCache::TIME_EMPTY));
            cache.bpm.update(None,  rewrite!(buf, "{}", ViewCache::BPM_EMPTY));
        }
    }
}