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//██Let me play the world's tiniest piano for you. ██
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//███████████████████████████████████████████████████
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#![allow(unused)]
#![allow(clippy::unit_arg)]
#![feature(adt_const_params)]
#![feature(associated_type_defaults)]
#![feature(if_let_guard)]
#![feature(impl_trait_in_assoc_type)]
#![feature(type_alias_impl_trait)]
#![feature(trait_alias)]
#![feature(type_changing_struct_update)]
#![feature(let_chains)]
#![feature(closure_lifetime_binder)]
#![feature(generic_const_exprs)]
#![feature(generic_arg_infer)]
pub use ::tek_engine:: *;
pub use ::tek_device::{self, *};
pub use ::tengri::{Usually, Perhaps, Has, MaybeHas};
pub use ::tengri::{has, maybe_has};
pub use ::tengri::dsl::*;
pub use ::tengri::input::*;
pub use ::tengri::output::*;
pub use ::tengri::tui::*;
pub use ::tengri::tui::ratatui;
pub use ::tengri::tui::ratatui::prelude::buffer::Cell;
pub use ::tengri::tui::ratatui::prelude::Color::{self, *};
pub use ::tengri::tui::ratatui::prelude::{Style, Stylize, Buffer, Modifier};
pub use ::tengri::tui::crossterm;
pub use ::tengri::tui::crossterm::event::{Event, KeyCode::{self, *}};
use std::path::{Path, PathBuf};
use std::sync::{Arc, RwLock};
use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering::Relaxed};
use std::error::Error;
use std::collections::BTreeMap;
use std::fmt::Write;
use ::tengri::tui::ratatui::prelude::Position;
use xdg::BaseDirectories;
mod app_dsl;  pub use self::app_dsl::*;
mod app_view; pub use self::app_view::*;
mod app_ctrl; pub use self::app_ctrl::*;
mod app_jack; pub use self::app_jack::*;
#[cfg(test)] mod app_test;
/// Total state
#[derive(Default, Debug)]
pub struct App {
    /// Must not be dropped for the duration of the process
    pub jack:    Jack<'static>,
    /// Display size
    pub size:    Measure<TuiOut>,
    /// Performance counter
    pub perf:    PerfModel,
    /// Available view modes and input bindings
    pub config:  Config,
    /// Currently selected mode
    pub mode:    Mode<Arc<str>>,
    /// Contains the currently edited musical arrangement
    pub project: Arrangement,
    /// Contains all recently created clips.
    pub pool:    Pool,
    /// Undo history
    pub history: Vec<(AppCommand, Option<AppCommand>)>,
    /// Dialog overlay
    pub dialog:  Dialog,
    /// Base color.
    pub color:   ItemTheme,
}
/// Configuration
#[derive(Default, Debug)]
pub struct Config {
    pub dirs:  BaseDirectories,
    pub modes: Arc<RwLock<BTreeMap<Arc<str>, Arc<Mode<Arc<str>>>>>>,
    pub binds: Arc<RwLock<BTreeMap<Arc<str>, EventMap<Option<TuiEvent>, Arc<str>>>>>,
}
#[derive(Default, Debug)]
pub struct Mode<D: Dsl + Ord> {
    pub path:  PathBuf,
    pub name:  Vec<D>,
    pub info:  Vec<D>,
    pub view:  Vec<D>,
    pub keys:  Vec<D>,
    pub modes: BTreeMap<D, Mode<D>>,
}
impl Config {
    const CONFIG: &'static str = "tek.edn";
    const DEFAULTS: &'static str = include_str!("../../tek.edn");
    pub fn init () -> Usually<Self> {
        let mut cfgs: Self = Default::default();
        cfgs.dirs = BaseDirectories::with_profile("tek", "v0");
        cfgs.init_file(Self::CONFIG, Self::DEFAULTS, |cfgs, dsl|cfgs.load_defs(dsl))?;
        Ok(cfgs)
    }
    pub fn init_file (
        &mut self, path: &str, defaults: &str, mut each: impl FnMut(&mut Self, &str)->Usually<()>
    ) -> Usually<()> {
        if self.dirs.find_config_file(path).is_none() {
            println!("Creating {path:?}");
            std::fs::write(self.dirs.place_config_file(path)?, defaults);
        }
        Ok(if let Some(path) = self.dirs.find_config_file(path) {
            println!("Loading {path:?}");
            let src = std::fs::read_to_string(&path)?;
            src.as_str().each(move|item|each(self, item))?;
        } else {
            return Err(format!("{path}: not found").into())
        })
    }
    pub fn load_defs <D: Dsl> (&mut self, dsl: D) -> Usually<()> {
        dsl.each(|item|{
            println!("{item:?}");
            Ok(match item.exp().head() {
                Ok(Some("keys")) if let Some(id) = item.exp().tail().head()? => {
                    self.binds.write().unwrap().insert(id.into(), {
                        let mut map = EventMap::new();
                        item.exp().tail().tail()?.each(|item|Ok({
                            if let Ok(Some(sym)) = item.exp().head().sym() {
                                map.add(TuiEvent::from_dsl(item.exp()?.head()?)?, Binding {
                                    command:     item.exp()?.tail()?.unwrap_or_default().into(),
                                    condition:   None,
                                    description: None,
                                    source:      None
                                });
                            } else if item.exp().head() == Ok(Some("see")) {
                                // TODO
                            } else {
                                return Err(format!("load_defs: unexpected: {item:?}").into())
                            }
                        }))?;
                        map
                    });
                },
                Ok(Some("mode")) if let Some(id) = item.exp().tail().head()? => {
                    self.modes.write().unwrap().insert(id.into(), {
                        let mut mode = Mode::default();
                        item.exp().tail().tail()?.each(|item|Ok(if let Ok(Some(exp)) = item.exp() {
                            match exp.head()? {
                                Some("name") => mode.name.push(
                                    exp.tail()?.map(|x|x.trim()).unwrap_or("").into()
                                ),
                                Some("info") => mode.info.push(
                                    exp.tail()?.map(|x|x.trim()).unwrap_or("").into()
                                ),
                                Some("keys") => if let Some(tail) = exp.tail()? {
                                    tail.each(|keys|Ok(mode.keys.push(keys.trim().into())))?;
                                } else {
                                    return Err(format!("load_view: empty keys: {exp}").into())
                                },
                                Some("mode") => if let (Some(name), Some(tail)) = (
                                    exp.tail()?.head()?, exp.tail()?.tail()?,
                                ) {
                                    let mut submode: Mode<Arc<str>> = Default::default();
                                    tail.each(|item|Ok(if let Ok(Some(exp)) = item.exp() {
                                        match exp.head()? {
                                            Some("keys") => if let Some(tail) = exp.tail()? {
                                                tail.each(|keys|Ok(mode.keys.push(keys.trim().into())))?;
                                            } else {
                                                return Err(format!("load_view: empty keys: {exp}").into())
                                            },
                                            _ => {
                                                return Err(format!("load_view: unexpected in mode {name}: {item:?}").into())
                                            }
                                        }
                                    } else if let Ok(Some(sym)) = item.sym() {
                                        // TODO
                                    } else {
                                        return Err(format!("load_view: unexpected in mode {name}: {item:?}").into())
                                    }))?;
                                    mode.modes.insert(name.trim().into(), submode);
                                } else {
                                    return Err(format!("load_view: empty mode: {exp}").into())
                                },
                                Some(_) => mode.view.push(exp.into()),
                                None => return Err(format!("load_view: empty: {exp}").into())
                            }
                        } else if let Ok(Some(sym)) = item.sym() {
                            mode.view.push(sym.into());
                        } else {
                            return Err(format!("load_view: unexpected: {dsl:?}").into())
                        }))?;
                        mode.into()
                    });
                },
                _ => return Err(format!("load_defs: unexpected: {item:?}").into())
            })
        })
    }
}
fn load_modules <D: Dsl, U> (dsl: D, cb: impl Fn(&str, &str)->Usually<U>) -> Usually<()> {
    //dsl!(dsl|module :id ..body|dsl!(body|@bind #info? ..commands|)
    if let Some(exp)  = dsl.exp()?
    && Some("module") == exp.head().key()?
    && let Some(tail) = exp.tail()?
    && let Some(id)   = tail.head().sym()?
    && let Some(body) = tail.tail()?
    {
        let _ = cb(id, body)?;
        Ok(())
    } else {
        return Err("unexpected: {exp:?}".into());
    }
}
/// Various possible dialog modes.
impl App {
    pub fn update_clock (&self) {
        ViewCache::update_clock(&self.project.clock.view_cache, self.clock(), self.size.w() > 80)
    }
    pub fn focused_editor (&self) -> bool {
        false
    }
}
has!(Jack<'static>:      |self: App|self.jack);
has!(Pool:               |self: App|self.pool);
has!(Dialog:             |self: App|self.dialog);
has!(Clock:              |self: App|self.project.clock);
has!(Option<MidiEditor>: |self: App|self.project.editor);
has!(Selection:          |self: App|self.project.selection);
has!(Vec<MidiInput>:     |self: App|self.project.midi_ins);
has!(Vec<MidiOutput>:    |self: App|self.project.midi_outs);
has!(Vec<Scene>:         |self: App|self.project.scenes);
has!(Vec<Track>:         |self: App|self.project.tracks);
has!(Measure<TuiOut>:    |self: App|self.size);
has_clips!(              |self: App|self.pool.clips);
maybe_has!(Track: |self: App| { MaybeHas::<Track>::get(&self.project) };
                              { MaybeHas::<Track>::get_mut(&mut self.project) });
maybe_has!(Scene: |self: App| { MaybeHas::<Scene>::get(&self.project) };
                              { MaybeHas::<Scene>::get_mut(&mut self.project) });
impl HasClipsSize   for App { fn clips_size (&self) -> &Measure<TuiOut> { &self.project.inner_size } }
impl HasTrackScroll for App { fn track_scroll (&self) -> usize { self.project.track_scroll() } }
impl HasSceneScroll for App { fn scene_scroll (&self) -> usize { self.project.scene_scroll() } }

#[derive(Debug, Clone, Default)]
pub enum Dialog {
    #[default] None,
    Help(usize),
    Menu(usize),
    Device(usize),
    Message(Arc<str>),
    Browser(BrowserTarget, Arc<Browser>),
    Options,
}

impl Dialog {
    fn menu_selected (&self) -> Option<usize> {
        if let Self::Menu(selected) = self { Some(*selected) } else { None }
    }
    fn device_kind (&self) -> Option<usize> {
        if let Self::Device(index) = self { Some(*index) } else { None }
    }
    fn device_kind_next (&self) -> Option<usize> {
        self.device_kind().map(|index|(index + 1) % device_kinds().len())
    }
    fn device_kind_prev (&self) -> Option<usize> {
        self.device_kind().map(|index|index.overflowing_sub(1).0.min(device_kinds().len().saturating_sub(1)))
    }
    fn message (&self) -> Option<&str> {
        todo!()
    }
    fn browser (&self) -> Option<&Arc<Browser>> {
        todo!()
    }
    fn browser_target (&self) -> Option<&BrowserTarget> {
        todo!()
    }
}