use crate::prelude::*;

mod transport;
mod chain;
mod sequencer;
mod sampler;
mod mixer;
mod looper;
mod plugin;
mod launcher;

pub use self::transport::Transport;
pub use self::chain::Chain;
pub use self::sequencer::Sequencer;
pub use self::sampler::Sampler;
pub use self::mixer::Mixer;
pub use self::looper::Looper;
pub use self::plugin::Plugin;
pub use self::launcher::Launcher;

use crossterm::event;
use ::jack::{AudioIn, AudioOut, MidiIn, MidiOut, Port, PortSpec, Client};

pub trait Device: Render + Handle + PortList + Send + Sync {
    fn boxed (self) -> Box<dyn Device> where Self: Sized + 'static {
        Box::new(self)
    }
}

pub fn run (device: impl Device + Send + Sync + 'static) -> Result<(), Box<dyn Error>> {
    let device = Arc::new(Mutex::new(device));
    let exited = Arc::new(AtomicBool::new(false));
    let _input_thread = {
        let poll = std::time::Duration::from_millis(100);
        let exited = exited.clone();
        let device = device.clone();
        spawn(move || loop {
            // Exit if flag is set
            if exited.fetch_and(true, Ordering::Relaxed) {
                break
            }
            // Listen for events and send them to the main thread
            if event::poll(poll).is_ok() {
                let event = event::read().unwrap();
                match event {
                    Event::Key(KeyEvent {
                        code:      KeyCode::Char('c'),
                        modifiers: KeyModifiers::CONTROL,
                        ..
                    }) => {
                        exited.store(true, Ordering::Relaxed);
                    },
                    _ => if device.lock().unwrap().handle(&AppEvent::Input(event)).is_err() {
                        break
                    }
                }
            }
        })
    };
    stdout().execute(EnterAlternateScreen)?;
    enable_raw_mode()?;
    let mut terminal = ratatui::Terminal::new(CrosstermBackend::new(stdout()))?;
    //better_panic::install();
    let better_panic_handler = better_panic::Settings::auto()
        .verbosity(better_panic::Verbosity::Full)
        .create_panic_handler();
    std::panic::set_hook(Box::new(move |info: &std::panic::PanicInfo|{
        stdout()
            .execute(crossterm::terminal::LeaveAlternateScreen)
            .unwrap();
        crossterm::terminal::disable_raw_mode()
            .unwrap();
        better_panic_handler(info);
        //writeln!(std::io::stderr(), "{}", info)
            //.unwrap();
        //writeln!(std::io::stderr(), "{:?}", ::backtrace::Backtrace::new())
            //.unwrap();
    }));
    let sleep = std::time::Duration::from_millis(16);
    loop {
        terminal.draw(|frame|{
            let area = frame.size();
            let buffer = frame.buffer_mut();
            device.lock().unwrap().render(buffer, area).expect("Failed to render content.");
        }).expect("Failed to render frame");
        if exited.fetch_and(true, Ordering::Relaxed) {
            break
        }
        std::thread::sleep(sleep);
    };
    //render_thread.join().expect("Failed to join render thread");
    stdout()
        .queue(crossterm::terminal::LeaveAlternateScreen)?
        .flush()?;
    crossterm::terminal::disable_raw_mode()?;
    Ok(())
}

impl<T: Render + Handle + PortList + Send + Sync> Device for T {}

pub trait Handle {
    // Handle an input event.
    // Returns Ok(true) if the device handled the event.
    // This is the mechanism which allows nesting of components;.
    fn handle (&mut self, _e: &AppEvent) -> Usually<bool> {
        Ok(false)
    }
}

pub trait Render {
    // Render something to an area of the buffer.
    // Returns area used by component.
    // This is insufficient but for the most basic dynamic layout algorithms.
    fn render (&self, _b: &mut Buffer, _a: Rect) -> Usually<Rect> {
        Ok(Rect { x: 0, y: 0, width: 0, height: 0 })
    }
}

pub trait Blit {
    // Render something to X, Y coordinates in a buffer, ignoring width/height.
    fn blit (&self, buf: &mut Buffer, x: u16, y: u16, style: Option<Style>);
}

impl<T: AsRef<str>> Blit for T {
    fn blit (&self, buf: &mut Buffer, x: u16, y: u16, style: Option<Style>) {
        if x < buf.area.width && y < buf.area.height {
            buf.set_string(x, y, self.as_ref(), style.unwrap_or(Style::default()))
        }
    }
}

pub trait PortList {
    fn audio_ins  (&self) -> Usually<Vec<String>> {
        Ok(vec![])
    }
    fn audio_outs (&self) -> Usually<Vec<String>> {
        Ok(vec![])
    }
    fn midi_ins   (&self) -> Usually<Vec<String>> {
        Ok(vec![])
    }
    fn midi_outs  (&self) -> Usually<Vec<String>> {
        Ok(vec![])
    }
    fn connect (&mut self, _connect: bool, _source: &str, _target: &str)
        -> Usually<()>
    {
        Ok(())
    }
    fn connect_all (&mut self, connections: &[(bool, &str, &str)])
        -> Usually<()>
    {
        for (connect, source, target) in connections.iter() {
            self.connect(*connect, source, target)?;
        }
        Ok(())
    }
}

impl Render for Box<dyn Device> {
    fn render (&self, b: &mut Buffer, a: Rect) -> Usually<Rect> {
        (**self).render(b, a)
    }
}

pub struct DevicePort<T: PortSpec> {
    pub name:    String,
    pub port:    Port<T>,
    pub connect: Vec<String>,
}

impl<T: PortSpec + Default> DevicePort<T> {
    pub fn new (client: &Client, name: &str, connect: &[&str]) -> Usually<Self> {
        let mut connects = vec![];
        for port in connect.iter() {
            connects.push(port.to_string());
        }
        Ok(Self {
            name: name.to_string(),
            port: client.register_port(name, T::default())?,
            connect: connects,
        })
    }
}

impl WidgetRef for &dyn Render {
    fn render_ref (&self, area: Rect, buf: &mut Buffer) {
        Render::render(*self, buf, area).expect("Failed to render device.");
    }
}

impl WidgetRef for dyn Render {
    fn render_ref (&self, area: Rect, buf: &mut Buffer) {
        Render::render(self, buf, area).expect("Failed to render device.");
    }
}

pub struct DynamicDevice<T> {
    pub state:   Arc<Mutex<T>>,
    pub render:  Mutex<Box<dyn FnMut(&T, &mut Buffer, Rect)->Usually<Rect> + Send>>,
    pub handle:  Arc<Mutex<Box<dyn FnMut(&mut T, &AppEvent)->Usually<bool> + Send>>>,
    pub process: Arc<Mutex<Box<dyn FnMut(&mut T, &Client, &ProcessScope)->Control + Send>>>,
    pub client: Option<DynamicAsyncClient>
}

impl<T> Handle for DynamicDevice<T> {
    fn handle (&mut self, event: &AppEvent) -> Usually<bool> {
        self.handle.lock().unwrap()(&mut *self.state.lock().unwrap(), event)
    }
}

impl<T> Render for DynamicDevice<T> {
    fn render (&self, buf: &mut Buffer, area: Rect) -> Usually<Rect> {
        self.render.lock().unwrap()(&*self.state.lock().unwrap(), buf, area)
    }
}

impl<T: PortList + Send + Sync + 'static> PortList for DynamicDevice<T> {
    fn audio_ins  (&self) -> Usually<Vec<String>> {
        self.state().audio_ins()
    }
    fn audio_outs (&self) -> Usually<Vec<String>> {
        self.state().audio_outs()
    }
    fn midi_ins   (&self) -> Usually<Vec<String>> {
        self.state().midi_ins()
    }
    fn midi_outs  (&self) -> Usually<Vec<String>> {
        self.state().midi_outs()
    }
}

type DynamicAsyncClient    = AsyncClient<DynamicNotifications, DynamicProcessHandler>;
type DynamicNotifications  = Notifications<Box<dyn Fn(AppEvent) + Send + Sync>>;
type DynamicProcessHandler = ClosureProcessHandler<BoxedProcessHandler>;

impl<T: Send + Sync + 'static> DynamicDevice<T> {
    fn new <'a, R, H, P> (render: R, handle: H, process: P, state: T) -> Self where
        R: FnMut(&T, &mut Buffer, Rect)    -> Usually<Rect> + Send + 'static,
        H: FnMut(&mut T, &AppEvent)        -> Usually<bool> + Send + 'static,
        P: FnMut(&mut T, &Client, &ProcessScope) -> Control + Send + 'static,
    {
        Self {
            state:   Arc::new(Mutex::new(state)),
            render:  Mutex::new(Box::new(render)),
            handle:  Arc::new(Mutex::new(Box::new(handle))),
            process: Arc::new(Mutex::new(Box::new(process))),
            client:  None,
        }
    }
    pub fn state (&self) -> std::sync::MutexGuard<'_, T> {
        self.state.lock().unwrap()
    }
    fn activate (mut self, client: Client) -> Usually<Self> {
        self.client = Some(client.activate_async(Notifications(Box::new({
            let state  = self.state.clone();
            let handle = self.handle.clone();
            move|event|{
                let mut state = state.lock().unwrap();
                let mut handle = handle.lock().unwrap();
                handle(&mut state, &event).unwrap();
            }
        }) as Box<dyn Fn(AppEvent) + Send + Sync>), ClosureProcessHandler::new(Box::new({
            let state   = self.state.clone();
            let process = self.process.clone();
            move|client: &Client, scope: &ProcessScope|{
                let mut state = state.lock().unwrap();
                let mut process = process.lock().unwrap();
                (process)(&mut state, client, scope)
            }
        }) as BoxedProcessHandler))?);
        Ok(self)
    }
}

#[derive(Debug)]
pub enum AppEvent {
    /// Terminal input
    Input(::crossterm::event::Event),
    /// Update values but not the whole form.
    Update,
    /// Update the whole form.
    Redraw,
    /// Device gains focus
    Focus,
    /// Device loses focus
    Blur,
    /// JACK notification
    Jack(JackEvent)
}

fn panic_hook (info: &std::panic::PanicInfo) {
    stdout()
        .execute(crossterm::terminal::LeaveAlternateScreen)
        .unwrap();
    crossterm::terminal::disable_raw_mode()
        .unwrap();
    writeln!(std::io::stderr(), "{}", info)
        .unwrap();
    writeln!(std::io::stderr(), "{:?}", ::backtrace::Backtrace::new())
        .unwrap();
}

#[derive(Debug)]
pub enum JackEvent {
    ThreadInit,
    Shutdown(ClientStatus, String),
    Freewheel(bool),
    SampleRate(Frames),
    ClientRegistration(String, bool),
    PortRegistration(PortId, bool),
    PortRename(PortId, String, String),
    PortsConnected(PortId, PortId, bool),
    GraphReorder,
    XRun,
}

pub struct Notifications<T: Fn(AppEvent) + Send>(T);

impl<T: Fn(AppEvent) + Send> NotificationHandler for Notifications<T> {
    fn thread_init (&self, _: &Client) {
        self.0(AppEvent::Jack(JackEvent::ThreadInit));
    }

    fn shutdown (&mut self, status: ClientStatus, reason: &str) {
        self.0(AppEvent::Jack(JackEvent::Shutdown(status, reason.into())));
    }

    fn freewheel (&mut self, _: &Client, enabled: bool) {
        self.0(AppEvent::Jack(JackEvent::Freewheel(enabled)));
    }

    fn sample_rate (&mut self, _: &Client, frames: Frames) -> Control {
        self.0(AppEvent::Jack(JackEvent::SampleRate(frames)));
        Control::Quit
    }

    fn client_registration (&mut self, _: &Client, name: &str, reg: bool) {
        self.0(AppEvent::Jack(JackEvent::ClientRegistration(name.into(), reg)));
    }

    fn port_registration (&mut self, _: &Client, id: PortId, reg: bool) {
        self.0(AppEvent::Jack(JackEvent::PortRegistration(id, reg)));
    }

    fn port_rename (&mut self, _: &Client, id: PortId, old: &str, new: &str) -> Control {
        self.0(AppEvent::Jack(JackEvent::PortRename(id, old.into(), new.into())));
        Control::Continue
    }

    fn ports_connected (&mut self, _: &Client, a: PortId, b: PortId, are: bool) {
        self.0(AppEvent::Jack(JackEvent::PortsConnected(a, b, are)));
    }

    fn graph_reorder (&mut self, _: &Client) -> Control {
        self.0(AppEvent::Jack(JackEvent::GraphReorder));
        Control::Continue
    }

    fn xrun (&mut self, _: &Client) -> Control {
        self.0(AppEvent::Jack(JackEvent::XRun));
        Control::Continue
    }
}