use crate::core::*;
use crate::model::*;

pub struct Track {
    pub name:       String,
    /// Play input through output.
    pub monitoring: bool,
    /// Write input to sequence.
    pub recording:  bool,
    /// Overdub input to sequence.
    pub overdub:    bool,
    /// Map: tick -> MIDI events at tick
    pub phrases:    Vec<Phrase>,
    /// Phrase selector
    pub sequence:   Option<usize>,
    /// Output from current sequence.
    pub midi_out:   Option<Port<MidiOut>>,
    midi_out_buf:   Vec<Vec<Vec<u8>>>,
    /// Device chain
    pub devices:    Vec<JackDevice>,
    /// Device selector
    pub device:     usize,
    /// Send all notes off
    /// FIXME: Some(nframes)?
    pub reset:      bool,
    /// Highlight keys on piano roll.
    pub notes_in:   [bool;128],
    /// Highlight keys on piano roll.
    pub notes_out:  [bool;128],
}
impl Track {
    pub fn new (
        name:    &str,
        phrases: Option<Vec<Phrase>>,
        devices: Option<Vec<JackDevice>>,
    ) -> Usually<Self> {
        Ok(Self {
            name:         name.to_string(),
            midi_out:     None,
            midi_out_buf: vec![vec![];16384],
            notes_in:     [false;128],
            notes_out:    [false;128],
            monitoring:   false,
            recording:    false,
            overdub:      true,
            sequence:     None,
            phrases:      phrases.unwrap_or_else(||Vec::with_capacity(16)),
            devices:      devices.unwrap_or_else(||Vec::with_capacity(16)),
            device:       0,
            reset:        true,
        })
    }
    pub fn get_device (&self, i: usize) -> Option<RwLockReadGuard<Box<dyn Device>>> {
        self.devices.get(i).map(|d|d.state.read().unwrap())
    }
    pub fn get_device_mut (&self, i: usize) -> Option<RwLockWriteGuard<Box<dyn Device>>> {
        self.devices.get(i).map(|d|d.state.write().unwrap())
    }
    pub fn device (&self) -> Option<RwLockReadGuard<Box<dyn Device>>> {
        self.get_device(self.device)
    }
    pub fn device_mut (&self) -> Option<RwLockWriteGuard<Box<dyn Device>>> {
        self.get_device_mut(self.device)
    }
    pub fn first_device (&self) -> Option<RwLockReadGuard<Box<dyn Device>>> {
        self.get_device(0)
    }
    pub fn connect_first_device (&self) -> Usually<()> {
        if let (Some(port), Some(device)) = (&self.midi_out, self.devices.get(0)) {
            device.client.as_client().connect_ports(&port, &device.midi_ins()?[0])?;
        }
        Ok(())
    }
    pub fn last_device (&self) -> Option<RwLockReadGuard<Box<dyn Device>>> {
        self.get_device(self.devices.len().saturating_sub(1))
    }
    pub fn connect_last_device (&self, app: &App) -> Usually<()> {
        Ok(match self.devices.get(self.devices.len().saturating_sub(1)) {
            Some(device) => {
                app.audio_out(0).map(|left|device.connect_audio_out(0, &left)).transpose()?;
                app.audio_out(1).map(|right|device.connect_audio_out(0, &right)).transpose()?;
                ()
            },
            None => ()
        })
    }
    pub fn add_device (&mut self, device: JackDevice) -> Usually<&mut JackDevice> {
        self.devices.push(device);
        let index = self.devices.len() - 1;
        Ok(&mut self.devices[index])
    }
    pub fn add_device_with_cb (
        &mut self,
        mut device: JackDevice,
        init: impl Fn(&Self, &mut JackDevice)->Usually<()>
    ) -> Usually<&mut JackDevice> {
        init(&self, &mut device)?;
        self.devices.push(device);
        let index = self.devices.len() - 1;
        Ok(&mut self.devices[index])
    }
    pub fn phrase (&self) -> Option<&Phrase> {
        if let Some(phrase) = self.sequence {
            return self.phrases.get(phrase)
        } else {
            None
        }
    }
    pub fn phrase_mut (&mut self) -> Option<&mut Phrase> {
        if let Some(phrase) = self.sequence {
            return self.phrases.get_mut(phrase)
        } else {
            None
        }
    }
    pub fn add_phrase (
        &mut self, name: &str, length: usize, data: Option<PhraseData>
    ) -> &mut Phrase {
        self.phrases.push(Phrase::new(name, length, data));
        let index = self.phrases.len() - 1;
        &mut self.phrases[index]
    }
    pub fn toggle_monitor (&mut self) {
        self.monitoring = !self.monitoring;
    }
    pub fn toggle_record (&mut self) {
        self.recording = !self.recording;
    }
    pub fn toggle_overdub (&mut self) {
        self.overdub = !self.overdub;
    }
    pub fn process (
        &mut self,
        input:    Option<MidiIter>,
        timebase: &Arc<Timebase>,
        playing:  Option<TransportState>,
        started:  Option<(usize, usize)>,
        quant:    usize,
        reset:    bool,
        scope:    &ProcessScope,
        (frame0, frames): (usize, usize),
        (_usec0,  _usecs):  (usize, usize),
        period:   f64,
    ) {
        // Clear the section of the output buffer that we will be using
        for frame in &mut self.midi_out_buf[0..frames] {
            frame.clear();
        }
        // Emit "all notes off" at start of buffer if requested
        if self.reset {
            all_notes_off(&mut self.midi_out_buf);
            self.reset = false;
        } else if reset {
            all_notes_off(&mut self.midi_out_buf);
        }
        // For highlighting keys and note repeat
        // Currently playing phrase
        if let (
            Some(TransportState::Rolling), Some((start_frame, _)), Some(phrase)
        ) = (
            playing, started, self.sequence.and_then(|id|self.phrases.get_mut(id))
        ) {
            phrase.process_out(
                &mut self.midi_out_buf,
                &mut self.notes_out,
                timebase,
                (frame0.saturating_sub(start_frame), frames, period)
            );
            // Monitor and record input
            if input.is_some() && (self.recording || self.monitoring) {
                // For highlighting keys and note repeat
                for (frame, event, bytes) in parse_midi_input(input.unwrap()) {
                    match event {
                        LiveEvent::Midi { message, .. } => {
                            if self.monitoring {
                                self.midi_out_buf[frame].push(bytes.to_vec())
                            }
                            if self.recording {
                                phrase.record_event({
                                    let pulse = timebase.frame_to_pulse(
                                        (frame0 + frame - start_frame) as f64
                                    );
                                    let quantized = (
                                        pulse / quant as f64
                                    ).round() as usize * quant;
                                    let looped = quantized % phrase.length;
                                    looped
                                }, message);
                            }
                            match message {
                                MidiMessage::NoteOn { key, .. } => {
                                    self.notes_in[key.as_int() as usize] = true;
                                }
                                MidiMessage::NoteOff { key, .. } => {
                                    self.notes_in[key.as_int() as usize] = false;
                                },
                                _ => {}
                            }
                        },
                        _ => {}
                    }
                }
            }
        } else if input.is_some() && self.monitoring {
            for (frame, event, bytes) in parse_midi_input(input.unwrap()) {
                self.process_monitor_event(frame, &event, bytes)
            }
        }
        if let Some(out) = &mut self.midi_out {
            write_midi_output(&mut out.writer(scope), &self.midi_out_buf, frames);
        }
    }

    #[inline]
    fn process_monitor_event (&mut self, frame: usize, event: &LiveEvent, bytes: &[u8]) {
        match event {
            LiveEvent::Midi { message, .. } => {
                self.write_to_output_buffer(frame, bytes);
                self.process_monitor_message(&message);
            },
            _ => {}
        }
    }

    #[inline] fn write_to_output_buffer (&mut self, frame: usize, bytes: &[u8]) {
        self.midi_out_buf[frame].push(bytes.to_vec());
    }

    #[inline]
    fn process_monitor_message (&mut self, message: &MidiMessage) {
        match message {
            MidiMessage::NoteOn { key, .. } => {
                self.notes_in[key.as_int() as usize] = true;
            }
            MidiMessage::NoteOff { key, .. } => {
                self.notes_in[key.as_int() as usize] = false;
            },
            _ => {}
        }
    }
}

impl App {
    pub fn new_track_name (&self) -> String {
        format!("Track {}", self.tracks.len() + 1)
    }
    pub fn add_track (
        &mut self,
        name: Option<&str>,
    ) -> Usually<&mut Track> {
        let name = name.ok_or_else(||self.new_track_name())?;
        self.tracks.push(Track::new(&name, None, None)?);
        self.track_cursor = self.tracks.len();
        Ok(&mut self.tracks[self.track_cursor - 1])
    }
    pub fn add_track_with_cb (
        &mut self,
        name: Option<&str>,
        init: impl FnOnce(&Client, &mut Track)->Usually<()>,
    ) -> Usually<&mut Track> {
        let name = name.ok_or_else(||self.new_track_name())?;
        let mut track = Track::new(&name, None, None)?;
        init(self.client(), &mut track)?;
        self.tracks.push(track);
        self.track_cursor = self.tracks.len();
        Ok(&mut self.tracks[self.track_cursor - 1])
    }
    pub fn track (&self) -> Option<(usize, &Track)> {
        match self.track_cursor { 0 => None, _ => {
            let id = self.track_cursor as usize - 1;
            self.tracks.get(id).map(|t|(id, t))
        } }
    }
    pub fn track_mut (&mut self) -> Option<(usize, &mut Track)> {
        match self.track_cursor { 0 => None, _ => {
            let id = self.track_cursor as usize - 1;
            self.tracks.get_mut(id).map(|t|(id, t))
        } }
    }
}