use crate::*;

/// Stores and displays time-related state.
pub struct TransportToolbar<E: Engine> {
    _engine: PhantomData<E>,
    /// Enable metronome?
    pub metronome: bool,
    /// Current sample rate, tempo, and PPQ.
    pub timebase:  Arc<Timebase>,
    /// JACK client handle (needs to not be dropped for standalone mode to work).
    pub jack:      Option<JackClient>,
    /// JACK transport handle.
    pub transport: Option<Transport>,
    /// Quantization factor
    /// Global frame and usec at which playback started
    pub started:   Option<(usize, usize)>,
    pub focused:   bool,
    pub focus:     TransportToolbarFocus,
    pub playing:   Option<TransportState>,
    pub bpm:       f64,
    pub quant:     usize,
    pub sync:      usize,
    pub frame:     usize,
    pub pulse:     usize,
    pub ppq:       usize,
    pub usecs:     usize,
}

impl<E: Engine> TransportToolbar<E> {
    pub fn new (transport: Option<Transport>) -> Self {
        let timebase = Arc::new(Timebase::default());
        Self {
            _engine:   Default::default(),
            focused:   false,
            focus:     TransportToolbarFocus::PlayPause,
            playing:   Some(TransportState::Stopped),
            bpm:       timebase.bpm(),
            quant:     24,
            sync:      timebase.ppq() as usize * 4,
            frame:     0,
            pulse:     0,
            ppq:       0,
            usecs:     0,
            metronome: false,
            started:   None,
            jack:      None,
            transport,
            timebase,
        }
    }
    pub fn toggle_play (&mut self) -> Usually<()> {
        let transport = self.transport.as_ref().unwrap();
        self.playing = match self.playing.expect("1st frame has not been processed yet") {
            TransportState::Stopped => {
                transport.start()?;
                Some(TransportState::Starting)
            },
            _ => {
                transport.stop()?;
                transport.locate(0)?;
                Some(TransportState::Stopped)
            },
        };
        Ok(())
    }
    pub fn update (&mut self, scope: &ProcessScope) -> (bool, usize, usize, usize, usize, f64) {
        let times = scope.cycle_times().unwrap();
        let CycleTimes { current_frames, current_usecs, next_usecs, period_usecs } = times;
        let chunk_size = scope.n_frames() as usize;
        let transport = self.transport.as_ref().unwrap().query().unwrap();
        self.frame = transport.pos.frame() as usize;
        let mut reset = false;
        if self.playing != Some(transport.state) {
            match transport.state {
                TransportState::Rolling => {
                    self.started = Some((current_frames as usize, current_usecs as usize));
                },
                TransportState::Stopped => {
                    self.started = None;
                    reset = true;
                },
                _ => {}
            }
        }
        self.playing = Some(transport.state);
        (
            reset,
            current_frames as usize,
            chunk_size as usize,
            current_usecs as usize,
            next_usecs as usize,
            period_usecs as f64
        )
    }
    pub fn bpm (&self) -> usize {
        self.timebase.bpm() as usize
    }
    pub fn ppq (&self) -> usize {
        self.timebase.ppq() as usize
    }
    pub fn pulse (&self) -> usize {
        self.timebase.frame_to_pulse(self.frame as f64) as usize
    }
    pub fn usecs (&self) -> usize {
        self.timebase.frame_to_usec(self.frame as f64) as usize
    }
    pub fn quant (&self) -> usize {
        self.quant
    }
    pub fn sync (&self) -> usize {
        self.sync
    }
}

impl<E: Engine> Audio for TransportToolbar<E> {
    fn process (&mut self, _: &Client, scope: &ProcessScope) -> Control {
        self.update(&scope);
        Control::Continue
    }
}

///////////////////////////////////////////////////////////////////////////////////////////////////

#[derive(Clone, Copy, PartialEq)]
pub enum TransportToolbarFocus { PlayPause, Bpm, Quant, Sync, Clock, }
impl TransportToolbarFocus {
    pub fn next (&mut self) {
        *self = match self {
            Self::PlayPause => Self::Bpm,
            Self::Bpm       => Self::Quant,
            Self::Quant     => Self::Sync,
            Self::Sync      => Self::Clock,
            Self::Clock     => Self::PlayPause,
        }
    }
    pub fn prev (&mut self) {
        *self = match self {
            Self::PlayPause => Self::Clock,
            Self::Bpm       => Self::PlayPause,
            Self::Quant     => Self::Bpm,
            Self::Sync      => Self::Quant,
            Self::Clock     => Self::Sync,
        }
    }
}