//! CLAP audio effect. All DSP state is owned by the processing thread.
mod params;
use crossbeam_queue::ArrayQueue;
use lathe_core::{AnalyzerFrame, Engine, HARMONICS};
use nih_plug::prelude::*;
use nih_plug_egui::{create_egui_editor, egui};
use params::LatheParams;
use std::sync::Arc;

struct EditorData {
    ui: lathe_ui::State,
    gestures: [bool; 8],
}
pub struct Lathe {
    params: Arc<LatheParams>,
    analyzer: Arc<ArrayQueue<AnalyzerFrame>>,
    engine: Option<Engine>,
    gains: [f32; HARMONICS],
    publish_count: usize,
    publish_interval: usize,
}
impl Default for Lathe {
    fn default() -> Self {
        Self {
            params: Arc::new(LatheParams::default()),
            analyzer: Arc::new(ArrayQueue::new(2)),
            engine: None,
            gains: [0.; HARMONICS],
            publish_count: 0,
            publish_interval: 1600,
        }
    }
}
impl Plugin for Lathe {
    const NAME: &'static str = "Lathe";
    const VENDOR: &'static str = "Bass Foundry";
    const URL: &'static str = "";
    const EMAIL: &'static str = "";
    const VERSION: &'static str = env!("CARGO_PKG_VERSION");
    const AUDIO_IO_LAYOUTS: &'static [AudioIOLayout] = &[
        AudioIOLayout {
            main_input_channels: NonZeroU32::new(2),
            main_output_channels: NonZeroU32::new(2),
            ..AudioIOLayout::const_default()
        },
        AudioIOLayout {
            main_input_channels: NonZeroU32::new(1),
            main_output_channels: NonZeroU32::new(1),
            ..AudioIOLayout::const_default()
        },
    ];
    const MIDI_INPUT: MidiConfig = MidiConfig::Basic;
    const SAMPLE_ACCURATE_AUTOMATION: bool = false;
    type SysExMessage = ();
    type BackgroundTask = ();
    fn params(&self) -> Arc<dyn Params> {
        self.params.clone()
    }
    fn editor(&mut self, _: AsyncExecutor<Self>) -> Option<Box<dyn Editor>> {
        let params = self.params.clone();
        let analyzer = self.analyzer.clone();
        create_egui_editor(
            params.editor.clone(),
            EditorData {
                ui: lathe_ui::State::default(),
                gestures: [false; 8],
            },
            |ctx, _| lathe_ui::style(ctx),
            move |ctx, setter, data| {
                while let Some(frame) = analyzer.pop() {
                    data.ui.accept_frame(frame);
                }
                let current = params.gains.read().map(|g| *g).unwrap_or([0.; HARMONICS]);
                let before = params.settings(&current);
                let mut edited = before;
                nih_plug_egui::resizable_window::ResizableWindow::new("lathe-editor")
                    .min_size(egui::vec2(
                        lathe_ui::WIDTH as f32 - 80.,
                        lathe_ui::HEIGHT as f32 - 40.,
                    ))
                    .show(ctx, &params.editor, |ui| {
                        lathe_ui::show(ui, &mut edited, &mut data.ui)
                    });
                params.apply(
                    setter,
                    &before,
                    &edited,
                    data.ui.gesture_active,
                    &mut data.gestures,
                );
                // Harmonic levels follow the audio.
                ctx.request_repaint_after(std::time::Duration::from_millis(40));
            },
        )
    }
    fn initialize(
        &mut self,
        layout: &AudioIOLayout,
        config: &BufferConfig,
        context: &mut impl InitContext<Self>,
    ) -> bool {
        let Ok(mut engine) = Engine::new(
            config.sample_rate,
            layout.main_input_channels.map_or(0, |v| v.get() as usize),
        ) else {
            return false;
        };
        let settings = self.params.settings(&self.gains);
        self.gains = settings.gains;
        if engine.set_settings(settings).is_err() {
            return false;
        }
        context.set_latency_samples(engine.latency_samples());
        self.publish_interval = (config.sample_rate / 30.) as usize;
        self.engine = Some(engine);
        true
    }
    fn reset(&mut self) {
        if let Some(e) = self.engine.as_mut() {
            e.reset();
        }
        self.publish_count = 0;
    }
    fn process(
        &mut self,
        buffer: &mut Buffer,
        _: &mut AuxiliaryBuffers,
        context: &mut impl ProcessContext<Self>,
    ) -> ProcessStatus {
        let Some(engine) = self.engine.as_mut() else {
            return ProcessStatus::Normal;
        };
        let settings = self.params.settings(&self.gains);
        self.gains = settings.gains;
        let _ = engine.set_settings(settings);
        let mut next = context.next_event();
        for (index, mut sample) in buffer.iter_samples().enumerate() {
            while let Some(event) = next {
                if event.timing() as usize > index {
                    break;
                }
                match event {
                    NoteEvent::NoteOn { note, velocity, .. } if velocity > 0. => {
                        engine.note_on(note)
                    }
                    NoteEvent::NoteOn { note, .. } | NoteEvent::NoteOff { note, .. } => {
                        engine.note_off(note)
                    }
                    NoteEvent::Choke { note, .. } => engine.note_off(note),
                    _ => {}
                }
                next = context.next_event();
            }
            let x = [
                *sample.get_mut(0).unwrap(),
                if engine.channels() == 2 {
                    *sample.get_mut(1).unwrap()
                } else {
                    0.
                },
            ];
            let out = engine.process_sample(x);
            for (c, value) in sample.into_iter().enumerate() {
                *value = out[c];
            }
            self.publish_count += 1;
            if self.publish_count >= self.publish_interval {
                self.analyzer.force_push(engine.take_analyzer());
                self.publish_count = 0;
            }
        }
        // The lookahead delay and filter tails must drain after input stops.
        ProcessStatus::KeepAlive
    }
}
impl ClapPlugin for Lathe {
    const CLAP_ID: &'static str = "io.storyboard.harmonic-eq";
    const CLAP_DESCRIPTION: Option<&'static str> =
        Some("EQ the harmonics of the played note: a cut on harmonic 3 stays on harmonic 3");
    const CLAP_MANUAL_URL: Option<&'static str> = None;
    const CLAP_SUPPORT_URL: Option<&'static str> = None;
    const CLAP_FEATURES: &'static [ClapFeature] = &[
        ClapFeature::AudioEffect,
        ClapFeature::Equalizer,
        ClapFeature::Stereo,
        ClapFeature::Mono,
    ];
}
nih_export_clap!(Lathe);