//! CLAP audio effect. All DSP state is owned by the processing thread.
mod params;
use crossbeam_queue::ArrayQueue;
use nih_plug::prelude::*;
use nih_plug_egui::{create_egui_editor, egui};
use params::{values, PatinaParams, COUNT};
use patina_core::{AnalyzerFrame, Engine, Monitor};
use std::sync::{
    atomic::{AtomicBool, AtomicU64, Ordering},
    Arc,
};

struct Shared {
    analyzer: ArrayQueue<AnalyzerFrame>,
    delta: AtomicBool,
    reset: AtomicU64,
}
pub struct Patina {
    params: Arc<PatinaParams>,
    shared: Arc<Shared>,
    engine: Option<Engine>,
    publish_count: usize,
    publish_interval: usize,
}
impl Default for Patina {
    fn default() -> Self {
        Self {
            params: Arc::new(PatinaParams::default()),
            shared: Arc::new(Shared {
                analyzer: ArrayQueue::new(3),
                delta: AtomicBool::new(false),
                reset: AtomicU64::new(0),
            }),
            engine: None,
            publish_count: 0,
            publish_interval: 1600,
        }
    }
}
impl Plugin for Patina {
    const NAME: &'static str = "Patina";
    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 SAMPLE_ACCURATE_AUTOMATION: bool = true;
    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 shared = self.shared.clone();
        create_egui_editor(
            params.editor.clone(),
            patina_ui::State::default(),
            |ctx, state| {
                state.delta = false;
                patina_ui::style(ctx);
            },
            move |ctx, setter, state| {
                let epoch = shared.reset.load(Ordering::Acquire);
                if epoch != state_epoch(ctx) {
                    state.delta = false;
                    store_epoch(ctx, epoch);
                }
                // Delta is never retained after editor close/reopen or a host reset.
                shared.delta.store(state.delta, Ordering::Release);
                while let Some(frame) = shared.analyzer.pop() {
                    state.accept_frame(frame);
                }
                let before = params.settings();
                let mut edited = before;
                nih_plug_egui::resizable_window::ResizableWindow::new("resonance-editor")
                    .min_size(egui::vec2(1040., 700.))
                    .show(ctx, &params.editor, |ui| {
                        patina_ui::show(ui, &mut edited, state)
                    });
                let old = values(&before);
                let new = values(&edited);
                let floats = params.floats();
                for i in 0..COUNT {
                    if new[i] != old[i] {
                        if !state.gestures[i] {
                            setter.begin_set_parameter(floats[i]);
                            state.gestures[i] = true;
                        }
                        setter.set_parameter(floats[i], new[i]);
                    }
                    if !state.gesture_active && state.gestures[i] {
                        setter.end_set_parameter(floats[i]);
                        state.gestures[i] = false;
                    }
                }
                if edited.knee != before.knee {
                    let knee = match edited.knee {
                        patina_core::Knee::Soft => params::KneeParam::Soft,
                        patina_core::Knee::Hard => params::KneeParam::Hard,
                    };
                    setter.begin_set_parameter(&params.knee);
                    setter.set_parameter(&params.knee, knee);
                    setter.end_set_parameter(&params.knee);
                }
                if edited.bypass != before.bypass {
                    setter.begin_set_parameter(&params.bypass);
                    setter.set_parameter(&params.bypass, edited.bypass);
                    setter.end_set_parameter(&params.bypass);
                }
                shared.delta.store(state.delta, Ordering::Release);
            },
        )
    }
    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;
        };
        if engine.set_settings(self.params.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);
        self.shared.delta.store(false, Ordering::Release);
        self.shared.reset.fetch_add(1, Ordering::AcqRel);
        true
    }
    fn reset(&mut self) {
        if let Some(e) = self.engine.as_mut() {
            e.reset();
        }
        self.publish_count = 0;
        self.shared.delta.store(false, Ordering::Release);
        self.shared.reset.fetch_add(1, Ordering::AcqRel);
    }
    fn process(
        &mut self,
        buffer: &mut Buffer,
        _: &mut AuxiliaryBuffers,
        _: &mut impl ProcessContext<Self>,
    ) -> ProcessStatus {
        let Some(engine) = self.engine.as_mut() else {
            return ProcessStatus::Normal;
        };
        let _ = engine.set_settings(self.params.settings());
        let delta = self.shared.delta.load(Ordering::Acquire) && self.params.editor.is_open();
        for mut sample in buffer.iter_samples() {
            let x = [
                *sample.get_mut(0).unwrap(),
                if engine.channels() == 2 {
                    *sample.get_mut(1).unwrap()
                } else {
                    0.
                },
            ];
            let out = engine.process_sample(x, Monitor { delta });
            for (c, value) in sample.into_iter().enumerate() {
                *value = out[c];
            }
            self.publish_count += 1;
            if self.publish_count >= self.publish_interval {
                if let Some(frame) = engine.take_analyzer() {
                    self.shared.analyzer.force_push(frame);
                }
                self.publish_count = 0;
            }
        }
        // The scheduler must drain its overlap buffers on silent input.
        ProcessStatus::KeepAlive
    }
}
fn state_epoch(ctx: &egui::Context) -> u64 {
    ctx.data(|d| d.get_temp(egui::Id::new("reset-epoch")).unwrap_or(0))
}
fn store_epoch(ctx: &egui::Context, e: u64) {
    ctx.data_mut(|d| d.insert_temp(egui::Id::new("reset-epoch"), e));
}
impl ClapPlugin for Patina {
    const CLAP_ID: &'static str = "io.narl.bass-foundry.patina";
    const CLAP_DESCRIPTION: Option<&'static str> =
        Some("Dynamic resonance attenuation with explicit tone protection");
    const CLAP_MANUAL_URL: Option<&'static str> = None;
    const CLAP_SUPPORT_URL: Option<&'static str> = None;
    const CLAP_FEATURES: &'static [ClapFeature] = &[
        ClapFeature::AudioEffect,
        ClapFeature::Compressor,
        ClapFeature::Stereo,
        ClapFeature::Mono,
    ];
}
nih_export_clap!(Patina);