//! egui editor: assembly + control layout.
//!
//! The aggregator. Builds the editor window and lays out the heading, the meter panel
//! ([`meter`]), the rolling plot ([`plot`]), and the (placeholder) per-channel slider columns.
//! Each visualiser owns its GUI state and drawing in its submodule; this module wires them
//! together and holds the shared [`EditorState`]. When the UI is redesigned the slider columns
//! get replaced and the visualisers stay as self-contained widgets.

use nih_plug::prelude::*;
use nih_plug_egui::{
    create_egui_editor,
    egui::{self, Vec2},
    resizable_window::ResizableWindow,
    widgets,
};
use std::sync::Arc;

use crate::meters::Meters;
use crate::params::{Codename206Params, CompressorParams};
use crate::Codename206;

mod crossover;
mod gain_curve;
mod meter;
mod plot;

/// Bottom of the dB scale shared by the meters and the plot (top is 0 dBFS).
const METER_FLOOR_DB: f32 = -60.0;

/// GUI-side editor state (not persisted): the per-widget state for the meter panel and the plot.
#[derive(Default)]
struct EditorState {
    meter: meter::MeterState,
    plot: plot::PlotState,
}

/// Build the plugin editor over shared handles to the params and meter state.
pub(crate) fn create(params: Arc<Codename206Params>, meters: Arc<Meters>) -> Option<Box<dyn Editor>> {
    let egui_state = params.editor_state.clone();
    create_egui_editor(
        params.editor_state.clone(),
        EditorState::default(),
        |_, _| {},
        move |egui_ctx, setter, state| {
            // Keep frames coming so the meters animate and the lamp can time out while open.
            egui_ctx.request_repaint();

            // One column of controls for a single compressor channel (placeholder layout).
            let band_col = |ui: &mut egui::Ui, title: &str, p: &CompressorParams| {
                // Roughly in signal order: input drive -> low shaper -> compressor -> output.
                ui.strong(title);
                ui.label("Pre-gain");
                ui.add(widgets::ParamSlider::for_param(&p.pre_gain_db, setter));
                ui.add(widgets::ParamSlider::for_param(&p.detection, setter));
                ui.label("Low Slope");
                ui.add(widgets::ParamSlider::for_param(&p.low_slope, setter));
                ui.label("Low Curve");
                ui.add(widgets::ParamSlider::for_param(&p.low_curve, setter));
                ui.label("Threshold");
                ui.add(widgets::ParamSlider::for_param(&p.threshold_db, setter));
                ui.label("Ratio");
                ui.add(widgets::ParamSlider::for_param(&p.ratio, setter));
                ui.label("Knee");
                ui.add(widgets::ParamSlider::for_param(&p.knee_db, setter));
                ui.label("Attack");
                ui.add(widgets::ParamSlider::for_param(&p.attack_ms, setter));
                ui.label("Release");
                ui.add(widgets::ParamSlider::for_param(&p.release_ms, setter));
                ui.label("Makeup");
                ui.add(widgets::ParamSlider::for_param(&p.makeup_db, setter));
                ui.label("Mix");
                ui.add(widgets::ParamSlider::for_param(&p.mix, setter));
            };

            // Resizable window; vertical scroll so every control stays reachable even when the
            // window is small. (Placeholder layout — the redesign will replace the slider columns.)
            ResizableWindow::new("editor")
                .min_size(Vec2::new(480.0, 320.0))
                .show(egui_ctx, egui_state.as_ref(), |ui| {
                    egui::ScrollArea::vertical().show(ui, |ui| {
                        ui.heading(Codename206::NAME);
                        meter::draw(ui, &meters, &mut state.meter);
                        ui.separator();
                        // Gain curve (left, square) beside the scrolling plot (right, fills the rest).
                        let selected = state.plot.selected;
                        ui.horizontal_top(|ui| {
                            ui.vertical(|ui| gain_curve::draw(ui, &params, selected));
                            ui.vertical(|ui| plot::draw(ui, &meters, &mut state.plot));
                        });
                        ui.separator();
                        crossover::draw(ui, &params, setter);
                        ui.separator();
                        // Global controls stacked vertically so they never overflow sideways.
                        egui::Grid::new("globals").num_columns(2).show(ui, |ui| {
                            ui.label("Look-ahead");
                            ui.add(widgets::ParamSlider::for_param(&params.look_ahead_ms, setter));
                            ui.end_row();
                            ui.label("Ceiling");
                            ui.add(widgets::ParamSlider::for_param(&params.output_ceiling_db, setter));
                            ui.end_row();
                            ui.label("Lim Release");
                            ui.add(widgets::ParamSlider::for_param(&params.limiter_release_ms, setter));
                            ui.end_row();
                        });
                        ui.separator();
                        ui.columns(4, |cols| {
                            band_col(&mut cols[0], "LOW", &params.low);
                            band_col(&mut cols[1], "MID", &params.mid);
                            band_col(&mut cols[2], "HIGH", &params.high);
                            band_col(&mut cols[3], "ALL", &params.all);
                        });
                    });
                });
        },
    )
}