/**
 * The editor of a Compressor node (#378), in a tab of its own like a Parametric EQ's. A knob for
 * each of its numbers and a switch for its auto-gain; the curve from level in to level out, whose threshold and ratio are dragged
 * on it; and the level coming in and going out over the last seconds, tinted where it is squeezed.
 * A drag is one undo step. A number fed from a link has its knob greyed: the link decides it.
 */
import { Container, type FederatedPointerEvent, Graphics, type Text } from 'pixi.js';
import { SetNodeParamCommand } from '../../core/commands/graphCommands';
import type { GraphNode } from '../../core/graph';
import { findGraphAsset, type Project } from '../../core/model/Project';
import type { PropertyValue } from '../../core/model/Properties';
import { AUTO_GAIN_REFERENCE_DB, compressorAutoGain } from '../../core/soundfx/dynamics';
import {
  autoGainOn,
  COMPRESS_AUTO_GAIN,
  COMPRESS_ROWS,
  SoundFxCompressor,
  tapId,
} from '../../core/soundfx/nodes';
import { soundLibrary } from '../../viewport/SoundLibrary';
import {
  Checkbox,
  clamp,
  crispText,
  HStack,
  Knob,
  Label,
  snapToStep,
  Spacer,
  Theme,
  textStyle,
  VStack,
  Widget,
} from '../../ui';
import { FramePreview } from '../framePreview';
import type { EditorState } from '../state';
import { TabHeader } from '../TabHeader';
import {
  type CompressorNumbers,
  compressorGainDb,
  CURVE_FLOOR_DB,
  curveDbAtX,
  curveDbAtY,
  curveOutDb,
  curvePoints,
  curveX,
  curveY,
  historyX,
  LEVEL_FLOOR_DB,
  LEVEL_WINDOW,
  LevelHistory,
  levelY,
  MIN_CURVE,
  MIN_LEVELS_WIDTH,
  picturesLayout,
  ratioFor,
  ratioHandle,
  reductionShapes,
  thresholdHandle,
} from './compressorView';

type Key = keyof typeof COMPRESS_ROWS;
const KEYS = Object.keys(COMPRESS_ROWS) as Key[];
/** The rows with the bounds every one of them has. */
const ROWS = Object.fromEntries(
  KEYS.map((key) => {
    const row = COMPRESS_ROWS[key];
    return [key, { min: row.min ?? 0, max: row.max ?? 0, step: row.step ?? 1, default: row.default }];
  }),
) as Record<Key, { min: number; max: number; step: number; default: number }>;

/** How the knobs turn: the times and the ratio have their useful part low in the range. */
const KNOBS: Record<Key, { label: string; taper: number; decimals: number }> = {
  threshold: { label: 'Threshold dB', taper: 1, decimals: 1 },
  ratio: { label: 'Ratio', taper: 2, decimals: 1 },
  knee: { label: 'Knee dB', taper: 1, decimals: 1 },
  attack: { label: 'Attack s', taper: 3, decimals: 3 },
  release: { label: 'Release s', taper: 2, decimals: 3 },
  makeup: { label: 'Makeup dB', taper: 1, decimals: 1 },
};

const HANDLE_RADIUS = 6;
const GRAB_RADIUS = HANDLE_RADIUS + 4;
const CURVE_STEPS = 120;
/** The dB lines of both pictures. */
const GRID_DB = [0, -12, -24, -36, -48];

/** What the pictures ask of the tab around them. */
interface CompressorHost {
  numbers(): CompressorNumbers;
  preview(key: Key, value: number): void;
  commit(key: Key, value: number): void;
  wired(key: Key): boolean;
}

/** Whether a press is near a point. */
const near = (at: { x: number; y: number }, x: number, y: number) =>
  Math.hypot(at.x - x, at.y - y) <= GRAB_RADIUS;

/** dB labels at the lines of a picture; hidden where the line is not in it. */
function gridLabels(parent: Container, count: number): Text[] {
  const muted = textStyle('small').clone();
  muted.fill = Theme.colors.textMuted;
  return Array.from({ length: count }, () => {
    const text = crispText({ text: '', style: muted });
    text.eventMode = 'none';
    parent.addChild(text);
    return text;
  });
}

/** The level coming in (grey) and going out (coloured) over the last seconds, newest at the right. */
class LevelPicture extends Widget {
  private readonly bg = new Graphics();
  private readonly lines = new Graphics();
  private readonly labels: Text[];
  readonly history = new LevelHistory();
  /** The time of the newest reading, in seconds. */
  private now = 0;

  constructor(private readonly host: CompressorHost) {
    super();
    this.minWidth = MIN_LEVELS_WIDTH;
    this.minHeight = MIN_CURVE;
    this.addChild(this.bg, this.lines);
    this.labels = gridLabels(this, GRID_DB.length);
  }

  read(now: number, levels: Parameters<LevelHistory['push']>[1]): void {
    this.now = now;
    this.history.push(now, levels, compressorGainDb(this.host.numbers()));
    this.redraw();
  }

  clear(): void {
    this.history.clear();
    this.redraw();
  }

  override redraw(): void {
    const c = Theme.colors;
    const { w, h } = this;
    this.bg.clear().rect(0, 0, w, h).fill(c.graphBackground).stroke({ color: c.border, width: 1 });
    GRID_DB.forEach((db, i) => {
      const y = Math.round(levelY(db, h)) + 0.5;
      this.bg.moveTo(0, y).lineTo(w, y);
      const text = this.labels[i]!;
      text.text = `${db}`;
      text.position.set(3, y - text.height - 1);
    });
    this.bg.stroke({ color: c.border, width: 1, alpha: 0.6 });
    const numbers = this.host.numbers();
    const threshold = Math.round(levelY(numbers.threshold, h)) + 0.5;
    this.bg.moveTo(0, threshold).lineTo(w, threshold).stroke({ color: c.accent, width: 1, alpha: 0.5 });

    this.lines.clear();
    const points = this.history.all;
    if (points.length < 2) return;
    for (const shape of reductionShapes(points, this.now, w, h))
      this.lines.poly(shape).fill({ color: c.accent, alpha: 0.25 });
    for (const [side, color, width] of [
      ['in', c.textMuted, 1],
      ['out', c.portAudio, 2],
    ] as const) {
      points.forEach((p, i) => {
        const x = historyX(p.t, this.now, w);
        const y = levelY(p[side], h);
        if (i === 0) this.lines.moveTo(x, y);
        else this.lines.lineTo(x, y);
      });
      this.lines.stroke({ color, width });
    }
  }
}

/** The curve from level in (across) to level out (up), with its threshold and ratio to drag. */
class CurvePicture extends Widget {
  /** The curve's square, inset so a handle on its edge is grabbed whole. */
  private readonly square = new Container();
  private readonly bg = new Graphics();
  private readonly lines = new Graphics();
  private readonly labels: Text[];
  private drag: Key | null = null;
  /** The level coming in now, for the point on the curve. */
  private heard = -Infinity;

  constructor(private readonly host: CompressorHost) {
    super();
    this.minWidth = MIN_CURVE;
    this.minHeight = MIN_CURVE;
    this.cursor = 'crosshair';
    this.square.position.set(GRAB_RADIUS, GRAB_RADIUS);
    this.square.addChild(this.bg, this.lines);
    this.addChild(this.square);
    this.labels = gridLabels(this.square, GRID_DB.length);
    this.on('pointerdown', (e: FederatedPointerEvent) => this.press(e));
    this.on('globalpointermove', (e: FederatedPointerEvent) => this.move(e));
    this.onPointerRelease(() => this.release());
  }

  private get size(): number {
    return Math.min(this.w, this.h) - GRAB_RADIUS * 2;
  }

  /** Where a handle is on screen – the check scripts aim with it. */
  handleGlobal(key: 'threshold' | 'ratio'): { x: number; y: number } {
    const n = this.host.numbers();
    const at = key === 'threshold' ? thresholdHandle(n, this.size) : ratioHandle(n, this.size);
    const origin = this.square.getGlobalPosition();
    return { x: origin.x + at.x, y: origin.y + at.y };
  }

  /** Where a level in and a level out are on screen. */
  pointGlobal(inDb: number, outDb: number): { x: number; y: number } {
    const origin = this.square.getGlobalPosition();
    return { x: origin.x + curveX(inDb, this.size), y: origin.y + curveY(outDb, this.size) };
  }

  hear(inDb: number): void {
    if (inDb === this.heard) return;
    this.heard = inDb;
    this.redraw();
  }

  private press(e: FederatedPointerEvent): void {
    if (e.button !== 0) return;
    const at = this.square.toLocal(e.global);
    const n = this.host.numbers();
    if (!this.host.wired('ratio') && near(ratioHandle(n, this.size), at.x, at.y)) this.drag = 'ratio';
    else if (!this.host.wired('threshold') && near(thresholdHandle(n, this.size), at.x, at.y))
      this.drag = 'threshold';
  }

  private move(e: FederatedPointerEvent): void {
    if (!this.drag) return;
    const at = this.square.toLocal(e.global);
    const n = this.host.numbers();
    if (this.drag === 'threshold') {
      const row = ROWS.threshold;
      this.host.preview(
        'threshold',
        clamp(snapToStep(curveDbAtX(at.x, this.size), row.step), row.min, row.max),
      );
      return;
    }
    this.host.preview('ratio', ratioFor(curveDbAtY(at.y, this.size), n, ROWS.ratio));
  }

  private release(): void {
    const key = this.drag;
    this.drag = null;
    if (key) this.host.commit(key, this.host.numbers()[key]);
  }

  override redraw(): void {
    const c = Theme.colors;
    const size = this.size;
    this.bg.clear().rect(0, 0, size, size).fill(c.graphBackground).stroke({ color: c.border, width: 1 });
    GRID_DB.forEach((db, i) => {
      const at = Math.round(curveX(db, size)) + 0.5;
      this.bg.moveTo(at, 0).lineTo(at, size);
      const y = Math.round(curveY(db, size)) + 0.5;
      this.bg.moveTo(0, y).lineTo(size, y);
      const text = this.labels[i]!;
      text.text = `${db}`;
      text.visible = db > CURVE_FLOOR_DB;
      text.position.set(3, y - text.height - 1);
    });
    this.bg.stroke({ color: c.border, width: 1, alpha: 0.6 });
    // What a curve without compressing would be.
    this.bg.moveTo(0, size).lineTo(size, 0).stroke({ color: c.textMuted, width: 1, alpha: 0.4 });

    const n = this.host.numbers();
    this.lines.clear();
    this.lines.poly(curvePoints(n, size, CURVE_STEPS), false).stroke({ color: c.accent, width: 2 });
    for (const [key, at] of [
      ['threshold', thresholdHandle(n, size)],
      ['ratio', ratioHandle(n, size)],
    ] as const) {
      this.lines.circle(at.x, at.y, HANDLE_RADIUS).fill(this.host.wired(key) ? c.control : c.accent);
      if (this.drag === key)
        this.lines.circle(at.x, at.y, HANDLE_RADIUS + 3).stroke({ color: c.symbol, width: 2 });
    }
    // The level auto-gain keeps as loud as it came in, and how far it is lifted to it.
    if (n.autoGain) {
      const x = curveX(AUTO_GAIN_REFERENCE_DB, size);
      const y = curveY(curveOutDb(AUTO_GAIN_REFERENCE_DB, n.threshold, n.knee, n.ratio), size);
      const to = curveY(AUTO_GAIN_REFERENCE_DB, size);
      this.lines.moveTo(x, y).lineTo(x, to).stroke({ color: c.symbol, width: 1, alpha: 0.6 });
      this.lines.circle(x, to, 3).stroke({ color: c.symbol, width: 1 });
    }
    if (this.heard > CURVE_FLOOR_DB) {
      const x = curveX(this.heard, size);
      const y = curveY(curveOutDb(this.heard, n.threshold, n.knee, n.ratio), size);
      this.lines.circle(x, y, 4).fill(c.portAudio);
    }
  }
}

/** The levels and the curve side by side, as `picturesLayout` places them. */
class Pictures extends Widget {
  constructor(
    private readonly levels: LevelPicture,
    private readonly curve: CurvePicture,
  ) {
    super();
    this.addChild(levels, curve);
  }

  override measure(): { w: number; h: number } {
    return { w: MIN_LEVELS_WIDTH + Theme.padding + MIN_CURVE, h: MIN_CURVE };
  }

  override layout(): void {
    const at = picturesLayout(this.w, this.h, Theme.padding);
    this.levels.position.set(0, 0);
    this.levels.resize(at.levels.w, at.levels.h);
    this.curve.position.set(at.curve.x, at.curve.y);
    this.curve.resize(at.curve.side, at.curve.side);
  }
}

/**
 * The tab of a Compressor node (#378): one editor, pointed at the node whose tab is showing, as
 * the EQ's is (#370).
 */
export class CompressorEditor extends VStack implements CompressorHost {
  readonly levels: LevelPicture;
  readonly curve: CurvePicture;
  readonly knobs = {} as Record<Key, Knob>;
  /** Auto-gain: a switch, with the dB it gives below it where a knob has its number. */
  readonly autoGain = new Checkbox(false);
  readonly autoGainDb = new Label('', { style: 'small' });
  private readonly autoColumn = new VStack({ gap: 2, align: 'center' });
  private assetId = '';
  private nodeId = '';
  /** The value a drag began with – its undo step's other side; undefined when none was typed in. */
  private before: { key: Key; value: PropertyValue | undefined } | null = null;
  private readonly title = new Label('Compressor', { style: 'bodyBold' });
  private readonly header = new TabHeader();
  private readonly body = new VStack({ gap: Theme.padding, padding: Theme.padding * 2 });
  private readonly perFrame: FramePreview;
  /** Readings so far, and the most taken away in one (checks). */
  seen = { frames: 0, in: -Infinity, out: -Infinity, reduction: 0 };

  constructor(private readonly state: EditorState) {
    super();
    this.perFrame = new FramePreview(state, 'compressor-knob');
    this.levels = new LevelPicture(this);
    this.curve = new CurvePicture(this);
    this.header.add(this.title);
    this.header.add(new Spacer(), 1);

    // The knobs in the middle of the bottom line, whatever the tab's width.
    const knobs = new HStack({ gap: Theme.padding * 2, align: 'center' });
    knobs.add(new Spacer(), 1);
    for (const key of KEYS) {
      const row = ROWS[key];
      const look = KNOBS[key];
      const knob = new Knob(look.label, row.default, {
        min: row.min,
        max: row.max,
        step: row.step,
        taper: look.taper,
        default: row.default,
        decimals: look.decimals,
        onInput: (value) => this.preview(key, value),
        onChange: (value) => this.commit(key, value),
      });
      this.knobs[key] = knob;
      knobs.add(knob);
    }
    // As tall as a knob, the switch where its dial is.
    const auto = this.autoColumn;
    auto.add(new Label(COMPRESS_AUTO_GAIN.label, { style: 'small' }));
    auto.add(new Spacer(), 1);
    auto.add(this.autoGain);
    auto.add(new Spacer(), 1);
    auto.add(this.autoGainDb);
    auto.minHeight = this.knobs.threshold.measure().h;
    auto.minWidth = this.knobs.threshold.measure().w;
    this.autoGain.onChange = (on) => this.switchAutoGain(on);
    knobs.add(auto);
    knobs.add(new Spacer(), 1);
    // The pictures take what height there is; the knobs stay on the bottom line.
    const pictures = new Pictures(this.levels, this.curve);
    this.body.add(pictures, 1);
    this.body.add(
      new Label('Knob: drag (Shift: fine), wheel, double-click: default. Curve: drag threshold and ratio.', {
        style: 'muted',
      }),
    );
    this.body.add(knobs);
    this.add(this.header);
    this.add(this.body, 1);
    // What a window of the tab needs at the least: every knob and the smallest pictures. The help
    // line is left out of the width: it is cut short instead.
    this.minWidth = Math.max(knobs.measure().w, pictures.measure().w) + this.body.padding * 2;
    this.minHeight = this.measure().h;
    state.on('project', () => this.sync());
  }

  show(assetId: string, nodeId: string): void {
    if (assetId !== this.assetId || nodeId !== this.nodeId) {
      this.perFrame.cancel();
      this.hideLevels();
      this.levels.clear();
      this.before = null;
      this.assetId = assetId;
      this.nodeId = nodeId;
      this.seen = { frames: 0, in: -Infinity, out: -Infinity, reduction: 0 };
    }
    this.sync();
  }

  close(): void {
    this.perFrame.cancel();
    this.hideLevels();
    const node = this.node();
    if (node) this.restore(node);
    this.assetId = '';
    this.nodeId = '';
  }

  get shownFor(): { assetId: string; nodeId: string } | null {
    return this.nodeId ? { assetId: this.assetId, nodeId: this.nodeId } : null;
  }

  /** Only called while the tab is seen: a reading of both sides, a frame on. */
  tick(): void {
    if (!this.nodeId) return;
    const id = tapId(this.assetId, this.nodeId);
    soundLibrary.listen(id);
    const levels = soundLibrary.nodeLevels(id, LEVEL_WINDOW);
    if (!levels && !this.levels.history.heard) return;
    this.levels.read(performance.now() / 1000, levels);
    this.curve.hear(levels?.in ?? -Infinity);
    if (levels && levels.in > LEVEL_FLOOR_DB) {
      this.seen = {
        frames: this.seen.frames + 1,
        in: Math.max(this.seen.in, levels.in),
        out: Math.max(this.seen.out, levels.out),
        reduction: Math.max(this.seen.reduction, levels.in - (levels.out - compressorGainDb(this.numbers()))),
      };
    }
  }

  /** The tab is not seen: no analyser is fed for it. */
  hideLevels(): void {
    if (this.nodeId) soundLibrary.unlisten(tapId(this.assetId, this.nodeId));
    this.curve.hear(-Infinity);
  }

  /** Whether the level picture is moving, so the tab has to be drawn every frame. */
  get moving(): boolean {
    return this.levels.history.heard;
  }

  private node(): GraphNode | null {
    return compressorNodeOf(this.state.project, this.assetId, this.nodeId);
  }

  numbers(): CompressorNumbers {
    const params = this.node()?.params ?? {};
    const numbers = {} as CompressorNumbers;
    for (const key of KEYS) {
      const value = params[key];
      numbers[key] = typeof value === 'number' && Number.isFinite(value) ? value : ROWS[key].default;
    }
    numbers.autoGain = autoGainOn(params, COMPRESS_AUTO_GAIN);
    return numbers;
  }

  /** The dB auto-gain gives at these numbers, or that it is off. */
  private showAutoGainDb(n: CompressorNumbers): void {
    const db = compressorAutoGain(n.threshold, n.knee, n.ratio);
    const text = n.autoGain ? `+${db.toFixed(1)} dB` : 'off';
    if (text === this.autoGainDb.text) return;
    this.autoGainDb.setText(text);
    this.autoColumn.relayout();
  }

  /** Auto-gain on or off: one undo step, as a click on a knob is. */
  private switchAutoGain(on: boolean): void {
    if (!this.node()) return;
    this.state.execute(new SetNodeParamCommand(this.assetId, this.nodeId, COMPRESS_AUTO_GAIN.key, on));
  }

  wired(key: Key): boolean {
    const graph = findGraphAsset(this.state.project, this.assetId)?.graph;
    return Boolean(graph?.edges.some((e) => e.to.node === this.nodeId && e.to.port === key));
  }

  /** Writes a number into the node as it is dragged; `commit` makes the undo step of it. */
  preview(key: Key, value: number): void {
    const node = this.node();
    if (!node) return;
    if (this.before?.key !== key) {
      this.restore(node);
      this.before = { key, value: node.params[key] };
    }
    node.params[key] = value;
    this.perFrame.request();
    this.showAutoGainDb(this.numbers());
    this.levels.invalidate();
    this.curve.invalidate();
  }

  commit(key: Key, value: number): void {
    this.perFrame.cancel();
    const node = this.node();
    if (!node) return;
    this.restore(node);
    if (node.params[key] === value) {
      this.state.preview();
      return;
    }
    this.state.execute(new SetNodeParamCommand(this.assetId, this.nodeId, key, value));
  }

  private restore(node: GraphNode): void {
    const before = this.before;
    if (!before) return;
    if (before.value === undefined) delete node.params[before.key];
    else node.params[before.key] = before.value;
    this.before = null;
  }

  private sync(): void {
    if (!this.node()) return;
    const numbers = this.numbers();
    for (const key of KEYS) {
      this.knobs[key].setValue(numbers[key]);
      this.knobs[key].setEnabled(!this.wired(key));
    }
    this.autoGain.setChecked(numbers.autoGain);
    this.showAutoGainDb(numbers);
    const title = `Compressor – ${findGraphAsset(this.state.project, this.assetId)?.name ?? ''}`;
    if (title !== this.title.text) {
      this.title.setText(title);
      this.relayout();
    }
    this.levels.invalidate();
    this.curve.invalidate();
  }
}

/** The Compressor node a tab is about, or null once it, or its asset, is gone. */
export function compressorNodeOf(project: Project, assetId: string, nodeId: string): GraphNode | null {
  const node = findGraphAsset(project, assetId)?.graph.nodes.find((n) => n.id === nodeId);
  return node?.type === SoundFxCompressor.type ? node : null;
}

/** What a Compressor's tab says: its asset's name, and which one it is when the asset has more. */
export function compressorTabLabel(project: Project, assetId: string, nodeId: string): string {
  const asset = findGraphAsset(project, assetId);
  if (!asset) return '';
  const all = asset.graph.nodes.filter((n) => n.type === SoundFxCompressor.type);
  const index = all.findIndex((n) => n.id === nodeId);
  return all.length > 1 ? `${asset.name} · Compressor ${index + 1}` : `${asset.name} · Compressor`;
}