/**
 * The Compressor's hardware panel (#379): every part on the plate and none over another, the meter's
 * scale and needle, the LEDs, and the grain of the plate the same every time. The Gain's plate
 * (#384) and how its one knob turns, the Pitch's knob and the Mix's lever and ends (#390), the
 * Pan's knob and ends on the Gain's plate (#392).
 */
import { describe, expect, it } from 'vitest';
import {
  type Box,
  brushStrokes,
  CAPTION_AIR,
  GAIN_LAYOUT,
  KNOB_CAPTION,
  GAIN_PANEL,
  GAIN_TAPER,
  gainReduction,
  knobBox,
  knobEnds,
  LED_COUNT,
  ledColour,
  ledDb,
  ledsLit,
  ledStep,
  METER_LABELS,
  METER_RANGE_DB,
  meterPosition,
  MIX_LAYOUT,
  MIX_PANEL,
  needleAngle,
  needleStep,
  PAN_TAPER,
  PANEL,
  PANEL_LAYOUT,
  PITCH_TAPER,
} from '../../src/editor/soundfx/hardwareView';
import { GAIN_ROW, PAN_ROW, PITCH_ROW } from '../../src/core/soundfx/nodes';
import { knobPosition } from '../../src/ui/knob';

const overlap = (a: Box, b: Box) => a.x < b.x + b.w && b.x < a.x + a.w && a.y < b.y + b.h && b.y < a.y + a.h;

describe('the plate', () => {
  const L = PANEL_LAYOUT;
  const parts: [string, Box][] = [
    ['title', L.title],
    ['lcd', L.lcd],
    ['autoGain', L.autoGain],
    ['meter', L.meter],
    ['leds', L.leds],
    ...Object.entries(L.knobs).map(([key, spot]): [string, Box] => [key, knobBox(spot)]),
  ];

  it('holds every part inside it, clear of the screws', () => {
    for (const [, box] of parts) {
      expect(box.x).toBeGreaterThanOrEqual(0);
      expect(box.y).toBeGreaterThanOrEqual(0);
      expect(box.x + box.w).toBeLessThanOrEqual(PANEL.w);
      expect(box.y + box.h).toBeLessThanOrEqual(PANEL.h);
      for (const screw of L.screws)
        expect(overlap(box, { x: screw.x - 7, y: screw.y - 7, w: 14, h: 14 })).toBe(false);
    }
  });

  it('puts no part over another', () => {
    const over = parts.flatMap(([a, boxA], i) =>
      parts.slice(i + 1).flatMap(([b, boxB]) => (overlap(boxA, boxB) ? [`${a}/${b}`] : [])),
    );
    expect(over).toEqual([]);
  });

  it('has the big knobs at its ends and the small ones beside the meter', () => {
    const { threshold, makeup, ratio, attack } = L.knobs;
    expect(threshold.size).toBeGreaterThan(ratio.size);
    expect(threshold.x).toBeLessThan(ratio.x);
    expect(ratio.x).toBeLessThan(L.meter.x);
    expect(attack.x).toBeGreaterThan(L.meter.x + L.meter.w);
    expect(makeup.x).toBeGreaterThan(attack.x);
  });

  it('is brushed the same every time, a stroke per row', () => {
    const strokes = brushStrokes(PANEL.h);
    expect(strokes).toHaveLength(PANEL.h);
    expect(brushStrokes(PANEL.h)).toEqual(strokes);
    const alphas = strokes.map((s) => s.alpha);
    expect(Math.max(...alphas) - Math.min(...alphas)).toBeGreaterThan(0.07);
    expect(strokes.some((s) => s.light) && strokes.some((s) => !s.light)).toBe(true);
  });
});

describe('the meter', () => {
  it('reads 0 dB at the right end, the range at the left, and the first dB about as wide as the last nine', () => {
    expect(meterPosition(0)).toBe(1);
    expect(meterPosition(METER_RANGE_DB)).toBe(0);
    expect(meterPosition(40)).toBe(0);
    expect(meterPosition(-3)).toBe(1);
    expect(1 - meterPosition(1)).toBeCloseTo(meterPosition(15) - meterPosition(24), 1);
    const spots = METER_LABELS.map(meterPosition);
    for (let i = 1; i < spots.length; i++) expect(spots[i]).toBeLessThan(spots[i - 1]!);
  });

  it('swings the needle symmetrically about straight up', () => {
    expect(needleAngle(0.5)).toBeCloseTo(-Math.PI / 2);
    expect(needleAngle(0) + needleAngle(1)).toBeCloseTo(-Math.PI);
    expect(needleAngle(1)).toBeGreaterThan(needleAngle(0));
  });

  it('moves the needle as a VU: most of the way in 300 ms, and there in the end', () => {
    let shown = 0;
    for (let t = 0; t < 0.3; t += 1 / 60) shown = needleStep(shown, 10, 1 / 60);
    expect(shown).toBeGreaterThan(9);
    expect(shown).toBeLessThan(10);
    expect(needleStep(0, 10, 1 / 60)).toBeLessThan(3);
    for (let i = 0; i < 60; i++) shown = needleStep(shown, 10, 1 / 60);
    expect(shown).toBe(10);
    // A long pause between two frames moves it no further than a quarter of a second does.
    expect(needleStep(5, 0, 10)).toBe(needleStep(5, 0, 0.25));
  });

  it('takes the gain after the compressing out of what it reads, and nothing from silence', () => {
    expect(gainReduction({ in: -10, out: -6 }, 10)).toBeCloseTo(6);
    expect(gainReduction({ in: -10, out: -10 }, 0)).toBe(0);
    expect(gainReduction({ in: -10, out: -2 }, 0)).toBe(0);
    expect(gainReduction({ in: -Infinity, out: -Infinity }, 0)).toBe(0);
    expect(gainReduction(null, 0)).toBe(0);
  });
});

describe('the LEDs', () => {
  it('light one every 3 dB up to 0, red at the top and green at the bottom', () => {
    expect(ledDb(LED_COUNT - 1)).toBe(0);
    expect(ledDb(LED_COUNT - 2)).toBe(-3);
    expect(ledColour(LED_COUNT - 1)).toBe('red');
    expect(ledColour(LED_COUNT - 2)).toBe('red');
    expect(ledColour(LED_COUNT - 4)).toBe('amber');
    expect(ledColour(0)).toBe('green');
    expect(ledsLit(-Infinity)).toBe(0);
    expect(ledsLit(0)).toBe(LED_COUNT);
    expect(ledsLit(-4)).toBe(LED_COUNT - 2);
  });

  it('go up at once and down by 20 dB a second', () => {
    expect(ledStep(-30, -6, 1 / 60)).toBe(-6);
    expect(ledStep(-6, -30, 0.1)).toBeCloseTo(-8);
    expect(ledStep(-6, -Infinity, 10)).toBe(-11);
  });
});

describe('the Gain (#384)', () => {
  const L = GAIN_LAYOUT;
  const knob = knobBox(L.knob);

  it('holds its knob in the middle of the plate, clear of the screws', () => {
    expect(knob.x).toBeGreaterThanOrEqual(0);
    expect(knob.x + knob.w).toBeLessThanOrEqual(GAIN_PANEL.w);
    // Its number hangs inside the dial (#382): from the caption down to the dial's edge is all it shows.
    const top = L.knob.y - L.knob.size / 2 - KNOB_CAPTION;
    const bottom = L.knob.y + L.knob.size / 2;
    expect(top).toBeGreaterThan(0);
    expect(top + CAPTION_AIR).toBe(GAIN_PANEL.h - bottom);
    expect(knob.x + knob.w / 2).toBe(GAIN_PANEL.w / 2);
    const shown = { ...knob, y: top, h: bottom - top };
    for (const screw of L.screws)
      expect(overlap(shown, { x: screw.x - 7, y: screw.y - 7, w: 14, h: 14 })).toBe(false);
  });

  it('turns 0 dB straight up and the quiet tail by in a fifth of the turn', () => {
    const range = { min: GAIN_ROW.min ?? 0, max: GAIN_ROW.max ?? 0, step: 0.5, taper: GAIN_TAPER };
    expect(knobPosition(0, range)).toBeCloseTo(0.5, 2);
    expect(knobPosition(-24, range)).toBeLessThan(0.22);
    expect(knobPosition(-6, range)).toBeGreaterThan(0.4);
  });
});

describe('the Pitch and the Mix (#390)', () => {
  it('turns the Pitch from 0 straight up, an octave either way alike and well inside the turn', () => {
    const range = {
      min: PITCH_ROW.min ?? 0,
      max: PITCH_ROW.max ?? 0,
      step: 0.1,
      taper: PITCH_TAPER,
      bipolar: true,
    };
    expect(knobPosition(0, range)).toBeCloseTo(0.5, 5);
    const up = knobPosition(12, range);
    expect(up - 0.5).toBeCloseTo(0.5 - knobPosition(-12, range), 5);
    expect(up).toBeGreaterThan(0.7);
    expect(up).toBeLessThan(0.75);
    expect(knobPosition(64, range)).toBe(1);
  });

  it('holds the Mix’s lever above the knob, centred and clear of it and of the screws', () => {
    const lever = MIX_LAYOUT.curve;
    const spot = MIX_LAYOUT.knob;
    const knob = knobBox(spot);
    expect(lever.x).toBeGreaterThanOrEqual(0);
    expect(lever.x + lever.w).toBeLessThanOrEqual(MIX_PANEL.w);
    expect(lever.x + lever.w / 2).toBe(MIX_PANEL.w / 2);
    expect(spot.x).toBe(MIX_PANEL.w / 2);
    // A lever that is down reaches 8 below its box (`Lever.redraw`).
    expect(lever.y + lever.h + 8).toBeLessThanOrEqual(knob.y);
    for (const screw of MIX_LAYOUT.screws)
      expect(overlap(lever, { x: screw.x - 7, y: screw.y - 7, w: 14, h: 14 })).toBe(false);
    // Below the dial as much air as on the Gain.
    expect(MIX_PANEL.h - (spot.y + spot.size / 2)).toBe(GAIN_PANEL.h - (GAIN_LAYOUT.knob.y + spot.size / 2));
    expect(MIX_PANEL.w).toBeLessThan(MIX_PANEL.h);
  });

  it('names the ends of the Mix’s turn just outside the dial, left and right below its middle', () => {
    const spot = MIX_LAYOUT.knob;
    const { a, b } = knobEnds(spot);
    for (const end of [a, b]) {
      expect(Math.hypot(end.x - spot.x, end.y - spot.y)).toBeGreaterThan(spot.size / 2);
      expect(end.y).toBeGreaterThan(spot.y);
      expect(end.y).toBeLessThan(MIX_PANEL.h);
    }
    expect(a.x).toBeLessThan(spot.x);
    expect(b.x).toBeGreaterThan(spot.x);
    expect(a.y).toBe(b.y);
  });
});

describe('the Pan (#392)', () => {
  it('turns from the middle straight up, as far left as right, the whole turn for -1 to 1', () => {
    const range = {
      min: PAN_ROW.min ?? 0,
      max: PAN_ROW.max ?? 0,
      step: 0.01,
      taper: PAN_TAPER,
      bipolar: true,
    };
    expect(knobPosition(0, range)).toBeCloseTo(0.5, 5);
    expect(knobPosition(0.5, range)).toBeCloseTo(0.75, 5);
    expect(knobPosition(-0.5, range)).toBeCloseTo(0.25, 5);
    expect(knobPosition(-1, range)).toBe(0);
    expect(knobPosition(1, range)).toBe(1);
  });

  it('names L and R at the ends of the turn inside the Gain’s plate, clear of the screws', () => {
    const spot = GAIN_LAYOUT.knob;
    const { a, b } = knobEnds(spot);
    for (const end of [a, b]) {
      expect(end.x).toBeGreaterThan(0);
      expect(end.x).toBeLessThan(GAIN_PANEL.w);
      expect(end.y).toBeLessThan(GAIN_PANEL.h);
      for (const screw of GAIN_LAYOUT.screws)
        expect(Math.hypot(end.x - screw.x, end.y - screw.y)).toBeGreaterThan(14);
    }
    expect(a.x).toBeLessThan(spot.x);
    expect(b.x).toBeGreaterThan(spot.x);
  });
});