/**
 * Automation of a song (#337): lanes of a track's volume and pan, their value along the song, and
 * how the scheduler takes a bus along them on the audio clock – in the Song tab, in a game, in a
 * composition and in a bake alike.
 */
import { describe, expect, it } from 'vitest';
import { CreateAssetCommand, SetAssetPropertyCommand } from '../../src/core/commands/assetCommands';
import { SetCompositionCommand } from '../../src/core/commands/compositionCommands';
import { SetPatternNotesCommand } from '../../src/core/commands/patternCommands';
import { SetSongCommand } from '../../src/core/commands/songCommands';
import type { CompositionAsset, SongAsset } from '../../src/core/model/Asset';
import { curveLookup } from '../../src/core/model/curve';
import { findAssetOf } from '../../src/core/model/Project';
import {
  type AutomationLane,
  heldLanes,
  laneMarks,
  laneValueAt,
  laneValueBefore,
  type SequenceLane,
  type SequenceLanePoint,
  sequenceLaneOf,
  unrolledLane,
} from '../../src/core/music/automation';
import { bakePrint } from '../../src/core/music/bake';
import { audioItemBus, compositionPlayings } from '../../src/core/music/compositionAudio';
import { dbToGain } from '../../src/core/music/level';
import {
  LEAD,
  type ScheduledAutomation,
  Scheduler,
  type SchedulerHost,
} from '../../src/core/music/Scheduler';
import { heldSongTracks, newItem, songSequence, trackBus } from '../../src/core/music/song';
import { songBuses } from '../../src/core/music/songBuses';
import { makeProject, roundTrip } from '../helpers';

const Q = 480;
const BAR = 4 * Q;

const pan = (points: SequenceLanePoint[]): SequenceLane => ({ bus: 'b', target: 'pan', points });

/** The marks with their ticks and values to a millionth, so a sum of floats reads as what it is. */
const rounded = (marks: { at: number; value: number; jump: boolean }[]) =>
  marks.map(({ at, value, jump }) => [Math.round(at * 1e6) / 1e6, Math.round(value * 1e6) / 1e6, jump]);

describe('the lanes of a track (#337)', () => {
  it('are held to a target each, points in whole ticks from 0 with values in range, in tick order', () => {
    expect(
      heldLanes([
        {
          target: 'pan',
          points: [
            { tick: 960.4, value: 3 },
            { tick: 0, value: -0.5, ease: 'sine-in' },
            { tick: -1, value: 0 },
            { tick: 10, value: Number.NaN },
          ],
        },
        { target: 'pan', points: [{ tick: 0, value: 1 }] },
        { target: 'volume', points: [] },
        { target: 'speed', points: [{ tick: 0, value: 1 }] },
        'volume',
        {
          target: 'volume',
          points: [
            { tick: 5, value: 0, ease: 'wobbly' },
            { tick: 0, value: -100, ease: 'linear' },
          ],
        },
      ]),
    ).toEqual([
      {
        target: 'pan',
        points: [
          { tick: 0, value: -0.5, ease: 'sine-in' },
          { tick: 960, value: 1 },
        ],
      },
      {
        target: 'volume',
        points: [
          { tick: 0, value: -60 },
          { tick: 5, value: 0 },
        ],
      },
    ]);
    expect(heldLanes('x')).toEqual([]);
  });

  it('are kept with their track when the project is saved, and a track without one has none', () => {
    const f = makeProject();
    const create = new CreateAssetCommand('song', 'Tune');
    f.stack.execute(create);
    const song = () => findAssetOf(f.project, create.asset.id, 'song') as SongAsset;
    const lane: AutomationLane = { target: 'volume', points: [{ tick: 0, value: -6, ease: 'expo-out' }] };
    const [first] = song().tracks;
    f.stack.execute(
      new SetSongCommand(song().id, {
        tracks: [
          { ...first!, automation: [lane] },
          { ...first!, id: 'plain', automation: [] },
        ],
      }),
    );
    const saved = roundTrip(f.project).assets.find((a) => a.id === song().id) as SongAsset;
    expect(saved.tracks.map((t) => t.automation)).toEqual([[lane], undefined]);
    expect(Object.keys(heldSongTracks([{ id: 'x' }])[0]!)).not.toContain('automation');
  });

  it('runs from each point to the next along its easing, holds outside them, and jumps where two meet', () => {
    const points: SequenceLanePoint[] = [
      { tick: 0, value: 0 },
      { tick: 100, value: 1, ease: 'step' },
      { tick: 200, value: 0, ease: 'sine-in' },
      { tick: 300, value: 1 },
      { tick: 300, value: -1 },
    ];
    const at = (tick: number) => laneValueAt(points, tick);
    const before = (tick: number) => laneValueBefore(points, tick);
    expect([at(-5), at(50), at(100), before(100)]).toEqual([0, 0.5, 1, 1]);
    // A step holds up to the next point, which it jumps to.
    expect([at(150), before(200), at(200)]).toEqual([1, 1, 0]);
    expect(at(250)).toBeCloseTo(1 - Math.cos(Math.PI / 4), 12);
    expect(before(300)).toBeCloseTo(1, 12);
    expect([at(300), at(400)]).toEqual([-1, -1]);
  });

  it('eases along a Curve asset it names, and linear once that is gone', () => {
    const f = makeProject();
    f.project.assets.push({
      id: 'cv',
      type: 'curve',
      name: 'Knee',
      props: {},
      points: [
        { x: 0, y: 0 },
        { x: 0.5, y: 0.9 },
        { x: 1, y: 1 },
      ],
    });
    const lane: AutomationLane = {
      target: 'pan',
      points: [
        { tick: 0, value: 0, ease: 'curve:cv' },
        { tick: 100, value: 1 },
      ],
    };
    const curves = curveLookup(f.project);
    expect(laneValueAt(sequenceLaneOf(lane, 'b', curves).points, 25)).toBeCloseTo(0.45, 9);
    f.project.assets.pop();
    expect(laneValueAt(sequenceLaneOf(lane, 'b', curveLookup(f.project)).points, 25)).toBe(0.25);
  });
});

describe('a lane over a window of the scheduler (#337)', () => {
  const sweep = pan([
    { tick: 0, value: -1 },
    { tick: 960, value: 1 },
  ]);

  it('is one ramp where the bus can ramp along it: a straight pan', () => {
    expect(rounded(laneMarks(sweep, 0, null, 0, 480, true, 9.6))).toEqual([
      [0, -1, true],
      [480, 0, false],
    ]);
    // Going on, it starts where the last window ended, as a ramp.
    expect(rounded(laneMarks(sweep, 0, null, 480, 600, false, 9.6))).toEqual([
      [480, 0, false],
      [600, 0.25, false],
    ]);
  });

  it('is read every step where the bus cannot: decibels in a gain, or an easing', () => {
    const fade: SequenceLane = {
      bus: 'b',
      target: 'volume',
      points: [
        { tick: 0, value: -60 },
        { tick: 960, value: 0 },
      ],
    };
    const marks = laneMarks(fade, 0, null, 0, 480, true, 9.6);
    // 0 and 480, and the 49 readings between.
    expect(marks).toHaveLength(51);
    expect(marks[0]).toEqual({ at: 0, value: 0, jump: true });
    for (const mark of marks) expect(mark.value).toBeCloseTo(dbToGain(-60 + (60 * mark.at) / 960), 12);
    expect(marks.slice(1).every((mark, i) => !mark.jump && mark.at > marks[i]!.at)).toBe(true);
    const eased = pan([
      { tick: 0, value: 0, ease: 'sine-in' },
      { tick: 100, value: 1 },
    ]);
    expect(laneMarks(eased, 0, null, 0, 100, true, 25).map((mark) => mark.at)).toEqual([0, 25, 50, 75, 100]);
  });

  it('jumps back with the playhead at the end of a loop, and where a step lands', () => {
    expect(rounded(laneMarks(sweep, 0, { start: 0, end: 960 }, 480, 1440, false, 9.6))).toEqual([
      [480, 0, false],
      [960, 1, false],
      [960, -1, true],
      [1440, 0, false],
    ]);
    const step = pan([
      { tick: 0, value: -1, ease: 'step' },
      { tick: 100, value: 1 },
    ]);
    expect(rounded(laneMarks(step, 0, null, 0, 200, true, 9.6))).toEqual([
      [0, -1, true],
      [100, 1, true],
      [200, 1, false],
    ]);
  });
});

describe('a lane round the loop of a song inside a composition (#337)', () => {
  it('is cut at the loop end and starts again there, each round on from where it was', () => {
    const points: SequenceLanePoint[] = [
      { tick: 0, value: -1 },
      { tick: 960, value: 1 },
    ];
    const unrolled = unrolledLane(points, { start: 0, end: 960 }, 480, 1440, 9.6);
    expect(unrolled).toEqual([
      { tick: 480, value: 0 },
      { tick: 960, value: 1 },
      { tick: 960, value: -1 },
      { tick: 1440, value: 0 },
    ]);
    expect(laneValueAt(unrolled, 700)).toBeCloseTo(laneValueAt(points, 700), 12);
    expect(laneValueAt(unrolled, 1200)).toBeCloseTo(laneValueAt(points, 240), 12);
  });

  it('keeps a whole easing as it is, and reads one cut in the middle every step', () => {
    const eased: SequenceLanePoint[] = [
      { tick: 0, value: 0, ease: 'sine-in' },
      { tick: 960, value: 1 },
    ];
    expect(unrolledLane(eased, null, 0, 1920, 96)).toEqual([
      { tick: 0, value: 0, ease: 'sine-in' },
      { tick: 960, value: 1 },
      { tick: 1920, value: 1 },
    ]);
    const cut = unrolledLane(eased, null, 480, 960, 96);
    expect(cut.map((p) => p.tick)).toEqual([480, 576, 672, 768, 864, 960]);
    for (const point of cut) {
      expect(point.ease).toBeUndefined();
      expect(point.value).toBeCloseTo(laneValueAt(eased, point.tick), 12);
    }
  });
});

/** A song "Tune" with a one-bar pattern of one note on its track, and a composition "Cut" at 10 fps. */
function makeTune() {
  const f = makeProject();
  const song = new CreateAssetCommand('song', 'Tune');
  const pattern = new CreateAssetCommand('pattern', 'Riff');
  const piano = new CreateAssetCommand('instrument', 'Piano');
  const comp = new CreateAssetCommand('composition', 'Cut', { fps: 10 });
  for (const command of [song, pattern, piano, comp]) f.stack.execute(command);
  f.stack.execute(new SetAssetPropertyCommand(pattern.asset.id, 'bars', 1));
  f.stack.execute(new SetAssetPropertyCommand(pattern.asset.id, 'instrument', piano.asset.id));
  f.stack.execute(
    new SetPatternNotesCommand(pattern.asset.id, [{ id: 'n1', tick: 0, length: Q, note: 60, velocity: 1 }]),
  );
  const tune = () => findAssetOf(f.project, song.asset.id, 'song') as SongAsset;
  const trackId = tune().tracks[0]!.id;
  f.stack.execute(
    new SetSongCommand(song.asset.id, {
      items: [newItem({ track: trackId, kind: 'pattern', asset: pattern.asset.id, tick: 0, length: BAR })],
    }),
  );
  const automate = (...automation: AutomationLane[]) =>
    f.stack.execute(new SetSongCommand(song.asset.id, { tracks: [{ ...tune().tracks[0]!, automation }] }));
  const cut = () => findAssetOf(f.project, comp.asset.id, 'composition') as CompositionAsset;
  return { ...f, tune, trackId, automate, cut };
}

describe('a song with automation (#337)', () => {
  it('plays its lanes on the buses of its tracks, which start where the lanes do', () => {
    const f = makeTune();
    expect(songSequence(f.project, f.tune()).lanes).toBeUndefined();
    expect(songBuses(f.project, f.tune())[0]).not.toHaveProperty('automated');
    f.automate({
      target: 'volume',
      points: [
        { tick: 0, value: -12 },
        { tick: BAR, value: 0 },
      ],
    });
    expect(songSequence(f.project, f.tune()).lanes).toEqual([
      {
        bus: trackBus(f.tune().id, f.trackId),
        target: 'volume',
        points: [
          { tick: 0, value: -12 },
          { tick: BAR, value: 0 },
        ],
      },
    ]);
    // The lane rules the volume, the fader the pan.
    expect(songBuses(f.project, f.tune())[0]).toMatchObject({
      gain: dbToGain(-12),
      pan: 0,
      automated: ['volume'],
    });
  });

  it('is a bake of its own, and one without automation keeps the print it had', () => {
    const f = makeTune();
    const plain = bakePrint(f.project, f.tune());
    const sweep = (to: number): AutomationLane => ({
      target: 'pan',
      points: [
        { tick: 0, value: 0.5 },
        { tick: BAR / 2, value: to },
      ],
    });
    f.automate(sweep(1));
    const panned = bakePrint(f.project, f.tune());
    expect(panned).not.toBe(plain);
    // Only later in the song: where its tracks start is the same.
    f.automate(sweep(-1));
    expect(bakePrint(f.project, f.tune())).not.toBe(panned);
    f.automate();
    expect(bakePrint(f.project, f.tune())).toBe(plain);
  });

  it('plays its lanes in a composition on the buses of its item, round its loop, in milliseconds', () => {
    const f = makeTune();
    f.automate({
      target: 'pan',
      points: [
        { tick: 0, value: -1 },
        { tick: BAR, value: 1 },
      ],
    });
    // From 1 s for 3 s, half a second into the song: it goes round its two-second bar once.
    const item = {
      id: 'it',
      track: f.cut().tracks[0]!.id,
      start: 10,
      length: 30,
      offset: 0.5,
      audio: { kind: 'song' as const, asset: f.tune().id, volume: 0, bus: '' },
    };
    f.stack.execute(new SetCompositionCommand(f.cut().id, { items: [item] }));
    const [playing] = compositionPlayings(f.project, f.cut());
    expect(playing!.sequence.lanes).toEqual([
      {
        bus: `${audioItemBus(f.cut().id, 'it')}:${f.trackId}`,
        target: 'pan',
        points: [
          { tick: 1000, value: -0.5 },
          { tick: 2500, value: 1 },
          { tick: 2500, value: -1 },
          { tick: 4000, value: 0.5 },
        ],
      },
    ]);
    expect(playing!.buses.map((bus) => bus.name)).toContain(`${audioItemBus(f.cut().id, 'it')}:${f.trackId}`);
  });
});

describe('the scheduler and a lane (#337)', () => {
  it('hands each window to the host on the audio clock, the first fresh, each going on from the last', () => {
    const automated: ScheduledAutomation[] = [];
    let time = 10;
    let pump: (() => void) | null = null;
    const host: SchedulerHost = {
      now: () => time,
      latency: () => 0,
      play: () => 0,
      automate: (automation) => void automated.push(automation),
      playing: () => false,
      stop: () => {},
      wake: (wake) => ((pump = wake), () => (pump = null)),
    };
    const lane = {
      ...pan([
        { tick: 0, value: -1 },
        { tick: BAR, value: 1 },
      ]),
      bus: 'song:s:t',
    };
    const scheduler = new Scheduler(host, () => ({ notes: [], lanes: [lane] }), { tempo: 120 });
    scheduler.start();
    for (let i = 0; i < 8; i++) {
      time += 0.025;
      pump!();
    }
    expect(automated.map((a) => [a.bus, a.target, a.fresh])).toEqual([
      ['song:s:t', 'pan', true],
      ...Array.from({ length: automated.length - 1 }, () => ['song:s:t', 'pan', false]),
    ]);
    expect(automated[0]!.marks[0]).toEqual({ at: 10 + LEAD, value: -1, jump: true });
    automated.slice(1).forEach((window, i) => {
      expect(window.marks[0]!.at).toBeCloseTo(automated[i]!.marks.at(-1)!.at, 12);
      expect(window.marks[0]!.jump).toBe(false);
    });
    // Two seconds a bar: from -1 by 1 a second.
    for (const { marks } of automated)
      for (const mark of marks) expect(mark.value).toBeCloseTo(-1 + (mark.at - 10 - LEAD), 9);
  });
});