import { describe, expect, it } from 'vitest';
import { CreateAssetCommand, SetAssetPropertyCommand } from '../../src/core/commands/assetCommands';
import { SetPatternNotesCommand } from '../../src/core/commands/patternCommands';
import { SetSongCommand, SetSongLoopCommand } from '../../src/core/commands/songCommands';
import type { PatternAsset, SongAsset } from '../../src/core/model/Asset';
import {
  heldSongItems,
  heldSongTracks,
  itemFrom,
  newItem,
  newTrack,
  type SongItem,
  type SongTrack,
  songGrid,
  songLength,
  songLoop,
  songMeter,
  songSequence,
  trackItemsBus,
} from '../../src/core/music/song';
import { songBuses } from '../../src/core/music/songBuses';
import { type ScheduledClip, Scheduler } from '../../src/core/music/Scheduler';
import { clipsIn, type Sequence } from '../../src/core/music/sequence';
import { secondsOfTicks } from '../../src/core/music/time';
import { schemaForAsset } from '../../src/core/properties/PropertySchema';
import { makeProject, roundTrip } from '../helpers';

const BAR = 1920;

/** A song with four tracks, a one-bar pattern of two notes played by "Piano", and a sound. */
function makeSong(tracks = 4) {
  const f = makeProject();
  const create = new CreateAssetCommand('song', 'Tune');
  const pattern = new CreateAssetCommand('pattern', 'Riff');
  const piano = new CreateAssetCommand('instrument', 'Piano');
  const organ = new CreateAssetCommand('instrument', 'Organ');
  for (const command of [create, pattern, piano, organ]) f.stack.execute(command);
  // A new song has one track; the tests lay things out on more, without an undo step of their own.
  const created = f.project.assets.find((a) => a.id === create.asset.id) as SongAsset;
  for (let i = created.tracks.length; i < tracks; i++) created.tracks.push(newTrack(i + 1));
  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: 480, note: 60, velocity: 1 },
      { id: 'n2', tick: 960, length: 1200, note: 64, velocity: 0.5 },
    ]),
  );
  f.project.assets.push({ id: 'snd', type: 'sound', name: 'Drum loop', props: {}, file: 'loop.wav' });
  const song = () => f.project.assets.find((a) => a.id === create.asset.id) as SongAsset;
  const track = (i: number) => song().tracks[i]!.id;
  const item = (fields: Partial<SongItem> & Pick<SongItem, 'tick' | 'length'>): SongItem => ({
    ...newItem({ track: track(0), kind: 'pattern', asset: pattern.asset.id, tick: 0, length: BAR }),
    ...fields,
  });
  const lay = (...items: SongItem[]) => f.stack.execute(new SetSongCommand(song().id, { items }));
  return {
    ...f,
    song,
    track,
    item,
    lay,
    patternId: pattern.asset.id,
    piano: piano.asset.id,
    organ: organ.asset.id,
  };
}

describe('the song asset (#334)', () => {
  it('starts with one track, nothing on it, at 120 BPM in 4/4 on a grid of a bar', () => {
    const f = makeSong(1);
    expect(f.song().tracks.map((t) => t.name)).toEqual(['Track 1']);
    expect(f.song().items).toEqual([]);
    expect(schemaForAsset(f.project, f.song()).map((d) => d.key)).toEqual([
      'tempo',
      'sign',
      'grid',
      'fx',
      'bus',
    ]);
    expect(songGrid(f.song().props)).toBe(BAR);
    f.stack.execute(new SetAssetPropertyCommand(f.song().id, 'grid', '1/8T'));
    expect(songGrid(f.song().props)).toBe(160);
  });

  it('is written in one of the signs from 1/2 to 9/8, else in 4/4 (#363)', () => {
    const f = makeSong();
    const sign = schemaForAsset(f.project, f.song()).find((d) => d.key === 'sign');
    expect([sign?.label, sign?.default]).toEqual(['Sign', '4/4']);
    expect(sign?.kind === 'enum' && sign.options.map((o) => o.value)).toEqual([
      '1/2',
      '2/2',
      '3/2',
      '1/4',
      '2/4',
      '3/4',
      '4/4',
      '5/4',
      '6/4',
      '5/8',
      '6/8',
      '7/8',
      '8/8',
      '9/8',
    ]);
    expect(songMeter(f.song().props)).toEqual({ beats: 4, unit: 4 });
    f.stack.execute(new SetAssetPropertyCommand(f.song().id, 'sign', '9/8'));
    expect([songMeter(f.song().props), songLength(f.song())]).toEqual([{ beats: 9, unit: 8 }, 9 * 240]);
    f.stack.execute(new SetAssetPropertyCommand(f.song().id, 'sign', '3/2'));
    expect(songMeter(f.song().props)).toEqual({ beats: 3, unit: 2 });
    expect([songMeter({ sign: '7/4' }), songMeter({ sign: 'x' })]).toEqual([
      { beats: 4, unit: 4 },
      { beats: 4, unit: 4 },
    ]);
  });

  it('is at least a bar long, else up to the bar line after its last item, and loops all of it', () => {
    const f = makeSong();
    expect(songLength(f.song())).toBe(BAR);
    f.lay(f.item({ tick: 0, length: 100 }));
    expect(songLength(f.song())).toBe(BAR);
    f.lay(f.item({ tick: 4 * BAR, length: 100 }));
    expect(songLength(f.song())).toBe(5 * BAR);
    expect(songLoop(f.song())).toEqual({ start: 0, end: 5 * BAR });
    f.stack.execute(new SetSongLoopCommand(f.song().id, { start: BAR, end: 2 * BAR }));
    expect(songLoop(f.song())).toEqual({ start: BAR, end: 2 * BAR });
    f.stack.undo();
    expect(f.song().loop).toBeUndefined();
  });

  it('keeps tracks and items to their rules on load, and a song survives the round trip', () => {
    const tracks = heldSongTracks([{ id: 'a', name: '', volume: 99, pan: -4, mute: 1 }, 'x', { id: 'a' }]);
    expect(tracks.map((t) => [t.name, t.volume, t.pan, t.mute])).toEqual([
      ['Track 1', 12, -1, false],
      ['Track 2', 0, 0, false],
    ]);
    expect(tracks[1]!.id).not.toBe('a');
    expect(heldSongTracks([])).toHaveLength(1);
    const items = heldSongItems(
      [
        {
          id: 'i',
          track: 'a',
          kind: 'pattern',
          asset: 'p',
          tick: 10.4,
          length: 0.2,
          offset: 3.7,
          volume: 5,
          transpose: 99,
        },
        { track: 'gone', kind: 'pattern', tick: 0, length: 10 },
        { track: 'a', kind: 'video', tick: 0, length: 10 },
        { track: 'a', kind: 'sound', tick: -1, length: 10 },
        { track: 'a', kind: 'sound', tick: 0, length: 10, offset: 1.25, volume: 30 },
      ],
      tracks,
    );
    // A sound item goes up to +12 dB, a pattern item's notes no louder than they are.
    expect(items.map((i) => [i.tick, i.length, i.offset, i.volume, i.transpose])).toEqual([
      [0, 10, 1.25, 12, 0],
      [10, 1, 4, 0, 48],
    ]);

    const f = makeSong();
    f.lay(f.item({ tick: BAR, length: BAR, transpose: -2, volume: -6 }));
    f.stack.execute(new SetSongLoopCommand(f.song().id, { start: 0, end: BAR }));
    const back = roundTrip(f.project).assets.find((a) => a.id === f.song().id) as SongAsset;
    expect([back.tracks, back.items, back.loop]).toEqual([f.song().tracks, f.song().items, f.song().loop]);
  });

  it('takes a track with its items, and an undo brings both back', () => {
    const f = makeSong();
    f.lay(f.item({ tick: 0, length: BAR }), f.item({ tick: 0, length: BAR, track: f.track(1) }));
    const before = JSON.stringify(f.song());
    const tracks = f.song().tracks.filter((t) => t.id !== f.track(0));
    f.stack.execute(new SetSongCommand(f.song().id, { tracks }));
    expect(f.song().items.map((i) => i.track)).toEqual([tracks[0]!.id]);
    f.stack.undo();
    expect(JSON.stringify(f.song())).toBe(before);
    expect(SetSongCommand.changes(f.song(), { items: f.song().items })).toBe(false);
  });
});

describe('what a song plays (#334)', () => {
  it('repeats a pattern for as long as its item is, each note held to the item and the pattern', () => {
    const f = makeSong();
    f.lay(f.item({ tick: BAR, length: 2 * BAR + 480 }));
    const { notes } = songSequence(f.project, f.song());
    expect(notes.map((n) => [n.tick, n.length, n.note])).toEqual([
      [BAR, 480, 60],
      [BAR + 960, 960, 64],
      [2 * BAR, 480, 60],
      [2 * BAR + 960, 960, 64],
      [3 * BAR, 480, 60],
    ]);
    expect(
      notes.every((n) => n.instrument === f.piano && n.bus === trackItemsBus(f.song().id, f.track(0))),
    ).toBe(true);
  });

  it('starts a pattern as far in as its offset says, moved by its transpose, with another instrument', () => {
    const f = makeSong();
    f.lay(f.item({ tick: 0, length: BAR, offset: 960, transpose: 12, instrument: f.organ, volume: -6 }));
    const { notes } = songSequence(f.project, f.song());
    expect(notes.map((n) => [n.tick, n.length, n.note, n.instrument])).toEqual([
      [0, 960, 76, f.organ],
      [960, 480, 72, f.organ],
    ]);
    expect(notes[0]!.volume).toBeCloseTo(0.501, 3);
  });

  it('plays a sound as a clip with its offset and FX, and leaves out what has nothing to play', () => {
    const f = makeSong();
    f.lay(
      f.item({
        kind: 'sound',
        asset: 'snd',
        tick: 480,
        length: BAR,
        offset: 0.25,
        fx: 'fx1',
        track: f.track(2),
      }),
      f.item({ kind: 'sound', asset: 'gone', tick: 0, length: BAR }),
      f.item({ asset: 'gone', tick: 0, length: BAR }),
    );
    expect(songSequence(f.project, f.song())).toEqual({
      notes: [],
      clips: [
        {
          tick: 480,
          length: BAR,
          sound: 'snd',
          fx: 'fx1',
          offset: 0.25,
          volume: 1,
          bus: trackItemsBus(f.song().id, f.track(2)),
        },
      ],
    });
  });

  it('silences a muted track, and while any track is soloed every one that is not', () => {
    const f = makeSong(2);
    const [a, b] = f.song().tracks;
    const sends = (tracks: SongTrack[]) =>
      songBuses(f.project, { ...f.song(), tracks }).flatMap((bus) =>
        bus.sends ? [bus.sends.map((s) => s.gain)] : [],
      );
    const level = songBuses(f.project, { ...f.song(), tracks: [{ ...a!, volume: -6, pan: 0.5 }, b!] })[0]!;
    expect(level.gain).toBeCloseTo(0.501, 3);
    expect(level.pan).toBe(0.5);
    expect(sends([a!, b!])).toEqual([[1], [1]]);
    expect(sends([{ ...a!, mute: true }, b!])).toEqual([[0], [1]]);
    expect(sends([{ ...a!, solo: true }, b!])).toEqual([[1], [0]]);
  });

  it('cuts an item in two where its rest plays on: ticks into a pattern, seconds into a sound', () => {
    const f = makeSong();
    const pattern = f.item({ tick: BAR, length: BAR, offset: 120 });
    expect(itemFrom(pattern, BAR + 480, 120)).toMatchObject({
      tick: BAR + 480,
      length: BAR - 480,
      offset: 600,
    });
    const sound = f.item({ kind: 'sound', asset: 'snd', tick: BAR, length: BAR, offset: 0.5 });
    expect(itemFrom(sound, BAR + 480, 120)).toMatchObject({ tick: BAR + 480, offset: 1 });
    expect(itemFrom(sound, BAR, 120)).toBeNull();
    expect(itemFrom(sound, 2 * BAR, 120)).toBeNull();
  });
});

describe('clips on the scheduler (#334)', () => {
  const clip = (tick: number, length: number) => ({
    tick,
    length,
    sound: 's',
    fx: '',
    offset: 0,
    volume: 1,
    bus: '',
  });
  const sequence: Sequence = { notes: [], clips: [clip(0, 4 * BAR), clip(2 * BAR, BAR)] };

  it('takes a clip up mid-way where the playhead starts, and only there', () => {
    expect(clipsIn(sequence, BAR, null, 0, 10, true).map((c) => [c.at, c.skip, c.length])).toEqual([
      [0, BAR, 3 * BAR],
    ]);
    expect(clipsIn(sequence, BAR, null, 0, 10, false)).toEqual([]);
    expect(clipsIn(sequence, BAR, null, BAR, BAR + 10, false).map((c) => [c.at, c.skip])).toEqual([[BAR, 0]]);
  });

  it('ends a clip at the end of the loop and takes it up again after the jump back', () => {
    const loop = { start: BAR, end: 2 * BAR + 960 };
    const due = clipsIn(sequence, BAR, loop, 0, 2 * BAR, true);
    expect(due.map((c) => [c.at, c.skip, c.length])).toEqual([
      [0, BAR, BAR + 960],
      [BAR, 0, 960],
      [BAR + 960, BAR, BAR + 960],
    ]);
  });

  it('hands a clip to the player at its second, as far into the sound as the playhead is', () => {
    const played: ScheduledClip[] = [];
    let now = 10;
    const scheduler = new Scheduler(
      {
        now: () => now,
        latency: () => 0,
        play: () => 0,
        playClip: (c) => played.push(c),
        playing: () => true,
        stop: () => {},
        wake: () => () => {},
      },
      () => ({ notes: [], clips: [{ ...clip(0, 4 * BAR), offset: 0.25, volume: 0.5, bus: 'b' }] }),
      { tempo: 120 },
    );
    scheduler.start(BAR + 480);
    expect(played).toHaveLength(1);
    expect(played[0]!.at).toBeCloseTo(10.05, 9);
    expect(played[0]!.offset).toBeCloseTo(0.25 + secondsOfTicks(BAR + 480, 120), 9);
    expect(played[0]!.duration).toBeCloseTo(secondsOfTicks(4 * BAR - BAR - 480, 120), 9);
    expect([played[0]!.volume, played[0]!.bus, played[0]!.tempo]).toEqual([0.5, 'b', 120]);
    now += 0.5;
    scheduler.pump();
    expect(played).toHaveLength(1);
  });

  it('gives the notes of a song their volume and track on the way to the player', () => {
    const f = makeSong();
    f.lay(f.item({ tick: 0, length: 480, volume: -6 }));
    const notes: unknown[] = [];
    const scheduler = new Scheduler(
      {
        now: () => 0,
        latency: () => 0,
        play: (n) => notes.push(n),
        playing: () => true,
        stop: () => {},
        wake: () => () => {},
      },
      () => songSequence(f.project, f.song()),
    );
    scheduler.start();
    expect(notes).toHaveLength(1);
    expect(notes[0]).toMatchObject({ note: 60, bus: trackItemsBus(f.song().id, f.track(0)) });
    expect((notes[0] as { volume: number }).volume).toBeCloseTo(0.501, 3);
  });
});

describe('a pattern laid out in a song', () => {
  it('is found by its id: an edit to the pattern is heard everywhere it lies', () => {
    const f = makeSong();
    f.lay(f.item({ tick: 0, length: BAR }), f.item({ tick: BAR, length: BAR, track: f.track(1) }));
    f.stack.execute(
      new SetPatternNotesCommand(f.patternId, [{ id: 'n', tick: 240, length: 10, note: 70, velocity: 1 }]),
    );
    expect(songSequence(f.project, f.song()).notes.map((n) => [n.tick, n.note])).toEqual([
      [240, 70],
      [BAR + 240, 70],
    ]);
    expect((f.project.assets.find((a) => a.id === f.patternId) as PatternAsset).notes).toHaveLength(1);
  });
});