/**
 * A game plays a song through Play song and ends it through Stop song (#336): from its start, then
 * round the loop of its ruler, its tracks on buses of their own, the whole of it faded in and out.
 */
import { describe, expect, it } from 'vitest';
import {
  CreateAssetCommand,
  CreateSoundCommand,
  SetAssetPropertyCommand,
} from '../../src/core/commands/assetCommands';
import { SetLoopCommand, SetPatternNotesCommand } from '../../src/core/commands/patternCommands';
import { SetSongCommand } from '../../src/core/commands/songCommands';
import type { InstrumentAsset, SongAsset } from '../../src/core/model/Asset';
import { bakePlayback, bakePrint, bakeSpans } from '../../src/core/music/bake';
import { goesBy, Playbacks, type SequencePlay } from '../../src/core/music/playbacks';
import { INTERVAL, LEAD, type ScheduledClip, type ScheduledNote } from '../../src/core/music/Scheduler';
import { newItem, newTrack, trackBus } from '../../src/core/music/song';
import { type AudioSink, type ClipTiming, SILENT_AUDIO } from '../../src/runtime/systems/Audio';
import { graphEditor, makeBehavior, makeSpriteScene, place, startWorld } from '../helpers';

const FILE = `${'b2'.repeat(32)}.wav`;
const Q = 480;
const BAR = 4 * Q;

/** An audio clock moved by hand, its timers run as it passes them. */
function fakeHost() {
  const host = {
    time: 0,
    sounding: new Set<number>(),
    pumps: new Set<() => void>(),
    loading: [] as (() => void)[],
    levels: [] as { id: number; gain: number; at: number; seconds: number }[],
    timers: [] as { at: number; then: () => void }[],
    closed: [] as number[],
  };
  const playbacks = new Playbacks({
    now: () => host.time,
    latency: () => 0,
    playing: (voice) => host.sounding.has(voice),
    stop: (voices) => {
      for (const voice of voices) host.sounding.delete(voice);
    },
    wake: (pump) => {
      host.pumps.add(pump);
      return () => host.pumps.delete(pump);
    },
    prepare: () => new Promise<void>((resolve) => host.loading.push(resolve)),
    level: (id, gain, at, seconds) => host.levels.push({ id, gain, at, seconds }),
    after: (at, then) => host.timers.push({ at, then }),
    closed: (id) => host.closed.push(id),
  });
  const run = (seconds: number) => {
    const end = host.time + seconds;
    while (host.time + INTERVAL <= end + 1e-9) {
      host.time += INTERVAL;
      for (const pump of [...host.pumps]) pump();
      for (const timer of host.timers.filter((t) => t.at <= host.time + 1e-9)) {
        host.timers.splice(host.timers.indexOf(timer), 1);
        timer.then();
      }
    }
  };
  const loaded = async () => {
    for (const resolve of host.loading.splice(0)) resolve();
    await Promise.resolve();
  };
  return { host, playbacks, run, loaded };
}

/**
 * Two bars at 120 BPM, two seconds each: a note on the first beat of each and a clip on the second
 * bar. Looped, the second bar is its loop.
 */
function song(struck: (ScheduledNote | ScheduledClip)[], options: Partial<SequencePlay> = {}): SequencePlay {
  let next = 100;
  const voice = () => next++;
  return {
    sequence: {
      notes: [0, BAR].map((tick, i) => ({ tick, length: Q, note: 60 + i, velocity: 1, instrument: 'piano' })),
      clips: [{ tick: BAR, length: Q, sound: 'drum', fx: '', offset: 0, volume: 1, bus: 'track' }],
    },
    tempo: 120,
    length: 2 * BAR,
    loop: { start: BAR, end: 2 * BAR },
    needs: { layers: [], files: [] },
    strike: (note) => (struck.push(note), voice()),
    strikeClip: (clip) => (struck.push(clip), voice()),
    ...options,
  };
}

const what = (struck: (ScheduledNote | ScheduledClip)[]) =>
  struck.map((s) => ('note' in s ? `note ${s.note}` : `clip ${s.sound}`));

describe('the songs a game plays', () => {
  it('plays the intro once, then runs round the loop, clips with the notes', async () => {
    const { playbacks, run, loaded } = fakeHost();
    const struck: (ScheduledNote | ScheduledClip)[] = [];
    playbacks.start(5, 'song:a', song(struck), '');
    await loaded();
    run(9);
    expect(what(struck).slice(0, 6)).toEqual([
      'note 60',
      'note 61',
      'clip drum',
      'note 61',
      'clip drum',
      'note 61',
    ]);
    const notes = struck.filter((s): s is ScheduledNote => 'note' in s);
    expect(notes[1]!.at - notes[0]!.at).toBeCloseTo(2, 9);
    expect(notes[2]!.at - notes[1]!.at).toBeCloseTo(2, 9);
    expect(playbacks.current()[0]?.clips[0]).toMatchObject({ sound: 'drum', bus: 'track' });
  });

  it('rises from silence to its volume over its fade in, from its first note on', async () => {
    const { host, playbacks, loaded } = fakeHost();
    playbacks.start(5, 'song:a', song([], { volume: 0.5, fadeIn: 3 }), '');
    host.time = 1;
    await loaded();
    expect(host.levels).toEqual([{ id: 5, gain: 0.5, at: 1 + LEAD, seconds: 3 }]);
  });

  it('starts its fade in with its first note heard, later by as much as its buses are late (#346)', async () => {
    const levels: { at: number }[] = [];
    let release = () => {};
    const playbacks = new Playbacks({
      now: () => 1,
      latency: () => 0,
      ahead: (id) => (id === 5 ? 0.125 : 0),
      playing: () => false,
      stop: () => {},
      wake: () => () => {},
      prepare: () => new Promise<void>((resolve) => (release = resolve)),
      level: (_id, _gain, at) => void levels.push({ at }),
      after: () => {},
    });
    const struck: (ScheduledNote | ScheduledClip)[] = [];
    playbacks.start(5, 'song:a', song(struck, { volume: 0.5, fadeIn: 3 }), '');
    release();
    await Promise.resolve();
    expect(levels).toEqual([{ at: 1 + LEAD + 0.125 }]);
    expect(struck[0]).toMatchObject({ at: 1 + LEAD + 0.125 });
  });

  it('fades out over its fade, playing on meanwhile, then is gone; a hard stop then ends it at once', async () => {
    const { host, playbacks, run, loaded } = fakeHost();
    const struck: (ScheduledNote | ScheduledClip)[] = [];
    playbacks.start(5, 'song:a', song(struck), '');
    playbacks.start(6, 'song:a', song([]), '');
    await loaded();
    run(1);
    playbacks.stopNamed('song:a', false, 4);
    expect(
      host.levels.slice(-2).map(({ id, gain, at, seconds }) => [id, gain, +at.toFixed(9), seconds]),
    ).toEqual([
      [5, 0, 1, 4],
      [6, 0, 1, 4],
    ]);
    run(2);
    expect([playbacks.has(5), playbacks.current()[0]?.fading]).toEqual([true, expect.closeTo(5, 9)]);
    expect(struck.length).toBeGreaterThan(1);
    playbacks.stopId(6);
    expect(playbacks.current().map((p) => p.id)).toEqual([5]);
    run(2.1);
    expect([playbacks.has(5), host.pumps.size, host.closed]).toEqual([false, 0, [6, 5]]);
  });

  it('never starts when a fade out began while its files were loading', async () => {
    const { host, playbacks, run, loaded } = fakeHost();
    const struck: (ScheduledNote | ScheduledClip)[] = [];
    playbacks.start(5, 'song:a', song(struck), '');
    playbacks.stopId(5, false, 1);
    await loaded();
    run(2);
    expect([struck.length, host.pumps.size, playbacks.has(5)]).toEqual([0, 0, false]);
  });

  it('goes by its own name, by its kind and by none – a kind never reaches the other', async () => {
    expect(['song:a', 'song:', '', 'pattern:', 'song:b'].map((name) => goesBy('song:a', name))).toEqual([
      true,
      true,
      true,
      false,
      false,
    ]);
    const { playbacks, loaded } = fakeHost();
    playbacks.start(1, 'song:a', song([]), '');
    playbacks.start(2, 'pattern:p', song([]), '');
    await loaded();
    playbacks.stopNamed('song:');
    expect(playbacks.current().map((p) => p.id)).toEqual([2]);
  });
});

/**
 * A scene whose behavior plays a song on start: on its first track a two-note pattern at bar 1, on
 * its second a sound at bar 2, the second track at -6 dB and panned left, the third soloed.
 */
function playingSong(params: Record<string, string | number | boolean> = {}) {
  const f = makeSpriteScene('Box');
  const sound = new CreateSoundCommand('Blip', FILE);
  f.stack.execute(sound);
  const ins = new CreateAssetCommand('instrument', 'Lead');
  f.stack.execute(ins);
  const lead = ins.asset as InstrumentAsset;
  lead.graph.nodes.find((n) => n.type === 'InstrumentSample')!.params.sound = sound.asset.id;
  const pattern = new CreateAssetCommand('pattern', 'Riff');
  f.stack.execute(pattern);
  f.stack.execute(new SetAssetPropertyCommand(pattern.asset.id, 'instrument', lead.id));
  f.stack.execute(new SetAssetPropertyCommand(pattern.asset.id, 'bars', 1));
  f.stack.execute(
    new SetPatternNotesCommand(pattern.asset.id, [
      { id: 'n1', tick: 0, length: Q, note: 60, velocity: 1 },
      { id: 'n2', tick: Q, length: Q, note: 64, velocity: 1 },
    ]),
  );
  const create = new CreateAssetCommand('song', 'Theme');
  f.stack.execute(create);
  const id = create.asset.id;
  const asset = () => f.project.assets.find((a) => a.id === id) as SongAsset;
  f.stack.execute(new SetAssetPropertyCommand(id, 'tempo', 90));
  // A new song has one track: two more to lay things out on.
  const [one, two, three] = [...asset().tracks, newTrack(2), newTrack(3)];
  f.stack.execute(
    new SetSongCommand(id, {
      tracks: [one, { ...two, volume: -6, pan: -1 }, three!],
      items: [
        newItem({ track: one.id, kind: 'pattern', asset: pattern.asset.id, tick: 0, length: BAR }),
        newItem({ track: two.id, kind: 'sound', asset: sound.asset.id, tick: BAR, length: BAR }),
      ],
    }),
  );
  f.stack.execute(new SetLoopCommand('song', id, { start: BAR, end: 2 * BAR }));
  const behavior = makeBehavior(f, 'Logic');
  const box = place(f, f.spriteId, { x: 0, y: 0 });
  place(f, behavior.id, { x: 0, y: 0 }, box);
  const edit = graphEditor(f, behavior);
  const start = edit.addNode('OnStart');
  const play = edit.addNode('PlaySong', { song: id, volume: 0.8, fadeIn: 2, ...params });
  edit.connect(start, 'exec', play, 'exec');
  return { ...f, songId: id, tracks: [one.id, two.id, three!.id], lead, edit, play };
}

function recordingAudio() {
  const sink = {
    ...SILENT_AUDIO,
    sequences: [] as { name: string; play: SequencePlay; owner: string }[],
    notes: [] as { name: string; volume: number; owner: string; bus?: string; at?: number }[],
    clips: [] as { file: string; clip: ClipTiming }[],
    stopped: [] as string[],
    playSequence: (name: string, play: SequencePlay, owner: string) => {
      sink.sequences.push({ name, play, owner });
      return 1000 + sink.sequences.length;
    },
    playNote: ((name, _layers, _params, volume, owner, _duration, timing = {}) => {
      sink.notes.push({ name, volume, owner, ...timing });
      return 1;
    }) satisfies AudioSink['playNote'],
    playClip: (file: string, clip: ClipTiming) => (sink.clips.push({ file, clip }), 2),
    stopSequence: (name: string, _letRing = false, fade = 0) => sink.stopped.push(`${name} (fade ${fade})`),
    stopPlayback: (id: number, fade: number) => sink.stopped.push(`playback ${id} (fade ${fade})`),
  };
  return sink;
}

describe('Play song', () => {
  it('hands over its bake while it holds, at the peak it had, its volume left live (#340)', () => {
    const f = playingSong();
    const song = f.project.assets.find((a) => a.id === f.songId) as SongAsset;
    const spans = bakeSpans({ tempo: 90, length: 2 * BAR, loop: { start: BAR, end: 2 * BAR } });
    const file = `${'c3'.repeat(6)}/${'d4'.repeat(32)}.ogg`;
    song.bake = { file, print: bakePrint(f.project, song), peak: 0.5, bytes: 1, ...spans };
    const audio = recordingAudio();
    startWorld(f, { behaviors: true, audio }).frame();
    expect(audio.sequences[0]?.play).toMatchObject({
      bake: { file, gain: 0.5, playback: bakePlayback(spans, true) },
      volume: 0.8,
      fadeIn: 2,
    });
    // The second track panned the other way: the song sounds otherwise, its notes are played.
    const tracks = song.tracks.map((track, i) => (i === 1 ? { ...track, pan: 1 } : track));
    f.stack.execute(new SetSongCommand(f.songId, { tracks }));
    const changed = recordingAudio();
    startWorld(f, { behaviors: true, audio: changed }).frame();
    expect(changed.sequences[0]?.play.bake).toBeUndefined();
  });

  it('hands the song to the player: its tempo, intro then loop, its tracks and the level of the whole', () => {
    const f = playingSong();
    const audio = recordingAudio();
    const { world, frame } = startWorld(f, { behaviors: true, audio });
    frame();
    const logic = world.entities.find((e) => e.name === 'Logic')!;
    const [asked] = audio.sequences;
    expect([asked?.name, asked?.owner]).toEqual([`song:${f.songId}`, logic.id]);
    expect(asked?.play).toMatchObject({
      tempo: 90,
      length: 2 * BAR,
      loop: { start: BAR, end: 2 * BAR },
      volume: 0.8,
      fadeIn: 2,
    });
    expect(asked?.play.sequence.notes.map((n) => [n.tick, n.note])).toEqual([
      [0, 60],
      [Q, 64],
    ]);
    expect(asked?.play.needs.files).toEqual([FILE]);
    const tracks = asked?.play.buses?.filter((b) => b.sends);
    expect(tracks?.map((b) => [b.name, +b.gain.toFixed(3), b.pan])).toEqual([
      [trackBus(f.songId, f.tracks[0]!), 1, 0],
      [trackBus(f.songId, f.tracks[1]!), 0.501, -1],
      [trackBus(f.songId, f.tracks[2]!), 1, 0],
    ]);
  });

  it('strikes notes on their track, owned like the playing, and clips at their volume on theirs', () => {
    const f = playingSong({ detached: true, loop: false, volume: 3 });
    const audio = recordingAudio();
    startWorld(f, { behaviors: true, audio }).frame();
    const [asked] = audio.sequences;
    expect([asked?.owner, asked?.play.loop, asked?.play.volume]).toEqual(['', null, 1]);
    const bus = trackBus(f.songId, f.tracks[1]!);
    asked!.play.strike({
      at: 3,
      duration: 0.25,
      note: 60,
      velocity: 1,
      instrument: f.lead.id,
      tempo: 90,
      bus,
    });
    asked!.play.strikeClip!({
      at: 4,
      duration: 2,
      offset: 0.5,
      sound: f.project.assets.find((a) => a.type === 'sound')!.id,
      fx: '',
      volume: 0.5,
      bus,
      tempo: 90,
    });
    expect(audio.notes).toEqual([
      { name: `instrument:${f.lead.id}`, volume: 1, owner: '', at: 3, tempo: 90, bus },
    ]);
    expect(audio.clips).toEqual([
      { file: FILE, clip: { at: 4, offset: 0.5, duration: 2, volume: 0.5, bus } },
    ]);
  });
});

describe('Stop song', () => {
  it('stops one song over its fade, every song for none, and one playing by its number', () => {
    const f = playingSong();
    const one = f.edit.addNode('StopSong', { song: f.songId, fadeOut: 1.5 });
    const all = f.edit.addNode('StopSong', { song: '' });
    const byNumber = f.edit.addNode('StopSong', { song: f.songId, fadeOut: 2 });
    f.edit.connect(f.play, 'exec', one, 'exec');
    f.edit.connect(one, 'exec', all, 'exec');
    f.edit.connect(all, 'exec', byNumber, 'exec');
    f.edit.connect(f.play, 'playback', byNumber, 'playback');
    const audio = recordingAudio();
    startWorld(f, { behaviors: true, audio }).frame();
    expect(audio.stopped).toEqual([
      `song:${f.songId} (fade 1.5)`,
      'song: (fade 0)',
      'playback 1001 (fade 2)',
    ]);
  });
});