import { CreateSoundCommand, SetAssetPropertyCommand } from '../../core/commands/assetCommands';
import { CompoundCommand } from '../../core/commands/CompoundCommand';
import { SetSongCommand } from '../../core/commands/songCommands';
import {
  newItem,
  SONG_GRID_KEY,
  SONG_GRID_OPTIONS,
  songLoop,
  songMeter,
  songSequence,
  songTempo,
} from '../../core/music/song';
import { roundAt } from '../../core/music/ghosts';
import { patternLength } from '../../core/music/pattern';
import { songBuses } from '../../core/music/songBuses';
import { sampleCount, takeName, takeStart, takeTrack, takeTrackIndex, wavBytes } from '../../core/music/take';
import { ticksOfSeconds } from '../../core/music/time';
import type { Asset, SongAsset } from '../../core/model/Asset';
import { findAssetOf } from '../../core/model/Project';
import { textOf } from '../../core/model/Properties';
import type { SoundStore } from '../../core/store/SoundStore';
import { Button, Dialog, Dropdown, Label, Menu, ui } from '../../ui';
import { Music } from '../../viewport/music';
import { soundLibrary } from '../../viewport/SoundLibrary';
import {
  type InputDevice,
  inputDevices,
  inputProblem,
  PEAK_SPAN,
  TakeRecorder,
} from '../../viewport/takeRecorder';
import { activateAsset } from '../actions';
import { AssetTabEditor } from '../AssetTabEditor';
import { claimTransport, releaseTransport } from '../music/transport';
import { TOOLBAR_ICON_SVG } from '../panels/toolbarIcons';
import type { EditorState } from '../state';
import { SongTimeline } from './SongTimeline';
import { TakeMeter } from './TakeMeter';

const INFO_WIDTH = 200;
const GRID_WIDTH = 64;
const INPUT_WIDTH = 104;
/** Where the browser keeps the input picked last. */
const INPUT_KEY = 'game-maker.record-input';

/** A take being recorded: the song it goes into, where, and the input it comes from. */
interface Take {
  recorder: TakeRecorder;
  songId: string;
  tick: number;
  index: number;
  tempo: number;
}

/**
 * The Song tab (#334): the tracks and their items, and in the header Play – the Space bar does the
 * same – and the grid items snap to. The song plays round its loop through the scheduler (#332); an
 * edit is heard from its next window on, a track's level and pan at once.
 *
 * Record (#342) plays the song from where the ruler says, once through and on past its end, and
 * takes the input meanwhile. Stop keeps the take: it goes up as WAV and lands on a track of its own
 * under the one clicked last, sound and item one undo step. Esc throws it away.
 */
export class SongEditor extends AssetTabEditor<SongAsset, SongTimeline> {
  /** Public for the check scripts. */
  readonly playButton: Button;
  readonly gridButton = new Dropdown('Bar', { width: GRID_WIDTH });
  readonly recordButton: Button;
  readonly inputButton = new Dropdown('Default input', { width: INPUT_WIDTH });
  readonly meter = new TakeMeter();
  readonly music = new Music(() => this.state.project);
  /** The song playing, `''` while none is. */
  private playingId = '';
  private take: Take | null = null;
  /** Waiting for the browser to give the input, or for a take to go up: Record waits too. */
  private busy = false;
  private inputs: InputDevice[] = [];
  private inputId = localStorage.getItem(INPUT_KEY) ?? '';
  /** What the scheduler was last told, so only a change is passed on. */
  private told = '';
  private readonly halt = () => this.stop();

  constructor(
    state: EditorState,
    private readonly sounds: SoundStore,
  ) {
    super(state, { infoWidth: INFO_WIDTH });
    this.playButton = new Button('Play', {
      icon: TOOLBAR_ICON_SVG.play,
      minWidth: 72,
      tooltip: 'Play the song round its loop (Space)',
      onClick: () => this.togglePlay(),
    });
    this.recordButton = new Button('Record', {
      icon: TOOLBAR_ICON_SVG.record,
      minWidth: 80,
      tooltip: 'Record from the input while the song plays – headphones keep the song out of the take',
      onClick: () => this.toggleRecord(),
    });
    this.inputButton.onClick = () => void this.openInputMenu();
    this.gridButton.onClick = () => this.openGridMenu();
    const timeline = new SongTimeline(state);
    timeline.onTogglePlay = () => this.togglePlay();
    timeline.onStart = (tick) => {
      if (this.isPlaying) this.music.current?.seek(tick);
    };
    timeline.onTracksPreview = (tracks) => {
      const asset = this.asset();
      if (asset && this.isPlaying) this.music.setBuses(songBuses(this.state.project, { ...asset, tracks }));
    };
    timeline.onOpenPattern = (item, tick) => {
      const song = this.asset();
      const pattern = findAssetOf(state.project, item.asset, 'pattern');
      if (song && pattern)
        state.patternPlaces.set(pattern.id, {
          songId: song.id,
          itemId: item.id,
          round: roundAt(item, patternLength(pattern), tick),
        });
      activateAsset(state, item.asset);
    };
    timeline.onDiscardTake = () => this.stop({ discard: true });
    this.mount(timeline, [
      this.playButton,
      this.recordButton,
      this.inputButton,
      this.meter,
      new Label('Grid', { style: 'muted' }),
      this.gridButton,
    ]);
    state.on('load', () => this.stop({ discard: true }));
    void this.listInputs();
  }

  override selectedId(): string {
    return this.state.selectedSongId ?? '';
  }

  override isMine(asset: Asset): asset is SongAsset {
    return asset.type === 'song';
  }

  get isPlaying(): boolean {
    return this.playingId !== '';
  }

  get isRecording(): boolean {
    return this.take !== null;
  }

  togglePlay(): void {
    if (this.isPlaying) this.stop();
    else this.play();
  }

  /** Plays the song shown from where the ruler says, round its loop. */
  play(): void {
    const asset = this.asset();
    if (!asset) return;
    claimTransport(this.halt);
    this.playingId = asset.id;
    this.told = this.settingsOf(asset);
    this.music.setBuses(songBuses(this.state.project, asset));
    void this.music.play(songSequence(this.state.project, asset), {
      tempo: songTempo(asset.props),
      meter: songMeter(asset.props),
      loop: songLoop(asset),
      from: this.canvas.start,
    });
    this.syncPlayButton();
  }

  /** Ends playing; a take being recorded is kept, or with `discard` thrown away. */
  stop(options: { discard?: boolean } = {}): void {
    releaseTransport(this.halt);
    this.music.stop();
    this.playingId = '';
    this.canvas.playhead = null;
    const take = this.take;
    this.take = null;
    this.meter.set(0);
    if (take && options.discard) {
      take.recorder.cancel();
      this.canvas.take = null;
      this.state.setNotice('Threw the take away');
    } else if (take) void this.keep(take);
    this.canvas.invalidate();
    this.syncPlayButton();
  }

  toggleRecord(): void {
    if (this.isRecording) this.stop();
    else void this.record();
  }

  /** Asks for the input, then plays the song from the cursor – once, on past its end – and takes it in. */
  async record(): Promise<void> {
    const asked = this.asset();
    if (!asked || this.busy) return;
    this.stop();
    this.busy = true;
    this.syncPlayButton();
    let recorder: TakeRecorder;
    try {
      recorder = await TakeRecorder.open(this.inputId);
    } catch (error) {
      this.state.setNotice(inputProblem(error), 'error');
      return;
    } finally {
      this.busy = false;
      this.syncPlayButton();
    }
    const asset = this.asset();
    if (!asset || asset.id !== asked.id) {
      recorder.cancel();
      return;
    }
    const tempo = songTempo(asset.props);
    const take: Take = {
      recorder,
      songId: asset.id,
      tick: this.canvas.start,
      index: takeTrackIndex(asset.tracks, this.canvas.pickedTrack),
      tempo,
    };
    claimTransport(this.halt);
    this.take = take;
    this.playingId = asset.id;
    this.told = this.settingsOf(asset);
    this.showTake(take, false);
    this.syncPlayButton();
    ui().focus.focus(this.canvas);
    this.music.setBuses(songBuses(this.state.project, asset));
    await this.music.play(songSequence(this.state.project, asset), {
      tempo,
      meter: songMeter(asset.props),
      loop: null,
      from: take.tick,
    });
    const anchor = this.music.current?.startedAt;
    if (this.take !== take || anchor === null || anchor === undefined) return;
    recorder.startAt(takeStart(anchor, soundLibrary.latency(), recorder.inputLatency));
    this.state.setNotice('Recording – Space or Stop keeps the take, Esc throws it away');
    void this.listInputs();
  }

  /** Only called while the tab is visible: the playhead follows what is heard, a take grows. */
  tick(): void {
    if (!this.isPlaying) return;
    this.canvas.playhead = this.music.current?.position().ticks ?? null;
    const take = this.take;
    if (take) {
      this.showTake(take, false);
      this.meter.set(take.recorder.level);
      if (take.recorder.full) {
        this.state.setNotice('The take is as long as a sound may be, so it was stopped');
        this.stop();
      }
    }
    this.canvas.invalidate();
  }

  override destroy(options?: Parameters<AssetTabEditor<SongAsset, SongTimeline>['destroy']>[0]): void {
    this.music.stop();
    this.take?.recorder.cancel();
    super.destroy(options);
  }

  private showTake(take: Take, uploading: boolean): void {
    const shown = this.canvas.currentAssetId === take.songId;
    this.canvas.take = shown
      ? {
          index: take.index,
          tick: take.tick,
          length: ticksOfSeconds(take.recorder.seconds, take.tempo),
          peaks: take.recorder.peaks,
          ticksPerPeak: ticksOfSeconds(PEAK_SPAN / take.recorder.sampleRate, take.tempo),
          uploading,
        }
      : null;
    this.canvas.invalidate();
  }

  /** The take as WAV to the server, then onto its track. */
  private async keep(take: Take): Promise<void> {
    this.busy = true;
    this.showTake(take, true);
    this.syncPlayButton();
    const parts = await take.recorder.finish();
    if (sampleCount(parts) === 0) {
      this.endUpload();
      this.state.setNotice('Nothing was recorded');
      return;
    }
    const song = findAssetOf(this.state.project, take.songId, 'song');
    const name = takeName(
      song?.name ?? 'Recording',
      this.state.project.assets.map((a) => a.name),
    );
    const seconds = sampleCount(parts) / take.recorder.sampleRate;
    await this.upload(take, wavBytes(parts, take.recorder.sampleRate), name, seconds);
  }

  private async upload(
    take: Take,
    wav: Uint8Array<ArrayBuffer>,
    name: string,
    seconds: number,
  ): Promise<void> {
    this.busy = true;
    this.syncPlayButton();
    try {
      const blob = new Blob([wav], { type: 'audio/wav' });
      const uploaded = await this.sounds.upload(blob, 'audio/wav', `${name}.wav`);
      this.endUpload();
      this.place(take, uploaded.file, name, seconds);
    } catch (error) {
      const reason = error instanceof Error ? error.message : String(error);
      new Dialog('The take could not be uploaded', reason, [
        {
          label: 'Download WAV',
          onClick: () => {
            this.endUpload();
            downloadWav(wav, name);
          },
        },
        {
          label: 'Discard',
          danger: true,
          onClick: () => {
            this.endUpload();
            this.state.setNotice('Threw the take away');
          },
        },
        { label: 'Retry', primary: true, onClick: () => void this.upload(take, wav, name, seconds) },
      ]).openCentered();
    }
  }

  private endUpload(): void {
    this.busy = false;
    this.canvas.take = null;
    this.canvas.invalidate();
    this.syncPlayButton();
  }

  /** The sound, its track and its item, one undo step; the song gone meanwhile, only the sound. */
  private place(take: Take, file: string, name: string, seconds: number): void {
    const create = new CreateSoundCommand(name, file);
    const song = findAssetOf(this.state.project, take.songId, 'song');
    if (!song) {
      if (this.state.execute(create)) this.state.setNotice(`Recorded "${name}" – its song is gone`);
      return;
    }
    const track = takeTrack();
    const tracks = [...song.tracks];
    tracks.splice(Math.min(take.index, tracks.length), 0, track);
    const length = Math.max(1, Math.floor(ticksOfSeconds(seconds, songTempo(song.props))));
    const item = newItem({ track: track.id, kind: 'sound', asset: create.asset.id, tick: take.tick, length });
    const placed = new SetSongCommand(song.id, { tracks, items: [...song.items, item] }, 'Record take');
    if (!this.state.execute(new CompoundCommand('Record take', [create, placed]))) return;
    if (this.canvas.currentAssetId === song.id) this.canvas.pick([item.id]);
    this.state.setNotice(`Recorded "${name}" (${clockText(seconds)})`);
  }

  private async listInputs(): Promise<void> {
    try {
      this.inputs = await inputDevices();
    } catch {
      this.inputs = [];
    }
    this.syncInputButton();
  }

  private async openInputMenu(): Promise<void> {
    await this.listInputs();
    new Menu([
      {
        label: 'Default input',
        current: !this.inputs.some((d) => d.id === this.inputId),
        onSelect: () => this.pickInput(''),
      },
      ...this.inputs.map((device) => ({
        label: device.label,
        current: device.id === this.inputId,
        onSelect: () => this.pickInput(device.id),
      })),
    ]).openBelow(this.inputButton);
  }

  private pickInput(id: string): void {
    this.inputId = id;
    if (id) localStorage.setItem(INPUT_KEY, id);
    else localStorage.removeItem(INPUT_KEY);
    this.syncInputButton();
  }

  private syncInputButton(): void {
    this.inputButton.setText(this.inputs.find((d) => d.id === this.inputId)?.label ?? 'Default input');
  }

  private openGridMenu(): void {
    const asset = this.asset();
    if (!asset) return;
    const current = textOf(asset.props[SONG_GRID_KEY] ?? 'bar');
    new Menu(
      SONG_GRID_OPTIONS.map((option) => ({
        label: option.label,
        current: option.value === current,
        onSelect: () =>
          this.state.execute(new SetAssetPropertyCommand(asset.id, SONG_GRID_KEY, option.value)),
      })),
    ).openBelow(this.gridButton);
  }

  private settingsOf(asset: SongAsset): string {
    return JSON.stringify([songTempo(asset.props), songMeter(asset.props), songLoop(asset)]);
  }

  /** What changed while playing goes to the scheduler and the tracks; another song shown stops it. */
  private follow(asset: SongAsset | null): void {
    if (!this.isPlaying) return;
    if (!asset || asset.id !== this.playingId) {
      this.stop();
      return;
    }
    this.music.edit(songSequence(this.state.project, asset));
    this.music.setBuses(songBuses(this.state.project, asset));
    const settings = this.settingsOf(asset);
    if (settings === this.told) return;
    this.told = settings;
    const scheduler = this.music.current;
    scheduler?.setTempo(songTempo(asset.props));
    scheduler?.setMeter(songMeter(asset.props));
    scheduler?.setLoop(this.take ? null : songLoop(asset));
  }

  private syncPlayButton(): void {
    const recording = this.isRecording;
    this.playButton.setIcon(this.isPlaying && !recording ? TOOLBAR_ICON_SVG.stop : TOOLBAR_ICON_SVG.play);
    this.playButton.setText(this.isPlaying && !recording ? 'Stop' : 'Play');
    this.recordButton.setIcon(recording ? TOOLBAR_ICON_SVG.stop : TOOLBAR_ICON_SVG.record);
    this.recordButton.setText(recording ? 'Stop' : 'Record');
    const asset = this.asset();
    this.playButton.setEnabled(asset !== null && !this.busy);
    this.recordButton.setEnabled(asset !== null && (recording || !this.busy));
    this.inputButton.setEnabled(!recording && !this.busy);
  }

  protected override infoText(asset: SongAsset): string {
    const tracks = asset.tracks.length;
    const items = asset.items.length;
    return `${tracks} ${tracks === 1 ? 'track' : 'tracks'} · ${items} ${items === 1 ? 'item' : 'items'}`;
  }

  protected override syncExtras(asset: SongAsset | null): void {
    this.fitButton.setEnabled(asset !== null);
    this.gridButton.setEnabled(asset !== null);
    this.syncPlayButton();
    const grid = asset ? textOf(asset.props[SONG_GRID_KEY] ?? 'bar') : 'bar';
    this.gridButton.setText(SONG_GRID_OPTIONS.find((o) => o.value === grid)?.label ?? 'Bar');
    this.follow(asset);
  }
}

/** "1:05" */
function clockText(seconds: number): string {
  const whole = Math.round(seconds);
  return `${Math.floor(whole / 60)}:${String(whole % 60).padStart(2, '0')}`;
}

/** Hands the take to the browser as a file, for when the server would not take it. */
function downloadWav(wav: Uint8Array<ArrayBuffer>, name: string): void {
  const url = URL.createObjectURL(new Blob([wav], { type: 'audio/wav' }));
  const link = document.createElement('a');
  link.href = url;
  link.download = `${name}.wav`;
  link.click();
  setTimeout(() => URL.revokeObjectURL(url), 60_000);
}