ep-133-project-export/src/lib/parsers.ts

import JSZip from 'jszip';
import {
  GroupFaderParam,
  Note,
  Pad,
  PadCode,
  Pattern,
  ProjectSettings,
  Scene,
  ScenesSettings,
  Sound,
} from '../types/types';
import { GROUPS, NOTE_NAMES, PADS, SKU_EP40 } from './constants';
import { parseWavMetadata } from './exporters/utils';
import { getFileMetadata, getFileNodeByPath } from './midi/fs';
import { TESoundMetadata } from './midi/types';
import { TarFile } from './untar';
import { calculateSoundLength } from './utils';

type SceneMeta = {
  a: number;
  b: number;
  c: number;
  d: number;
};

type IntermediateScenes = Record<
  number,
  {
    name: string;
    groups: Record<string, { bars: number; notes: Record<number, Note[]> }>;
  }
>;

const defaultProjectSettings = {
  bpm: 120,
  scale: 0,
  rootNote: 0,
  groupFaderParams: {
    a: { 0: -1, 1: -1, 2: -1, 3: -1, 4: -1, 5: -1, 6: -1, 7: -1, 8: -1, 9: -1, 10: -1, 11: -1 },
    b: { 0: -1, 1: -1, 2: -1, 3: -1, 4: -1, 5: -1, 6: -1, 7: -1, 8: -1, 9: -1, 10: -1, 11: -1 },
    c: { 0: -1, 1: -1, 2: -1, 3: -1, 4: -1, 5: -1, 6: -1, 7: -1, 8: -1, 9: -1, 10: -1, 11: -1 },
    d: { 0: -1, 1: -1, 2: -1, 3: -1, 4: -1, 5: -1, 6: -1, 7: -1, 8: -1, 9: -1, 10: -1, 11: -1 },
  },
  faderAssignment: { a: 0, b: 0, c: 0, d: 0 },
};

const defaultScenesSettings = {
  timeSignature: { numerator: 4, denominator: 4 },
};

export function noteNumberToName(noteNumber: number): string {
  const noteIndex = noteNumber % 12;
  const octave = Math.floor(noteNumber / 12) - 1;

  return `${NOTE_NAMES[noteIndex]}${octave}`;
}

function timeStretch(data: number): Pad['timeStretch'] {
  switch (data) {
    case 1:
      return 'bpm';
    case 2:
      return 'bars';
    case 3:
      return 'rev';
    default:
      return 'off';
  }
}

function timeStretchBars(data: number) {
  switch (data) {
    case 0:
      return 1;
    case 1:
      return 2;
    case 2:
      return 4;
    case 255:
      return 0.5;
    case 254:
      return 0.25;
    default:
      return 0;
  }
}

function bytesToFloat32(bytes: Uint8Array): number {
  const buffer = new ArrayBuffer(4);
  const view = new DataView(buffer);

  bytes.forEach((b, i) => {
    view.setUint8(i, b);
  });

  return view.getFloat32(0, true);
}

function genPadFileName(group: string, pad: number) {
  return `pads/${group}/p${String(pad).padStart(2, '0')}`;
}

function chunkArray(arr: Uint8Array, size: number, offset = 0) {
  const result = [];

  for (let i = offset; i < arr.length; i += size) {
    result.push(arr.slice(i, i + size));
  }
  return result;
}

export async function collectSounds(files: TarFile[]) {
  const soundIds = new Set<number>();

  for (let g = 0; g < 4; g++) {
    for (let i = 1; i <= 12; i++) {
      const file = files.find((f) => f.name === genPadFileName(GROUPS[g].id, i));

      if (file?.data) {
        const soundId = (file.data[2] << 8) + file.data[1];
        if (soundId > 0 && soundId < 1000) {
          soundIds.add(soundId);
        }
      }
    }
  }

  const selectedSounds: Sound[] = [];

  for (const soundId of soundIds) {
    const fileNode = await getFileNodeByPath(`/sounds/${String(soundId).padStart(3, '0')}.pcm`);

    if (!fileNode) {
      console.warn(`Sound file for sound ID ${soundId} not found`);
      continue;
    }

    const meta = await getFileMetadata<TESoundMetadata>(fileNode.nodeId);

    selectedSounds.push({
      id: soundId,
      fileNode,
      meta,
    });
  }

  return selectedSounds;
}

export function collectPads(files: TarFile[], sounds: Sound[]) {
  const result: Record<string, Pad[]> = {};

  for (const group of GROUPS) {
    result[group.id] = [];

    for (let i = 1; i <= 12; i++) {
      const file = files.find((f) => f.name === genPadFileName(group.id, i));
      if (file?.data) {
        const soundId = (file.data[2] << 8) + file.data[1];
        const sound = sounds.find((s) => s.id === soundId);
        const pitch = file.data[17] <= 12 ? file.data[17] : -(256 - file.data[17]); // pitch from -12 to +12
        const pitchDecimal = file.data[26];
        const pan = (file.data[18] >= 240 ? -(256 - file.data[18]) : file.data[18]) / 16; // normalized pan
        const trimLeft = (file.data[6] << 16) + (file.data[5] << 8) + file.data[4];
        const trimRight = trimLeft + (file.data[10] << 16) + (file.data[9] << 8) + file.data[8];

        result[group.id].push({
          pad: i,
          group: group.id,
          name: `${group.name} ${PADS[i - 1]}`,
          file,
          rawData: file.data,
          soundId,
          pan,
          volume: file.data[16],
          attack: file.data[19],
          release: file.data[20],
          trimLeft,
          trimRight,
          playMode: file.data[23] === 0 ? 'oneshot' : file.data[23] === 1 ? 'key' : 'legato',
          soundLength: sound ? calculateSoundLength(sound) : 0,
          pitch: Math.max(-12, Math.min(12, parseFloat(`${pitch}.${pitchDecimal}`))),
          rootNote: file.data[24],
          timeStretch: timeStretch(file.data[21]),
          timeStretchBpm: Number(bytesToFloat32(file.data.slice(12, 16)).toFixed(2)),
          timeStretchBars: timeStretchBars(file.data[25]),
          inChokeGroup: file.data[22] === 1,
          midiChannel: file.data[3],
        });
      }
    }
  }

  return result;
}

function parsePatterns(data: Uint8Array, startOffset: number = 4) {
  const chunks = chunkArray(data, 8, startOffset);
  const notes: Record<number, Note[]> = {};

  chunks.forEach((chunk) => {
    // I discovered there could be some weird chunks with pad numbers not multiple of 8
    // since I don't know what they are, just skip them
    if (chunk[2] % 8 !== 0) {
      return;
    }

    const pad = chunk[2] / 8;
    if (!notes[pad]) {
      notes[pad] = [];
    }

    notes[pad].push({
      note: chunk[3],
      position: (chunk[1] << 8) + chunk[0],
      duration: (chunk[6] << 8) + chunk[5],
      velocity: chunk[4],
    });
  });

  return {
    bars: data[1],
    notes,
  };
}

function getPatternsForScene(scenesIntermediate: IntermediateScenes, scenePatternUsage: SceneMeta) {
  const patterns: Pattern[] = [];

  for (const group of ['a', 'b', 'c', 'd'] as const) {
    const scene = scenePatternUsage[group];
    const lookupSceneData = scenesIntermediate[scene];

    if (lookupSceneData?.groups[group]) {
      const groupData = lookupSceneData.groups[group];
      Object.entries(groupData.notes).forEach(([padNum, notes]) => {
        patterns.push({
          pad: `${group}${padNum}` as PadCode,
          group,
          notes,
          bars: groupData.bars,
        });
      });
    }
  }

  return patterns;
}

export function collectScenesAndPatterns(files: TarFile[], sku: string) {
  const scenesIntermediateData: IntermediateScenes = {};
  const scenes: Record<string, Scene> = {};
  const scenePatternUsage: Record<string, SceneMeta> = {};

  // build default scene metadata (in case "scenes" file is missing)
  for (let i = 1; i <= 99; i++) {
    scenePatternUsage[i] = {
      a: i,
      b: i,
      c: i,
      d: i,
    };
  }

  // build group/pattern lookup table
  const scenesFile = files.find((f) => f.name === 'scenes' && f.type === 'file');
  if (scenesFile?.data) {
    const chunks = chunkArray(scenesFile.data, 6, 7);
    chunks.forEach((chunk, i) => {
      if (i > 98) {
        return;
      }

      scenePatternUsage[i + 1] = {
        a: chunk[0],
        b: chunk[1],
        c: chunk[2],
        d: chunk[3],
      };
    });
  }

  for (const file of files) {
    if (!file.name.startsWith('patterns') || file.type !== 'file' || !file.data) {
      continue;
    }

    const matches = file.name.match(/patterns\/([abcd])(\d+)/);
    if (!matches) {
      continue;
    }

    const [, group, scene] = matches;
    const sceneIndex = Number(scene);
    if (!scenesIntermediateData[sceneIndex]) {
      scenesIntermediateData[sceneIndex] = {
        name: String(scene).padStart(2, '0'),
        groups: {},
      };
    }

    // build intermediate scenes data
    // will be used to resolve patterns later using sceneMetadata
    scenesIntermediateData[sceneIndex] = {
      ...scenesIntermediateData[sceneIndex],
      groups: {
        ...scenesIntermediateData[sceneIndex].groups,
        [group]: parsePatterns(file.data, sku === SKU_EP40 ? 6 : 4), // EP-40 has 6-byte header
      },
    };
  }

  Object.entries(scenesIntermediateData).forEach(([sceneIndex, sceneData]) => {
    if (!scenePatternUsage[sceneIndex]) {
      return;
    }

    const patterns = getPatternsForScene(scenesIntermediateData, scenePatternUsage[sceneIndex]);
    if (patterns.length === 0) {
      return;
    }

    scenes[sceneIndex] = {
      name: sceneData.name,
      patterns,
    };
  });

  return Object.values(scenes).sort((a, b) => a.name.localeCompare(b.name));
}

export function collectSettings(files: TarFile[]): ProjectSettings {
  const settings = files.find((f) => f.name === 'settings' && f.type === 'file');

  if (!settings || !settings.data) {
    console.warn('Could not find "settings" file');

    return {
      ...defaultProjectSettings,
      rawData: new Uint8Array(),
    };
  }

  const faderParamsData: GroupFaderParam = {};

  for (const groupNum of [0, 1, 2, 3]) {
    const groupId = GROUPS[groupNum].id;
    for (let paramNum = 0; paramNum <= 11; paramNum++) {
      faderParamsData[groupId] = {
        ...faderParamsData[groupId],
        [paramNum]: Number(
          bytesToFloat32(
            settings.data.slice(
              24 + groupNum * 48 + paramNum * 4,
              28 + groupNum * 48 + paramNum * 4,
            ),
          ).toFixed(2),
        ),
      };
    }
  }

  return {
    bpm: Number(bytesToFloat32(settings.data.slice(4, 8)).toFixed(2)),
    scale: settings.data?.[222] ?? 0,
    rootNote: settings.data?.[223] ?? 0,
    groupFaderParams: faderParamsData,
    faderAssignment: {
      a: settings.data[216],
      b: settings.data[217],
      c: settings.data[218],
      d: settings.data[219],
    },
    rawData: settings.data,
  };
}

export function collectEffects(files: TarFile[]) {
  const fxFile = files.find((f) => f.name === 'fx_settings' && f.type === 'file');

  if (!fxFile || !fxFile.data) {
    console.warn('Could not find "fx_settings" file');

    return {
      rawData: new Uint8Array(),
      effectType: 0,
      param1: 0,
      param2: 0,
    };
  }

  const effectType = fxFile.data[4];
  const param1 = bytesToFloat32(
    fxFile.data.slice(12 + (effectType - 1) * 4, 16 + (effectType - 1) * 4),
  );
  const param2 = bytesToFloat32(
    fxFile.data.slice(76 + (effectType - 1) * 4, 80 + (effectType - 1) * 4),
  );

  return {
    rawData: fxFile.data,
    effectType,
    param1,
    param2,
  };
}

export function collectScenesSettings(files: TarFile[]): ScenesSettings {
  const scenesSettingsFile = files.find((f) => f.name === 'scenes' && f.type === 'file');

  if (!scenesSettingsFile || !scenesSettingsFile.data) {
    console.warn('Could not find "scenes" file');
    return defaultScenesSettings;
  }

  const numerator = scenesSettingsFile.data[11];
  const denominator = scenesSettingsFile.data[12];

  return {
    ...defaultScenesSettings,
    timeSignature: { numerator, denominator },
  };
}

export async function loadSoundsFromBackup(
  unzippedBackup: JSZip,
  projectFiles: TarFile[],
): Promise<Sound[]> {
  const soundIds = new Set<number>();

  for (let group = 0; group < 4; group++) {
    for (let pad = 1; pad <= 12; pad++) {
      const file = projectFiles.find((f) => f.name === genPadFileName(GROUPS[group].id, pad));

      if (file?.data) {
        const soundId = (file.data[2] << 8) + file.data[1];
        if (soundId > 0 && soundId < 1000) {
          soundIds.add(soundId);
        }
      }
    }
  }

  const selectedSounds: Sound[] = [];

  for (const soundId of soundIds) {
    const wavFile = Object.values(unzippedBackup.files).find((file) =>
      file.name.startsWith(`/sounds/${String(soundId).padStart(3, '0')} `),
    );

    if (!wavFile) {
      console.warn(`Sound file for sound ID ${soundId} not found in backup`);
      continue;
    }

    const soundFile = unzippedBackup.file(wavFile.name);
    if (!soundFile) {
      console.warn(`Sound file for sound ID ${soundId} not found in backup`);
      continue;
    }

    const soundData = await soundFile.async('uint8array');
    const fileName = (soundFile.name.split('/').pop()?.split(' ').slice(1).join(' ') || '').replace(
      '.wav',
      '',
    );
    const fileNode = {
      nodeId: soundId,
      flags: 0,
      fileSize: soundData.length,
      fileName,
      fileType: 'file' as const,
    };

    let wavMeta: ReturnType<typeof parseWavMetadata>;
    try {
      wavMeta = parseWavMetadata(soundData);
    } catch (err) {
      console.warn(`Failed to parse WAV metadata for sound ${soundId}:`, err);
      wavMeta = {
        channels: 1,
        samplerate: 44100,
        format: 's16' as const,
        rootNote: 60,
        teMeta: null,
      };
    }

    const te = wavMeta.teMeta;

    selectedSounds.push({
      id: soundId,
      fileNode,
      meta: {
        channels: wavMeta.channels,
        samplerate: wavMeta.samplerate,
        format: wavMeta.format,
        crc: 0,
        name: fileName,
        'sound.loopstart': (te?.['sound.loopstart'] as number) ?? 0,
        'sound.loopend': (te?.['sound.loopend'] as number) ?? 0,
        'sound.amplitude': (te?.['sound.amplitude'] as number) ?? 1,
        'sound.playmode':
          (te?.['sound.playmode'] as TESoundMetadata['sound.playmode']) ?? 'oneshot',
        'sound.pan': (te?.['sound.pan'] as number) ?? 0,
        'sound.pitch': (te?.['sound.pitch'] as number) ?? 0,
        'sound.rootnote': wavMeta.rootNote,
        'time.mode': (te?.['time.mode'] as string) ?? '',
        'sound.bpm': 0,
        'envelope.attack': (te?.['envelope.attack'] as number) ?? 0,
        'envelope.release': (te?.['envelope.release'] as number) ?? 0,
      },
    });
  }

  return selectedSounds;
}