index.js

const registry = new Map();

export function addDecoder(cases, importFn) {
  if (!Array.isArray(cases)) {
    cases = [cases]; // eslint-disable-line no-param-reassign
  }
  cases.forEach((c) => registry.set(c, importFn));
}

export async function getDecoder(fileDirectory) {
  const importFn = registry.get(fileDirectory.Compression);
  if (!importFn) {
    throw new Error(`Unknown compression method identifier: ${fileDirectory.Compression}`);
  }
  const Decoder = await importFn();
  return new Decoder(fileDirectory);
}

// Add default decoders to registry (end-user may override with other implementations)
addDecoder([undefined, 1], () => import('./raw.js').then((m) => m.default));
addDecoder(5, () => import('./lzw.js').then((m) => m.default));
addDecoder(6, () => {
  throw new Error('old style JPEG compression is not supported.');
});
addDecoder(7, () => import('./jpeg.js').then((m) => m.default));
addDecoder([8, 32946], () => import('./deflate.js').then((m) => m.default));
addDecoder(32773, () => import('./packbits.js').then((m) => m.default));
addDecoder(34887, () => import('./lerc.js')
  .then(async (m) => {
    await m.zstd.init();
    return m;
  })
  .then((m) => m.default),
);
addDecoder(50000, () => import('./zstd.js')
  .then(async (m) => {
    await m.zstd.init();
    return m;
  })
  .then((m) => m.default),
);
addDecoder(50001, () => import('./webimage.js').then((m) => m.default));