DecompressionStream

const loadGzipText = async (url) => {
  const response = await fetch(url);
  if (!response.ok) throw new Error(`HTTP ${response.status}`);

  // Bytes entpacken und direkt als Text dekodieren
  const textStream = response.body
    .pipeThrough(new DecompressionStream('gzip'))
    .pipeThrough(new TextDecoderStream());

  return await new Response(textStream).text();
};

const text = await loadGzipText('/data/export.json.gz');
const data = JSON.parse(text);
console.log(`Datensätze: ${data.length}`);

const compress = async (str) => {
  const stream = new Blob([str]).stream()
    .pipeThrough(new CompressionStream('deflate-raw'));
  return new Uint8Array(await new Response(stream).arrayBuffer());
};

const decompress = async (bytes) => {
  const stream = new Blob([bytes]).stream()
    .pipeThrough(new DecompressionStream('deflate-raw'));
  return await new Response(stream).text();
};

const original = 'Hallo Welt! '.repeat(100);
const packed = await compress(original);
const restored = await decompress(packed);

console.log(original.length, packed.length);
console.log(restored === original);

const input = document.querySelector('#gzFile');

input.addEventListener('change', async () => {
  const file = input.files[0];
  if (!file) return;

  const ds = new DecompressionStream('gzip');
  // Datei in den Eingang schreiben (läuft parallel)
  file.stream().pipeTo(ds.writable).catch((err) => {
    console.error('Eingabe fehlgeschlagen:', err);
  });

  const reader = ds.readable
    .pipeThrough(new TextDecoderStream())
    .getReader();

  let chars = 0;
  try {
    while (true) {
      const { value, done } = await reader.read();
      if (done) break;
      chars += value.length; // Chunk verarbeiten
    }
    console.log(`Entpackt: ${chars} Zeichen`);
  } catch (err) {
    console.error('Keine gültige gzip-Datei:', err.name);
  }
});