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import xxhash from "xxhash-wasm";
export async function bundle(entries) {  if (!Archive.xxhash) {    Archive.xxhash = xxhash();  }  if (Archive.xxhash instanceof Promise) {    Archive.xxhash = await Archive.xxhash;  }  const encoder = new TextEncoder();  const encode = (str) => encoder.encode(str);  const length = 18 +    Array.from(entries).reduce(      (acc, { name, type, size }) => acc + 11 + encode(name).length + encode(type).length + size,      0,    );  const buffer = new Uint8Array(length);  const dv = new DataView(new ArrayBuffer(8));  const h32 = Archive.xxhash.create32();  dv.setUint32(0, length);  buffer.set(encode("ESMARCHIVE"));  buffer.set(new Uint8Array(dv.buffer), 10);  let offset = 18;  for (const entry of entries) {    const name = encode(entry.name);    const type = encode(entry.type);    const content = new Uint8Array(await entry.arrayBuffer());    if (name.length > 0xffff || type.length > 0xff) {      throw new Error("entry name or type too long");    }    dv.setUint16(0, name.length);    buffer.set(new Uint8Array(dv.buffer.slice(0, 2)), offset);    offset += 2;    buffer.set(name, offset);    offset += name.length;    buffer.set(new Uint8Array([type.length]), offset);    offset += 1;    buffer.set(type, offset);    offset += type.length;    dv.setUint32(0, Math.round((entry.lastModified ?? 0) / 1000)); // convert to seconds    dv.setUint32(4, content.length);    buffer.set(new Uint8Array(dv.buffer), offset);    offset += 8;    buffer.set(content, offset);    offset += content.length;    h32.update(name);    h32.update(type);    h32.update(new Uint8Array(dv.buffer));    h32.update(content);  }  dv.setUint32(0, h32.digest());  buffer.set(new Uint8Array(dv.buffer.slice(0, 4)), 14);  return buffer;}
export class Archive {  #buffer;  #checksum;  #entries = {};
  static invalidFormat = new Error("Invalid esm archive format");
  constructor(buffer) {    this.#buffer = buffer.buffer ?? buffer;    this.#parse();  }
  #parse() {    const dv = new DataView(this.#buffer);    const decoder = new TextDecoder();    const readUint32 = (offset) => dv.getUint32(offset);    const readString = (offset, length) => decoder.decode(new Uint8Array(this.#buffer, offset, length));    if (this.#buffer.byteLength < 18 || readString(0, 10) !== "ESMARCHIVE") {      throw Archive.invalidFormat;    }    const length = readUint32(10);    if (length !== this.#buffer.byteLength) {      throw Archive.invalidFormat;    }    this.#checksum = readUint32(14);    let offset = 18;    while (offset < dv.byteLength) {      const nameLen = dv.getUint16(offset);      offset += 2;      const name = readString(offset, nameLen);      offset += nameLen;      const typeLen = dv.getUint8(offset);      offset += 1;      const type = readString(offset, typeLen);      offset += typeLen;      const lastModified = readUint32(offset) * 1000; // convert to ms      offset += 4;      const size = readUint32(offset);      offset += 4;      this.#entries[name] = { name, type, lastModified, offset, size };      offset += size;    }  }
  get checksum() {    return this.#checksum;  }
  get entries() {    return Object.values(this.#entries).map(({ offset, ...rest }) => rest);  }
  exists(name) {    return name in this.#entries;  }
  openFile(name) {    const info = this.#entries[name];    return info ? new File([this.#buffer.slice(info.offset, info.offset + info.size)], info.name, info) : null;  }}