/**
 * Base64 carriage for real `@colyseus/schema` binary state on the JSON
 * `Envelope` wire.
 *
 * The replication seam encodes host state with the REAL `@colyseus/schema`
 * `Encoder`, which emits a `Uint8Array`. Every P2P transport (browser-hosted
 * WebRTC, universal WebSocket, forced/​fallback Cloudflare relay, in-process
 * loopback) carries an `Envelope` that is `JSON.stringify`'d, so the binary
 * patch/snapshot bytes ride as a base64 STRING field inside that envelope —
 * universal, and unchanged by `JSON.stringify`. There is deliberately no
 * native binary frame kind: a raw binary frame during join is the live signal
 * `client.ts`'s H4 guard uses to detect a real Colyseus server, and a separate
 * binary-frame optimization is out of scope here.
 *
 * `btoa`/`atob` exist in browsers and in Node ≥16 (`globalThis`), so these work
 * in the deployed static bundle and in headless unit tests without a Buffer
 * dependency.
 */

const CHUNK = 0x8000;

export function bytesToBase64(bytes: Uint8Array): string {
  let binary = '';
  for (let i = 0; i < bytes.length; i += CHUNK) {
    binary += String.fromCharCode(...bytes.subarray(i, i + CHUNK));
  }
  return btoa(binary);
}

export function base64ToBytes(base64: string): Uint8Array {
  const binary = atob(base64);
  const bytes = new Uint8Array(binary.length);
  for (let i = 0; i < binary.length; i++) bytes[i] = binary.charCodeAt(i);
  return bytes;
}