/**
 * Converte Float32Array (áudio capturado do microfone) para PCM 16-bit Little Endian ArrayBuffer.
 */
export function float32ToInt16LE(pcm: Float32Array): ArrayBuffer {
  const view = new DataView(new ArrayBuffer(pcm.length * 2));
  for (let i = 0; i < pcm.length; i += 1) {
    let s = pcm[i] ?? 0;
    if (Number.isNaN(s)) s = 0;
    else if (s > 1) s = 1;
    else if (s < -1) s = -1;
    view.setInt16(i * 2, s < 0 ? Math.round(s * 32768) : Math.round(s * 32767), true);
  }
  return view.buffer;
}

/**
 * Converte PCM 16-bit Little Endian ArrayBuffer recebido do DataChannel para Float32Array (playback).
 */
export function int16LEToFloat32(buf: ArrayBuffer): Float32Array {
  const view = new DataView(buf);
  const n = Math.floor(buf.byteLength / 2);
  const out = new Float32Array(n);
  for (let i = 0; i < n; i += 1) {
    out[i] = view.getInt16(i * 2, true) / 32768;
  }
  return out;
}