class FluidSynthBridge extends AudioWorkletProcessor {
  constructor() {
    super();
    this.leftQ = [];
    this.rightQ = [];
    this.called = 0;
    this.port.onmessage = (e) => {
      const d = e.data;
      if (d.type === 'PCM') {
        this.leftQ.push(d.L);
        this.rightQ.push(d.R);
      }
    };
  }

  process(inputs, outputs) {
    const out = outputs[0];
    if (!out) return true;
    this.called++;
    const len = out[0].length;
    const qL = this.leftQ;
    const qR = this.rightQ;
    let fi = 0;
    let si = 0;
    for (let i = 0; i < len; i++) {
      if (fi >= qL.length) { out[0][i] = 0; out[1][i] = 0; continue; }
      out[0][i] = qL[fi][si];
      out[1][i] = qR[fi][si];
      si++;
      if (si >= qL[fi].length) { fi++; si = 0; }
    }
    if (fi > 0) {
      this.leftQ.splice(0, fi);
      this.rightQ.splice(0, fi);
      this.port.postMessage({ type: 'CONSUMED', n: fi });
    }
    return true;
  }
}

registerProcessor('fluidsynth-bridge', FluidSynthBridge);