import { EventEmitter } from 'node:events';
import { acquireQvac, releaseQvac, loadAuxiliaryModel, unloadAuxiliaryModel, qvacSdk, withQvacMaster, assertSdkVersion } from './qvac-master.js';

export function pcmS16le(samples, sampleRate = 44_100) {
  if (Array.isArray(samples)) return { samples: Int16Array.from(samples), sampleRate };
  if (samples instanceof Int16Array) return { samples, sampleRate };
  const bytes = toUint8(samples);
  const even = bytes.byteLength - (bytes.byteLength % 2);
  const copy = bytes.buffer.slice(bytes.byteOffset, bytes.byteOffset + even);
  return { samples: new Int16Array(copy), sampleRate };
}

function toUint8(samples) {
  if (!samples) return new Uint8Array(0);
  if (samples instanceof ArrayBuffer) return new Uint8Array(samples);
  if (ArrayBuffer.isView(samples)) return new Uint8Array(samples.buffer, samples.byteOffset, samples.byteLength);
  if (typeof samples === 'string') return Uint8Array.from(Buffer.from(samples));
  if (Array.isArray(samples) || samples.length != null) return Uint8Array.from(Buffer.from(samples));
  return new Uint8Array(0);
}

export class QvacVoiceAdapter extends EventEmitter {
  constructor({ role = 'both', asrModel = process.env.JARVIS_ASR_MODEL || 'WHISPER_TINY', ttsModel = process.env.JARVIS_TTS_MODEL || 'TTS_EN_SUPERTONIC_Q8_0' } = {}) {
    super(); this.role = role; this.asrModel = asrModel; this.ttsModel = ttsModel; this.asrId = null; this.ttsId = null; this.asrSession = null; this.acquired = false;
  }

  async start() {
    if (this.acquired) return;
    assertSdkVersion();
    await acquireQvac({ auxiliaryOnly: true }); this.acquired = true;
    try {
      if (this.role !== 'tts') this.asrId = await loadAuxiliaryModel(this.asrModel, { vadModelSrc: 'VAD_SILERO_5_1_2', audio_format: 's16le', language: 'en', no_timestamps: true, vad_params: { threshold: 0.6, min_speech_duration_ms: 300, min_silence_duration_ms: 700, max_speech_duration_s: 15, speech_pad_ms: 200 } }, 'whispercpp-transcription');
      if (this.role !== 'asr') this.ttsId = await loadAuxiliaryModel(this.ttsModel, { ttsEngine: 'supertonic', language: 'en', voice: 'F1', ttsSpeed: 1.05, ttsNumInferenceSteps: 5 }, 'tts-ggml');
    } catch (error) { await this.stop(); throw error; }
  }

  writeAudio(chunk) { this.asrSession?.write(Buffer.from(chunk)); }
  async transcribeAudio(audio) {
    if (!this.asrId) throw new Error('Speech recognition is unavailable');
    const sdk = await qvacSdk();
    // Local VAD has already bounded this utterance. Avoid a second streaming
    // VAD gate, which can discard a complete short push-to-talk recording.
    return withQvacMaster(() => sdk.transcribe({ modelId: this.asrId, audioChunk: Buffer.from(audio) }));
  }
  async *transcripts() { if (!this.asrSession) throw new Error('voice adapter is not started'); yield* this.asrSession; }
  endAudio() { this.asrSession?.end(); }

  async speak(text) {
    if (!this.ttsId) throw new Error('Speech output is unavailable');
    const sdk = await qvacSdk();
    const samples = await withQvacMaster(async () => {
      const result = await sdk.textToSpeech({ modelId: this.ttsId, text: String(text).replace(/[`]/g, "'"), inputType: 'text', stream: false });
      if (result?.buffer != null) return await result.buffer;
      if (result?.bufferStream) {
        const chunks = [];
        for await (const chunk of result.bufferStream) chunks.push(Buffer.from(chunk));
        return Buffer.concat(chunks);
      }
      return result;
    });
    return pcmS16le(samples, 44_100);
  }

  async stop() {
    try { this.asrSession?.destroy?.(); } catch {}
    this.asrSession = null;
    if (this.ttsId) await unloadAuxiliaryModel(this.ttsId).catch(() => {});
    if (this.asrId) await unloadAuxiliaryModel(this.asrId).catch(() => {});
    this.ttsId = this.asrId = null;
    if (this.acquired) { this.acquired = false; releaseQvac(); }
  }
}