import { EventEmitter } from 'node:events';
import { spawn } from 'node:child_process';

/**
 * Wake engines consume PCM frames. A production wake model can be attached
 * through `detect(frame)`, keeping the daemon independent from a Python or
 * native openWakeWord installation. The default detector is intentionally
 * disabled until a local model command is configured; it never pretends that
 * an energy spike is the wake phrase.
 */
export class WakeEngine extends EventEmitter {
  constructor({ phrases = ['hey jarvis', 'jarvis', 'okay jarvis'], detect } = {}) {
    super();
    this.phrases = phrases.map((phrase) => String(phrase).trim().toLowerCase()).filter(Boolean);
    this.detect = detect;
    this.active = true;
  }

  push(frame) {
    if (!this.active || typeof this.detect !== 'function') return false;
    const result = this.detect(frame);
    if (!result) return false;
    const phrase = typeof result === 'string' ? result : result.phrase;
    if (!phrase || !this.phrases.includes(String(phrase).toLowerCase())) return false;
    this.emit('wake', String(phrase));
    return true;
  }

  pause() { this.active = false; }
  resume() { this.active = true; }
  close() { this.pause(); this.removeAllListeners(); }
}

/** Adapter for a local openWakeWord/sherpa bridge. The bridge receives raw
 * PCM on stdin and prints one detected phrase per line on stdout. */
export class ProcessWakeEngine extends WakeEngine {
  constructor({ command, ...options } = {}) { super(options); this.command = command; this.process = null; this._spawn = options.spawnImpl || spawn; }
  start() {
    if (this.process || !this.command) return this;
    this.process = this._spawn(this.command, { shell: true, stdio: ['pipe', 'pipe', 'pipe'] });
    let pending = '';
    this.process.stdout?.on('data', (chunk) => {
      pending += String(chunk);
      const lines = pending.split(/\r?\n/); pending = lines.pop() || '';
      for (const line of lines) this.pushDetection(line.trim());
    });
    this.process.on('error', (error) => this.emit('error', error));
    this.process.stderr?.on('data', () => {});
    this.process.stdin?.on('error', (error) => this.emit('error', error));
    this.process.on('close', () => { this.process = null; this.emit('unavailable'); });
    return this;
  }
  push(frame) { if (this.active && this.process?.stdin?.writable) this.process.stdin.write(Buffer.from(frame)); }
  pushDetection(phrase) {
    const value = String(phrase || '').toLowerCase();
    if (this.active && this.phrases.includes(value)) this.emit('wake', value);
  }
  close() { super.close(); this.process?.kill('SIGTERM'); this.process = null; }
}

export function createWakeEngine(options = {}) {
  return options.command || process.env.JARVIS_WAKE_COMMAND ? new ProcessWakeEngine({ ...options, command: options.command || process.env.JARVIS_WAKE_COMMAND }) : new WakeEngine(options);
}

export function normalizeWakePhrases(value) {
  return String(value || '').split(',').map((v) => v.trim().toLowerCase()).filter(Boolean);
}