Emotional Butterfly Effect

export async function analyzeSentiment(
  text: string
): Promise<SentimentResult> {
  const res = await fetch('/api/sentiment', {
    method: 'POST',
    body: JSON.stringify({ text }),
  });
  // returns { score: -1..1, label, intensity }
  return res.json();
}

// Gọi fire-and-forget sau khi post đã lưu
export async function recordMoodEvent(
  score: number, intensity: number
) {
  const ts = Date.now();
  // ZADD mood:events <timestamp> <score:intensity>
  await redis.zadd('mood:events', {
    score: ts,
    member: `${score}:${intensity}:${ts}`,
  });
  // tự dọn events cũ hơn 120s
  await redis.zremrangebyscore(
    'mood:events', 0, ts - 120_000
  );
}

export async function computeMood(): Promise<MoodState> {
  const now = Date.now();
  const members = await redis.zrangebyscore(
    'mood:events', now - 60_000, now
  );
  if (!members.length) return NEUTRAL;

  let weightedSum = 0, totalWeight = 0;
  for (const m of members) {
    const [score, intensity] = m.split(':').map(Number);
    weightedSum += score * intensity;
    totalWeight += intensity;
  }
  const avg = weightedSum / totalWeight;

  // hysteresis: chỉ đổi state nếu vượt ngưỡng ±0.05
  return applyHysteresis(avg, currentState);
}

class AmbientAudioController {
  private ctx: AudioContext;
  private gains: Record<MoodState, GainNode>;
  private current: MoodState = 'NEUTRAL';

  crossfadeTo(next: MoodState, dur = 3) {
    const now = this.ctx.currentTime;
    // fade out current
    this.gains[this.current].gain
      .linearRampToValueAtTime(0, now + dur);
    // fade in next
    this.gains[next].gain
      .linearRampToValueAtTime(1, now + dur);
    this.current = next;
  }

  // Gọi sau gesture đầu tiên
  async resume() {
    await this.ctx.resume();
  }
}

export function MoodProvider({ children }) {
  const [mood, setMood] = useState<MoodState>('NEUTRAL');

  useEffect(() => {
    const ch = ably.channels.get('global:mood');
    ch.subscribe('update', ({ data }) => {
      setMood(data.state);
      // cập nhật CSS vars
      document.documentElement.style
        .setProperty('--mood-brightness',
          THEME[data.state].brightness);
      // crossfade audio
      audio.crossfadeTo(data.state);
      // haptic nếu Energy Pulse
      if (data.energyPulse)
        navigator.vibrate([80, 40, 80]);
    });
    return () => ch.unsubscribe();
  }, []);

  return <MoodCtx.Provider value={mood}>{children}</MoodCtx.Provider>;
}