/**
 * Emotion → physical-cue rewriting. Models render emotion better from physical
 * cues ("eyes wide, jaw slack") than from named emotions ("scared"). ADVISORY +
 * ADDITIVE: only moderate emotions are mapped; EXTREMES (panic, terror, rage,
 * ecstatic, ...) are deliberately left named so the model pushes the
 * performance. Unmapped names pass through unchanged.
 */
export const EMOTION_PHYSICAL_CUE_MAP: Readonly<Record<string, string>> = {
  calm: 'shoulders relaxed, breathing even, jaw unclenched, gaze steady',
  scared: 'eyes wide, jaw slack, breath shallow and quick, shoulders drawn up',
  afraid: 'eyes wide, jaw slack, breath shallow and quick, shoulders drawn up',
  angry: 'jaw clenched, eyes narrowed, nostrils flared, shoulders squared',
  sad: 'eyes downcast and glassy, mouth corners pulled down, shoulders sunk',
  surprised: 'eyebrows raised high, eyes round, mouth parted, head drawn back',
  tense: 'jaw set, breath held, fingers curled tight, muscles rigid',
  nervous: 'eyes flicking, throat swallowing, fingers fidgeting, weight shifting',
  confused: 'brows knitted, head tilted, eyes searching, mouth slightly open',
  joyful: 'eyes crinkled at the corners, cheeks lifted, easy open smile',
  happy: 'eyes crinkled at the corners, cheeks lifted, easy open smile',
  determined: 'jaw set, eyes locked forward, brow level, chin slightly lowered',
  shaken: 'breath unsteady, hands trembling, gaze unfocused, shoulders caved',
  wary: 'eyes narrowed and tracking, chin tucked, weight back on the heels',
  relieved: 'shoulders dropping, a long slow exhale, brow smoothing',
  defiant: 'chin raised, eyes hard, mouth a flat line, stance widened',
};

/**
 * Map a named emotion to its physical-cue descriptor. Advisory: an unmapped or
 * deliberately-excluded (extreme) emotion is returned unchanged, never dropped
 * and never throws. `undefined` in → `undefined` out.
 */
export function rewriteEmotionAsPhysical(emotion: string | undefined): string | undefined {
  if (emotion === undefined) return undefined;
  const key = emotion.trim().toLowerCase();
  return EMOTION_PHYSICAL_CUE_MAP[key] ?? emotion;
}