/** Explicit performance canon; absent traits never produce invented behaviour. */
export interface CharacterPerformance {
  voice?: string;
  movement?: string;
  stillness?: string;
}
export interface FilmmakingCharacterContext extends CharacterPerformance {
  slot?: string;
  description: string;
}
export function performanceTraits(value: unknown): CharacterPerformance {
  if (!value || typeof value !== 'object') return {};
  const record = value as Record<string, unknown>;
  return Object.fromEntries(['voice', 'movement', 'stillness'].flatMap(key =>
    typeof record[key] === 'string' && record[key].trim() ? [[key, record[key].trim()]] : []));
}
export function performanceDirection(name: string, traits: CharacterPerformance): string {
  const parts = [
    traits.movement ? `Movement: ${traits.movement}` : '',
    traits.stillness ? `Stillness: ${traits.stillness}` : '',
    traits.voice ? `Voice (only when speaking is authorised by the audio contract): ${traits.voice}` : '',
  ].filter(Boolean);
  return parts.length ? `${name}: ${parts.join(' ')}` : '';
}
export function mergePerformanceCanon(...sources: unknown[]): Map<string, CharacterPerformance> {
  const result = new Map<string, CharacterPerformance>();
  for (const source of sources) {
    if (!Array.isArray(source)) continue;
    for (const entry of source) {
      if (!entry || typeof entry.name !== 'string') continue;
      const key = entry.name.trim().toLowerCase();
      result.set(key, { ...result.get(key), ...performanceTraits(entry) });
    }
  }
  return result;
}

/** Contextual behaviour replaces habitual movement without changing vocal identity. */
export function adaptPerformanceContext(
  canon: Map<string, FilmmakingCharacterContext>,
  actors: Array<{ character: string; behaviour: string }> = [],
): Map<string, FilmmakingCharacterContext> {
  const result = new Map(canon);
  for (const actor of actors) {
    const prior = result.get(actor.character);
    if (prior) result.set(actor.character, { ...prior, movement: actor.behaviour, stillness: undefined });
  }
  return result;
}