// HEAD/Range probes are advisory. Dropping an image changes numbered roles in
// a multi-image edit and must never turn a two-image replacement into one image.
export function selectCanvasReferenceImages(params: {
  requested: string[];
  reachable: string[];
  requiredCount?: number;
}) {
  if (params.requiredCount) {
    if (params.requested.length !== params.requiredCount) {
      throw new Error(`此编辑任务必须提供 ${params.requiredCount} 张不同的完整参考图`);
    }
    return [...params.requested];
  }
  return params.reachable.length ? params.reachable : params.requested;
}