export const LAYOUT_REPLACE_SUPPORT_PROMPT = [
  "只观察这张图中主体商品本身的下缘与支撑方式，不比较其他图片，不根据商品类别或广告文案猜测。",
  "supportType只能选：flush=下缘连续且没有可见独立支脚，包含贴地底座；legs=实际可见独立柜腿、支撑脚或脚轮；suspended=明确悬挂；not_applicable=该类别不适用支撑结构检查（如服装、食品）；unclear=主体下缘被完全遮住或图片无法辨认。",
  "这是可见结构识别，不是力学分析：不要因无法证明柜底每处都与地面接触、看不到背面或不确定隐藏的支撑而填写unclear。清楚可见连续下缘而没有独立腿脚就填flush；实际可见腿脚就填legs。",
  "贴地底座的接触阴影不是腿。只有实际看到独立支撑才选legs，不要凭空想象隐藏的脚。关注实际商品，忽略海报图标、数字及其他独立摆件。",
  '只返回JSON，supportType填写上述英文枚举之一：{"supportType":"从枚举中选择","confidence":0.95}。',
].join("\n");

export type LayoutReplaceSupport = "flush" | "legs" | "suspended" | "not_applicable" | "unclear";

export function parseLayoutReplaceSupport(text: string) {
  let value: { supportType?: unknown; confidence?: unknown };
  try { value = JSON.parse(text.trim().replace(/^```(?:json)?\s*/i, "").replace(/\s*```$/, "")); }
  catch { throw new Error("商品支撑结构检查未返回有效结论"); }
  if (!value || !["flush", "legs", "suspended", "not_applicable", "unclear"].includes(String(value.supportType)) ||
    typeof value.confidence !== "number" || value.confidence < 0 || value.confidence > 1) throw new Error("商品支撑结构检查不完整");
  return { supportType: value.supportType as LayoutReplaceSupport, confidence: value.confidence };
}

export function compareLayoutReplaceSupport(source: ReturnType<typeof parseLayoutReplaceSupport>, result: ReturnType<typeof parseLayoutReplaceSupport>) {
  if (source.supportType === "not_applicable") return { passed: true, reason: "" };
  if (source.supportType === "unclear" || result.supportType === "unclear" || source.confidence < .8 || result.confidence < .8) {
    return { passed: false, reason: "无法可靠确认商品下缘的支撑结构" };
  }
  const names = { flush: "贴地底座", legs: "独立腿脚或脚轮", suspended: "悬挂", not_applicable: "类别不适用", unclear: "不清晰" };
  return source.supportType === result.supportType ? { passed: true, reason: "" }
    : { passed: false, reason: `原商品为${names[source.supportType]}，结果却为${names[result.supportType]}，支撑结构已改变` };
}