// Ratio and dimension formatting helpers.
// Keep compatibility with a few legacy mojibake tokens, but never emit them.
// normalizeRatioForPlatform / formatUploadedImageRatio 因依赖平台规格表与 CloneImageItem，
// 暂留在 EcommercePage.tsx，后续随 platformSpec 一起整理。

const LEGACY_MULTIPLY_SIGN = "\u8133";
const LEGACY_FULLWIDTH_COLON = "\u951b?";
const LEGACY_PRODUCT_IMAGE_LABEL = "\u935f\u55d7\u6427\u9365?";

export const normalizeRatioToken = (value: string) =>
  value
    .replaceAll("\u00a0", " ")
    .replaceAll(LEGACY_MULTIPLY_SIGN, "×")
    .replaceAll("*", "×")
    .replaceAll("：", ":")
    .replaceAll(LEGACY_FULLWIDTH_COLON, ":")
    .replace(/\s+/g, " ")
    .trim();

export const quickSetRatioOptions = ["1:1", "3:4", "4:3", "9:16", "16:9"];

export const greatestCommonDivisor = (left: number, right: number): number => {
  let a = Math.abs(left);
  let b = Math.abs(right);
  while (b) {
    [a, b] = [b, a % b];
  }
  return a || 1;
};

export const formatAspectRatio = (width: number, height: number) => {
  const divisor = greatestCommonDivisor(width, height);
  return `${Math.round(width / divisor)}:${Math.round(height / divisor)}`;
};

export const getQuickSetRatioValue = (value: string) => {
  const normalizedValue = normalizeRatioToken(value);
  if (quickSetRatioOptions.includes(normalizedValue)) return normalizedValue;
  const sizeMatch = normalizedValue.match(/(\d+)\s*[×xX]\s*(\d+)/u);
  if (sizeMatch) {
    const width = Number(sizeMatch[1]);
    const height = Number(sizeMatch[2]);
    if (Number.isFinite(width) && Number.isFinite(height) && width > 0 && height > 0) {
      const aspect = formatAspectRatio(width, height);
      if (quickSetRatioOptions.includes(aspect)) return aspect;
    }
  }
  const ratioMatch = normalizedValue.match(/(\d+)\s*[:：]\s*(\d+)/u);
  if (ratioMatch) {
    const aspect = `${Number(ratioMatch[1])}:${Number(ratioMatch[2])}`;
    if (quickSetRatioOptions.includes(aspect)) return aspect;
  }
  return quickSetRatioOptions[0]!;
};

export const formatRatioDisplayValue = (value: string) => {
  const normalizedValue = normalizeRatioToken(value);
  const sizeMatch = normalizedValue.match(/(\d+)\s*[×xX]\s*(\d+)\s*px?/u);
  if (sizeMatch) {
    const width = Number(sizeMatch[1]);
    const height = Number(sizeMatch[2]);
    return `${width}×${height}px\u00a0\u00a0\u00a0${formatAspectRatio(width, height)}`;
  }
  return normalizedValue
    .replace("淘宝主图 / SKU 图 ", "淘宝主图 / SKU 图 ")
    .replace("京东主图 / SKU 图 ", "京东主图 / SKU 图 ")
    .replace("详情页宽", "详情页宽")
    .replace("短视频", "短视频")
    .replace("主图", "主图")
    .replace("商品主图", "商品主图")
    .replace(LEGACY_PRODUCT_IMAGE_LABEL, "商品图")
    .replace(/\s+:/g, ":")
    .replace(/:\s+/g, ":");
};

export const getRatioDisplayParts = (value: string) => {
  const display = formatRatioDisplayValue(value).replace(/\u00a0/g, " ").replace(/\s+/g, " ").trim();
  const aspectMatch = display.match(/(\d+\s*[:：]\s*\d+)(?!.*\d+\s*[:：]\s*\d+)/u);
  const aspect = aspectMatch?.[1]?.replace(/\s+/g, "") ?? "自适应";
  const size = aspectMatch ? display.replace(aspectMatch[0], "").trim() : display;
  return {
    size: size || "原图比例",
    aspect,
  };
};

/** Extract CSS aspect-ratio from a ratio string like "1000x1000px   1:1" -> "1 / 1" */
export const parseRatioToAspectCss = (ratioStr: string): string => {
  const match = ratioStr.match(/(\d+)\D+(\d+)/u);
  if (!match) return "1 / 1";
  return `${match[1]} / ${match[2]}`;
};

export const supportedImageApiRatios = ["1:1", "3:4", "4:3", "9:16", "16:9"] as const;
export type SupportedImageApiRatio = typeof supportedImageApiRatios[number];

export const toSupportedImageApiRatio = (width: number, height: number): SupportedImageApiRatio => {
  if (!Number.isFinite(width) || !Number.isFinite(height) || width <= 0 || height <= 0) return "1:1";
  let bestRatio: SupportedImageApiRatio = "1:1";
  let bestScore = Number.POSITIVE_INFINITY;
  const target = Math.log(width / height);
  for (const ratio of supportedImageApiRatios) {
    const [left, right] = ratio.split(":").map(Number);
    const score = Math.abs(target - Math.log(left / right));
    if (score < bestScore) {
      bestRatio = ratio;
      bestScore = score;
    }
  }
  return bestRatio;
};

/** Normalize ratio display string ("1000×1000px   1:1") to an image API aspect ratio ("1:1"). */
export const normalizeRatioForApi = (ratioStr: string): string => {
  const normalizedValue = normalizeRatioToken(ratioStr);
  const explicitRatios = Array.from(normalizedValue.matchAll(/(\d+(?:\.\d+)?)\s*:\s*(\d+(?:\.\d+)?)/g));
  const explicitRatio = explicitRatios.at(-1);
  if (explicitRatio) {
    return toSupportedImageApiRatio(Number(explicitRatio[1]), Number(explicitRatio[2]));
  }

  const sizeMatch = normalizedValue.match(/(\d+(?:\.\d+)?)\s*[×xX*]\s*(\d+(?:\.\d+)?)/u);
  if (!sizeMatch) return "1:1";
  return toSupportedImageApiRatio(Number(sizeMatch[1]), Number(sizeMatch[2]));
};