import { parseChineseInteger } from './health-chinese-numerals.mjs';

const BP_PAIR = /(\d{2,3})\s*[/／]\s*(\d{2,3})/;
const BP_ALT = /高压\s*(\d{2,3}).{0,8}低压\s*(\d{2,3})/;
const BP_CN = /(?:血压|收缩压|高压)?\s*([零〇一二两三四五六七八九十百千万壹贰叁肆伍陆柒捌玖]{1,8})\s*(?:[/／比]|和|跟)\s*([零〇一二两三四五六七八九十百千万壹贰叁肆伍陆柒捌玖]{1,6})/;
const BP_CN_ALT = /高压\s*([零〇一二两三四五六七八九十百千万壹贰叁肆伍陆柒捌玖]{1,8})\s*低压\s*([零〇一二两三四五六七八九十百千万壹贰叁肆伍陆柒捌玖]{1,6})/;

export function extractBloodPressurePair(text) {
  const raw = String(text ?? '').trim();
  if (!raw) return null;

  const direct = raw.match(BP_PAIR);
  if (direct) {
    return { systolic: Number(direct[1]), diastolic: Number(direct[2]), source: 'numeric' };
  }

  const alt = raw.match(BP_ALT);
  if (alt) {
    return { systolic: Number(alt[1]), diastolic: Number(alt[2]), source: 'alt_label' };
  }

  const cn = raw.match(BP_CN);
  if (cn) {
    const systolic = parseChineseInteger(cn[1]);
    const diastolic = parseChineseInteger(cn[2]);
    if (systolic != null && diastolic != null) {
      return { systolic, diastolic, source: 'chinese' };
    }
  }

  const cnAlt = raw.match(BP_CN_ALT);
  if (cnAlt) {
    const systolic = parseChineseInteger(cnAlt[1]);
    const diastolic = parseChineseInteger(cnAlt[2]);
    if (systolic != null && diastolic != null) {
      return { systolic, diastolic, source: 'chinese_alt' };
    }
  }

  if (/血压/.test(raw) && /\d{2,3}/.test(raw)) {
    const nums = [...raw.matchAll(/\d{2,3}/g)].map((m) => Number(m[0]));
    if (nums.length >= 2) {
      return { systolic: nums[0], diastolic: nums[1], source: 'numeric_loose' };
    }
  }

  return null;
}