/* Shared, deterministic matching logic. No account identifiers are retained. */
(() => {
  const norm = value => String(value ?? '').normalize('NFKD').replace(/[\u0300-\u036f]/g, '').toLowerCase().replace(/[^a-z0-9]+/g, ' ').trim();
  const clean = value => typeof value === 'string' ? value.slice(0, 160).trim() : '';
  function extract(payload, bank = 'capital-one') {
    const result = []; let visited = 0;
    function walk(value, depth) {
      if (!value || typeof value !== 'object' || depth > 16 || ++visited > 50000) return;
      const merchant = bank === 'rogers' ? value.merchant : value.transactionMerchant;
      const amount = bank === 'rogers' && /^-?\d+(?:\.\d+)?$/.test(String(value.amount?.value)) ? Number(value.amount.value) : value.transactionAmount;
      if (merchant && /^\d{4}$/.test(String(merchant.categoryCode)) && Number.isFinite(amount)) {
        if (bank === 'rogers') {
          const name = clean(merchant.name);
          if (name) result.push({bank, name, amount,
            last4: /\d{4}$/.exec(clean(value.cardNumber))?.[0] || '',
            holder: clean(value.name?.nameOnCard),
            date: clean(value.date).slice(0, 10), postedDate: clean(value.postedDate).slice(0, 10),
            state: clean(value.activityStatus), mcc: String(merchant.categoryCode),
            type: clean(merchant.category), category: clean(merchant.categoryDescription)});
        } else {
        const name = clean(value.transactionDescription || merchant.name);
        if (name) result.push({
          bank, name, amount: Math.abs(amount),
          last4: /^\d{4}$/.test(value.transactingCardLastFour) ? value.transactingCardLastFour : '',
          date: clean(value.transactionDisplayDate || value.transactionDate).slice(0, 10),
          state: clean(value.transactionState), mcc: String(merchant.categoryCode),
          type: clean(merchant.merchantType || merchant.parentCategory || value.displayCategory),
          category: clean(merchant.category)
        });
        }
      }
      for (const child of Object.values(value)) walk(child, depth + 1);
    }
    walk(payload, 0); return result.slice(0, 5000);
  }
  function valid(record) {
    return record && typeof record.name === 'string' && record.name.length > 0 && record.name.length <= 160 &&
      typeof record.amount === 'number' && Number.isFinite(record.amount) &&
      (!record.bank || ['capital-one','rogers'].includes(record.bank)) &&
      ['holder','postedDate'].every(k => record[k] === undefined || (typeof record[k] === 'string' && record[k].length <= 160)) &&
      /^\d{4}$/.test(record.mcc) && ['last4','date','state','type','category'].every(k => typeof record[k] === 'string' && record[k].length <= 160);
  }
  function candidates(text, records, context = {}) {
    const normalized = ` ${norm(text)} `;
    const amounts = [...String(text).matchAll(/(?:-\s*)?\$?\s*(?:-\s*)?(?:\d{1,3}(?:,\d{3})+|\d+)\.\d{2}(?!\d)/g)]
      .filter(m => !/\d/.test(String(text)[m.index - 1] || ''))
      .map(m => Number(m[0].replace(/[$,\s]/g, '')));
    const months = ['jan','feb','mar','apr','may','jun','jul','aug','sep','oct','nov','dec'];
    function dateMatches(r) {
      return [r.date, r.postedDate].some(date => {
        if (!/^\d{4}-\d{2}-\d{2}$/.test(date || '')) return false;
        const [year,month,day] = date.split('-').map(Number);
        return normalized.includes(` ${year} ${String(month).padStart(2,'0')} ${String(day).padStart(2,'0')} `) ||
          new RegExp(`(?:^| )${months[month-1]}[a-z]* ${day} ${year}(?: |$)`).test(norm(text));
      });
    }
    return records.filter(r => normalized.includes(` ${norm(r.name)} `) && amounts.some(a => Math.abs((r.bank === 'rogers' ? a : Math.abs(a)) - r.amount) < 0.005) &&
      (r.bank === 'rogers' ? dateMatches(r) && (!context.holder || !r.holder || norm(context.holder) === norm(r.holder)) :
        (!r.last4 || new RegExp(`(^|\\D)${r.last4}(?!\\d)`).test(text))));
  }
  function unique(records) {
    if (!records.length) return null;
    const signatures = new Set(records.map(r => JSON.stringify([r.mcc, r.type, r.category])));
    return signatures.size === 1 ? records[0] : null;
  }
  const api = { norm, extract, valid, candidates, unique };
  if (typeof module !== 'undefined' && module.exports) module.exports = api;
  else globalThis.MerchantLensCore = api;
})();