import type { ElectricMonthGroup } from '../types';

export function summarizeElectricMonths(months: ElectricMonthGroup[] | null) {
  const source = months ?? [];
  const totalKwh = source.reduce((sum, month) => sum + (month.kwh || 0), 0);
  const totalFee = source.reduce((sum, month) => sum + (month.fee || 0), 0);
  const activeDays = source.reduce(
    (sum, month) => sum + month.rows.filter(row => row.kwh > 0).length,
    0,
  );
  const abnormalDays = source.reduce(
    (sum, month) => sum + month.rows.filter(row => Math.abs(row.chainPct) >= 0.3).length,
    0,
  );

  return {
    totalKwh,
    totalFee,
    activeDays,
    abnormalDays,
    avgKwh: activeDays > 0 ? totalKwh / activeDays : 0,
    avgPrice: totalKwh > 0 ? totalFee / totalKwh : 0,
    hasFeeDetail: totalFee > 0,
  };
}