import { jalaliMonthName, toJalali } from '../common/jalali';

export const BIRTHDAY_SMS_DEFAULT = '{نام} عزیز، تولدتان مبارک.';

export type BirthdayRow = {
  id: string;
  firstName: string;
  lastName: string;
  mobile: string | null;
  birthDate: Date;
};

export type BirthdayPick = {
  id: string;
  firstName: string;
  lastName: string;
  mobile: string | null;
  day: number;
};

export function fillBirthdaySmsText(template: string, firstName: string, lastName: string) {
  const name = `${firstName} ${lastName}`.trim().replace(/\s+/g, ' ');
  return template.replaceAll('{نام}', name).replaceAll('{name}', name).trim();
}

function tehranJalali(d: Date) {
  const [gy, gm, gd] = new Intl.DateTimeFormat('en-CA', {
    timeZone: 'Asia/Tehran',
    year: 'numeric',
    month: '2-digit',
    day: '2-digit',
  })
    .format(d)
    .split('-')
    .map(Number);
  return toJalali(gy, gm, gd);
}

function birthJalali(d: Date) {
  return toJalali(d.getUTCFullYear(), d.getUTCMonth() + 1, d.getUTCDate());
}

/** متولدین ماه جاری تهران. پیش‌نمایش فقط روزهای امروز و بعد است. */
export function selectMonthBirthdays(people: BirthdayRow[], now = new Date(), previewLimit = 6) {
  const today = tehranJalali(now);
  const matched = people.flatMap((person) => {
    const birth = birthJalali(person.birthDate);
    if (birth.jm !== today.jm) return [];
    return [
      {
        id: person.id,
        firstName: person.firstName,
        lastName: person.lastName,
        mobile: person.mobile,
        day: birth.jd,
      },
    ];
  });
  const byDay = (a: BirthdayPick, b: BirthdayPick) => a.day - b.day || a.firstName.localeCompare(b.firstName, 'fa');
  const upcoming = matched.filter((row) => row.day >= today.jd).sort(byDay);
  const passed = matched.filter((row) => row.day < today.jd).sort(byDay);
  return {
    month: today.jm,
    monthName: jalaliMonthName(today.jm),
    today: today.jd,
    total: matched.length,
    preview: upcoming.slice(0, previewLimit),
    items: [...upcoming, ...passed],
  };
}