const HIJRI_MONTHS = [
  "Muharrem",
  "Safer",
  "Rebiülevvel",
  "Rebiülahir",
  "Cemaziyelevvel",
  "Cemaziyelahir",
  "Receb",
  "Şaban",
  "Ramazan",
  "Şevval",
  "Zilkade",
  "Zilhicce",
];

const DAYS = [
  "Pazar",
  "Pazartesi",
  "Salı",
  "Çarşamba",
  "Perşembe",
  "Cuma",
  "Cumartesi",
];

export function gregorianToHijri(date = new Date()) {
  // Türkiye coğrafi hizalaması ve Hilal takvimi için +2 gün adjustment
  const adjustment = 2;
  const adjustedDate = new Date(
    date.getTime() + adjustment * 24 * 60 * 60 * 1000,
  );

  const year = adjustedDate.getFullYear();
  const month = adjustedDate.getMonth() + 1;
  const day = adjustedDate.getDate();

  let a = Math.floor((14 - month) / 12);
  let y = year + 4800 - a;
  let m = month + 12 * a - 3;
  let jdn =
    day +
    Math.floor((153 * m + 2) / 5) +
    365 * y +
    Math.floor(y / 4) -
    Math.floor(y / 100) +
    Math.floor(y / 400) -
    32045;

  let l = jdn - 1948440 + 10632;
  let n = Math.floor((l - 1) / 10631);
  l = l - 10631 * n + 354;
  let j =
    Math.floor((10985 - l) / 5316) * Math.floor((50 * l) / 17719) +
    Math.floor(l / 5670) * Math.floor((43 * l) / 15238);
  l =
    l -
    Math.floor((30 - j) / 15) * Math.floor((17719 * j) / 50) -
    Math.floor(j / 16) * Math.floor((15238 * j) / 43) +
    29;

  let hijriMonth = Math.floor((24 * l) / 709);
  let hijriDay = l - Math.floor((709 * hijriMonth) / 24);
  let hijriYear = 30 * n + j - 30;

  if (hijriMonth > 12) {
    hijriMonth -= 12;
    hijriYear += 1;
  }

  const weekday = DAYS[date.getDay()];

  return {
    year: hijriYear,
    month: hijriMonth,
    day: hijriDay,
    monthName: HIJRI_MONTHS[hijriMonth - 1],
    weekday,
  };
}

export function calculateMissedPrayers(birthDate, gender, mukallafAge = 15) {
  const birth = new Date(birthDate);
  const today = new Date();
  today.setHours(0, 0, 0, 0);

  const mukallafDate = new Date(birth);
  mukallafDate.setFullYear(mukallafDate.getFullYear() + mukallafAge);

  if (today <= mukallafDate) {
    return { fajr: 0, dhuhr: 0, asr: 0, maghrib: 0, isha: 0, vitr: 0, days: 0 };
  }

  const diffTime = today - mukallafDate;
  const days = Math.floor(diffTime / (1000 * 60 * 60 * 24));

  return {
    fajr: days,
    dhuhr: days,
    asr: days,
    maghrib: days,
    isha: days,
    vitr: days,
    days,
  };
}

export function getHijriBirthDate(birthDate) {
  return gregorianToHijri(new Date(birthDate));
}