region desktop khmer date

// return 0-29
function get_bodithey($year) {
  $ahk = get_aharkun($year);
  $avml = floor((11 * $ahk + 25)  / 692);
  $m = $avml + $ahk + 29;
  return ($m % 30);
}

// return 0-291
function get_avoman($year) {
  $ahk = get_aharkun($year);
  $avm = (11 * $ahk + 25)  % 692;
  return $avm;
}

// return int
function get_aharkun($ad_year) {
  $beyear = get_be_year($ad_year);
  $t = $beyear * 292207 + 499;
  $ahk = floor($t / 800) + 4;
  return $ahk;
}

// return 1-800
function kromthupul($be_year) {
   $akh = get_akhakun_mod($be_year);
   $krom = 800 - $akh;
   return $krom;
}

function is_khmer_solar_leap($year) {
   $be_year = get_be_year($year); 
   $krom = kromthupul($be_year);
   if ($krom <= 207) return 1;
   else return 0;
}
 
function get_akhakun_mod($be_year) {
   $t = $be_year * 292207 + 499;
   $ahkmod = $t % 800;
   return $ahkmod;
}

// return 0:regular, 1:leap month, 2:leap day, 3:leap day and month
function get_bodithey_leap($ad_year) {
  $result = 0;
  $a = get_avoman($ad_year);
  $b = get_bodithey($ad_year);

  // check bodithey leap month
  $bodithey_leap = 0;
  if ($b >= 25 || $b <= 5) {
    $bodithey_leap = 1;
  }
  // check for avoman leap-day based on gregorian leap
  $avoman_leap = 0;
  if (is_khmer_solar_leap($ad_year)) {
    if ($a <= 126) $avoman_leap = 1;
  } else {
    if ($a <=137) {
      // check for avoman case 137/0, 137 must be normal year (p.26)
      if (get_avoman($ad_year + 1) == 0) {
        $avoman_leap = 0;
      } else $avoman_leap = 1;
    }
  }

  // case of 25/5 consecutively
  // only bodithey 5 can be leap-month, so set bodithey 25 to none
  if ($b == 25) {
    $next_b = get_bodithey($ad_year + 1);
    if ($next_b == 5) $bodithey_leap = 0;
  }

  // case of 24/6 consecutively, 24 must be leap-month
  if ($b == 24) {
    $next_b = get_bodithey($ad_year + 1);
    if ($next_b == 6) $bodithey_leap = 1;
  }
  
  // format leap result (0:regular, 1:month, 2:day, 3:both)
  if ($bodithey_leap == 1 && $avoman_leap == 1) {
    $result = 3;
  } else if ($bodithey_leap == 1) {
    $result = 1;
  } else if ($avoman_leap == 1) {
    $result = 2;
  } else $result = 0;

  return $result;
}

// return 0:regular, 1:leap month, 2:leap day (no leap month and day together)
function get_protetin_leap($adyear) {
  $b = get_bodithey_leap($adyear);
  if ($b == 3) { 
    return 1;
  }
  if ($b == 2 || $b == 1) { 
    return $b;
  }
  // case of previous year is 3
  if (get_bodithey_leap($adyear - 1) == 3) { 
    return 2;
  }
  // normal case
  return 0;
}