<?php
/******************************
 Project: InfoCA, 2021
 Version: PHP 5-7
 Author : M. Kukic, TIM-CA
 Note   :
******************************/

$y=2021;
$m=3;
$d=3;
$mesec=GetMoon ($y, $m, $d);

//echo $mesec;

switch ($mesec) {
  case "0":
    echo "Tamani - mladi Mesec";
    break;
  case "1":
    echo "Mladi Mesec, obasjan desno 1�49%, vidljiv popodne i posle sumraka";
    break;
  case "2":
    echo "Mesec prve �etvrtine, obasjan desno 50%, vidljiv popodne i rano uve�e";
    break;
  case "3":
    echo "Rastu�i Mesec, obasjan desno 51�99%, vidljivo kasno popodne i vec�i deo noc�i";
    break;
  case "4":
    echo "Pun Mesec, potpuno obasjan, vidljiv od zalaska Sunca do izlaska Sunca - celu no�";
    break;
  case "5":
    echo "Opadaju�i Mesec, obasjan levo 99-51%, vidljiv vec�i deo noc�i i rano jutro";
    break;
  case "6":
    echo "Mesec trec�e �etvrtine, obasjan levo 50%, vidljiv kasno uve�e i ujutro";
    break;	
  case "7":
    echo "Mesec u opadanju, obasjan deno 49-1%, vidljiv pred zoru i jutro";
    break;	
	
  default:
    echo "Prora�un nije uspeo!";
}

/*
Returning values:

0 -> New moon
1 -> Waxing crescent moon Right 1�49% visible Left 1�49% visible afternoon and post-dusk 3 pm
2 -> First quarter moon Right 50% visible Left 50% visible afternoon and early night 6 pm
3 -> Waxing gibbous moon Right 51�99% visible Left 51�99% visible late afternoon and most of night 9 pm
4 -> Full moon Fully visible Fully visible sunset to sunrise (all night) 12 midnight
5 -> Waning gibbous moon Left 51�99% visible Right 51�99% visible most of night and early morning 3 am
6 -> Third quarter moon Left 50% visible Right 50% visible late night and morning 6 am
7 -> Waning crescent moon Left 1�49% visible Right 1�49% visible pre-dawn and morning 9 am
0 -> Dark moon

0 -> Mladi mesec
1 -> Debeli mesec, polumesec Desno 1�49% vidljivo Levo 1�49% vidljivo popodne i posle sumraka 15:00
2 -> Mesec prve �etvrtine Desno 50% vidljivo Levo 50% vidljivo popodne i rano uve�e 18 sati
3 -> Vo�tani gibavi mesec Desno 51�99% vidljivo Levo 51�99% vidljivo kasno popodne i vec�i deo noc�i 21 sat
4 -> Pun mesec Potpuno vidljiv Potpuno vidljiv zalazak sunca do izlaska sunca (celu noc�) 12 ponoc�i
5 -> Silazni gibavi mesec Levo 51�99% vidljivo Desno 51�99% vidljivo vec�i deo noc�i i rano jutro 3:00
6 -> Mesec trec�e �etvrtine Levo 50% vidljivo Desno 50% vidljivo kasno uve�e i ujutro 6:00
7 -> Mesec u opadanju Levo 1�49% vidljivo Desno 1�49% vidljivo pred zoru i jutro 9:00
0 -> Tamni mesec

*/

function GetMoon ($y, $m, $d)
{
    $c = 0;
    $e = 0;
    $jd = 0.0;
    $b = 0;

    if ($m < 3) {
        $y = $y -1;
        $m = $m + 12;
    }
    $m = $m + 1;
    $c = 365.25 * $y;
    $e = 30.6 * $m;
    $jd = $c + $e + $d-694039.09;  	/* jd is total days elapsed */
    $jd /= 29.53; 					/* divide by the moon cycle (29.53 days) */
    $b = floor(jd); 				/* int(jd) -> b, take integer part of jd */
    $jd = $jd - $b;					/* subtract integer part to leave fractional part of original jd */
    $b = round($jd * 8); 			/* scale fraction from 0-8 and round by adding 0.5 */
    $b = $b & 7; 					/* 0 and 8 are the same so turn 8 into 0 */
    return $b;
}
?>