#!/usr/bin/env perl
use utf8;
###############################################################################
# This program computes the Ordinal Day of a date.
# 
# Copyright © 2020 Richard Lesh.  All rights reserved.
###############################################################################

use POSIX qw(floor);
use Utils;
use strict;
use warnings;

###############################################################################
# Returns true if a year is a leap year.
###############################################################################
sub is_leap_year {
    my ($Y) = @_;
    return $Y % 4 == 0 && $Y % 100 != 0 || $Y % 400 == 0;
}

###############################################################################
# This function computes the Oridnal Date or number of
# days starting with January 1 of the year in the proleptic 
# Gregorian calendar.
# Source: https://en.wikipedia.org/wiki/Ordinal_date
###############################################################################
sub ordinal_date {
    my ($M, $D, $Y) = @_;

    my $od = $D;
    if ($M == 2) {
        $od += 31;
    } else {
        $od += floor(30.6 * $M - 91.4);
        $od += is_leap_year($Y) ? 60 : 59;
    }
    return $od;
}

MAIN:
{
    my $month = 0;
    my $day = 0;
    my $year = 0;
    if (scalar(@ARGV) == 3) {
        $month = Utils::stoiWithDefault($ARGV[0], 0);
        $day = Utils::stoiWithDefault($ARGV[1], 0);
        $year = Utils::stoiWithDefault($ARGV[2], 0);
    } else {
        print Utils::messageFormat("Syntax: \{0:s\} month day year", "OrdinalDate2"), "\n";
        print "Syntax: ", "OrdinalDate2", " \{month\} \{day\} \{year\}\n";
        exit 1;
    }

    my $od = ordinal_date($month, $day, $year);
    print Utils::messageFormat("\{0:d\}/\{1:d\}/\{2:d\} = \{3:d\} Ordinal Date", $month, $day, $year, $od), "\n";
}