#!/usr/bin/perl -l
# Use a CPAN module that is *not* installed! Is this a good idea?
# Posted to perlmonks.org by an Anonymous Monk on Sun Jun 17 2018
#
# In this example, if the Astro::MoonPhase module is not installed,
# the use_cpan sub will parse the error, download the module page 
# from metacpan, parse that for the source code uri, download the
# raw module source, eval that string, and proceed normally as if 
# the module was installed! It does not work with all modules and 
# the concept is presented to the Monastery for contemplation.
#__QKB__

use strict;
use warnings;

eval { require Astro::MoonPhase };
use_cpan($@) if $@;

my @phases = Astro::MoonPhase::phasehunt();
print q~LOCALTIME     = ~, scalar localtime time;
print q~New Moon      = ~, scalar localtime $phases[0];
print q~First quarter = ~, scalar localtime $phases[1];
print q~Full moon     = ~, scalar localtime $phases[2];
print q~Last quarter  = ~, scalar localtime $phases[3];
print q~New Moon      = ~, scalar localtime $phases[4];

sub use_cpan
{
	my ($module) = @_;
	if ($module =~ /install the (\S+) module/) {
		my $modname = $1;
        	require  HTTP::Tiny;
        	my $pm = HTTP::Tiny->new->get("https://metacpan.org/pod/$modname");
        	for ($pm->{content} =~ /Source<\/a>\s*\(<a href="([^"]+)">raw/) {
		        $pm = HTTP::Tiny->new->get($1);
			eval $pm->{content};
			last
		}
	}
}