#!/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__
# Hacked by usemodperl: use Carp. Added module cache.

use strict;
use warnings;
use Carp 'croak';

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
{
	local ($_) = @_;
	if (/install the (\S+) module/) {
		 my $module = $1;
		 my $moddir = '.perlmod';
		(my $modloc =  $module) =~ s/::/__/g;
		    $modloc = "$moddir/$modloc";

		if (-d $moddir and -e $modloc) {
			open my $fh, '<', $modloc or croak "$!";
			@_ = <$fh>; close $fh; 
			$_ = join "\n", @_;
			eval $_ or croak;
		}
		else {
			require HTTP::Tiny;
			$_ = HTTP::Tiny->new->get("https://metacpan.org/pod/$module");
			croak unless $_->{content};

			for ($_->{content} =~ /Source<\/a>\s*\(<a href="([^"]+)">raw/) {
				$_ = HTTP::Tiny->new->get($1);
				$_ = $_->{content} ? $_->{content} : croak;
				eval $_ or croak;
				eval mkdir $moddir; croak $@ if $@;
				if (open my $fh, '>', $modloc or croak "$!") {
					print $fh $_; close $fh;
				}
				last
			}
		}
	}
}