#!/usr/bin/perl -w

# author: J Robert Ray <jrray@gentoo.org>
# 
#
# History: 
# 12/03/02: mcummings; Added checks for /var/db/pkg and manually installed 
#	modules
# 11/07/02: jrray : Initial upload to bug 3450
#
#

use strict;
use File::Spec;
use CPAN;

unless (@ARGV) {
	print "Feed me perl modules on the command line\n";
	exit;
}

my $overlay_dir = `grep ^PORTDIR_OVERLAY= /etc/make.conf`;
chomp $overlay_dir;
$overlay_dir =~ s/.*?="?(.*?)"?$/$1/;

if (!$overlay_dir)
	{ $overlay_dir = '/tmp/perl-modules'; }
	
$overlay_dir = '/tmp/perl-modules';
unless (-d $overlay_dir) {
	mkdir $overlay_dir, 0755 or die "Couldn't create '$overlay_dir': $|";
}

my $perldev_overlay = File::Spec->catfile($overlay_dir, 'dev-perl');
unless (-d $perldev_overlay) {
	mkdir $perldev_overlay, 0755 or die "Couldn't create '$perldev_overlay': $|";
}

#Commented out since we will be using a temp overlay
#unless (length $overlay_dir && -d $overlay_dir) {
#	print "You need to set PORTDIR_OVERLAY in /etc/make.conf for this to work\n";
#	exit;
#}

sub printbig
{
	print '*' x 72, "\n";
	print '*', "\n";
	print '*', "\n";
	print '*  ', @_;
	print '*', "\n";
	print '*', "\n";
	print '*' x 72, "\n";
}

sub ebuild_exists($)
{
	my ($dir) = @_;

	# check the main portage tree
	return 1 if (-d File::Spec->catfile('/usr/portage/dev-perl', $dir));

	# check the overlay
	return 1 if (-d File::Spec->catfile($perldev_overlay, $dir));

	# check to see if we've pseduo-built this before
	return 1 if (-d File::Spec->catfile('/var/tmp/db/dev-perl', $dir));

	return 0;
}
sub module_exists ($) 
{
	my ($module) = @_;
        #check to see if the user has manually installed the module
	return 1 if (&module_check($module));
		
}
sub module_check ($)
{
	my $check = $_;
	my $tmp = "use $check;";
	my $tmpinstalled = 0;
	eval $tmp; $tmpinstalled = 1 unless $@;
	if ($tmpinstalled == 1)
		{ return 1;}
	else
		{ return 0;}
}
sub portage_dir ($)
{
	my $obj = shift;

	my $file = $obj->cpan_file;
	# turn this into a directory name suitable for portage tree
	return unless ($file =~ m|.*/(.*)-[^-]+\.|);
	return $1;
}

sub create_ebuild ($$$$$)
{
	my ($module, $dir, $file, $prereq_pm, $MD5) = @_;

	# First, make the directory
	my $fulldir = File::Spec->catdir($perldev_overlay, $dir);
	my $filesdir = File::Spec->catdir($fulldir, 'files');
	mkdir $fulldir, 0755 or die "Couldn't create '$fulldir': $!";
	mkdir $filesdir, 0755 or die "Couldn't create '$filesdir': $!";

	# What to call this ebuild?
	unless ($file =~ m#(.*)/(.*?)\.(?:tar|tgz|zip|bz2|gz)#) {
		print STDERR "Couldn't turn '$file' into an ebuild name\n";
		return;
	}
	my ($modpath, $filename) = ($1, $2);
	my $ebuild = File::Spec->catdir($fulldir, "$filename.ebuild");
	my $digest = File::Spec->catdir($filesdir, "digest-$filename");

	my $desc = $module->description;

	open EBUILD, ">$ebuild" or die "Could not write to '$ebuild': $!";
	print EBUILD <<"HERE";


# Copyright 1999-2002 Gentoo Technologies, Inc.
# Distributed under the terms of the GNU General Public License v2

inherit perl-module

S=\${WORKDIR}/\${P}
DESCRIPTION="$desc"
SRC_URI="http://www.cpan.org/modules/by-authors/id/$modpath/\${P}.tar.gz"
HOMEPAGE="http://www.cpan.org/modules/by-authors/id/$modpath/\${P}.readme"

SLOT="0"
LICENSE="Artistic | GPL-2"
KEYWORDS="x86 ppc alpha"

HERE

	if ($prereq_pm && keys %$prereq_pm) {

		print EBUILD q|DEPEND="|;

		my $first = 1;
		for (keys %$prereq_pm) {
			my $obj = CPAN::Shell->expandany($_);
			my $dir = portage_dir($obj);
			print EBUILD "\n\t" unless $first;
			print EBUILD "dev-perl/$dir";
			$first = 0;
		}
		print EBUILD qq|"\n\n|;
	}

	close EBUILD;

	# write the digest too
	open DIGEST, ">$digest" or die "Could not write to '$digest': $!";
	print DIGEST $MD5, "\n";
	close DIGEST;
}

sub install_module ($);
sub install_module ($)
{
	my ($module_name) = @_;

	my $obj = CPAN::Shell->expandany($module_name);
	unless (ref $obj eq "CPAN::Module") {
		print STDERR "Don't know what '$module_name' is\n";
		return;
	}

	my $file = $obj->cpan_file;
	my $dir = portage_dir($obj);
	unless ($dir) {
		print STDERR "Couldn't turn '$file' into a directory name\n";
		return;
	}

	if (ebuild_exists($dir)) {
		printbig "Module already exists for '$module_name': $dir\n";
		return;
	}
	if (module_exists($module_name)) {
		printbig "Module already installed for '$module_name'\n";
		return;
	}

	printbig "Need to create ebuild for '$module_name': $dir\n";

	# check depends ... with CPAN have to make the module
	# before it can tell us what the depends are, this stinks

	$CPAN::Config->{prerequisites_policy} = "";
	$CPAN::Config->{inactivity_timeout} = 30;

	my $pack = $CPAN::META->instance('CPAN::Distribution', $file);
	$pack->called_for($obj->id);
	$pack->make;
	$pack->unforce if $pack->can("unforce") && exists $obj->{'force_update'};
	delete $obj->{'force_update'};

	# grab the MD5 checksum for the source file now
	my $localfile = $pack->{localfile};
	(my $base = $file) =~ s|.*/(.*)|$1|;
	my $MD5 = sprintf "MD5 %s %s %d",
		(split/\s/,`md5sum $localfile`)[0],
		$base,
		-s $localfile;

	# make ebuilds for all the prereqs
	my $prereq_pm = $pack->prereq_pm;
	install_module($_) for (keys %$prereq_pm);

	create_ebuild($obj, $dir, $file, $prereq_pm, $MD5);

	printbig "You may now install '$module_name' by typing 'emerge $dir'\n";
}

install_module($_) for (@ARGV);