#!/usr/bin/perl

use v5.012;
use strict;
use warnings;

use Cwd 'abs_path';
use POSIX ':sys_wait_h';

sub find_ports($);
sub process_port($ $ $);

MAIN:
{
	my ($base, $tgt) = ('.', '/usr/ports');

	my @ports = find_ports $base;
	say '===> Processing '.scalar(@ports)." ports:".
	    join '', map "\n  $_", sort @ports;
	process_port $_, $base, $tgt for @ports;
}

sub find_ports($)
{
	my ($base) = @_;
	my @res;

	opendir my $db, $base or die "opendir($base): $!\n";
	while (my $d = readdir $db) {
		next if $d eq '.' || $d eq '..';
		chdir $db or die "chdir($base): $!\n";
		next unless -d $d;

		opendir my $ds, $d or die "opendir($base/$d): $!\n";
		while (my $p = readdir $ds) {
			next if $p eq '.' || $p eq '..';
			chdir $ds or die "chdir($base/$d): $!\n";
			next unless -d $p && -f "$p/Makefile" && -f "$p/pkg-plist";

			push @res, "$d/$p";
		}
		closedir $ds or die "closedir($base/$d): $!\n";
	}
	closedir $db or die "closedir($base): $!\n";

	return @res;
}

sub process_port($ $ $)
{
	my ($port, $base, $tgt) = @_;

	my ($basename, $tgtname) = ("$base/$port", "$tgt/$port");
	my $baseabs = abs_path($basename);

	say "\n===> $port: $basename -> $tgtname";
	if (-l $tgtname) {
		my $lname = readlink $tgtname or die "readlink($tgtname): $!\n";
		if (abs_path($lname) ne $baseabs) {
			die "FIXME: remove $tgtname to be replaced by a symlink to $baseabs";
		}
		else { say "just fine: $tgtname is a symlink to $baseabs"; }
	} elsif (-d $tgtname) {
		my @cmd = ('rsync', '-av', '--delete', '--', "$baseabs/", "$tgtname/");
		my $res = system { $cmd[0] } @cmd;
		if (!WIFEXITED($res) || WEXITSTATUS($res) != 0) {
			die "@cmd failed\n";
		}
		say "just fine: rsynced $baseabs to $tgtname successfully";
	} elsif (-e $tgtname) {
		unlink $tgtname or die "unlink($tgtname): $!\n";
	}

	if (! -e $tgtname) {
		say "creating a symlink: $baseabs -> $tgtname";
		symlink $baseabs, $tgtname or
		    die "symlink($baseabs, $tgtname): $!\n";
	}
}