#!/usr/bin/perl
#
# vim: set ts=4:noet
#
# sboconfig
# script to handle sbotools configuration
#
# authors: Jacob Pipkin <j@dawnrazor.net>
#          Luke Williams <xocel@iquidus.org>
#          Andreas Guldstrand <andreas.guldstrand@gmail.com>
# license: WTFPL <http://sam.zoy.org/wtfpl/COPYING>

use 5.16.0;
use strict;
use warnings FATAL => 'all';
use SBO::Lib qw/ usage_error script_error $tempdir open_read open_fh %config $conf_dir $conf_file show_version /;
use File::Basename;
use Getopt::Long qw(:config no_ignore_case_always);
use File::Copy;
use File::Path qw(make_path);
use File::Temp qw(tempfile);;

my $self = basename($0);

sub show_usage {
	print <<"EOF";
Usage: $self [options] [arguments]

Options:
  -h: this screen.
  -v: version information.
  -l: show current options.

Config options (defaults shown):
  -c|--clean FALSE:
      NOCLEAN: if TRUE, do NOT clean up after building by default.
  -d|--distclean FALSE:
      DISTCLEAN: if TRUE, DO clean distfiles by default after building.
  -j|--jobs FALSE:
      JOBS: numeric -j setting to feed to make for multicore systems.
  -p|--pkg-dir FALSE:
      PKG_DIR: set a directory to store packages in.
  -s|--sbo-home /usr/sbo:
      SBO_HOME: set the SBo directory.
  -o|--local-overrides FALSE:
      LOCAL_OVERRIDES: a directory containing local overrides.
  -V|--slackware-version FALSE:
      SLACKWARE_VERSION: use the SBo repository for this version.
  -r|--repo FALSE:
      REPO: use a repository other than SBo.

EOF
	return 1;
}

my %options;

GetOptions(\%options, 'help|h', 'version|v', 'list|l', 'noclean|c=s',
	'distclean|d=s', 'jobs|j=s', 'pkg-dir|p=s', 'sbo-home|s=s',
	'local-overrides|o=s', 'slackware-version|V=s', 'repo|r=s');

if ($options{help}) { show_usage(); exit 0 }
if ($options{version}) { show_version(); exit 0 }

my %valid_confs = (
	noclean             => 'NOCLEAN',
	distclean           => 'DISTCLEAN',
	jobs                => 'JOBS',
	'pkg-dir'           => 'PKG_DIR',
	'sbo-home'          => 'SBO_HOME',
	'local-overrides'   => 'LOCAL_OVERRIDES',
	'slackware-version' => 'SLACKWARE_VERSION',
	'repo'              => 'REPO',
);

my %params = (
	NOCLEAN           => 'c|--noclean',
	DISTCLEAN         => 'd|--distclean',
	JOBS              => 'j|--jobs',
	PKG_DIR           => 'p|--pkg-dir',
	SBO_HOME          => 's|--sbo-home',
	LOCAL_OVERRIDES   => 'o|--local-overrides',
	SLACKWARE_VERSION => 'V|--slackware-version',
	REPO              => 'r|--repo',
);

if (exists $options{list}) {
	my @keys = sort {$a cmp $b} keys %config;
	say "sboconfig -$params{$_}:\n    $_=$config{$_}" for @keys;
	exit 0;
}

if (not %options) {
	show_usage();
	exit 0;
}

# setup what's being changed, sanity check.
my %changes;
for my $key (keys %valid_confs) {
	my $value = $valid_confs{$key};
	$changes{$value} = $options{$key} if exists $options{$key};
}

my $warn = 'You have provided an invalid parameter for';

if (exists $changes{NOCLEAN}) {
	usage_error("$warn -c") unless $changes{NOCLEAN} =~ /^(TRUE|FALSE)$/;
}
if (exists $changes{DISTCLEAN}) {
	usage_error("$warn -d") unless $changes{DISTCLEAN} =~ /^(TRUE|FALSE)$/;
}
if (exists $changes{JOBS}) {
	usage_error("$warn -j") unless $changes{JOBS} =~ /^(\d+|FALSE)$/;
}
if (exists $changes{PKG_DIR}) {
	usage_error("$warn -p") unless $changes{PKG_DIR} =~ qr#^(/|FALSE$)#;
}
if (exists $changes{SBO_HOME}) {
	usage_error("$warn -s") unless $changes{SBO_HOME} =~ qr#^/#;
}
if (exists $changes{LOCAL_OVERRIDES}) {
	usage_error("$warn -o") unless $changes{LOCAL_OVERRIDES} =~ qr#^(/|FALSE$)#;
}
if (exists $changes{SLACKWARE_VERSION}) {
	usage_error("$warn -V") unless $changes{SLACKWARE_VERSION} =~ m/^(\d+\.\d+|FALSE)$/;
}

# safely modify our conf file; write its contents to a temp file, modify the
# temp file, write the contents of the temp file back to the conf file
# TODO: if multiple options are provided to this script, this sub should write
# them all at once, instead of only a single one and having to call it once for
# each option specified to the script.
sub config_write {
	my ($key, $val) = @_;
	script_error('config_write requires two arguments.') unless @_ == 2;
	if (! -d $conf_dir) {
		mkdir $conf_dir or usage_error("Unable to create $conf_dir. Exiting.");
	}
	if (-f $conf_file) {
		my $tempfh = tempfile(DIR => $tempdir);
		my ($conffh, $exit) = open_read($conf_file);
		if ($exit) {
			warn $conffh;
			exit $exit;
		}
		my $conftents = do {local $/; <$conffh>};
		print {$tempfh} $conftents;
		# tie the temp file so that if $key is already there, we just change 
		# that line and untie it
		tie my @temp, 'Tie::File', $tempfh;
		my $has;
		my $regex = qr/\A\Q$key\E=/;
		# TODO: fix this monstrosity
		FIRST: for my $tmpline (@temp) {
			$has++, $tmpline = "$key=$val", last FIRST if $tmpline =~ $regex;
		}
		untie @temp;
		# otherwise, append our new $key=$value pair
		print {$tempfh} "$key=$val\n" unless $has;
		# then overwrite the conf file with the contents of the temp file
		seek $tempfh, 0, 0;
		my $contents = do {local $/; <$tempfh>};
		close $conffh;
		($conffh, $exit) = open_fh($conf_file, '>');
		if ($exit) {
			warn $conffh;
			exit $exit;
		}
		print {$conffh} $contents or return();
	} else {
		# no config file, easiest case of all.
		my ($fh, $exit) = open_fh($conf_file, '>') or return();
		if ($exit) {
			warn $fh;
			exit $exit;
		}
		print {$fh} "$key=$val\n";
		close $fh;
	}
	return 1;
}

for my $key (keys %changes) {
	my $value = $changes{$key};
	say "Setting $key to $value...";
	config_write($key, $value);
}

exit 0;