#!/bin/php
<?php

/*
  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program. If not, see <http://www.gnu.org/licenses/>.
*/

const N="\n";
const SNAME='xstoxfces';
const SVERS='0.1.3';

$opts=[
'xscreensaver_user_conf_file'=>null,
'xscreensaver_conf_dir'=>'/usr/share/xscreensaver/config',
'xscreensaver_exec_dir'=>'/usr/lib/xscreensaver',
'xfce_screensaver_desktop_files_dir'=>null,
'preserve_xscreensaver_exclusions'=>false,
'preserve_xscreensaver_arguments'=>false
];

$help=
'SYNOPSIS

'.SNAME.' [options]

DESCRIPTION

This is '.SNAME.' v'.SVERS.', a CLI php script that makes xscreensaver’s
screensavers available to «Xfce screensaver»’s users.
Currently, «Xfce screensaver» supports xscreensaver’s screensavers, but does
not automatically make them available to users. This script just converts
xscreensaver’s screensavers «.xml» definition files to «.desktop» files and
saves these «.desktop» files in a directory where «Xfce screensaver» will
consider them (by default «$HOME/.local/share/applications/screensavers»);
in addition, it can optionally exclude screensavers and preserve their
configuration (that is, their arguments) according to an xscreensaver’s
user configuration file («$HOME/.xscreensaver» by default).

OPTIONS

-h, --help
 Show this help text and exit.

-p, --preserve_xscreensaver_exclusions
 With this option '.SNAME.' will exclude those screensavers which the user
 may have excluded using xscreensaver-settings’s «Random Screen Saver»
 option, by detecting them from xscreensaver’s user configuration file
 («$HOME/.xscreensaver» by default).

-P, --preserve_xscreensaver_arguments
 With this option '.SNAME.' will preserve every screensaver’s arguments which
 the user may have set using xscreensaver-settings, by detecting them from
 xscreensaver’s user configuration file («$HOME/.xscreensaver» by default).

-C, --xscreensaver_user_conf_file <file path>
 If '.SNAME.' is invoked with «--preserve_xscreensaver_exclusions»
 or «--preserve_xscreensaver_arguments» (see the previous two options’
 descriptions), it will try to automatically detect xscreensaver’s user
 configuration file’s path («$HOME/.xscreensaver» by default). If it fails,
 or if you want to specify a different xscreensaver configuration file, you
 can do it explicitly with this option.

-c, --xscreensaver_conf_dir <directory path>
 With this option you can explicitly specify the xscreensaver configuration
 directory, that is the system directory where xscreensaver stores all the
 «.xml» files defining its screensavers.
 DEFAULT: «'.$opts['xscreensaver_conf_dir'].'»

-e, --xscreensaver_exec_dir <directory path>
 With this option you can explicitly specify the xscreensaver executables
 directory, that is the system directory where xscreensaver stores all its
 screensavers’ executable files.
 DEFAULT: «'.$opts['xscreensaver_exec_dir'].'»

-d, --xfce_screensaver_desktop_files_dir <directory path>
 With this option you can explicitly specify '.SNAME.'’s «output directory»
 path, that should be the path to a directory where «Xfce screensaver» expects
 to find «.desktop» files defining screensavers (by default
 «$HOME/.local/share/applications/screensavers»).

NOTES

You can use '.SNAME.' to make xscreensaver’s screensavers available to every
user of «Xfce screensaver» by running '.SNAME.' as root and setting
«--xfce_screensaver_desktop_files_dir» (see above) to the system directory
where «Xfce screensaver» expects to find the «.desktop» files defining all the
screensavers and their configurations (usually
«/usr/share/applications/screensavers»).

EXIT VALUES

0: regular run
1: fatal error

DISCLAIMER AND LICENSE

This program comes with ABSOLUTELY NO WARRANTY; for details see the source.
This is free software, and you are welcome to redistribute it under certain
conditions; see <http://www.gnu.org/licenses/> for details.'.N;

/*$chome=getenv('XDG_CONFIG_HOME',true);
echo($chome.N);*/

for ($i=1; $i<$argc; $i++) {
	if ($argv[$i][0]=='-') {
		switch ($argv[$i]) {
			case '--makereadme':
				file_put_contents(__DIR__.'/README.md','```text'.N.$help.'```'.N);
				exit(0);
				break;
			case '-h':
			case '--help':
				echo($help);
				exit(0);
				break;
			case '-C':
			case '--xscreensaver_user_conf_file':
				if (isset($argv[$i+1])) {
					$i++;
					$opts['xscreensaver_user_conf_file']=preg_replace('#^(.*)/*$#uU','$1',$argv[$i]);
				} else {
					fwrite(STDERR,'Error: option «'.$argv[$i].'» requires an argument (use «-h» or «--help» for more info).'.N);
					exit(0);
				}
				break;
			case '-c':
			case '--xscreensaver_conf_dir':
				if (isset($argv[$i+1])) {
					$i++;
					$opts['xscreensaver_conf_dir']=preg_replace('#^(.*)/*$#uU','$1',$argv[$i]);
				} else {
					fwrite(STDERR,'Error: option «'.$argv[$i].'» requires an argument (use «-h» or «--help» for more info).'.N);
					exit(0);
				}
				break;
			case '-e':
			case '--xscreensaver_exec_dir':
				if (isset($argv[$i+1])) {
					$i++;
					$opts['xscreensaver_exec_dir']=preg_replace('#^(.*)/*$#uU','$1',$argv[$i]);
				} else {
					fwrite(STDERR,'Error: option «'.$argv[$i].'» requires an argument (use «-h» or «--help» for more info).'.N);
					exit(0);
				}
				break;
			case '-d':
			case '--xfce_screensaver_desktop_files_dir':
				if (isset($argv[$i+1])) {
					$i++;
					$opts['xfce_screensaver_desktop_files_dir']=preg_replace('#^(.*)/*$#uU','$1',$argv[$i]);
				} else {
					fwrite(STDERR,'Error: option «'.$argv[$i].'» requires an argument (use «-h» or «--help» for more info).'.N);
					exit(0);
				}
				break;
			case '-p':
			case '--preserve_xscreensaver_exclusions':
				$opts['preserve_xscreensaver_exclusions']=true;
				break;
			case '-P':
			case '--preserve_xscreensaver_arguments':
				$opts['preserve_xscreensaver_arguments']=true;
				break;
			default:
				fwrite(STDERR,'Error: «'.$argv[$i].'» is not a valid option.'.N);
				exit(1);
		}
	} else {
		fwrite(STDERR,'Error: «'.$argv[$i].'» is not a valid option.'.N);
		exit(1);
	}
}
//print_r($opts); exit(0);

if (is_null($opts['xfce_screensaver_desktop_files_dir'])) {
	$home=@getenv('HOME');
	if ($home===false) {
		fwrite(STDERR,'Error: could not get «HOME» environment variable, you’ll have to specify «xfce_screensaver_desktop_files_dir» by yourself (use «-h» or «--help» for more info).'.N);
		exit(1);
	} else {
		$opts['xfce_screensaver_desktop_files_dir']=$home.'/.local/share/applications/screensavers';
	}
}

if (is_null($opts['xscreensaver_user_conf_file']) && ($opts['preserve_xscreensaver_exclusions'] || $opts['preserve_xscreensaver_arguments'])) {
	$home=@getenv('HOME');
	if ($home===false) {
		fwrite(STDERR,'Error: could not get «HOME» environment variable, you’ll have to specify «xscreensaver_user_conf_file» by yourself (use «-h» or «--help» for more info).'.N);
		exit(1);
	} else {
		$opts['xscreensaver_user_conf_file']=$home.'/.xscreensaver';
	}
}

if ($opts['preserve_xscreensaver_exclusions'] || $opts['preserve_xscreensaver_arguments']) {
	$buff=@file($opts['xscreensaver_user_conf_file'],FILE_IGNORE_NEW_LINES|FILE_SKIP_EMPTY_LINES);
	if ($buff===false) {
		fwrite(STDERR,'Error: could not open «'.$opts['xscreensaver_user_conf_file'].'».'.N);
		exit(1);
	}
	$xscrs=[];
	$i=0;
	$c=count($buff);
	while ($i<$c) {
		if (preg_match('/^([\-\d\S ]+)?\t{4}([\S\d \-_]+)\s+(\\\n)?\\\$/uU',$buff[$i],$matches)===1) {
			//print_r($matches);
			$cmd=$matches[2];
			//echo($cmd.'|'.N);
			($matches[1]!='' && $matches[1][0]==='-') ? $active=false : $active=true;
			preg_match('/^(\S+).*$/',$matches[2],$matches);
			//print_r($matches);
			$fn=$matches[1];
			//echo($buff[$i].N);
			//echo($matches[2].N);
			while (substr($buff[$i],-3)!=="\\n\\") {
				$i++;
				//echo('`-> '.$buff[$i].N);
				preg_match('/^\s+([\S\d \-_]+)\s+.*$/u',$buff[$i],$matches);
				//print_r($matches);
				$cmd.=' '.$matches[1];
			}
			$xscrs[$fn]=['cmd'=>$cmd,'active'=>$active];
		}
		$i++;
	}
	//print_r($xscrs);
}

$dh=@opendir($opts['xscreensaver_conf_dir']);

if ($dh===false) {
	fwrite(STDERR,'Error: could not open «'.$opts['xscreensaver_conf_dir'].'».'.N);
	exit(1);
}

if (!file_exists($opts['xfce_screensaver_desktop_files_dir'])) {
	if (mkdir($opts['xfce_screensaver_desktop_files_dir'],0755,true)===false) {
		fwrite(STDERR,'Error: could not create «'.$opts['xfce_screensaver_desktop_files_dir'].'».'.N);
		exit(1);
	}
}

while (($fp=readdir($dh))!==false) {
	if (preg_match('/\.xml$/iu',$fp)===1) {
		$fp=$opts['xscreensaver_conf_dir'].'/'.$fp;
		$xml=@simplexml_load_file($fp);
		if ($xml!==false) {
			if (isset($xml['name']) && isset($xml['_label']) && isset($xml->command['arg'])) {
				$ofp=$opts['xfce_screensaver_desktop_files_dir'].'/'.$xml['name'].'.desktop';
				if (is_file($ofp) && @unlink($ofp)===false)
					fwrite(STDERR,'Warning: could not delete «'.$ofp.'».'.N);
				$cmd=$xml['name'].' '.$xml->command['arg'];
				if ($opts['preserve_xscreensaver_arguments'] && isset($xscrs[(string)$xml['name']]['cmd']))
					$cmd=$xscrs[(string)$xml['name']]['cmd'];
				if (!$opts['preserve_xscreensaver_exclusions'] || $xscrs[(string)$xml['name']]['active']) {
					$cont=
'[Desktop Entry]
Type=Application
Name='.$xml['_label'].'
TryExec='.$opts['xscreensaver_exec_dir'].'/'.$xml['name'].'
Exec='.$opts['xscreensaver_exec_dir'].'/'.$cmd.'
Categories=Screensaver;
Hidden=true'.N;
					if (@file_put_contents($ofp,$cont)===false)
						fwrite(STDERR,'Warning: trying to add «'.$xml['name'].'», could not write into «'.$ofp.'».'.N);
					else
						echo('Added «'.$xml['name'].'»'.N);
				} else {
					echo('Ignored «'.$xml['name'].'»'.N);
				}
			} else {
				fwrite(STDERR,'Warning: «'.$fp.'» does not contain one or more required info.'.N);
			}
		} else {
			fwrite(STDERR,'Warning: could not parse «'.$fp.'».'.N);
		}
	}
}

closedir($dh);
exit(0);

?>