<?php
/**
 * ResizeOnUpload Plugin
 *
 * Events: OnFileManagerUpload
 * Author: Vasiliy Naumkin <bezumkin@yandex.ru>
 * Required: PhpThumbOf snippet for resizing images
 */

if ($modx->event->name != 'OnFileManagerUpload') {return;}

/* Settings */
$config = array(
    '/' => array(           // default config
        'w' => 800          // max width of uploaded images
        ,'h' => 600         // max height of uploaded images
        ,'zc' => 0          // zoom & crop
        ,'bg' => '#fff'     // backgroud, needed only for zc=0
        ,'q' => 100         // quality
    )
    //,'/assets/images/' => array()
);

/*----------*/
$file = $modx->event->params['files']['file'];
$directory = $modx->event->params['directory'];
if ($file['error'] != 0) {return;}

$name = $file['name'];
$extensions = explode(',', $modx->getOption('upload_images'));

if (array_key_exists($directory, $config)) {
	$config = $config[$directory];
}
else {
	$config = $config['/'];
}

$filename = MODX_BASE_PATH . $directory . $name;
$ext = substr(strrchr($name, '.'), 1);
if (in_array($ext, $extensions)) {
	$sizes = getimagesize($filename);
	$format = substr($sizes['mime'],6);
	if ($sizes[0] > $config['w'] || $sizes[1] > $config['h']) {
		if ($sizes[0] < $config['w']) {$config['w'] = $sizes[0];}
		if ($sizes[1] < $config['h']) {$config['h'] = $sizes[1];}
		
		$options = '';
		foreach ($config as $k => $v) {
			$options .= '&'.$k.'='.$v;
		}
		$resized = $modx->runSnippet('PhpThumbOf', array(
			'input' => $directory.$name
			,'options' => $options
		));
		rename(MODX_BASE_PATH . substr($resized, 1), $filename);
	}
}

// source: https://bezumkin.ru/sections/components/118/