<?php namespace ProcessWire;

/**
 * ProcessWire HTML Purifier module
 *
 * Serves as a front-end to the HTML Purifier software:
 * http://htmlpurifier.org
 *
 * USAGE:
 *
 *   $purifier = $modules->get('MarkupHTMLPurifier');
 *   $cleanHTML = $purifier->purify($dirtyHTML); 
 *
 * To specify custom settings to HTML Purifier, perform set()
 * calls before calling purify(). For example, UTF-8 encoding
 * is assumed, so if you wanted ISO-8859-1 instead, you'd do:
 *
 *   $purifier->set('Core.Encoding', 'ISO-8859-1'); 
 *
 * For a full list of HTML Purifier config options, see: 
 * http://htmlpurifier.org/live/configdoc/plain.html
 *
 * HTML Purifier by: http://htmlpurifier.org
 * ProcessWire module by Ryan Cramer
 * 
 * @method void initConfig(\HTMLPurifier_Config $settings, \HTMLPurifier_HTMLDefinition $def)
 *
 */

class MarkupHTMLPurifier extends WireData implements Module {

	public static function getModuleInfo() {
		return array(
			'title' => 'HTML Purifier', 
			'summary' => 'Front-end to the HTML Purifier library.', 
			'version' => 497, 
			'singular' => false, 
			'autoload' => false, 
		);
	}

	/**
	 * HTML Purifier settings
	 * 
	 * @var \HTMLPurifier_Config|null
	 *
	 */
	protected $settings = null;

	/**
	 * HTML Purifier Raw HTML definition
	 * 
	 * @var \HTMLPurifier_HTMLDefinition|null
	 * 
	 */
	protected $def = null;

	/**
	 * Cached instance of HTMLPurifier
	 *
	 */
	protected $purifier = null; 

	/**
	 * Generate HTML Purifier settings object
	 *
	 */
	public function __construct() {
		parent::__construct();
		require_once(dirname(__FILE__) . '/htmlpurifier/HTMLPurifier.standalone.php'); 
		$this->settings = \HTMLPurifier_Config::createDefault();
		$this->settings->autoFinalize = false;
	}

	/**
	 * Initialize the module and create default settings
	 *
	 */
	public function init() {
		$this->settings->set('Cache.SerializerPath', $this->getCachePath());
		$this->settings->set('Attr.AllowedRel', array('nofollow', 'noopener', 'noreferrer'));
		$this->settings->set('HTML.DefinitionID', 'html5-definitions');
		$this->settings->set('HTML.DefinitionRev', 1);
		$this->def = $this->settings->maybeGetRawHTMLDefinition();
		if($this->def) {
			$this->def->addElement('figure', 'Block', 'Optional: (figcaption, Flow) | (Flow, figcaption) | Flow', 'Common');
			$this->def->addElement('figcaption', 'Inline', 'Flow', 'Common');
			$this->initConfig($this->settings, $this->def); 
		}
	}

	/**
	 * Method to allow hooks to further initialize HTMLPurifier config/settings
	 * 
	 * ~~~~~
	 * $wire->addHook('MarkupHTMLPurifier::initSettings', function($event) {
	 *   $def = $event->arguments(1); 
	 *   $def->addAttribute('a', 'data-ext', 'Text');
	 * }); 
	 * ~~~~~
	 * 
	 * @param \HTMLPurifier_Config $settings
	 * @param \HTMLPurifier_HTMLDefinition $def
	 * @since 3.0.173
	 * 
	 */
	protected function ___initConfig($settings, $def) { }
	
	/**
	 * Return the cache path used by HTML Purifier
	 * 
	 * @param bool $create Create if not exists?
	 * @return string
	 *
	 */
	protected function getCachePath($create = true)  {
		$cachePath = $this->wire()->config->paths->cache . $this->className() . '/';
		if($create && !is_dir($cachePath)) $this->wire()->files->mkdir($cachePath); 
		return $cachePath;
	}

	/**
	 * Clear the HTML Purifier cache
	 * 
	 * @since 3.0.173
	 * 
	 */
	public function clearCache() {
		$cachePath = $this->getCachePath(false);
		if(is_dir($cachePath)) $this->wire()->files->rmdir($cachePath, true); 
	}

	/**
	 * Return the current settings
	 *
	 * @return \HTMLPurifier_Config|null
	 *
	 */
	public function getConfig() {
		return $this->settings; 
	}

	/**
	 * Get HTML Purifier raw HTML definition
	 * 
	 * @return \HTMLPurifier_HTMLDefinition|null
	 * @since 3.0.173
	 * 
	 */
	public function getDef() {
		return $this->def;
	}

	/**
	 * Get the HTMLPurifier instance
	 *
	 * @return \HTMLPurifier
	 *
	 */
	public function getPurifier() {
		if(is_null($this->purifier)) $this->purifier = new \HTMLPurifier($this->settings); 	
		return $this->purifier; 
	}

	/**
	 * Purify the given dirty HTML and return the clean HTML
	 *
	 * @param string Dirty HTML
 	 * @return string Clean HTML
	 *
	 */
	public function purify($html) {
		
		// purify
		$html = $this->getPurifier()->purify($html);
	
		return $html;
	}

	/**
	 * Set an HTMLPurifier config option 
	 *
	 * See configuration options at: http://htmlpurifier.org/live/configdoc/plain.html
	 *
	 * @param string $key
	 * @param string|array|mixed $value
	 * @return WireData|MarkupHTMLPurifier
	 *
	 */
	public function set($key, $value) {
		if(strpos($key, '.')) {
			// HTML Purifier setting: http://htmlpurifier.org/live/configdoc/plain.html
			$this->purifier = null;
			$this->settings->set($key, $value); 
			return $this;	
		} 
		// some other setting
		return parent::set($key, $value); 
	}

	/**
	 * Get an HTMLPurifier config option
	 *
 	 * @param string $key
	 * @return string|null
	 *
	 */
	public function get($key) {
		if(strpos($key, '.')) return $this->settings->get($key);
		return parent::get($key);
	}

	/**
	 * Uninstall by removing the cache path and files
	 *
	 */
	public function ___uninstall() {
		$cachePath = $this->getCachePath();
		wireRmdir($cachePath, true); 
		$this->message("Removed: $cachePath"); 
	}

}