roundcube-easy-unsubscribe/easy_unsubscribe.php

<?php

class easy_unsubscribe extends rcube_plugin {

	public $task = 'mail';
	private $message_headers_done = false;
	private $unsubscribe_img;

	function init() {
        ini_set('display_errors', '1');
        ini_set('display_startup_errors', '1');
        error_reporting(E_ALL);

		$rcmail = rcmail::get_instance();
		$layout = $rcmail->config->get('layout');

		$this->add_hook('message_headers_output', array($this, 'message_headers'));
		$this->add_hook('storage_init', array($this, 'storage_init'));
		
		$this->include_stylesheet('easy_unsubscribe.css');
		$this->include_script('easy_unsubscribe.js');

		$this->add_texts('localization/');

		$rcmail->output->add_label('easy_unsubscribe.confirm');
	}
	
	public function storage_init($p) {
        $p['fetch_raw_body'] = true;
		$p['fetch_headers'] = trim($p['fetch_headers'] . ' ' . strtoupper('List-Unsubscribe'));
		return $p;

	}

    public function decodeMimeHeader($header)  {
        $elements = imap_mime_header_decode($header);

        return array_reduce($elements, function ($carry, $element) {
            return $carry . $element->text;
        }, '');
    }

    public function extractUnsubscribeUrls($content) {
		// Array to store all patterns we want to match
		$patterns = [
			// Standard <a> tag pattern
			'/<a\s+(?:[^>]*?\s+)?href=(["\'])((?:https?:)?\/\/[^"\']*?(?:unsubscribe)[^"\']*)\1/i',

			// Square bracket pattern [URL] common in email templates
			'/\[\s*((?:https?:)?\/\/[^\]]*?(?:unsubscribe)[^\]]*)\s*\]/i',

			// Bare URLs with unsubscribe/esclick
			'/((?:https?:)?\/\/[^\s<>\[\]"\']*?(?:unsubscribe)[^\s<>\[\]"\']*)/i'
		];
		
		$allUrls = [];
		foreach ($patterns as $pattern) {
			$matches = [];
			preg_match_all($pattern, $content, $matches);

			// For the first pattern, we want group 2, for others group 1
			$groupIndex = (strpos($pattern, 'href') !== false) ? 2 : 1;
			if (!empty($matches[$groupIndex])) {
				$allUrls = array_merge($allUrls, $matches[$groupIndex]);
			}
		}
		
		// Remove duplicates and clean URLs
		$allUrls = array_unique($allUrls);
		$cleanUrls = array_map(function($url) {
			return trim($url);
		}, $allUrls);

		return array_values(array_filter($cleanUrls));
    }



    public function message_headers($p) {
        if($this->message_headers_done === false) {

			$this->message_headers_done = true;

            $urls = [];

            $rcmail = rcmail::get_instance();
            $body = quoted_printable_decode($rcmail->storage->get_raw_body($p['uid']));

            $urls = array_merge($urls, $this->extractUnsubscribeUrls($body));

            $ListUnsubscribe = $this->decodeMimeHeader($p['headers']->others['list-unsubscribe'] ?? '');
			if (preg_match_all('/<(.+)>/mU', $ListUnsubscribe, $items, PREG_PATTERN_ORDER)) {
				foreach ( $items[1] as $uri ) {
                    $urls[] = $uri;
				}
			}

            $urls = array_unique($urls);

            $exclude_strings = ['?', 'esputnik', 'unsubscribe/'];

            foreach ($urls as $uri) {
                if (str_contains($uri, 'mailto')) continue;

                $should_continue = false;
                foreach ($exclude_strings as $exclude_string) {
                    if (str_contains($uri, $exclude_string)) {
                        $should_continue = true;
                        break;
                    }
                }
                if (!$should_continue) continue;


                $this->unsubscribe_img .= '<a class="easy_unsubscribe_link" title="'.$uri.'" data-href="'. htmlentities($uri) .'" target="_blank" onclick="easy_unsubscribe_click(this);"><img src="plugins/easy_unsubscribe/icon.png" alt="' . $this->gettext('unsubscribe') . '" /></a>';
            }

		}

		if(isset($p['output']['subject'])) {
			$p['output']['subject']['value'] = $p['output']['subject']['value'] . $this->unsubscribe_img;
			$p['output']['subject']['html'] = 1;
		}

		return $p;

	}

}