Bookshelf/umbra-bookshelf/includes/email/class-umbra-email-sender.php

<?php
// Copyright 2026 Umbra Tools (umbratools.com)
// SPDX-License-Identifier: Apache-2.0

/**
 * Email Sender Class
 *
 * @package Umbra_Simple_Email
 */

if (!defined('ABSPATH')) {
    exit;
}

class Umbra_Email_Sender {
    /**
     * Send newsletter to all subscribers
     *
     * @param string $subject Newsletter subject.
     * @param string $content Newsletter HTML content.
     * @return array
     */
    public static function send_newsletter($subject, $content) {
        $settings = Umbra_Simple_Email::get_settings();

        if (empty($settings['gmail_address']) || empty($settings['gmail_password'])) {
            return array(
                'success' => false,
                'message' => esc_html__('Gmail not configured', 'umbra-bookshelf'),
            );
        }

        $subscribers = Umbra_Simple_Email::get_subscribers();

        if (empty($subscribers)) {
            return array(
                'success' => false,
                'message' => esc_html__('No subscribers found', 'umbra-bookshelf'),
            );
        }

        $business = Umbra_Simple_Email::get_business_info();
        $html = self::build_email_html($subject, $content, $business);

        $sent = 0;

        foreach ($subscribers as $subscriber) {
            if ($subscriber->status === 'subscribed') {
                $result = self::send_single_email(
                    $subscriber->email,
                    $subject,
                    $html,
                    $subscriber->first_name
                );

                if ($result) {
                    $sent++;
                }
            }
        }

        return array(
            'success' => true,
            'count'   => $sent,
        );
    }

    /**
     * Send single email
     *
     * @param string $to        Recipient email.
     * @param string $subject   Email subject.
     * @param string $html       Email HTML.
     * @param string $first_name First name.
     * @return bool
     */
    private static function send_single_email($to, $subject, $html, $first_name = '') {
        $settings = Umbra_Simple_Email::get_settings();

        // Replace placeholder with actual unsubscribe link
        $token = Umbra_Simple_Email::generate_unsubscribe_token($to);
        $unsubscribe_url = add_query_arg(array(
            'email'  => rawurlencode($to),
            'token'  => $token,
        ), home_url('/unsubscribe/'));

        $html = str_replace('{{unsubscribe_url}}', esc_url($unsubscribe_url), $html);
        $html = str_replace('{{subscriber_email}}', esc_html($to), $html);

        if ($first_name) {
            $html = str_replace('{{first_name}}', esc_html($first_name), $html);
        } else {
            $html = str_replace('{{first_name}}', '', $html);
        }

        $headers = array(
            'Content-Type: text/html; charset=UTF-8',
            'From: ' . $settings['sender_name'] . ' <' . $settings['gmail_address'] . '>',
        );

        if (!empty($settings['reply_to'])) {
            $headers[] = 'Reply-To: ' . $settings['reply_to'];
        }

        $headers[] = 'MIME-Version: 1.0';

        return wp_mail($to, $subject, $html, $headers);
    }

    /**
     * Build email HTML
     *
     * @param string $subject  Subject.
     * @param string $content Content.
     * @param array  $business Business info.
     * @return string
     */
    private static function build_email_html($subject, $content, $business) {
        $site_url = get_bloginfo('url');
        $site_name = get_bloginfo('name');

        $address_html = '';
        if ($business['name']) {
            $address_html = '<p>' . esc_html($business['name']) . '<br>';
            if ($business['address_1']) {
                $address_html .= esc_html($business['address_1']) . '<br>';
            }
            if ($business['city']) {
                $address_html .= esc_html($business['city']);
                if ($business['country']) {
                    $address_html .= ', ' . esc_html($business['country']);
                }
            }
            $address_html .= '</p>';
        }

        return '<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>' . esc_html($subject) . '</title>
    <style>
        body { margin: 0; padding: 0; font-family: Georgia, serif; font-size: 16px; line-height: 1.6; color: #2C2C2C; background-color: #F5F0E8; }
        .email-container { max-width: 600px; margin: 0 auto; background-color: #ffffff; }
        .email-header { background-color: #1B3A6B; padding: 30px; text-align: center; }
        .email-header h1 { color: #C8A96E; margin: 0; font-size: 28px; }
        .email-body { padding: 30px; }
        .email-footer { background-color: #EDE4D0; padding: 20px 30px; text-align: center; font-size: 12px; color: #555555; }
        a { color: #2E6DA4; }
        .unsubscribe-link { color: #888888; text-decoration: underline; }
        h2 { color: #1B3A6B; }
        p { margin: 0 0 15px; }
    </style>
</head>
<body>
    <div class="email-container">
        <div class="email-header">
            <h1>' . esc_html($site_name) . '</h1>
        </div>
        <div class="email-body">
            ' . $content . '
        </div>
        <div class="email-footer">
            <p>
                <a href="' . esc_url($site_url) . '">' . esc_html($site_url) . '</a>
            </p>
            ' . $address_html . '
            <p>
                <a href="{{unsubscribe_url}}" class="unsubscribe-link">Unsubscribe</a> from this mailing list.
            </p>
            <p>You received this email because you signed up for updates from ' . esc_html($site_name) . '.</p>
        </div>
    </div>
</body>
</html>';
    }

    /**
     * Encrypt password
     *
     * @param string $password Plain password.
     * @return string
     */
    public static function encrypt_password($password) {
        $key = defined('AUTH_KEY') ? AUTH_KEY : 'bdm_email_secret';
        $iv = openssl_random_pseudo_bytes(16);

        $encrypted = openssl_encrypt($password, 'AES-256-CBC', $key, 0, $iv);

        return base64_encode($iv . $encrypted);
    }

    /**
     * Decrypt password
     *
     * @param string $encrypted Encrypted password.
     * @return string
     */
    public static function decrypt_password($encrypted) {
        $data = base64_decode($encrypted);

        $key = defined('AUTH_KEY') ? AUTH_KEY : 'bdm_email_secret';

        $iv = substr($data, 0, 16);
        $ciphertext = substr($data, 16);

        return openssl_decrypt($ciphertext, 'AES-256-CBC', $key, 0, $iv);
    }
}