Umbra-Bookshelf/umbra-bookshelf/includes/email/class-umbra-email-admin.php

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

/**
 * Email Admin Class
 *
 * @package Umbra_Simple_Email
 */

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

class Umbra_Simple_Email_Admin {
    private static $instance = null;

    /**
     * Get instance
     *
     * @return Umbra_Simple_Email_Admin
     */
    public static function instance() {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    /**
     * Constructor
     */
    private function __construct() {
        add_action('admin_enqueue_scripts', array($this, 'enqueue_assets'));
    }

    /**
     * Enqueue admin assets
     *
     * @param string $hook Current admin page.
     */
    public function enqueue_assets($hook) {
        // Matches the submenu slugs registered by Umbra_Simple_Email::add_menu_pages().
        if (strpos($hook, 'umbra-bookshelf-subscribers') !== false
            || strpos($hook, 'umbra-bookshelf-newsletter') !== false
            || strpos($hook, 'umbra-bookshelf-email-settings') !== false) {

            wp_enqueue_style(
                'umbra-bookshelf-email-admin',
                UMBRA_BOOKSHELF_URL . 'email/assets/css/admin.css',
                array(),
                UMBRA_BOOKSHELF_EMAIL_VERSION
            );

            wp_enqueue_script(
                'umbra-bookshelf-email-admin',
                UMBRA_BOOKSHELF_URL . 'email/assets/js/admin.js',
                array('jquery'),
                UMBRA_BOOKSHELF_EMAIL_VERSION,
                true
            );
        }
    }

    /**
     * Subscribers page
     */
    public static function subscribers_page() {
        global $wpdb;
        $table_name = $wpdb->prefix . 'bd_subscribers';

        if (isset($_POST['bd_export_subscribers'])) {
            check_admin_referer('bd_export_subscribers');

            header('Content-Type: text/csv');
            header('Content-Disposition: attachment; filename=subscribers-' . date('Y-m-d') . '.csv');

            $subscribers = $wpdb->get_results(
                "SELECT email, first_name, status, subscribed_at FROM {$table_name} WHERE status = 'subscribed'"
            );

            printf("Email,First Name,Status,Subscribed Date\n");
            foreach ($subscribers as $sub) {
                printf("%s,%s,%s,%s\n",
                    esc_html($sub->email),
                    esc_html($sub->first_name),
                    esc_html($sub->status),
                    esc_html($sub->subscribed_at)
                );
            }
            exit;
        }

        $subscribers = $wpdb->get_results("SELECT * FROM {$table_name} ORDER BY subscribed_at DESC");
        $total = count($subscribers);
        $subscribed = $wpdb->get_var("SELECT COUNT(*) FROM {$table_name} WHERE status = 'subscribed'");
        $unsubscribed = $wpdb->get_var("SELECT COUNT(*) FROM {$table_name} WHERE status = 'unsubscribed'");

        echo '<div class="wrap">';
        echo '<h1>' . esc_html__('Subscribers', 'bd-simpleemail') . '</h1>';

        echo '<div class="bd-email-stats">';
        printf('<div class="stat-box"><h2>%d</h2><p>%s</p></div>', esc_html($total), esc_html__('Total', 'bd-simpleemail'));
        printf('<div class="stat-box"><h2>%d</h2><p>%s</p></div>', esc_html($subscribed), esc_html__('Active', 'bd-simpleemail'));
        printf('<div class="stat-box"><h2>%d</h2><p>%s</p></div>', esc_html($unsubscribed), esc_html__('Unsubscribed', 'bd-simpleemail'));
        echo '</div>';

        echo '<form method="post">';
        wp_nonce_field('bd_export_subscribers');
        echo '<p><input type="submit" name="bd_export_subscribers" class="button" value="' . esc_attr__('Export CSV', 'bd-simpleemail') . '"></p>';
        echo '</form>';

        echo '<table class="widefat">';
        echo '<thead><tr><th>ID</th><th>Email</th><th>First Name</th><th>Status</th><th>Subscribed</th><th>Unsubscribed</th></tr></thead>';
        echo '<tbody>';

        foreach ($subscribers as $sub) {
            printf('<tr><td>%d</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td><td>%s</td></tr>',
                esc_html($sub->id),
                esc_html($sub->email),
                esc_html($sub->first_name),
                esc_html($sub->status),
                esc_html($sub->subscribed_at),
                $sub->unsubscribed_at ? esc_html($sub->unsubscribed_at) : '-'
            );
        }

        echo '</tbody></table></div>';
    }

    /**
     * New newsletter page
     */
    public static function new_newsletter_page() {
        $error = '';
        $success = '';

        if (isset($_POST['bd_send_newsletter']) && check_admin_referer('bd_send_newsletter')) {
            $subject = sanitize_text_field($_POST['subject'] ?? '');
            $content = wp_kses_post($_POST['content'] ?? '');
            $ai_generate = isset($_POST['ai_generate']);
            $publish_blog = isset($_POST['publish_blog']);

            if ($ai_generate && $subject) {
                $prompt = sanitize_textarea_field($_POST['ai_prompt'] ?? '');
                $content = self::generate_newsletter($subject, $prompt);
            }

            if ($content) {
                $result = Umbra_Email_Sender::send_newsletter($subject, $content);

                if ($result['success']) {
                    self::log_newsletter($subject, $content, $result['count']);
                    $success = sprintf(
                        esc_html__('Newsletter sent to %d subscribers!', 'bd-simpleemail'),
                        $result['count']
                    );

                    if ($publish_blog && $subject) {
                        self::publish_as_blog_post($subject, $content);
                    }
                } else {
                    $error = $result['message'];
                }
            } else {
                $error = esc_html__('Content is required', 'bd-simpleemail');
            }
        }

        $settings = Umbra_Simple_Email::get_settings();
        $has_ai = !empty($settings['gemini_api_key']);

        echo '<div class="wrap">';
        echo '<h1>' . esc_html__('New Newsletter', 'bd-simpleemail') . '</h1>';

        if ($error) {
            printf('<div class="error"><p>%s</p></div>', esc_html($error));
        }

        if ($success) {
            printf('<div class="updated"><p>%s</p></div>', esc_html($success));
        }

        if (!$has_ai) {
            echo '<div class="notice notice-warning"><p>' . esc_html__('Gemini API key not configured. AI generation disabled.', 'bd-simpleemail') . '</p></div>';
        }

        echo '<form method="post" id="newsletter-form">';
        wp_nonce_field('bd_send_newsletter');

        echo '<table class="form-table">';
        echo '<tr><th>' . esc_html__('Subject', 'bd-simpleemail') . '</th>';
        echo '<td><input type="text" name="subject" class="large-text" required></td></tr>';

        if ($has_ai) {
            echo '<tr><th>' . esc_html__('AI Generate', 'bd-simpleemail') . '</th>';
            echo '<td><input type="checkbox" name="ai_generate" id="ai_generate" value="1"> ';
            echo '<label for="ai_generate">' . esc_html__('Use Gemini AI to generate content', 'bd-simpleemail') . '</label></td></tr>';

            echo '<tr class="ai-prompt-row" style="display:none;"><th>' . esc_html__('Prompt', 'bd-simpleemail') . '</th>';
            echo '<td><textarea name="ai_prompt" rows="4" class="large-text" placeholder="' . esc_attr__('Describe what the newsletter should contain...', 'bd-simpleemail') . '"></textarea></td></tr>';
        }

        echo '<tr><th>' . esc_html__('Content', 'bd-simpleemail') . '</th>';
        echo '<td><textarea name="content" rows="20" class="large-text" id="newsletter-content"></textarea></td></tr>';

        echo '<tr><th>' . esc_html__('Options', 'bd-simpleemail') . '</th>';
        echo '<td><input type="checkbox" name="publish_blog" id="publish_blog" value="1"> ';
        echo '<label for="publish_blog">' . esc_html__('Also publish as blog post', 'bd-simpleemail') . '</label></td></tr>';
        echo '</table>';

        echo '<p><input type="submit" name="bd_send_newsletter" class="button button-primary" value="' . esc_attr__('Send Newsletter', 'bd-simpleemail') . '"></p>';
        echo '</form>';

        echo '<script>
        jQuery(document).ready(function($) {
            $("#ai_generate").on("change", function() {
                $(".ai-prompt-row").toggle(this.checked);
            });
        });
        </script>';

        echo '</div>';
    }

    /**
     * Settings page
     */
    public static function settings_page() {
        if (isset($_POST['bd_save_email_settings'])) {
            check_admin_referer('bd_email_settings');

            update_option('bdm_gmail_address', sanitize_email($_POST['gmail_address'] ?? ''));
            update_option('bdm_sender_name', sanitize_text_field($_POST['sender_name'] ?? ''));
            update_option('bdm_reply_to', sanitize_email($_POST['reply_to'] ?? ''));

            if (!empty($_POST['gmail_password'])) {
                update_option('bdm_gmail_password', Umbra_Email_Sender::encrypt_password($_POST['gmail_password']));
            }

            if (!empty($_POST['gemini_api_key'])) {
                update_option('bdm_gemini_api_key', sanitize_text_field($_POST['gemini_api_key']));
            }

            echo '<div class="updated"><p>' . esc_html__('Settings saved.', 'bd-simpleemail') . '</p></div>';
        }

        $settings = Umbra_Simple_Email::get_settings();
        $business = Umbra_Simple_Email::get_business_info();

        echo '<div class="wrap">';
        echo '<h1>' . esc_html__('BD SimpleEmail Settings', 'bd-simpleemail') . '</h1>';

        echo '<form method="post">';
        wp_nonce_field('bd_email_settings');

        echo '<h2>' . esc_html__('Gmail Configuration', 'bd-simpleemail') . '</h2>';
        echo '<p>' . esc_html__('Configure your Gmail account for sending newsletters via SMTP.', 'bd-simpleemail') . '</p>';

        echo '<table class="form-table">';
        echo '<tr><th>' . esc_html__('Gmail Address', 'bd-simpleemail') . '</th>';
        printf('<td><input type="email" name="gmail_address" value="%s" class="regular-text"></td></tr>',
            esc_attr($settings['gmail_address'])
        );

        echo '<tr><th>' . esc_html__('App Password', 'bd-simpleemail') . '</th>';
        echo '<td><input type="password" name="gmail_password" class="regular-text" placeholder="' . esc_attr__('Leave blank to keep current', 'bd-simpleemail') . '">';
        echo '<p class="description"><a href="https://support.google.com/accounts/answer/185833" target="_blank">' . esc_html__('Learn how to generate an app password', 'bd-simpleemail') . '</a></p></td></tr>';

        echo '<tr><th>' . esc_html__('Sender Name', 'bd-simpleemail') . '</th>';
        printf('<td><input type="text" name="sender_name" value="%s" class="regular-text"></td></tr>',
            esc_attr($settings['sender_name'])
        );

        echo '<tr><th>' . esc_html__('Reply-To', 'bd-simpleemail') . '</th>';
        printf('<td><input type="email" name="reply_to" value="%s" class="regular-text"></td></tr>',
            esc_attr($settings['reply_to'])
        );
        echo '</table>';

        echo '<h2>' . esc_html__('Gemini AI', 'bd-simpleemail') . '</h2>';
        echo '<table class="form-table">';
        echo '<tr><th>' . esc_html__('API Key', 'bd-simpleemail') . '</th>';
        printf('<td><input type="text" name="gemini_api_key" value="%s" class="regular-text">',
            esc_attr($settings['gemini_api_key'])
        );
        echo '<p class="description"><a href="https://makersuite.google.com/app/apikey" target="_blank">' . esc_html__('Get your API key', 'bd-simpleemail') . '</a></p></td></tr>';
        echo '</table>';

        echo '<h2>' . esc_html__('Business Information (CAN-SPAM)', 'bd-simpleemail') . '</h2>';
        echo '<p>' . esc_html__('These fields are required for CAN-SPAM compliance.', 'bd-simpleemail') . '</p>';
        echo '<table class="form-table">';
        printf('<tr><th>' . esc_html__('Business Name', 'bd-simpleemail') . '</th><td>%s</td></tr>', esc_html($business['name']) ?: '-');
        printf('<tr><th>' . esc_html__('Address', 'bd-simpleemail') . '</th><td>%s</td></tr>',
            esc_html($business['address_1']) . '<br>' . esc_html($business['address_2']) . '<br>' . esc_html($business['city']) . '<br>' . esc_html($business['country'])
        );
        printf('<tr><th>' . esc_html__('Phone', 'bd-simpleemail') . '</th><td>%s</td></tr>', esc_html($business['phone']) ?: '-');
        echo '</table>';

        submit_button(esc_html__('Save Settings', 'bd-simpleemail'), 'primary', 'bd_save_email_settings');
        echo '</form></div>';
    }

    /**
     * Generate newsletter with Gemini AI
     *
     * @param string $subject Newsletter subject.
     * @param string $prompt   User prompt.
     * @return string
     */
    private static function generate_newsletter($subject, $prompt) {
        $settings = Umbra_Simple_Email::get_settings();

        if (empty($settings['gemini_api_key'])) {
            return '';
        }

        $system_instruction = "You are a professional newsletter writer for an author. Write engaging, concise newsletter content in HTML format. Use <p> for paragraphs, <h2> for headings, and <ul> for lists. Keep it friendly but professional.";

        $full_prompt = $system_instruction . "\n\nSubject: " . $subject . "\n\nAdditional instructions: " . $prompt;

        $api_url = 'https://generativelanguage.googleapis.com/v1beta/models/gemini-pro:generateContent?key=' . $settings['gemini_api_key'];

        $body = array(
            'contents' => array(
                array(
                    'parts' => array(
                        array('text' => $full_prompt)
                    )
                )
            ),
            'generationConfig' => array(
                'temperature' => 0.9,
                'maxOutputTokens' => 2048,
            ),
        );

        $response = wp_remote_post($api_url, array(
            'body'    => json_encode($body),
            'headers' => array('Content-Type' => 'application/json'),
        ));

        if (is_wp_error($response)) {
            return '';
        }

        $data = json_decode(wp_remote_retrieve_body($response), true);

        if (isset($data['candidates'][0]['content']['parts'][0]['text'])) {
            return $data['candidates'][0]['content']['parts'][0]['text'];
        }

        return '';
    }

    /**
     * Log newsletter send
     *
     * @param string $subject           Subject.
     * @param string $content           Content.
     * @param int    $recipient_count   Recipient count.
     */
    private static function log_newsletter($subject, $content, $recipient_count) {
        global $wpdb;
        $table_name = $wpdb->prefix . 'bd_newsletters';

        $wpdb->insert($table_name, array(
            'subject'         => $subject,
            'body_html'       => $content,
            'sent_at'         => current_time('mysql'),
            'recipient_count' => $recipient_count,
        ));
    }

    /**
     * Publish newsletter as blog post
     *
     * @param string $subject Subject.
     * @param string $content  Content.
     * @return int Post ID.
     */
    private static function publish_as_blog_post($subject, $content) {
        return wp_insert_post(array(
            'post_title'   => $subject,
            'post_content' => $content,
            'post_status'  => 'publish',
            'post_type'    => 'post',
        ));
    }
}