<?php
require_once __DIR__ . '/../db/config.php';
require_once __DIR__ . '/../mail/MailService.php';

class NotificationService
{
    /**
     * Send a notification for a specific event.
     *
     * @param string $eventName The event name (e.g., 'shipment_created')
     * @param array $user The recipient user array (must contain 'email' and 'full_name')
     * @param array $data Data to replace in placeholders (e.g., ['shipment_id' => 123])
     * @param string|null $lang 'en' or 'ar'. If null, sends both combined.
     */
    public static function send(string $eventName, array $user, array $data = [], ?string $lang = null)
    {
        $pdo = db();
        $stmt = $pdo->prepare("SELECT * FROM notification_templates WHERE event_name = ?");
        $stmt->execute([$eventName]);
        $template = $stmt->fetch();

        if (!$template) {
            error_log("Notification template not found: $eventName");
            return;
        }

        // Prepare data for replacement
        $placeholders = [];
        $values = [];
        $data['user_name'] = $user['full_name'] ?? 'User';
        
        foreach ($data as $key => $val) {
            $placeholders[] = '{' . $key . '}';
            $values[] = $val;
        }

        // Determine Subject and Body based on Lang
        $subject = '';
        $body = '';
        $whatsapp = '';

        if ($lang === 'en') {
            $subject = $template['email_subject_en'];
            $body = $template['email_body_en'];
            $whatsapp = $template['whatsapp_body_en'];
        } elseif ($lang === 'ar') {
            $subject = $template['email_subject_ar'];
            $body = $template['email_body_ar'];
            $whatsapp = $template['whatsapp_body_ar'];
        } else {
            // Combined
            $subject = $template['email_subject_en'] . ' / ' . $template['email_subject_ar'];
            $body = $template['email_body_en'] . "\n\n---\n\n" . $template['email_body_ar'];
            $whatsapp = $template['whatsapp_body_en'] . "\n\n" . $template['whatsapp_body_ar'];
        }

        // Replace
        $subject = str_replace($placeholders, $values, $subject);
        $body = str_replace($placeholders, $values, $body);
        $whatsapp = str_replace($placeholders, $values, $whatsapp);

        // Send Email
        if (!empty($user['email'])) {
            // Convert newlines to BR for HTML
            $htmlBody = nl2br(htmlspecialchars($body));
            MailService::sendMail($user['email'], $subject, $htmlBody, $body);
        }

        // Log WhatsApp (Mock)
        // In a real app, this would call Twilio/Meta API
        error_log("WHATSAPP Notification to {$user['email']} (Phone N/A): $whatsapp");
    }
}