<?php
require_once __DIR__ . '/../db/config.php';
require_once __DIR__ . '/../mail/MailService.php';
require_once __DIR__ . '/app.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 'id', 'email', 'full_name', 'role')
     * @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);
        }

        // Send WhatsApp if enabled
        if (get_setting('whatsapp_enabled') === '1') {
            $phone = self::getPhoneNumber($user);
            if ($phone) {
                self::sendWhatsApp($phone, $whatsapp);
            } else {
                error_log("WHATSAPP Notification skipped for {$user['email']}: Phone number not found.");
            }
        }
    }

    /**
     * Retrieve phone number for a user, fetching from profile if necessary.
     */
    private static function getPhoneNumber(array $user): ?string
    {
        if (!empty($user['phone'])) {
            return $user['phone'];
        }

        if (empty($user['id']) || empty($user['role'])) {
            return null;
        }

        $pdo = db();
        if ($user['role'] === 'shipper') {
            $stmt = $pdo->prepare("SELECT phone FROM shipper_profiles WHERE user_id = ?");
            $stmt->execute([$user['id']]);
            return $stmt->fetchColumn() ?: null;
        } elseif ($user['role'] === 'truck_owner') {
            $stmt = $pdo->prepare("SELECT phone FROM truck_owner_profiles WHERE user_id = ?");
            $stmt->execute([$user['id']]);
            return $stmt->fetchColumn() ?: null;
        }

        return null;
    }

    /**
     * Send a WhatsApp message via Wablas API.
     */
    public static function sendWhatsApp(string $phone, string $message)
    {
        // 1. Format Phone Number
        // Remove non-numeric characters
        $phone = preg_replace('/[^0-9]/', '', $phone);

        // If 8 digits, prepend 968 (Oman country code)
        if (strlen($phone) === 8) {
            $phone = '968' . $phone;
        }

        // 2. Get Settings
        $domain = get_setting('wablas_domain');
        $token = get_setting('wablas_api_token');

        if (!$domain || !$token) {
            error_log("WHATSAPP Error: Wablas domain or token not configured.");
            return;
        }

        // Ensure domain has no trailing slash and correct scheme
        $domain = rtrim($domain, '/');
        if (!preg_match('/^https?:\\/', $domain)) {
            $domain = 'https://' . $domain;
        }

        // 3. Send API Request
        // Endpoint: /api/send-message (StandardWablas)
        $url = $domain . "/api/send-message";

        $data = [
            'phone' => $phone,
            'message' => $message,
        ];

        $ch = curl_init($url);
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            "Authorization: $token",
            "Content-Type: application/json" // Wablas often accepts JSON or form-data. Trying JSON first, or form-data if that fails.
            // Actually, many Wablas instances use form-data or x-www-form-urlencoded. 
            // Let's try standard POST fields which curl sends as application/x-www-form-urlencoded by default if passing array.
        ]);
        
        // Resetting headers to just Authorization for form-urlencoded default
        curl_setopt($ch, CURLOPT_HTTPHEADER, [
            "Authorization: $token"
        ]);
        curl_setopt($ch, CURLOPT_POST, true);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($ch, CURLOPT_TIMEOUT, 10);
        curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false); // For dev env

        $response = curl_exec($ch);
        $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        $error = curl_error($ch);
        curl_close($ch);

        if ($error) {
            error_log("WHATSAPP cURL Error: $error");
            return;
        }

        // Log result
        error_log("WHATSAPP Sent to $phone. Status: $httpCode. Response: " . substr($response, 0, 100));
    }
}