<?php
class Notification {
    private $db;
    private $mailer;
    
    public function __construct($db, $mailer) {
        $this->db = $db;
        $this->mailer = $mailer;
    }
    
    public function createNotification($user_id, $type, $message, $data = null) {
        $stmt = $this->db->prepare("INSERT INTO notifications (user_id, type, message, data, created_at) VALUES (?, ?, ?, ?, NOW())");
        $data_json = $data ? json_encode($data) : null;
        $stmt->bind_param('isss', $user_id, $type, $message, $data_json);
        $stmt->execute();
        
        // Send email notification if enabled
        $this->sendEmailNotification($user_id, $type, $message);
        
        // Send push notification if enabled
        $this->sendPushNotification($user_id, $type, $message);
        
        return $stmt->insert_id;
    }
    
    public function getUserNotifications($user_id, $limit = 10, $offset = 0) {
        $stmt = $this->db->prepare("SELECT * FROM notifications WHERE user_id = ? ORDER BY created_at DESC LIMIT ? OFFSET ?");
        $stmt->bind_param('iii', $user_id, $limit, $offset);
        $stmt->execute();
        return $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
    }
    
    public function markAsRead($notification_id, $user_id) {
        $stmt = $this->db->prepare("UPDATE notifications SET read_at = NOW() WHERE id = ? AND user_id = ?");
        $stmt->bind_param('ii', $notification_id, $user_id);
        return $stmt->execute();
    }
    
    public function markAllAsRead($user_id) {
        $stmt = $this->db->prepare("UPDATE notifications SET read_at = NOW() WHERE user_id = ? AND read_at IS NULL");
        $stmt->bind_param('i', $user_id);
        return $stmt->execute();
    }
    
    public function getUnreadCount($user_id) {
        $stmt = $this->db->prepare("SELECT COUNT(*) as count FROM notifications WHERE user_id = ? AND read_at IS NULL");
        $stmt->bind_param('i', $user_id);
        $stmt->execute();
        $result = $stmt->get_result()->fetch_assoc();
        return $result['count'];
    }
    
    private function sendEmailNotification($user_id, $type, $message) {
        // Get user email
        $stmt = $this->db->prepare("SELECT email, notification_preferences FROM users WHERE id = ?");
        $stmt->bind_param('i', $user_id);
        $stmt->execute();
        $user = $stmt->get_result()->fetch_assoc();
        
        if ($user && $this->shouldSendEmail($user['notification_preferences'], $type)) {
            $this->mailer->sendEmail(
                $user['email'],
                "New Notification from ShubraVeil",
                $message
            );
        }
    }
    
    private function sendPushNotification($user_id, $type, $message) {
        // Get user's push notification token
        $stmt = $this->db->prepare("SELECT push_token, notification_preferences FROM users WHERE id = ?");
        $stmt->bind_param('i', $user_id);
        $stmt->execute();
        $user = $stmt->get_result()->fetch_assoc();
        
        if ($user && $this->shouldSendPush($user['notification_preferences'], $type) && $user['push_token']) {
            // Initialize Firebase
            $firebase = new \Kreait\Firebase\Factory();
            $messaging = $firebase->createMessaging();
            
            $message = \Kreait\Firebase\Messaging\CloudMessage::withTarget('token', $user['push_token'])
                ->withNotification([
                    'title' => 'ShubraVeil',
                    'body' => $message
                ]);
            
            try {
                $messaging->send($message);
            } catch (\Exception $e) {
                // Log error but don't throw
                error_log("Push notification failed: " . $e->getMessage());
            }
        }
    }
    
    private function shouldSendEmail($preferences, $type) {
        $prefs = json_decode($preferences, true);
        return isset($prefs['email'][$type]) ? $prefs['email'][$type] : true;
    }
    
    private function shouldSendPush($preferences, $type) {
        $prefs = json_decode($preferences, true);
        return isset($prefs['push'][$type]) ? $prefs['push'][$type] : true;
    }
}