<?php

declare(strict_types=1);

namespace ServerManager\Services;

use ServerManager\Core\App;
use ServerManager\Core\Database;
use ServerManager\Core\Logger;

class FCMService
{
    private Database $db;
    private Logger $logger;
    private string $serverKey;

    public function __construct()
    {
        $this->db = Database::getInstance();
        $this->logger = Logger::getInstance();
        $config = App::getConfig();

        $this->serverKey = $config['fcm']['server_key'] ?? $_ENV['FCM_SERVER_KEY'] ?? '';
    }

    public function isConfigured(): bool
    {
        return !empty($this->serverKey);
    }

    public function sendToUser(int $userId, string $title, string $body, string $type = 'info', ?int $notificationId = null): bool
    {
        if (!$this->isConfigured()) {
            return false;
        }

        $tokens = $this->db->fetchAll(
            'SELECT token FROM user_fcm_tokens WHERE user_id = ?',
            [$userId]
        );

        if (empty($tokens)) {
            return false;
        }

        $success = true;
        foreach ($tokens as $row) {
            $result = $this->sendToDevice($row['token'], $title, $body, $type, $notificationId);
            if (!$result) $success = false;
        }

        return $success;
    }

    public function sendToAll(string $title, string $body, string $type = 'info', ?int $notificationId = null): int
    {
        if (!$this->isConfigured()) {
            return 0;
        }

        $tokens = $this->db->fetchAll('SELECT DISTINCT token FROM user_fcm_tokens');
        if (empty($tokens)) return 0;

        $sent = 0;
        foreach ($tokens as $row) {
            if ($this->sendToDevice($row['token'], $title, $body, $type, $notificationId)) {
                $sent++;
            }
        }

        return $sent;
    }

    private function sendToDevice(string $token, string $title, string $body, string $type, ?int $notificationId): bool
    {
        $payload = [
            'to' => $token,
            'priority' => 'high',
            'notification' => [
                'title' => $title,
                'body' => $body,
                'sound' => 'default',
            ],
            'data' => [
                'type' => $type,
                'notification_id' => (string) ($notificationId ?? 0),
                'click_action' => 'OPEN_NOTIFICATIONS',
            ],
            'android' => [
                'priority' => 'high',
                'notification' => [
                    'channel_id' => match ($type) {
                        'error', 'warning' => 'notifications_alerts',
                        default => 'notifications_general',
                    },
                    'priority' => match ($type) {
                        'error' => 'high',
                        default => 'default',
                    },
                    'sound' => 'default',
                ],
            ],
        ];

        $ch = curl_init('https://fcm.googleapis.com/fcm/send');
        curl_setopt_array($ch, [
            CURLOPT_POST => true,
            CURLOPT_HTTPHEADER => [
                'Content-Type: application/json',
                'Authorization: key=' . $this->serverKey,
            ],
            CURLOPT_POSTFIELDS => json_encode($payload),
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT => 15,
        ]);

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

        if ($httpCode !== 200) {
            $this->logger->error('FCM send failed', [
                'http_code' => $httpCode,
                'response' => substr($response, 0, 500),
            ]);
            return false;
        }

        return true;
    }
}