<?php

declare(strict_types=1);

namespace App\Services;

use App\Core\DB;

class NotificationService
{
    public function createForUsers(array $userIds, string $type, string $title, ?string $message = null, ?array $payload = null): void
    {
        $userIds = array_values(array_unique(array_map('intval', $userIds)));
        $userIds = array_filter($userIds, fn($id) => $id > 0);

        if (empty($userIds)) {
            return;
        }

        $pdo = DB::connection();

        $stmt = $pdo->prepare("
            INSERT INTO notifications (
                user_id,
                type,
                title,
                message,
                payload_json,
                is_read,
                created_at
            ) VALUES (?, ?, ?, ?, ?, 0, NOW())
        ");

        $payloadJson = $payload ? json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES) : null;

        foreach ($userIds as $userId) {
            $stmt->execute([
                $userId,
                $type,
                $title,
                $message,
                $payloadJson,
            ]);
        }
    }

    public function getUnreadCount(int $userId): int
    {
        $pdo = DB::connection();

        $stmt = $pdo->prepare("
            SELECT COUNT(*)
            FROM notifications
            WHERE user_id = ?
              AND is_read = 0
        ");
        $stmt->execute([$userId]);

        return (int)$stmt->fetchColumn();
    }

    public function getLatest(int $userId, int $limit = 20): array
    {
        $pdo = DB::connection();

        $stmt = $pdo->prepare("
            SELECT *
            FROM notifications
            WHERE user_id = ?
            ORDER BY id DESC
            LIMIT ?
        ");
        $stmt->bindValue(1, $userId, \PDO::PARAM_INT);
        $stmt->bindValue(2, $limit, \PDO::PARAM_INT);
        $stmt->execute();

        return $stmt->fetchAll();
    }

    public function markAllRead(int $userId): void
    {
        $pdo = DB::connection();

        $stmt = $pdo->prepare("
            UPDATE notifications
            SET is_read = 1,
                read_at = NOW()
            WHERE user_id = ?
              AND is_read = 0
        ");
        $stmt->execute([$userId]);
    }
}