在Laravel中实现数据库通知的聚合与去重：避免频繁通知更新计数

// app/Services/NotificationAggregator.php
<?php

namespace App\Services;

use App\Models\User;
use App\Notifications\NewPostMatchedSearch;
use Illuminate\Notifications\DatabaseNotification;
use Carbon\Carbon;

class NotificationAggregator
{
    /**
     * 根据条件分发或聚合“新帖子匹配搜索”通知。
     *
     * @param User $notifiable 接收通知的用户
     * @param object $search 匹配的搜索对象
     * @param int $timeWindowMinutes 聚合时间窗口（分钟）
     * @return void
     */
    public function dispatchAggregatedPostSearchNotification(
        User $notifiable,
        object $search,
        int $timeWindowMinutes = 30
    ): void {
        $aggregationKey = $search->id; // 使用搜索ID作为聚合键
        $timeWindowStart = Carbon::now()->subMinutes($timeWindowMinutes);

        // 尝试查找在指定时间窗口内已存在的、可聚合的通知
        $existingNotification = $notifiable->notifications()
            ->where('type', NewPostMatchedSearch::class) // 确保是同类型的通知
            ->where('data->search', $aggregationKey) // 根据聚合键筛选
            ->where('created_at', '>=', $timeWindowStart) // 在时间窗口内创建的通知
            ->first();

        if ($existingNotification) {
            // 如果找到现有通知，则更新它
            $data = $existingNotification->data;
            $currentCount = $data['count'] ?? 0;
            $newCount = $currentCount + 1;

            // 更新通知数据
            $data['count'] = $newCount;
            $data['content']['en'] = "{$newCount} new posts matched with your saved search {$search->title} has been posted, Press here to view more.";

            $existingNotification->update([
                'data' => $data,
                'updated_at' => Carbon::now(), // 更新updated_at以反映最新活动
            ]);
            // 注意：这里没有调用 $notifiable->notify()，因此不会创建新通知。
        } else {
            // 如果没有找到现有通知，则分发一条新的通知
            // 初始计数为1
            $notifiable->notify(new NewPostMatchedSearch($search, 1));
        }
    }
}

// app/Notifications/NewPostMatchedSearch.php
<?php

namespace App\Notifications;

use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Notifications\Notification;
use Illuminate\Notifications\Messages\DatabaseMessage;

class NewPostMatchedSearch extends Notification implements ShouldQueue
{
    use Queueable;

    protected $search;
    protected $initialCount; // 用于新通知的初始计数

    /**
     * 创建一个新的通知实例。
     *
     * @param object $search 匹配的搜索对象
     * @param int $initialCount 新通知的初始计数 (默认为1)
     * @return void
     */
    public function __construct(object $search, int $initialCount = 1)
    {
        $this->search = $search;
        $this->initialCount = $initialCount;
    }

    /**
     * 获取通知的传递渠道。
     *
     * @param object $notifiable
     * @return array<int, string>
     */
    public function via(object $notifiable): array
    {
        return ['database'];
    }

    /**
     * 将通知转换为数据库存储的数组格式。
     *
     * @param object $notifiable
     * @return array<string, mixed>
     */
    public function toDatabase(object $notifiable): array
    {
        return [
            'content' => [
                'en' => "{$this->initialCount} new post matched with your saved search {$this->search->title} has been posted, Press here to view more.",
            ],
            'count' => $this->initialCount,
            'search' => $this->search->id, // 存储聚合键
            'parameters' => $this->search->parameters,
        ];
    }
}

// 例如，在Post创建或匹配搜索的逻辑中
use App\Services\NotificationAggregator;
use App\Models\User;
use App\Models\Search;
use App\Models\Post;

// 假设我们有一个用户、一个搜索和一篇新帖子
$user = User::find(1);
$search = Search::find(101);
$post = Post::find(200);

// 注入或解析 NotificationAggregator 服务
$aggregator = app(NotificationAggregator::class);

// 调用聚合分发方法
$aggregator->dispatchAggregatedPostSearchNotification($user, $search, 30); // 30分钟聚合窗口