From b29d792c8600e9730dcd4ff9c0dea5d931c64982 Mon Sep 17 00:00:00 2001
From: Daniel Supernault <danielsupernault@gmail.com>
Date: Mon, 30 Sep 2024 02:55:44 -0600
Subject: [PATCH] Add PushNotificationService

---
 app/Services/PushNotificationService.php | 123 +++++++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 app/Services/PushNotificationService.php

diff --git a/app/Services/PushNotificationService.php b/app/Services/PushNotificationService.php
new file mode 100644
index 00000000..8acb07ac
--- /dev/null
+++ b/app/Services/PushNotificationService.php
@@ -0,0 +1,123 @@
+<?php
+
+namespace App\Services;
+
+use App\User;
+use Exception;
+use Illuminate\Support\Facades\Cache;
+use Illuminate\Support\Facades\Redis;
+use Log;
+
+class PushNotificationService
+{
+    public const ACTIVE_LIST_KEY = 'pf:services:push-notify:active_deliver:';
+
+    public const NOTIFY_TYPES = ['follow', 'like', 'mention', 'comment'];
+
+    public const DEEP_CHECK_KEY = 'pf:services:push-notify:deep-check:';
+
+    public const PUSH_GATEWAY_VERSION = '1.0';
+
+    public const LOTTERY_ODDS = 20;
+
+    public const CACHE_LOCK_SECONDS = 10;
+
+    public static function get($list)
+    {
+        return Redis::smembers(self::ACTIVE_LIST_KEY.$list);
+    }
+
+    public static function set($listId, $memberId)
+    {
+        if (! in_array($listId, self::NOTIFY_TYPES)) {
+            return false;
+        }
+        $user = User::whereProfileId($memberId)->first();
+        if (! $user || $user->status || $user->deleted_at) {
+            return false;
+        }
+
+        return Redis::sadd(self::ACTIVE_LIST_KEY.$listId, $memberId);
+    }
+
+    public static function check($listId, $memberId)
+    {
+        return random_int(1, self::LOTTERY_ODDS) === 1
+            ? self::isMemberDeepCheck($listId, $memberId)
+            : self::isMember($listId, $memberId);
+    }
+
+    public static function isMember($listId, $memberId)
+    {
+        try {
+            return Redis::sismember(self::ACTIVE_LIST_KEY.$listId, $memberId);
+        } catch (Exception $e) {
+            return false;
+        }
+    }
+
+    public static function isMemberDeepCheck($listId, $memberId)
+    {
+        $lock = Cache::lock(self::DEEP_CHECK_KEY.$listId, self::CACHE_LOCK_SECONDS);
+
+        try {
+            $lock->block(5);
+            $actualCount = User::whereNull('status')->where('notify_enabled', true)->where('notify_'.$listId, true)->count();
+            $cachedCount = self::count($listId);
+            if ($actualCount != $cachedCount) {
+                self::warmList($listId);
+                $user = User::where('notify_enabled', true)->where('profile_id', $memberId)->first();
+
+                return $user ? (bool) $user->{"notify_{$listId}"} : false;
+            } else {
+                return self::isMember($listId, $memberId);
+            }
+        } catch (Exception $e) {
+            Log::error('Failed during deep membership check: '.$e->getMessage());
+
+            return false;
+        } finally {
+            optional($lock)->release();
+        }
+    }
+
+    public static function removeMember($listId, $memberId)
+    {
+        return Redis::srem(self::ACTIVE_LIST_KEY.$listId, $memberId);
+    }
+
+    public static function removeMemberFromAll($memberId)
+    {
+        foreach (self::NOTIFY_TYPES as $type) {
+            self::removeMember($type, $memberId);
+        }
+
+        return 1;
+    }
+
+    public static function count($listId)
+    {
+        if (! in_array($listId, self::NOTIFY_TYPES)) {
+            return false;
+        }
+
+        return Redis::scard(self::ACTIVE_LIST_KEY.$listId);
+    }
+
+    public static function warmList($listId)
+    {
+        if (! in_array($listId, self::NOTIFY_TYPES)) {
+            return false;
+        }
+        $key = self::ACTIVE_LIST_KEY.$listId;
+        Redis::del($key);
+        foreach (User::where('notify_'.$listId, true)->cursor() as $acct) {
+            if ($acct->status || $acct->deleted_at || ! $acct->profile_id || ! $acct->notify_enabled) {
+                continue;
+            }
+            Redis::sadd($key, $acct->profile_id);
+        }
+
+        return self::count($listId);
+    }
+}