[PM-19659] Clean up Notifications code (#6244)

* Move PushType to Platform Folder

- Move the PushType next to the rest of push notification code
- Specifically exclude it from needing Platform code review
- Add tests establishing rules Platform has for usage of this enum, making it safe to have no owner

* Move NotificationHub code into Platform/Push directory

* Update NotificationHub namespace imports

* Add attribute for storing push type metadata

* Rename Push Engines to have PushEngine suffix

* Move Push Registration items to their own directory

* Push code move

* Add expected usage comment

* Add Push feature registration method

- Make method able to be called multipes times with no ill effects

* Add Push Registration service entrypoint and tests

* Use new service entrypoints

* Test changes

src/Core/Enums/PushType.cs

@@ -1,35 +0,0 @@
-namespace Bit.Core.Enums;
-
-public enum PushType : byte
-{
-    SyncCipherUpdate = 0,
-    SyncCipherCreate = 1,
-    SyncLoginDelete = 2,
-    SyncFolderDelete = 3,
-    SyncCiphers = 4,
-
-    SyncVault = 5,
-    SyncOrgKeys = 6,
-    SyncFolderCreate = 7,
-    SyncFolderUpdate = 8,
-    SyncCipherDelete = 9,
-    SyncSettings = 10,
-
-    LogOut = 11,
-
-    SyncSendCreate = 12,
-    SyncSendUpdate = 13,
-    SyncSendDelete = 14,
-
-    AuthRequest = 15,
-    AuthRequestResponse = 16,
-
-    SyncOrganizations = 17,
-    SyncOrganizationStatusChanged = 18,
-    SyncOrganizationCollectionSettingChanged = 19,
-
-    Notification = 20,
-    NotificationStatus = 21,
-
-    RefreshSecurityTasks = 22
-}

src/Core/Models/PushNotification.cs

@@ -1,9 +1,11 @@
-#nullable enable
-using Bit.Core.Enums;
+using Bit.Core.Enums;
 using Bit.Core.NotificationCenter.Enums;
 
 namespace Bit.Core.Models;
 
+// New push notification payload models should not be defined in this file
+// they should instead be defined in file owned by your team.
+
 public class PushNotificationData<T>
 {
     public PushNotificationData(PushType type, T payload, string? contextId)

src/Core/Platform/Push/Engines/AzureQueuePushEngine.cs

@@ -1,5 +1,4 @@
-#nullable enable
-using System.Text.Json;
+using System.Text.Json;
 using Azure.Storage.Queues;
 using Bit.Core.Context;
 using Bit.Core.Enums;
@@ -13,17 +12,16 @@ using Microsoft.Extensions.Logging;
 
 namespace Bit.Core.Platform.Push.Internal;
 
-public class AzureQueuePushNotificationService : IPushEngine
+public class AzureQueuePushEngine : IPushEngine
 {
     private readonly QueueClient _queueClient;
     private readonly IHttpContextAccessor _httpContextAccessor;
 
-    public AzureQueuePushNotificationService(
+    public AzureQueuePushEngine(
         [FromKeyedServices("notifications")] QueueClient queueClient,
         IHttpContextAccessor httpContextAccessor,
         IGlobalSettings globalSettings,
-        ILogger<AzureQueuePushNotificationService> logger,
-        TimeProvider timeProvider)
+        ILogger<AzureQueuePushEngine> logger)
     {
         _queueClient = queueClient;
         _httpContextAccessor = httpContextAccessor;

src/Core/Platform/Push/Engines/MultiServicePushNotificationService.cs

@@ -1,5 +1,4 @@
-#nullable enable
-using Bit.Core.Enums;
+using Bit.Core.Enums;
 using Bit.Core.Settings;
 using Bit.Core.Vault.Entities;
 using Microsoft.Extensions.Logging;
@@ -8,7 +7,7 @@ namespace Bit.Core.Platform.Push.Internal;
 
 public class MultiServicePushNotificationService : IPushNotificationService
 {
-    private readonly IEnumerable<IPushEngine> _services;
+    private readonly IPushEngine[] _services;
 
     public Guid InstallationId { get; }
 
@@ -22,7 +21,8 @@ public class MultiServicePushNotificationService : IPushNotificationService
         GlobalSettings globalSettings,
         TimeProvider timeProvider)
     {
-        _services = services;
+        // Filter out any NoopPushEngine's
+        _services = [.. services.Where(engine => engine is not NoopPushEngine)];
 
         Logger = logger;
         Logger.LogInformation("Hub services: {Services}", _services.Count());

src/Core/Platform/Push/Engines/NoopPushEngine.cs

@@ -1,10 +1,9 @@
-#nullable enable
-using Bit.Core.Enums;
+using Bit.Core.Enums;
 using Bit.Core.Vault.Entities;
 
 namespace Bit.Core.Platform.Push.Internal;
 
-internal class NoopPushNotificationService : IPushEngine
+internal class NoopPushEngine : IPushEngine
 {
     public Task PushCipherAsync(Cipher cipher, PushType pushType, IEnumerable<Guid>? collectionIds) => Task.CompletedTask;
 

src/Core/Platform/Push/Engines/NotificationsApiPushEngine.cs

@@ -1,5 +1,4 @@
-#nullable enable
-using Bit.Core.Context;
+using Bit.Core.Context;
 using Bit.Core.Enums;
 using Bit.Core.Models;
 using Bit.Core.Services;
@@ -8,23 +7,22 @@ using Bit.Core.Vault.Entities;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 
-// This service is not in the `Internal` namespace because it has direct external references.
-namespace Bit.Core.Platform.Push;
+namespace Bit.Core.Platform.Push.Internal;
 
 /// <summary>
 /// Sends non-mobile push notifications to the Azure Queue Api, later received by Notifications Api.
 /// Used by Cloud-Hosted environments.
 /// Received by AzureQueueHostedService message receiver in Notifications project.
 /// </summary>
-public class NotificationsApiPushNotificationService : BaseIdentityClientService, IPushEngine
+public class NotificationsApiPushEngine : BaseIdentityClientService, IPushEngine
 {
     private readonly IHttpContextAccessor _httpContextAccessor;
 
-    public NotificationsApiPushNotificationService(
+    public NotificationsApiPushEngine(
         IHttpClientFactory httpFactory,
         GlobalSettings globalSettings,
         IHttpContextAccessor httpContextAccessor,
-        ILogger<NotificationsApiPushNotificationService> logger)
+        ILogger<NotificationsApiPushEngine> logger)
         : base(
             httpFactory,
             globalSettings.BaseServiceUri.InternalNotifications,

src/Core/Platform/Push/Engines/RelayPushEngine.cs

@@ -1,5 +1,4 @@
-#nullable enable
-using Bit.Core.Context;
+using Bit.Core.Context;
 using Bit.Core.Enums;
 using Bit.Core.IdentityServer;
 using Bit.Core.Models;
@@ -19,18 +18,18 @@ namespace Bit.Core.Platform.Push.Internal;
 /// Used by Self-Hosted environments.
 /// Received by PushController endpoint in Api project.
 /// </summary>
-public class RelayPushNotificationService : BaseIdentityClientService, IPushEngine
+public class RelayPushEngine : BaseIdentityClientService, IPushEngine
 {
     private readonly IDeviceRepository _deviceRepository;
     private readonly IHttpContextAccessor _httpContextAccessor;
 
 
-    public RelayPushNotificationService(
+    public RelayPushEngine(
         IHttpClientFactory httpFactory,
         IDeviceRepository deviceRepository,
         GlobalSettings globalSettings,
         IHttpContextAccessor httpContextAccessor,
-        ILogger<RelayPushNotificationService> logger)
+        ILogger<RelayPushEngine> logger)
         : base(
             httpFactory,
             globalSettings.PushRelayBaseUri,

src/Core/Platform/Push/IPushEngine.cs

@@ -1,8 +1,7 @@
-#nullable enable
-using Bit.Core.Enums;
+using Bit.Core.Enums;
 using Bit.Core.Vault.Entities;
 
-namespace Bit.Core.Platform.Push;
+namespace Bit.Core.Platform.Push.Internal;
 
 public interface IPushEngine
 {

src/Core/Platform/Push/IPushNotificationService.cs

@@ -1,5 +1,4 @@
-#nullable enable
-using Bit.Core.AdminConsole.Entities;
+using Bit.Core.AdminConsole.Entities;
 using Bit.Core.Auth.Entities;
 using Bit.Core.Enums;
 using Bit.Core.Models;
@@ -10,10 +9,27 @@ using Microsoft.Extensions.Logging;
 
 namespace Bit.Core.Platform.Push;
 
+/// <summary>
+/// Used to Push notifications to end-user devices.
+/// </summary>
+/// <remarks>
+/// New notifications should not be wired up inside this service. You may either directly call the
+/// <see cref="PushAsync"/> method in your service to send your notification or if you want your notification
+/// sent by other teams you can make an extension method on this service with a well typed definition
+/// of your notification. You may also make your own service that injects this and exposes methods for each of
+/// your notifications.
+/// </remarks>
 public interface IPushNotificationService
 {
+    private const string ServiceDeprecation = "Do not use the services exposed here, instead use your own services injected in your service.";
+
+    [Obsolete(ServiceDeprecation, DiagnosticId = "BWP0001")]
     Guid InstallationId { get; }
+
+    [Obsolete(ServiceDeprecation, DiagnosticId = "BWP0001")]
     TimeProvider TimeProvider { get; }
+
+    [Obsolete(ServiceDeprecation, DiagnosticId = "BWP0001")]
     ILogger Logger { get; }
 
     #region Legacy method, to be removed soon.
@@ -80,7 +96,9 @@ public interface IPushNotificationService
             Payload = new UserPushNotification
             {
                 UserId = userId,
+#pragma warning disable BWP0001 // Type or member is obsolete
                 Date = TimeProvider.GetUtcNow().UtcDateTime,
+#pragma warning restore BWP0001 // Type or member is obsolete
             },
             ExcludeCurrentContext = false,
         });
@@ -94,7 +112,9 @@ public interface IPushNotificationService
             Payload = new UserPushNotification
             {
                 UserId = userId,
+#pragma warning disable BWP0001 // Type or member is obsolete
                 Date = TimeProvider.GetUtcNow().UtcDateTime,
+#pragma warning restore BWP0001 // Type or member is obsolete
             },
             ExcludeCurrentContext = false,
         });
@@ -108,7 +128,9 @@ public interface IPushNotificationService
             Payload = new UserPushNotification
             {
                 UserId = userId,
+#pragma warning disable BWP0001 // Type or member is obsolete
                 Date = TimeProvider.GetUtcNow().UtcDateTime,
+#pragma warning restore BWP0001 // Type or member is obsolete
             },
             ExcludeCurrentContext = false,
         });
@@ -122,7 +144,9 @@ public interface IPushNotificationService
             Payload = new UserPushNotification
             {
                 UserId = userId,
+#pragma warning disable BWP0001 // Type or member is obsolete
                 Date = TimeProvider.GetUtcNow().UtcDateTime,
+#pragma warning restore BWP0001 // Type or member is obsolete
             },
             ExcludeCurrentContext = false,
         });
@@ -136,7 +160,9 @@ public interface IPushNotificationService
             Payload = new UserPushNotification
             {
                 UserId = userId,
+#pragma warning disable BWP0001 // Type or member is obsolete
                 Date = TimeProvider.GetUtcNow().UtcDateTime,
+#pragma warning restore BWP0001 // Type or member is obsolete
             },
             ExcludeCurrentContext = false,
         });
@@ -150,7 +176,9 @@ public interface IPushNotificationService
             Payload = new UserPushNotification
             {
                 UserId = userId,
+#pragma warning disable BWP0001 // Type or member is obsolete
                 Date = TimeProvider.GetUtcNow().UtcDateTime,
+#pragma warning restore BWP0001 // Type or member is obsolete
             },
             ExcludeCurrentContext = excludeCurrentContextFromPush,
         });
@@ -231,7 +259,9 @@ public interface IPushNotificationService
             ClientType = notification.ClientType,
             UserId = notification.UserId,
             OrganizationId = notification.OrganizationId,
+#pragma warning disable BWP0001 // Type or member is obsolete
             InstallationId = notification.Global ? InstallationId : null,
+#pragma warning restore BWP0001 // Type or member is obsolete
             TaskId = notification.TaskId,
             Title = notification.Title,
             Body = notification.Body,
@@ -246,7 +276,9 @@ public interface IPushNotificationService
         {
             // TODO: Think about this a bit more
             target = NotificationTarget.Installation;
+#pragma warning disable BWP0001 // Type or member is obsolete
             targetId = InstallationId;
+#pragma warning restore BWP0001 // Type or member is obsolete
         }
         else if (notification.UserId.HasValue)
         {
@@ -260,7 +292,9 @@ public interface IPushNotificationService
         }
         else
         {
+#pragma warning disable BWP0001 // Type or member is obsolete
             Logger.LogWarning("Invalid notification id {NotificationId} push notification", notification.Id);
+#pragma warning restore BWP0001 // Type or member is obsolete
             return Task.CompletedTask;
         }
 
@@ -285,7 +319,9 @@ public interface IPushNotificationService
             ClientType = notification.ClientType,
             UserId = notification.UserId,
             OrganizationId = notification.OrganizationId,
+#pragma warning disable BWP0001 // Type or member is obsolete
             InstallationId = notification.Global ? InstallationId : null,
+#pragma warning restore BWP0001 // Type or member is obsolete
             TaskId = notification.TaskId,
             Title = notification.Title,
             Body = notification.Body,
@@ -302,7 +338,9 @@ public interface IPushNotificationService
         {
             // TODO: Think about this a bit more
             target = NotificationTarget.Installation;
+#pragma warning disable BWP0001 // Type or member is obsolete
             targetId = InstallationId;
+#pragma warning restore BWP0001 // Type or member is obsolete
         }
         else if (notification.UserId.HasValue)
         {
@@ -316,7 +354,9 @@ public interface IPushNotificationService
         }
         else
         {
+#pragma warning disable BWP0001 // Type or member is obsolete
             Logger.LogWarning("Invalid notification status id {NotificationId} push notification", notification.Id);
+#pragma warning restore BWP0001 // Type or member is obsolete
             return Task.CompletedTask;
         }
 
@@ -398,7 +438,9 @@ public interface IPushNotificationService
             Payload = new UserPushNotification
             {
                 UserId = userId,
+#pragma warning disable BWP0001 // Type or member is obsolete
                 Date = TimeProvider.GetUtcNow().UtcDateTime,
+#pragma warning restore BWP0001 // Type or member is obsolete
             },
             ExcludeCurrentContext = false,
         });
@@ -406,6 +448,12 @@ public interface IPushNotificationService
 
     Task PushCipherAsync(Cipher cipher, PushType pushType, IEnumerable<Guid>? collectionIds);
 
+    /// <summary>
+    /// Pushes a notification to devices based on the settings given to us in <see cref="PushNotification{T}"/>.
+    /// </summary>
+    /// <typeparam name="T">The type of the payload to be sent along with the notification.</typeparam>
+    /// <param name="pushNotification"></param>
+    /// <returns>A task that is NOT guarunteed to have sent the notification by the time the task resolves.</returns>
     Task PushAsync<T>(PushNotification<T> pushNotification)
         where T : class;
 }

src/Core/Platform/Push/IPushRelayer.cs

@@ -1,6 +1,4 @@
-#nullable enable
-
-using System.Text.Json;
+using System.Text.Json;
 using Bit.Core.Enums;
 
 namespace Bit.Core.Platform.Push.Internal;

src/Core/Platform/Push/NotificationHub/INotificationHubClientProxy.cs

@@ -1,8 +1,6 @@
 using Microsoft.Azure.NotificationHubs;
 
-namespace Bit.Core.NotificationHub;
-
-#nullable enable
+namespace Bit.Core.Platform.Push.Internal;
 
 public interface INotificationHubProxy
 {

src/Core/Platform/Push/NotificationHub/INotificationHubPool.cs

@@ -1,8 +1,6 @@
 using Microsoft.Azure.NotificationHubs;
 
-namespace Bit.Core.NotificationHub;
-
-#nullable enable
+namespace Bit.Core.Platform.Push.Internal;
 
 public interface INotificationHubPool
 {

src/Core/Platform/Push/NotificationHub/NotificationHubClientProxy.cs

@@ -1,8 +1,6 @@
 using Microsoft.Azure.NotificationHubs;
 
-namespace Bit.Core.NotificationHub;
-
-#nullable enable
+namespace Bit.Core.Platform.Push.Internal;
 
 public class NotificationHubClientProxy : INotificationHubProxy
 {

src/Core/Platform/Push/NotificationHub/NotificationHubConnection.cs

@@ -6,9 +6,7 @@ using Bit.Core.Settings;
 using Bit.Core.Utilities;
 using Microsoft.Azure.NotificationHubs;
 
-namespace Bit.Core.NotificationHub;
-
-#nullable enable
+namespace Bit.Core.Platform.Push.Internal;
 
 public class NotificationHubConnection
 {

src/Core/Platform/Push/NotificationHub/NotificationHubPool.cs

@@ -3,9 +3,7 @@ using Bit.Core.Utilities;
 using Microsoft.Azure.NotificationHubs;
 using Microsoft.Extensions.Logging;
 
-namespace Bit.Core.NotificationHub;
-
-#nullable enable
+namespace Bit.Core.Platform.Push.Internal;
 
 public class NotificationHubPool : INotificationHubPool
 {

src/Core/Platform/Push/NotificationHub/NotificationHubPushEngine.cs

@@ -1,28 +1,23 @@
-#nullable enable
-using System.Text.Json;
+using System.Text.Json;
 using System.Text.RegularExpressions;
 using Bit.Core.Context;
 using Bit.Core.Enums;
 using Bit.Core.Models;
 using Bit.Core.Models.Data;
-using Bit.Core.Platform.Push;
-using Bit.Core.Platform.Push.Internal;
 using Bit.Core.Repositories;
 using Bit.Core.Settings;
 using Bit.Core.Vault.Entities;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 
-namespace Bit.Core.NotificationHub;
-
-#nullable enable
+namespace Bit.Core.Platform.Push.Internal;
 
 /// <summary>
 /// Sends mobile push notifications to the Azure Notification Hub.
 /// Used by Cloud-Hosted environments.
 /// Received by Firebase for Android or APNS for iOS.
 /// </summary>
-public class NotificationHubPushNotificationService : IPushEngine, IPushRelayer
+public class NotificationHubPushEngine : IPushEngine, IPushRelayer
 {
     private readonly IInstallationDeviceRepository _installationDeviceRepository;
     private readonly IHttpContextAccessor _httpContextAccessor;
@@ -30,11 +25,11 @@ public class NotificationHubPushNotificationService : IPushEngine, IPushRelayer
     private readonly INotificationHubPool _notificationHubPool;
     private readonly ILogger _logger;
 
-    public NotificationHubPushNotificationService(
+    public NotificationHubPushEngine(
         IInstallationDeviceRepository installationDeviceRepository,
         INotificationHubPool notificationHubPool,
         IHttpContextAccessor httpContextAccessor,
-        ILogger<NotificationHubPushNotificationService> logger,
+        ILogger<NotificationHubPushEngine> logger,
         IGlobalSettings globalSettings)
     {
         _installationDeviceRepository = installationDeviceRepository;

src/Core/Platform/Push/NotificationInfoAttribute.cs

@@ -0,0 +1,44 @@
+using Bit.Core.Enums;
+
+namespace Bit.Core.Platform.Push;
+
+/// <summary>
+/// Used to annotate information about a given <see cref="PushType"/>.
+/// </summary>
+[AttributeUsage(AttributeTargets.Field)]
+public class NotificationInfoAttribute : Attribute
+{
+    // Once upon a time we can feed this information into a C# analyzer to make sure that we validate
+    // the callsites of IPushNotificationService.PushAsync uses the correct payload type for the notification type
+    // for now this only exists as forced documentation to teams who create a push type.
+
+    // It's especially on purpose that we allow ourselves to take a type name via just the string,
+    // this allows teams to make a push type that is only sent with a payload that exists in a separate assembly than
+    // this one.
+
+    public NotificationInfoAttribute(string team, Type payloadType)
+        // It should be impossible to reference an unnamed type for an attributes constructor so this assertion should be safe.
+        : this(team, payloadType.FullName!)
+    {
+        Team = team;
+    }
+
+    public NotificationInfoAttribute(string team, string payloadTypeName)
+    {
+        ArgumentException.ThrowIfNullOrWhiteSpace(team);
+        ArgumentException.ThrowIfNullOrWhiteSpace(payloadTypeName);
+
+        Team = team;
+        PayloadTypeName = payloadTypeName;
+    }
+
+    /// <summary>
+    /// The name of the team that owns this <see cref="PushType"/>.
+    /// </summary>
+    public string Team { get; }
+
+    /// <summary>
+    /// The fully qualified type name of the payload that should be used when sending a notification of this type.
+    /// </summary>
+    public string PayloadTypeName { get; }
+}

src/Core/Platform/Push/PushNotification.cs

@@ -6,6 +6,9 @@ namespace Bit.Core.Platform.Push;
 /// <summary>
 /// Contains constants for all the available targets for a given notification.
 /// </summary>
+/// <remarks>
+/// Please reach out to the Platform team if you need a new target added.
+/// </remarks>
 public enum NotificationTarget
 {
     /// <summary>

src/Core/Platform/Push/PushServiceCollectionExtensions.cs

@@ -0,0 +1,82 @@
+using Azure.Storage.Queues;
+using Bit.Core.Platform.Push;
+using Bit.Core.Platform.Push.Internal;
+using Bit.Core.Settings;
+using Bit.Core.Utilities;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+
+namespace Microsoft.Extensions.DependencyInjection;
+
+/// <summary>
+/// Extension methods for adding the Push feature.
+/// </summary>
+public static class PushServiceCollectionExtensions
+{
+    /// <summary>
+    /// Adds a <see cref="IPushNotificationService"/> to the services that can be used to send push notifications to
+    /// end user devices. This method is safe to be ran multiple time provided <see cref="GlobalSettings"/> does not 
+    /// change between calls.
+    /// </summary>
+    /// <param name="services">The <see cref="IServiceCollection"/> to add services to.</param>
+    /// <param name="globalSettings">The <see cref="GlobalSettings"/> to use to configure services.</param>
+    /// <returns>The <see cref="IServiceCollection"/> for additional chaining.</returns>
+    public static IServiceCollection AddPush(this IServiceCollection services, GlobalSettings globalSettings)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+        ArgumentNullException.ThrowIfNull(globalSettings);
+
+        services.TryAddSingleton(TimeProvider.System);
+        services.TryAddSingleton<IPushNotificationService, MultiServicePushNotificationService>();
+
+        if (globalSettings.SelfHosted)
+        {
+            if (globalSettings.Installation.Id == Guid.Empty)
+            {
+                throw new InvalidOperationException("Installation Id must be set for self-hosted installations.");
+            }
+
+            if (CoreHelpers.SettingHasValue(globalSettings.PushRelayBaseUri) &&
+                CoreHelpers.SettingHasValue(globalSettings.Installation.Key))
+            {
+                // TODO: We should really define the HttpClient we will use here
+                services.AddHttpClient();
+                services.AddHttpContextAccessor();
+                // We also depend on IDeviceRepository but don't explicitly add it right now.
+                services.TryAddEnumerable(ServiceDescriptor.Singleton<IPushEngine, RelayPushEngine>());
+            }
+
+            if (CoreHelpers.SettingHasValue(globalSettings.InternalIdentityKey) &&
+                CoreHelpers.SettingHasValue(globalSettings.BaseServiceUri.InternalNotifications))
+            {
+                // TODO: We should really define the HttpClient we will use here
+                services.AddHttpClient();
+                services.AddHttpContextAccessor();
+                services.TryAddEnumerable(ServiceDescriptor.Singleton<IPushEngine, NotificationsApiPushEngine>());
+            }
+        }
+        else
+        {
+            services.TryAddSingleton<INotificationHubPool, NotificationHubPool>();
+            services.AddHttpContextAccessor();
+
+            // We also depend on IInstallationDeviceRepository but don't explicitly add it right now.
+            services.TryAddEnumerable(ServiceDescriptor.Singleton<IPushEngine, NotificationHubPushEngine>());
+
+            services.TryAddSingleton<IPushRelayer, NotificationHubPushEngine>();
+
+            if (CoreHelpers.SettingHasValue(globalSettings.Notifications?.ConnectionString))
+            {
+                services.TryAddKeyedSingleton("notifications", static (sp, _) =>
+                {
+                    var gs = sp.GetRequiredService<GlobalSettings>();
+                    return new QueueClient(gs.Notifications.ConnectionString, "notifications");
+                });
+
+                // We not IHttpContextAccessor will be added above, no need to do it here.
+                services.TryAddEnumerable(ServiceDescriptor.Singleton<IPushEngine, AzureQueuePushEngine>());
+            }
+        }
+
+        return services;
+    }
+}

src/Core/Platform/Push/PushType.cs

@@ -0,0 +1,93 @@
+using Bit.Core.Platform.Push;
+
+// TODO: This namespace should change to `Bit.Core.Platform.Push`
+namespace Bit.Core.Enums;
+
+/// <summary>
+/// 
+/// </summary>
+/// <remarks>
+/// <para>
+/// When adding a new enum member you must annotate it with a <see cref="NotificationInfoAttribute"/> 
+/// this is enforced with a unit test. It is preferred that you do NOT add new usings for the type referenced
+/// in <see cref="NotificationInfoAttribute"/>.
+/// </para>
+/// <para>
+/// You may and are 
+/// </para>
+/// </remarks>
+public enum PushType : byte
+{
+    // When adding a new enum member you must annotate it with a NotificationInfoAttribute  this is enforced with a unit
+    // test. It is preferred that you do NOT add new usings for the type referenced for the payload. You are also
+    // encouraged to define the payload type in your own teams owned code.
+
+    [NotificationInfo("@bitwarden/team-vault-dev", typeof(Models.SyncCipherPushNotification))]
+    SyncCipherUpdate = 0,
+
+    [NotificationInfo("@bitwarden/team-vault-dev", typeof(Models.SyncCipherPushNotification))]
+    SyncCipherCreate = 1,
+
+    [NotificationInfo("@bitwarden/team-vault-dev", typeof(Models.SyncCipherPushNotification))]
+    SyncLoginDelete = 2,
+
+    [NotificationInfo("@bitwarden/team-vault-dev", typeof(Models.SyncFolderPushNotification))]
+    SyncFolderDelete = 3,
+
+    [NotificationInfo("@bitwarden/team-vault-dev", typeof(Models.UserPushNotification))]
+    SyncCiphers = 4,
+
+    [NotificationInfo("not-specified", typeof(Models.UserPushNotification))]
+    SyncVault = 5,
+
+    [NotificationInfo("@bitwarden/team-admin-console-dev", typeof(Models.UserPushNotification))]
+    SyncOrgKeys = 6,
+
+    [NotificationInfo("@bitwarden/team-vault-dev", typeof(Models.SyncFolderPushNotification))]
+    SyncFolderCreate = 7,
+
+    [NotificationInfo("@bitwarden/team-vault-dev", typeof(Models.SyncFolderPushNotification))]
+    SyncFolderUpdate = 8,
+
+    [NotificationInfo("@bitwarden/team-vault-dev", typeof(Models.SyncCipherPushNotification))]
+    SyncCipherDelete = 9,
+
+    [NotificationInfo("not-specified", typeof(Models.UserPushNotification))]
+    SyncSettings = 10,
+
+    [NotificationInfo("not-specified", typeof(Models.UserPushNotification))]
+    LogOut = 11,
+
+    [NotificationInfo("@bitwarden/team-tools-dev", typeof(Models.SyncSendPushNotification))]
+    SyncSendCreate = 12,
+
+    [NotificationInfo("@bitwarden/team-tools-dev", typeof(Models.SyncSendPushNotification))]
+    SyncSendUpdate = 13,
+
+    [NotificationInfo("@bitwarden/team-tools-dev", typeof(Models.SyncSendPushNotification))]
+    SyncSendDelete = 14,
+
+    [NotificationInfo("@bitwarden/team-auth-dev", typeof(Models.AuthRequestPushNotification))]
+    AuthRequest = 15,
+
+    [NotificationInfo("@bitwarden/team-auth-dev", typeof(Models.AuthRequestPushNotification))]
+    AuthRequestResponse = 16,
+
+    [NotificationInfo("not-specified", typeof(Models.UserPushNotification))]
+    SyncOrganizations = 17,
+
+    [NotificationInfo("@bitwarden/team-billing-dev", typeof(Models.OrganizationStatusPushNotification))]
+    SyncOrganizationStatusChanged = 18,
+
+    [NotificationInfo("@bitwarden/team-admin-console-dev", typeof(Models.OrganizationCollectionManagementPushNotification))]
+    SyncOrganizationCollectionSettingChanged = 19,
+
+    [NotificationInfo("not-specified", typeof(Models.NotificationPushNotification))]
+    Notification = 20,
+
+    [NotificationInfo("not-specified", typeof(Models.NotificationPushNotification))]
+    NotificationStatus = 21,
+
+    [NotificationInfo("@bitwarden/team-vault-dev", typeof(Models.UserPushNotification))]
+    RefreshSecurityTasks = 22,
+}

src/Core/Platform/PushRegistration/IPushRegistrationService.cs

@@ -1,10 +1,10 @@
-#nullable enable
-
-using Bit.Core.Enums;
-using Bit.Core.NotificationHub;
+using Bit.Core.Enums;
+using Bit.Core.Platform.PushRegistration;
 
+// TODO: Change this namespace to `Bit.Core.Platform.PushRegistration
 namespace Bit.Core.Platform.Push;
 
+
 public interface IPushRegistrationService
 {
     Task CreateOrUpdateRegistrationAsync(PushRegistrationData data, string deviceId, string userId, string identifier, DeviceType type, IEnumerable<string> organizationIds, Guid installationId);

src/Core/Platform/PushRegistration/NoopPushRegistrationService.cs

@@ -1,9 +1,7 @@
-#nullable enable
+using Bit.Core.Enums;
+using Bit.Core.Platform.Push;
 
-using Bit.Core.Enums;
-using Bit.Core.NotificationHub;
-
-namespace Bit.Core.Platform.Push.Internal;
+namespace Bit.Core.Platform.PushRegistration.Internal;
 
 public class NoopPushRegistrationService : IPushRegistrationService
 {

src/Core/Platform/PushRegistration/NotificationHubPushRegistrationService.cs

@@ -6,14 +6,13 @@ using System.Text.Json;
 using Bit.Core.Enums;
 using Bit.Core.Models.Data;
 using Bit.Core.Platform.Push;
+using Bit.Core.Platform.Push.Internal;
 using Bit.Core.Repositories;
 using Bit.Core.Utilities;
 using Microsoft.Azure.NotificationHubs;
 using Microsoft.Extensions.Logging;
 
-namespace Bit.Core.NotificationHub;
-
-#nullable enable
+namespace Bit.Core.Platform.PushRegistration.Internal;
 
 public class NotificationHubPushRegistrationService : IPushRegistrationService
 {

src/Core/Platform/PushRegistration/PushRegistrationData.cs

@@ -1,6 +1,4 @@
-namespace Bit.Core.NotificationHub;
-
-#nullable enable
+namespace Bit.Core.Platform.PushRegistration;
 
 public record struct WebPushRegistrationData
 {

src/Core/Platform/PushRegistration/PushRegistrationServiceCollectionExtensions.cs

@@ -0,0 +1,54 @@
+using Bit.Core.Platform.Push;
+using Bit.Core.Platform.Push.Internal;
+using Bit.Core.Platform.PushRegistration.Internal;
+using Bit.Core.Settings;
+using Bit.Core.Utilities;
+using Microsoft.Extensions.DependencyInjection.Extensions;
+
+namespace Microsoft.Extensions.DependencyInjection;
+
+/// <summary>
+/// Extension methods for adding the Push Registration feature.
+/// </summary>
+public static class PushRegistrationServiceCollectionExtensions
+{
+    /// <summary>
+    /// Adds a <see cref="IPushRegistrationService"/> to the service collection.
+    /// </summary>
+    /// <param name="services">The <see cref="IServiceCollection"/> to add services to.</param>
+    /// <returns>The <see cref="IServiceCollection"/> for chaining.</returns>
+    public static IServiceCollection AddPushRegistration(this IServiceCollection services)
+    {
+        ArgumentNullException.ThrowIfNull(services);
+
+        // TODO: Should add feature that brings in IInstallationDeviceRepository once that is featurized
+
+        // Register all possible variants under there concrete type.
+        services.TryAddSingleton<RelayPushRegistrationService>();
+        services.TryAddSingleton<NoopPushRegistrationService>();
+
+        services.AddHttpClient();
+        services.TryAddSingleton<INotificationHubPool, NotificationHubPool>();
+        services.TryAddSingleton<NotificationHubPushRegistrationService>();
+
+        services.TryAddSingleton<IPushRegistrationService>(static sp =>
+        {
+            var globalSettings = sp.GetRequiredService<GlobalSettings>();
+
+            if (globalSettings.SelfHosted)
+            {
+                if (CoreHelpers.SettingHasValue(globalSettings.PushRelayBaseUri) &&
+                    CoreHelpers.SettingHasValue(globalSettings.Installation.Key))
+                {
+                    return sp.GetRequiredService<RelayPushRegistrationService>();
+                }
+
+                return sp.GetRequiredService<NoopPushRegistrationService>();
+            }
+
+            return sp.GetRequiredService<NotificationHubPushRegistrationService>();
+        });
+
+        return services;
+    }
+}

src/Core/Platform/PushRegistration/RelayPushRegistrationService.cs

@@ -1,14 +1,12 @@
-#nullable enable
-
-using Bit.Core.Enums;
+using Bit.Core.Enums;
 using Bit.Core.IdentityServer;
 using Bit.Core.Models.Api;
-using Bit.Core.NotificationHub;
+using Bit.Core.Platform.Push;
 using Bit.Core.Services;
 using Bit.Core.Settings;
 using Microsoft.Extensions.Logging;
 
-namespace Bit.Core.Platform.Push.Internal;
+namespace Bit.Core.Platform.PushRegistration.Internal;
 
 public class RelayPushRegistrationService : BaseIdentityClientService, IPushRegistrationService
 {

src/Core/Services/IDeviceService.cs

@@ -1,6 +1,6 @@
 using Bit.Core.Auth.Models.Api.Request;
 using Bit.Core.Entities;
-using Bit.Core.NotificationHub;
+using Bit.Core.Platform.PushRegistration;
 
 namespace Bit.Core.Services;
 

src/Core/Services/Implementations/DeviceService.cs

@@ -3,8 +3,8 @@ using Bit.Core.Auth.Utilities;
 using Bit.Core.Entities;
 using Bit.Core.Enums;
 using Bit.Core.Exceptions;
-using Bit.Core.NotificationHub;
 using Bit.Core.Platform.Push;
+using Bit.Core.Platform.PushRegistration;
 using Bit.Core.Repositories;
 using Bit.Core.Settings;