Extracted restore behavior.

src/Squidex.Domain.Apps.Entities/Backup/BackupGrain.cs

@@ -11,7 +11,6 @@ using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using NodaTime;
-using Orleans;
 using Orleans.Concurrency;
 using Squidex.Domain.Apps.Entities.Backup.State;
 using Squidex.Domain.Apps.Events;
@@ -191,28 +190,28 @@ namespace Squidex.Domain.Apps.Entities.Backup
                                 var assetVersion = 0L;
                                 var assetId = Guid.Empty;
 
-                                if (parsedEvent.Payload is AssetCreated assetCreated)
+                                switch (parsedEvent.Payload)
                                 {
-                                    assetId = assetCreated.AssetId;
-                                    assetVersion = assetCreated.FileVersion;
+                                    case AssetCreated assetCreated:
+                                        assetId = assetCreated.AssetId;
+                                        assetVersion = assetCreated.FileVersion;
+                                        break;
+                                    case AssetUpdated asetUpdated:
+                                        assetId = asetUpdated.AssetId;
+                                        assetVersion = asetUpdated.FileVersion;
+                                        break;
                                 }
 
-                                if (parsedEvent.Payload is AssetUpdated asetUpdated)
+                                await writer.WriteEventAsync(@event, attachment =>
                                 {
-                                    assetId = asetUpdated.AssetId;
-                                    assetVersion = asetUpdated.FileVersion;
-                                }
-
-                                await writer.WriteEventAsync(eventData, async attachmentStream =>
-                                {
-                                    await assetStore.DownloadAsync(assetId.ToString(), assetVersion, null, attachmentStream);
+                                    return assetStore.DownloadAsync(assetId.ToString(), assetVersion, null, attachment);
                                 });
 
                                 job.HandledAssets++;
                             }
                             else
                             {
-                                await writer.WriteEventAsync(eventData);
+                                await writer.WriteEventAsync(@event);
                             }
 
                             job.HandledEvents++;

src/Squidex.Domain.Apps.Entities/Backup/EventStreamReader.cs

@@ -34,7 +34,7 @@ namespace Squidex.Domain.Apps.Entities.Backup
             }
         }
 
-        public async Task ReadEventsAsync(Func<EventData, Stream, Task> eventHandler)
+        public async Task ReadEventsAsync(Func<StoredEvent, Stream, Task> eventHandler)
         {
             Guard.NotNull(eventHandler, nameof(eventHandler));
 
@@ -52,18 +52,16 @@ namespace Squidex.Domain.Apps.Entities.Backup
                     break;
                 }
 
-                EventData eventData;
+                StoredEvent eventData;
 
                 using (var stream = eventEntry.Open())
                 {
                     using (var textReader = new StreamReader(stream))
                     {
-                        eventData = (EventData)JsonSerializer.Deserialize(textReader, typeof(EventData));
+                        eventData = (StoredEvent)JsonSerializer.Deserialize(textReader, typeof(StoredEvent));
                     }
                 }
 
-                readEvents++;
-
                 var attachmentFolder = readAttachments / MaxItemsPerFolder;
                 var attachmentPath = $"attachments/{attachmentFolder}/{readEvents}.blob";
                 var attachmentEntry = archive.GetEntry(attachmentPath);
@@ -81,6 +79,8 @@ namespace Squidex.Domain.Apps.Entities.Backup
                 {
                     await eventHandler(eventData, null);
                 }
+
+                readEvents++;
             }
         }
     }

src/Squidex.Domain.Apps.Entities/Backup/EventStreamWriter.cs

@@ -36,13 +36,9 @@ namespace Squidex.Domain.Apps.Entities.Backup
             }
         }
 
-        public async Task WriteEventAsync(EventData eventData, Func<Stream, Task> attachment = null)
+        public async Task WriteEventAsync(StoredEvent storedEvent, Func<Stream, Task> attachment = null)
         {
-            var eventObject =
-                new JObject(
-                    new JProperty("type", eventData.Type),
-                    new JProperty("payload", eventData.Payload),
-                    new JProperty("metadata", eventData.Metadata));
+            var eventObject = JObject.FromObject(storedEvent);
 
             var eventFolder = writtenEvents / MaxItemsPerFolder;
             var eventPath = $"events/{eventFolder}/{writtenEvents}.json";
@@ -59,8 +55,6 @@ namespace Squidex.Domain.Apps.Entities.Backup
                 }
             }
 
-            writtenEvents++;
-
             if (attachment != null)
             {
                 var attachmentFolder = writtenAttachments / MaxItemsPerFolder;
@@ -74,6 +68,8 @@ namespace Squidex.Domain.Apps.Entities.Backup
 
                 writtenAttachments++;
             }
+
+            writtenEvents++;
         }
     }
 }

src/Squidex.Domain.Apps.Entities/Backup/Handlers/HandlerBase.cs

@@ -0,0 +1,55 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Squidex.Infrastructure;
+using Squidex.Infrastructure.Commands;
+using Squidex.Infrastructure.EventSourcing;
+using Squidex.Infrastructure.States;
+
+namespace Squidex.Domain.Apps.Entities.Backup.Handlers
+{
+    public abstract class HandlerBase
+    {
+        private readonly IStore<Guid> store;
+
+        protected HandlerBase(IStore<Guid> store)
+        {
+            Guard.NotNull(store, nameof(store));
+
+            this.store = store;
+        }
+
+        protected async Task RebuildManyAsync(IEnumerable<Guid> ids, Func<Guid, Task> action)
+        {
+            foreach (var id in ids)
+            {
+                await action(id);
+            }
+        }
+
+        protected async Task RebuildAsync<TState, TGrain>(Guid key, Func<Envelope<IEvent>, TState, TState> func) where TState : IDomainState, new()
+        {
+            var state = new TState
+            {
+                Version = EtagVersion.Empty
+            };
+
+            var persistence = store.WithSnapshotsAndEventSourcing<TState, Guid>(typeof(TGrain), key, s => state = s, e =>
+            {
+                state = func(e, state);
+
+                state.Version++;
+            });
+
+            await persistence.ReadAsync();
+            await persistence.WriteSnapshotAsync(state);
+        }
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/Handlers/RestoreApp.cs

@@ -0,0 +1,50 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using Squidex.Domain.Apps.Events.Apps;
+using Squidex.Infrastructure;
+using Squidex.Infrastructure.EventSourcing;
+using Squidex.Infrastructure.States;
+using Squidex.Infrastructure.Tasks;
+
+namespace Squidex.Domain.Apps.Entities.Backup.Handlers
+{
+    public sealed class RestoreApp : HandlerBase, IRestoreHandler
+    {
+        private NamedId<Guid> appId;
+
+        public string Name { get; } = "App";
+
+        public RestoreApp(IStore<Guid> store)
+            : base(store)
+        {
+        }
+
+        public Task HandleAsync(Envelope<IEvent> @event, Stream attachment)
+        {
+            if (@event.Payload is AppCreated appCreated)
+            {
+                appId = appCreated.AppId;
+            }
+
+            return TaskHelper.Done;
+        }
+
+        public Task ProcessAsync()
+        {
+            return TaskHelper.Done;
+        }
+
+        public Task CompleteAsync()
+        {
+            return TaskHelper.Done;
+        }
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/Handlers/RestoreAssets.cs

@@ -0,0 +1,72 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using Squidex.Domain.Apps.Entities.Assets;
+using Squidex.Domain.Apps.Entities.Assets.State;
+using Squidex.Domain.Apps.Events.Assets;
+using Squidex.Infrastructure;
+using Squidex.Infrastructure.Assets;
+using Squidex.Infrastructure.EventSourcing;
+using Squidex.Infrastructure.States;
+using Squidex.Infrastructure.Tasks;
+
+namespace Squidex.Domain.Apps.Entities.Backup.Handlers
+{
+    public sealed class RestoreAssets : HandlerBase, IRestoreHandler
+    {
+        private readonly HashSet<Guid> assetIds = new HashSet<Guid>();
+        private readonly IAssetStore assetStore;
+
+        public string Name { get; } = "Assets";
+
+        public RestoreAssets(IStore<Guid> store, IAssetStore assetStore)
+            : base(store)
+        {
+            Guard.NotNull(assetStore, nameof(assetStore));
+
+            this.assetStore = assetStore;
+        }
+
+        public async Task HandleAsync(Envelope<IEvent> @event, Stream attachment)
+        {
+            var assetVersion = 0L;
+            var assetId = Guid.Empty;
+
+            switch (@event.Payload)
+            {
+                case AssetCreated assetCreated:
+                    assetId = assetCreated.AssetId;
+                    assetVersion = assetCreated.FileVersion;
+                    assetIds.Add(assetCreated.AssetId);
+                    break;
+                case AssetUpdated asetUpdated:
+                    assetId = asetUpdated.AssetId;
+                    assetVersion = asetUpdated.FileVersion;
+                    break;
+            }
+
+            if (attachment != null)
+            {
+                await assetStore.UploadAsync(assetId.ToString(), assetVersion, null, attachment);
+            }
+        }
+
+        public Task ProcessAsync()
+        {
+            return RebuildManyAsync(assetIds, id => RebuildAsync<AssetState, AssetGrain>(id, (e, s) => s.Apply(e)));
+        }
+
+        public Task CompleteAsync()
+        {
+            return TaskHelper.Done;
+        }
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/Handlers/RestoreContents.cs

@@ -0,0 +1,54 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using Squidex.Domain.Apps.Entities.Contents;
+using Squidex.Domain.Apps.Entities.Contents.State;
+using Squidex.Domain.Apps.Events.Contents;
+using Squidex.Infrastructure.EventSourcing;
+using Squidex.Infrastructure.States;
+using Squidex.Infrastructure.Tasks;
+
+namespace Squidex.Domain.Apps.Entities.Backup.Handlers
+{
+    public sealed class RestoreContents : HandlerBase, IRestoreHandler
+    {
+        private readonly HashSet<Guid> contentIds = new HashSet<Guid>();
+
+        public string Name { get; } = "Contents";
+
+        public RestoreContents(IStore<Guid> store)
+            : base(store)
+        {
+        }
+
+        public Task HandleAsync(Envelope<IEvent> @event, Stream attachment)
+        {
+            switch (@event.Payload)
+            {
+                case ContentCreated contentCreated:
+                    contentIds.Add(contentCreated.ContentId);
+                    break;
+            }
+
+            return TaskHelper.Done;
+        }
+
+        public Task ProcessAsync()
+        {
+            return RebuildManyAsync(contentIds, id => RebuildAsync<ContentState, ContentGrain>(id, (e, s) => s.Apply(e)));
+        }
+
+        public Task CompleteAsync()
+        {
+            return TaskHelper.Done;
+        }
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/Handlers/RestoreRules.cs

@@ -0,0 +1,70 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using Orleans;
+using Squidex.Domain.Apps.Entities.Rules;
+using Squidex.Domain.Apps.Entities.Rules.State;
+using Squidex.Domain.Apps.Events.Apps;
+using Squidex.Domain.Apps.Events.Rules;
+using Squidex.Infrastructure;
+using Squidex.Infrastructure.EventSourcing;
+using Squidex.Infrastructure.States;
+using Squidex.Infrastructure.Tasks;
+
+namespace Squidex.Domain.Apps.Entities.Backup.Handlers
+{
+    public sealed class RestoreRules : HandlerBase, IRestoreHandler
+    {
+        private readonly HashSet<Guid> ruleIds = new HashSet<Guid>();
+        private readonly IGrainFactory grainFactory;
+        private Guid appId;
+
+        public string Name { get; } = "Rules";
+
+        public RestoreRules(IStore<Guid> store, IGrainFactory grainFactory)
+            : base(store)
+        {
+            Guard.NotNull(grainFactory, nameof(grainFactory));
+
+            this.grainFactory = grainFactory;
+        }
+
+        public Task HandleAsync(Envelope<IEvent> @event, Stream attachment)
+        {
+            switch (@event.Payload)
+            {
+                case AppCreated appCreated:
+                    appId = appCreated.AppId.Id;
+                    break;
+                case RuleCreated ruleCreated:
+                    ruleIds.Add(ruleCreated.RuleId);
+                    break;
+                case RuleDeleted ruleDeleted:
+                    ruleIds.Remove(ruleDeleted.RuleId);
+                    break;
+            }
+
+            return TaskHelper.Done;
+        }
+
+        public async Task ProcessAsync()
+        {
+            await RebuildManyAsync(ruleIds, id => RebuildAsync<RuleState, RuleGrain>(id, (e, s) => s.Apply(e)));
+
+            await grainFactory.GetGrain<IRulesByAppIndex>(appId).RebuildAsync(ruleIds);
+        }
+
+        public Task CompleteAsync()
+        {
+            return TaskHelper.Done;
+        }
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/Handlers/RestoreSchemas.cs

@@ -0,0 +1,75 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Orleans;
+using Squidex.Domain.Apps.Core.Schemas;
+using Squidex.Domain.Apps.Entities.Schemas;
+using Squidex.Domain.Apps.Entities.Schemas.State;
+using Squidex.Domain.Apps.Events.Apps;
+using Squidex.Domain.Apps.Events.Schemas;
+using Squidex.Infrastructure;
+using Squidex.Infrastructure.EventSourcing;
+using Squidex.Infrastructure.States;
+using Squidex.Infrastructure.Tasks;
+
+namespace Squidex.Domain.Apps.Entities.Backup.Handlers
+{
+    public sealed class RestoreSchemas : HandlerBase, IRestoreHandler
+    {
+        private readonly HashSet<NamedId<Guid>> schemaIds = new HashSet<NamedId<Guid>>();
+        private readonly Dictionary<string, Guid> schemasByName = new Dictionary<string, Guid>();
+        private readonly FieldRegistry fieldRegistry;
+        private readonly IGrainFactory grainFactory;
+        private Guid appId;
+
+        public string Name { get; } = "Schemas";
+
+        public RestoreSchemas(IStore<Guid> store, FieldRegistry fieldRegistry, IGrainFactory grainFactory)
+            : base(store)
+        {
+            Guard.NotNull(fieldRegistry, nameof(fieldRegistry));
+            Guard.NotNull(grainFactory, nameof(grainFactory));
+
+            this.fieldRegistry = fieldRegistry;
+
+            this.grainFactory = grainFactory;
+        }
+
+        public Task HandleAsync(Envelope<IEvent> @event, Stream attachment)
+        {
+            switch (@event.Payload)
+            {
+                case AppCreated appCreated:
+                    appId = appCreated.AppId.Id;
+                    break;
+                case SchemaCreated schemaCreated:
+                    schemaIds.Add(schemaCreated.SchemaId);
+                    schemasByName[schemaCreated.SchemaId.Name] = schemaCreated.SchemaId.Id;
+                    break;
+            }
+
+            return TaskHelper.Done;
+        }
+
+        public async Task ProcessAsync()
+        {
+            await RebuildManyAsync(schemaIds.Select(x => x.Id), id => RebuildAsync<SchemaState, SchemaGrain>(id, (e, s) => s.Apply(e, fieldRegistry)));
+
+            await grainFactory.GetGrain<ISchemasByAppIndex>(appId).RebuildAsync(schemasByName);
+        }
+
+        public Task CompleteAsync()
+        {
+            return TaskHelper.Done;
+        }
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/IRestoreGrain.cs

@@ -0,0 +1,21 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using System.Threading.Tasks;
+using Squidex.Infrastructure;
+using Squidex.Infrastructure.Orleans;
+
+namespace Squidex.Domain.Apps.Entities.Backup
+{
+    public interface IRestoreGrain
+    {
+        Task RestoreAsync(Uri url, RefToken user);
+
+        Task<J<IRestoreJob>> GetStateAsync();
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/IRestoreHandler.cs

@@ -0,0 +1,24 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System.IO;
+using System.Threading.Tasks;
+using Squidex.Infrastructure.EventSourcing;
+
+namespace Squidex.Domain.Apps.Entities.Backup
+{
+    public interface IRestoreHandler
+    {
+        string Name { get; }
+
+        Task HandleAsync(Envelope<IEvent> @event, Stream attachment);
+
+        Task ProcessAsync();
+
+        Task CompleteAsync();
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/IRestoreJob.cs

@@ -0,0 +1,23 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using NodaTime;
+
+namespace Squidex.Domain.Apps.Entities.Backup
+{
+    public interface IRestoreJob
+    {
+        Uri Uri { get; }
+
+        Instant Started { get; }
+
+        bool IsFailed { get; }
+
+        string Status { get; }
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/RestoreGrain.cs

@@ -5,14 +5,213 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
+using System;
+using System.Collections.Generic;
+using System.Net.Http;
+using System.Threading.Tasks;
+using NodaTime;
+using Orleans;
+using Squidex.Domain.Apps.Entities.Backup.State;
+using Squidex.Domain.Apps.Events;
+using Squidex.Infrastructure;
+using Squidex.Infrastructure.Assets;
+using Squidex.Infrastructure.EventSourcing;
+using Squidex.Infrastructure.Log;
 using Squidex.Infrastructure.Orleans;
+using Squidex.Infrastructure.States;
+using Squidex.Infrastructure.Tasks;
 
 namespace Squidex.Domain.Apps.Entities.Backup
 {
-    public sealed class RestoreGrain : GrainOfString
+    public sealed class RestoreGrain : GrainOfString, IRestoreGrain
     {
-        public RestoreGrain()
+        private static readonly Duration UpdateDuration = Duration.FromSeconds(1);
+        private readonly IClock clock;
+        private readonly IAssetStore assetStore;
+        private readonly IEventDataFormatter eventDataFormatter;
+        private readonly IAppCleanerGrain appCleaner;
+        private readonly ISemanticLog log;
+        private readonly IEventStore eventStore;
+        private readonly IBackupArchiveLocation backupArchiveLocation;
+        private readonly IStore<string> store;
+        private readonly IEnumerable<IRestoreHandler> handlers;
+        private RestoreState state = new RestoreState();
+        private IPersistence<RestoreState> persistence;
+
+        public RestoreGrain(
+            IAssetStore assetStore,
+            IBackupArchiveLocation backupArchiveLocation,
+            IClock clock,
+            IEventStore eventStore,
+            IEventDataFormatter eventDataFormatter,
+            IGrainFactory grainFactory,
+            IEnumerable<IRestoreHandler> handlers,
+            ISemanticLog log,
+            IStore<Guid> store)
+        {
+            Guard.NotNull(assetStore, nameof(assetStore));
+            Guard.NotNull(backupArchiveLocation, nameof(backupArchiveLocation));
+            Guard.NotNull(clock, nameof(clock));
+            Guard.NotNull(eventStore, nameof(eventStore));
+            Guard.NotNull(eventDataFormatter, nameof(eventDataFormatter));
+            Guard.NotNull(grainFactory, nameof(grainFactory));
+            Guard.NotNull(handlers, nameof(handlers));
+            Guard.NotNull(store, nameof(store));
+            Guard.NotNull(log, nameof(log));
+
+            this.assetStore = assetStore;
+            this.backupArchiveLocation = backupArchiveLocation;
+            this.clock = clock;
+            this.eventStore = eventStore;
+            this.eventDataFormatter = eventDataFormatter;
+            this.handlers = handlers;
+            this.store = store;
+            this.log = log;
+        }
+
+        public override async Task OnActivateAsync(string key)
+        {
+            persistence = store.WithSnapshots<RestoreState, string>(GetType(), key, s => state = s);
+
+            await persistence.ReadAsync();
+
+            await CleanupAsync();
+        }
+
+        public Task RestoreAsync(Uri url, RefToken user)
+        {
+            if (state.Job != null)
+            {
+                throw new DomainException("A restore operation is already running.");
+            }
+
+            state.Job = new RestoreStateJob { Started = clock.GetCurrentInstant(), Uri = url, User = user };
+
+            return ProcessAsync();
+        }
+
+        private async Task CleanupAsync()
+        {
+            if (state.Job != null)
+            {
+                state.Job.Status = "Failed due application restart";
+                state.Job.IsFailed = true;
+
+                if (state.Job.AppId != Guid.Empty)
+                {
+                    appCleaner.EnqueueAppAsync(state.Job.AppId).Forget();
+                }
+
+                await persistence.WriteSnapshotAsync(state);
+            }
+        }
+
+        private async Task ProcessAsync()
+        {
+            try
+            {
+                await DoAsync(
+                    "Downloading Backup",
+                    "Downloaded Backup",
+                    DownloadAsync);
+
+                await DoAsync(
+                    "Reading Events",
+                    "Readed Events",
+                    ReadEventsAsync);
+
+                foreach (var handler in handlers)
+                {
+                    await DoAsync($"{handler.Name} Proessing", $"{handler.Name} Processed", handler.ProcessAsync);
+                }
+
+                foreach (var handler in handlers)
+                {
+                    await DoAsync($"{handler.Name} Completing", $"{handler.Name} Completed", handler.CompleteAsync);
+                }
+
+                state.Job = null;
+            }
+            catch (Exception ex)
+            {
+                log.LogError(ex, w => w
+                    .WriteProperty("action", "makeBackup")
+                    .WriteProperty("status", "failed")
+                    .WriteProperty("backupId", state.Job.Id.ToString()));
+
+                state.Job.IsFailed = true;
+
+                if (state.Job.AppId != Guid.Empty)
+                {
+                    appCleaner.EnqueueAppAsync(state.Job.AppId).Forget();
+                }
+            }
+            finally
+            {
+                await persistence.WriteSnapshotAsync(state);
+            }
+        }
+
+        private async Task DownloadAsync()
+        {
+            using (var client = new HttpClient())
+            {
+                using (var sourceStream = await client.GetStreamAsync(state.Job.Uri.ToString()))
+                {
+                    using (var targetStream = await backupArchiveLocation.OpenStreamAsync(state.Job.Id))
+                    {
+                        await sourceStream.CopyToAsync(targetStream);
+                    }
+                }
+            }
+        }
+
+        private async Task ReadEventsAsync()
+        {
+            using (var stream = await backupArchiveLocation.OpenStreamAsync(state.Job.Id))
+            {
+                using (var reader = new EventStreamReader(stream))
+                {
+                    var eventIndex = 0;
+
+                    await reader.ReadEventsAsync(async (@event, attachment) =>
+                    {
+                        var eventData = @event.Data;
+
+                        var parsedEvent = eventDataFormatter.Parse(eventData);
+
+                        if (parsedEvent.Payload is SquidexEvent squidexEvent)
+                        {
+                            squidexEvent.Actor = state.Job.User;
+                        }
+
+                        foreach (var handler in handlers)
+                        {
+                            await handler.HandleAsync(parsedEvent, attachment);
+                        }
+
+                        await eventStore.AppendAsync(Guid.NewGuid(), @event.StreamName, new List<EventData> { @event.Data });
+
+                        eventIndex++;
+
+                        state.Job.Status = $"Handled event {eventIndex}";
+                    });
+                }
+            }
+        }
+
+        private async Task DoAsync(string start, string end, Func<Task> action)
+        {
+            state.Job.Status = start;
+
+            await action();
+
+            state.Job.Status = end;
+        }
+
+        public Task<J<IRestoreJob>> GetStateAsync()
         {
+            return Task.FromResult<J<IRestoreJob>>(state.Job);
         }
     }
 }

src/Squidex.Domain.Apps.Entities/Backup/State/RestoreState.cs

@@ -0,0 +1,17 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using Newtonsoft.Json;
+
+namespace Squidex.Domain.Apps.Entities.Backup.State
+{
+    public class RestoreState
+    {
+        [JsonProperty]
+        public RestoreStateJob Job { get; set; }
+    }
+}

src/Squidex.Domain.Apps.Entities/Backup/State/RestoreStateJob.cs

@@ -0,0 +1,38 @@
+// ==========================================================================
+//  Squidex Headless CMS
+// ==========================================================================
+//  Copyright (c) Squidex UG (haftungsbeschraenkt)
+//  All rights reserved. Licensed under the MIT license.
+// ==========================================================================
+
+using System;
+using Newtonsoft.Json;
+using NodaTime;
+using Squidex.Infrastructure;
+
+namespace Squidex.Domain.Apps.Entities.Backup.State
+{
+    public sealed class RestoreStateJob : IRestoreJob
+    {
+        [JsonProperty]
+        public Guid Id { get; set; } = Guid.NewGuid();
+
+        [JsonProperty]
+        public Guid AppId { get; set; }
+
+        [JsonProperty]
+        public RefToken User { get; set; }
+
+        [JsonProperty]
+        public Uri Uri { get; set; }
+
+        [JsonProperty]
+        public Instant Started { get; set; }
+
+        [JsonProperty]
+        public string Status { get; set; }
+
+        [JsonProperty]
+        public bool IsFailed { get; set; }
+    }
+}

src/Squidex.Domain.Apps.Entities/Tags/GrainTagService.cs

@@ -49,6 +49,11 @@ namespace Squidex.Domain.Apps.Entities.Tags
             return GetGrain(appId, group).GetTagsAsync();
         }
 
+        public Task RebuildTagsAsync(Guid appId, string group, Dictionary<string, string> allTags)
+        {
+            return GetGrain(appId, group).RebuildTagsAsync(allTags);
+        }
+
         public Task ClearAsync(Guid appId)
         {
             return GetGrain(appId, TagGroups.Assets).ClearAsync();

src/Squidex.Domain.Apps.Entities/Tags/ITagGrain.cs

@@ -22,5 +22,6 @@ namespace Squidex.Domain.Apps.Entities.Tags
         Task<Dictionary<string, int>> GetTagsAsync();
 
         Task ClearAsync();
+        Task RebuildTagsAsync(Dictionary<string, string> allTags);
     }
 }

src/Squidex.Domain.Apps.Entities/Tags/ITagService.cs

@@ -20,5 +20,7 @@ namespace Squidex.Domain.Apps.Entities.Tags
         Task<Dictionary<string, string>> DenormalizeTagsAsync(Guid appId, string group, HashSet<string> ids);
 
         Task<Dictionary<string, int>> GetTagsAsync(Guid appId, string group);
+
+        Task RebuildTagsAsync(Guid appId, string group, Dictionary<string, string> allTags);
     }
 }

src/Squidex.Domain.Apps.Entities/Tags/TagGrain.cs

@@ -58,6 +58,11 @@ namespace Squidex.Domain.Apps.Entities.Tags
             return persistence.DeleteAsync();
         }
 
+        public Task RebuildTagsAsync(Dictionary<string, string> allTags)
+        {
+            throw new NotImplementedException();
+        }
+
         public async Task<HashSet<string>> NormalizeTagsAsync(HashSet<string> names, HashSet<string> ids)
         {
             var result = new HashSet<string>();

src/Squidex.Infrastructure.GetEventStore/EventSourcing/Formatter.cs

@@ -24,6 +24,7 @@ namespace Squidex.Infrastructure.EventSourcing
             var eventData = new EventData { Type = @event.EventType, Payload = body, Metadata = meta };
 
             return new StoredEvent(
+                @event.EventStreamId,
                 resolvedEvent.OriginalEventNumber.ToString(),
                 resolvedEvent.Event.EventNumber,
                 eventData);

src/Squidex.Infrastructure.MongoDb/EventSourcing/MongoEventStore_Reader.cs

@@ -60,7 +60,7 @@ namespace Squidex.Infrastructure.EventSourcing
                             var eventData = e.ToEventData();
                             var eventToken = new StreamPosition(commitTimestamp, commitOffset, commit.Events.Length);
 
-                            result.Add(new StoredEvent(eventToken, eventStreamOffset, eventData));
+                            result.Add(new StoredEvent(streamName, eventToken, eventStreamOffset, eventData));
                         }
                     }
                 }
@@ -111,7 +111,7 @@ namespace Squidex.Infrastructure.EventSourcing
                             var eventData = e.ToEventData();
                             var eventToken = new StreamPosition(commitTimestamp, commitOffset, commit.Events.Length);
 
-                            await callback(new StoredEvent(eventToken, eventStreamOffset, eventData));
+                            await callback(new StoredEvent(commit.EventStream, eventToken, eventStreamOffset, eventData));
 
                             commitOffset++;
                         }

src/Squidex.Infrastructure/EventSourcing/StoredEvent.cs

@@ -9,14 +9,17 @@ namespace Squidex.Infrastructure.EventSourcing
 {
     public sealed class StoredEvent
     {
+        public string StreamName { get; }
+
         public string EventPosition { get; }
 
         public long EventStreamNumber { get; }
 
         public EventData Data { get; }
 
-        public StoredEvent(string eventPosition, long eventStreamNumber, EventData data)
+        public StoredEvent(string streamName, string eventPosition, long eventStreamNumber, EventData data)
         {
+            Guard.NotNullOrEmpty(streamName, nameof(streamName));
             Guard.NotNullOrEmpty(eventPosition, nameof(eventPosition));
             Guard.NotNull(data, nameof(data));
 
@@ -24,6 +27,8 @@ namespace Squidex.Infrastructure.EventSourcing
 
             EventPosition = eventPosition;
             EventStreamNumber = eventStreamNumber;
+
+            StreamName = streamName;
         }
     }
 }

tests/Squidex.Domain.Apps.Entities.Tests/Backup/EventStreamTests.cs

@@ -18,7 +18,7 @@ namespace Squidex.Domain.Apps.Entities.Backup
     {
         public sealed class EventInfo
         {
-            public EventData Data { get; set; }
+            public StoredEvent Stored { get; set; }
 
             public byte[] Attachment { get; set; }
         }
@@ -33,7 +33,7 @@ namespace Squidex.Domain.Apps.Entities.Backup
             for (var i = 0; i < 1000; i++)
             {
                 var eventData = new EventData { Type = i.ToString(), Metadata = i, Payload = i };
-                var eventInfo = new EventInfo { Data = eventData };
+                var eventInfo = new EventInfo { Stored = new StoredEvent("S", "1", 2, eventData) };
 
                 if (i % 10 == 0)
                 {
@@ -49,11 +49,11 @@ namespace Squidex.Domain.Apps.Entities.Backup
                 {
                     if (@event.Attachment == null)
                     {
-                        await reader.WriteEventAsync(@event.Data);
+                        await reader.WriteEventAsync(@event.Stored);
                     }
                     else
                     {
-                        await reader.WriteEventAsync(@event.Data, s => s.WriteAsync(@event.Attachment, 0, 1));
+                        await reader.WriteEventAsync(@event.Stored, s => s.WriteAsync(@event.Attachment, 0, 1));
                     }
                 }
             }
@@ -64,9 +64,9 @@ namespace Squidex.Domain.Apps.Entities.Backup
 
             using (var reader = new EventStreamReader(stream))
             {
-                await reader.ReadEventsAsync(async (eventData, attachment) =>
+                await reader.ReadEventsAsync(async (stored, attachment) =>
                 {
-                    var eventInfo = new EventInfo { Data = eventData };
+                    var eventInfo = new EventInfo { Stored = stored };
 
                     if (attachment != null)
                     {

tests/Squidex.Infrastructure.Tests/EventSourcing/Grains/EventConsumerGrainTests.cs

@@ -173,7 +173,7 @@ namespace Squidex.Infrastructure.EventSourcing.Grains
         [Fact]
         public async Task Should_invoke_and_update_position_when_event_received()
         {
-            var @event = new StoredEvent(Guid.NewGuid().ToString(), 123, eventData);
+            var @event = new StoredEvent("Stream", Guid.NewGuid().ToString(), 123, eventData);
 
             await sut.OnActivateAsync(consumerName);
             await sut.ActivateAsync();
@@ -195,7 +195,7 @@ namespace Squidex.Infrastructure.EventSourcing.Grains
             A.CallTo(() => formatter.Parse(eventData, true))
                 .Throws(new TypeNameNotFoundException());
 
-            var @event = new StoredEvent(Guid.NewGuid().ToString(), 123, eventData);
+            var @event = new StoredEvent("Stream", Guid.NewGuid().ToString(), 123, eventData);
 
             await sut.OnActivateAsync(consumerName);
             await sut.ActivateAsync();
@@ -214,7 +214,7 @@ namespace Squidex.Infrastructure.EventSourcing.Grains
         [Fact]
         public async Task Should_not_invoke_and_update_position_when_event_is_from_another_subscription()
         {
-            var @event = new StoredEvent(Guid.NewGuid().ToString(), 123, eventData);
+            var @event = new StoredEvent("Stream", Guid.NewGuid().ToString(), 123, eventData);
 
             await sut.OnActivateAsync(consumerName);
             await sut.ActivateAsync();
@@ -302,7 +302,7 @@ namespace Squidex.Infrastructure.EventSourcing.Grains
             A.CallTo(() => eventConsumer.On(envelope))
                 .Throws(ex);
 
-            var @event = new StoredEvent(Guid.NewGuid().ToString(), 123, eventData);
+            var @event = new StoredEvent("Stream", Guid.NewGuid().ToString(), 123, eventData);
 
             await sut.OnActivateAsync(consumerName);
             await sut.ActivateAsync();
@@ -329,7 +329,7 @@ namespace Squidex.Infrastructure.EventSourcing.Grains
             A.CallTo(() => formatter.Parse(eventData, true))
                 .Throws(ex);
 
-            var @event = new StoredEvent(Guid.NewGuid().ToString(), 123, eventData);
+            var @event = new StoredEvent("Stream", Guid.NewGuid().ToString(), 123, eventData);
 
             await sut.OnActivateAsync(consumerName);
             await sut.ActivateAsync();
@@ -356,7 +356,7 @@ namespace Squidex.Infrastructure.EventSourcing.Grains
             A.CallTo(() => eventConsumer.On(envelope))
                 .Throws(exception);
 
-            var @event = new StoredEvent(Guid.NewGuid().ToString(), 123, eventData);
+            var @event = new StoredEvent("Stream", Guid.NewGuid().ToString(), 123, eventData);
 
             await sut.OnActivateAsync(consumerName);
             await sut.ActivateAsync();

tests/Squidex.Infrastructure.Tests/EventSourcing/RetrySubscriptionTests.cs

@@ -90,7 +90,7 @@ namespace Squidex.Infrastructure.EventSourcing
         [Fact]
         public async Task Should_forward_event_from_inner_subscription()
         {
-            var ev = new StoredEvent("1", 2, new EventData());
+            var ev = new StoredEvent("Stream", "1", 2, new EventData());
 
             await OnEventAsync(eventSubscription, ev);
             await sut.StopAsync();
@@ -102,7 +102,7 @@ namespace Squidex.Infrastructure.EventSourcing
         [Fact]
         public async Task Should_not_forward_event_when_message_is_from_another_subscription()
         {
-            var ev = new StoredEvent("1", 2, new EventData());
+            var ev = new StoredEvent("Stream", "1", 2, new EventData());
 
             await OnEventAsync(A.Fake<IEventSubscription>(), ev);
             await sut.StopAsync();

tests/Squidex.Infrastructure.Tests/States/PersistenceEventSourcingTests.cs

@@ -56,7 +56,7 @@ namespace Squidex.Infrastructure.States
         [Fact]
         public async Task Should_ignore_old_events()
         {
-            var storedEvent = new StoredEvent("1", 0, new EventData());
+            var storedEvent = new StoredEvent("1", "1", 0, new EventData());
 
             A.CallTo(() => eventStore.QueryAsync(key, 0))
                 .Returns(new List<StoredEvent> { storedEvent });
@@ -252,7 +252,7 @@ namespace Squidex.Infrastructure.States
             foreach (var @event in events)
             {
                 var eventData = new EventData();
-                var eventStored = new StoredEvent(i.ToString(), i, eventData);
+                var eventStored = new StoredEvent(i.ToString(), i.ToString(), i, eventData);
 
                 eventsStored.Add(eventStored);