Pbe 4109 implement state sync after disconnecting (#152)

* Move CreatedAt to EventBase

* Implement retrieving missed WS events during disconnection period

* Create test implementation for the state recovery after disconnected period

* cleanup + improve test scenarios

* cleanup

* Fix potential null ref

* rename var + add todo

* Fix null reference

* Fix cache null ref

* Add 1 more test case to sync tests

* Sort channel messages. This can be needed when client reconnects and sends a message before /sync result is returned and processed

* Fix null ref on Channel.Type

Author: sierpinskid

Assets/Plugins/StreamChat/Core/InternalDTO/Responses/SyncResponseInternalDTO.cs

@@ -23,7 +23,7 @@ internal partial class SyncResponseInternalDTO
         /// List of events
         /// </summary>
         [Newtonsoft.Json.JsonProperty("events", Required = Newtonsoft.Json.Required.Default, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
-        public System.Collections.Generic.List<EventInternalDTO> Events { get; set; } = new System.Collections.Generic.List<EventInternalDTO>();
+        public System.Collections.Generic.List<object> Events { get; set; } = new System.Collections.Generic.List<object>();
 
         /// <summary>
         /// List of CIDs that user can't access

Assets/Plugins/StreamChat/Core/LowLevelClient/API/ChannelApi.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Threading.Tasks;
 using StreamChat.Core.Helpers;
+using StreamChat.Core.InternalDTO.Requests;
 using StreamChat.Core.InternalDTO.Responses;
 using StreamChat.Core.LowLevelClient.API.Internal;
 using StreamChat.Core.LowLevelClient.Models;
@@ -141,6 +142,12 @@ public Task SendTypingStartEventAsync(string channelType, string channelId)
         public Task SendTypingStopEventAsync(string channelType, string channelId)
             => _internalChannelApi.SendTypingStopEventAsync(channelType, channelId);
 
+        public async Task<SyncResponse> SyncAsync(SyncRequest syncRequest)
+        {
+            var dto = await _internalChannelApi.SyncAsync(syncRequest.TrySaveToDto());
+            return dto.ToDomain<SyncResponseInternalDTO, SyncResponse>();
+        }
+
         private readonly IInternalChannelApi _internalChannelApi;
     }
 }

Assets/Plugins/StreamChat/Core/LowLevelClient/API/IChannelApi.cs

@@ -150,5 +150,8 @@ Task<MarkReadResponse> MarkReadAsync(string channelType, string channelId,
         Task SendTypingStartEventAsync(string channelType, string channelId);
 
         Task SendTypingStopEventAsync(string channelType, string channelId);
+
+        //StreamTodo: perhaps we can skip this declaration and use the Internal one directly
+        Task<SyncResponse> SyncAsync(SyncRequest syncRequest); 
     }
 }

Assets/Plugins/StreamChat/Core/LowLevelClient/API/Internal/IInternalChannelApi.cs

@@ -52,5 +52,7 @@ Task<MarkReadResponseInternalDTO> MarkReadAsync(string channelType, string chann
         Task SendTypingStartEventAsync(string channelType, string channelId);
 
         Task SendTypingStopEventAsync(string channelType, string channelId);
+
+        Task<SyncResponseInternalDTO> SyncAsync(SyncRequestInternalDTO syncRequest);
     }
 }

Assets/Plugins/StreamChat/Core/LowLevelClient/API/Internal/InternalChannelApi.cs

@@ -133,5 +133,8 @@ public Task SendTypingStopEventAsync(string channelType, string channelId)
             {
                 Type = WSEventType.TypingStop
             });
+
+        public Task<SyncResponseInternalDTO> SyncAsync(SyncRequestInternalDTO syncRequest)
+            => Post<SyncRequestInternalDTO, SyncResponseInternalDTO>($"/sync", syncRequest);
     }
 }

Assets/Plugins/StreamChat/Core/LowLevelClient/API/Internal/InternalMessageApi.cs

@@ -1,5 +1,4 @@
-using System.Net.Http;
-using System.Threading.Tasks;
+using System.Threading.Tasks;
 using StreamChat.Core.InternalDTO.Requests;
 using StreamChat.Core.InternalDTO.Responses;
 using StreamChat.Core.Web;

Assets/Plugins/StreamChat/Core/LowLevelClient/Events/EventBase.cs

@@ -2,6 +2,8 @@ namespace StreamChat.Core.LowLevelClient.Events
 {
     public abstract class EventBase
     {
+        public System.DateTimeOffset CreatedAt { get; set; }
+
         private System.Collections.Generic.Dictionary<string, object> _additionalProperties = new System.Collections.Generic.Dictionary<string, object>();
 
         [Newtonsoft.Json.JsonExtensionData]

Assets/Plugins/StreamChat/Core/LowLevelClient/Events/EventChannelDeleted.cs

@@ -15,8 +15,6 @@ public sealed class EventChannelDeleted : EventBase,
 
         public string Cid { get; set; }
 
-        public System.DateTimeOffset? CreatedAt { get; set; }
-
         public string Team { get; set; }
 
         public string Type { get; set; }

Assets/Plugins/StreamChat/Core/LowLevelClient/Events/EventChannelHidden.cs

@@ -18,8 +18,6 @@ public sealed class EventChannelHidden : EventBase,
 
         public bool? ClearHistory { get; set; }
 
-        public System.DateTimeOffset? CreatedAt { get; set; }
-
         public string Type { get; set; }
 
         public User User { get; set; }

Assets/Plugins/StreamChat/Core/LowLevelClient/Events/EventChannelTruncated.cs

@@ -17,8 +17,6 @@ public sealed class EventChannelTruncated : EventBase,
 
         public string Cid { get; set; }
 
-        public System.DateTimeOffset? CreatedAt { get; set; }
-
         public string Type { get; set; }
 
         EventChannelTruncated ILoadableFrom<ChannelTruncatedEventInternalDTO, EventChannelTruncated>.LoadFromDto(