Add ClosedAt column to Channels table and update timestamp on closure

src/Data/Models/Channel.cs

@@ -47,6 +47,12 @@ public enum ChannelStatus
 
         public ChannelStatus Status { get; set; }
 
+        /// <summary>
+        /// Timestamp at which the channel transitioned to <see cref="ChannelStatus.Closed"/>.
+        /// Null while the channel is open or for channels closed before this column existed.
+        /// </summary>
+        public DateTimeOffset? ClosedAt { get; set; }
+
         /// <summary>
         /// Indicates if this channel was created by NodeGuard
         /// </summary>

src/Data/Repositories/ChannelRepository.cs

@@ -186,6 +186,8 @@ public async Task<List<Channel>> GetAll()
         {
             using var applicationDbContext = _dbContextFactory.CreateDbContext();
 
+            type.SetUpdateDatetime();
+
             //Automapper to avoid creation of entities
             type = _mapper.Map<Channel, Channel>(type);
 
@@ -340,6 +342,7 @@ public async Task<List<Channel>> GetAllManagedByUserNodes(string loggedUserId)
             }
 
             channel.Status = Channel.ChannelStatus.Closed;
+            channel.ClosedAt = DateTimeOffset.UtcNow;
 
             var markAsClosed = _repository.Update(channel, applicationDbContext);
 

src/Jobs/ChannelMonitorJob.cs

@@ -206,6 +206,7 @@ public async Task MarkClosedChannelsAsClosed(Node source, List<Channel>? channel
                 if (channel == null)
                 {
                     openChannel.Status = ChannelStatus.Closed;
+                    openChannel.ClosedAt = DateTimeOffset.UtcNow;
                     await dbContext.SaveChangesAsync();
                 }
             }

src/Jobs/NodeChannelSubscribeJob.cs

@@ -166,6 +166,7 @@ public async Task NodeUpdateManagement(ChannelEventUpdate channelEventUpdate, No
                 else
                 {
                     channelToClose.Status = Channel.ChannelStatus.Closed;
+                    channelToClose.ClosedAt = DateTimeOffset.UtcNow;
                     var updateChannel = _channelRepository.Update(channelToClose);
                     if (!updateChannel.Item1)
                     {