[server] Add protocol event to remove a line segment by unique id

Nibriboard/Client/Messages/LineRemoveMessage.cs

@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using Nibriboard.RippleSpace;
+
+namespace Nibriboard.Client.Messages
+{
+	public class LineRemoveMessage : Message
+	{
+		/// <summary>
+		/// A reference to the chunk that contains the line to remove.
+		/// </summary>
+		public RawChunkReference ContainingChunk;
+
+		/// <summary>
+		/// The unique id of the line segment to remove.
+		/// </summary>
+		public string UniqueId;
+
+		public LineRemoveMessage()
+		{
+		}
+
+		/// <summary>
+		/// Returns the raw ContainingChunk as a ChunkReference.
+		/// </summary>
+		/// <param name="plane">The plane to put the chunk reference on.</param>
+		/// <returns>The containing chunk as a regular chunk reference.</returns>
+		public ChunkReference ConvertedContainingChunk(Plane plane)
+		{
+			if(ContainingChunk.planeName as string != plane.Name)
+				throw new InvalidDataException($"Error: A raw reference was for the plane " +
+					"'{rawRef.planeName}', but the plane '{plane.Name}' " +
+					"was specified as the plane to lay the chunk references onto!");
+			
+			return new ChunkReference(plane, ContainingChunk.x, ContainingChunk.y);
+		}
+	}
+}

Nibriboard/Client/NibriClient.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Threading.Tasks;
-using System.Text;
 using System.Linq;
 using System.Reflection;
 
@@ -59,6 +58,7 @@ namespace Nibriboard.Client
 			["LineStart"] = typeof(LineStartMessage),
 			["LinePart"] = typeof(LinePartMessage),
 			["LineComplete"] = typeof(LineCompleteMessage),
+			["LineRemove"] = typeof(LineRemoveMessage),
 			["ViewportUpdate"] = typeof(ViewportUpdateMessage)
 		};
 
@@ -189,7 +189,7 @@ namespace Nibriboard.Client
 		#region Message Sending
 
 		/// <summary>
-		/// Sends a <see cref="Nibriboard.Client.Messages.Message"/> to the client.
+		/// Sends a <see cref="Message"/> to the client.
 		/// If you *really* need to send a raw message to the client, you can do so with the SendRawa() method.
 		/// </summary>
 		/// <param name="message">The message to send.</param>
@@ -487,6 +487,19 @@ namespace Nibriboard.Client
 			await CurrentPlane.AddLine(line);
 		}
 
+		/// <summary>
+		/// Handles messages requesting that a line be removed from a chunk.
+		/// </summary>
+		/// <param name="message">The message to handle.</param>
+		protected async Task handleLineRemoveMessage(LineRemoveMessage message)
+		{
+			bool removeSuccess = await CurrentPlane.RemoveLineSegment(
+				message.ConvertedContainingChunk(CurrentPlane),
+				message.UniqueId
+			);
+			Log.WriteLine("[NibriClient#{1}] " + (removeSuccess ? "Removed" : "Failed to remove") + " line segment with unique id {0} from {1}", message.UniqueId, message.ConvertedContainingChunk(CurrentPlane));
+		}
+
 		#endregion
 
 		#region RippleSpace Event Handlers

Nibriboard/Nibriboard.csproj

@@ -137,6 +137,7 @@
 		<Compile Include="Client\Messages\ViewportUpdateMessage.cs" />
 		<Compile Include="NibriboardApp.cs" />
 		<Compile Include="Utilities\LineSimplifier.cs" />
+		<Compile Include="Client\Messages\LineRemoveMessage.cs" />
 	</ItemGroup>
 	<!--
 	<ItemGroup>

Nibriboard/RippleSpace/Chunk.cs

@@ -199,6 +199,15 @@ namespace Nibriboard.RippleSpace
 			OnChunkUpdate(this, new ChunkUpdateEventArgs() { UpdateType = ChunkUpdateType.Addition });
 		}
 
+		/// <summary>
+		/// Removes the line in this chunk with the specified unique id.
+		/// </summary>
+		/// <param name="targetLineUniqueId">The id of the line to remove.</param>
+		public bool Remove(string targetLineUniqueId)
+		{
+			return lines.RemoveAll((line) => line.UniqueId == targetLineUniqueId) > 0;
+		}
+
 		public IEnumerator<DrawnLine> GetEnumerator()
 		{
 			UpdateAccessTime();

Nibriboard/RippleSpace/Plane.cs

@@ -229,6 +229,12 @@ namespace Nibriboard.RippleSpace
 			}
 		}
 
+		public async Task<bool> RemoveLineSegment(ChunkReference containingChunk, string targetLineUniqueId)
+		{
+			Chunk chunk = await FetchChunk(containingChunk);
+			return chunk.Remove(targetLineUniqueId);
+		}
+
 		public void PerformMaintenance()
 		{
 			// Be lazy and don't bother to perform maintenance if it's not needed