From 7b71e568177f1d827316dd3930ac64fd2921f5c0 Mon Sep 17 00:00:00 2001
From: Craftplacer <craftplacer@outlook.de>
Date: Thu, 2 Jan 2020 17:07:28 +0100
Subject: [PATCH] Initial commit

---
 .../API/Requests/MarkChannelAsReadRequest.cs  | 21 +++++++++++++++++++
 osu.Game/Online/Chat/Channel.cs               |  8 +++++++
 osu.Game/Online/Chat/ChannelManager.cs        |  8 +++++++
 3 files changed, 37 insertions(+)
 create mode 100644 osu.Game/Online/API/Requests/MarkChannelAsReadRequest.cs

diff --git a/osu.Game/Online/API/Requests/MarkChannelAsReadRequest.cs b/osu.Game/Online/API/Requests/MarkChannelAsReadRequest.cs
new file mode 100644
index 0000000000..3f28037816
--- /dev/null
+++ b/osu.Game/Online/API/Requests/MarkChannelAsReadRequest.cs
@@ -0,0 +1,21 @@
+// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
+// See the LICENCE file in the repository root for full licence text.
+
+using osu.Game.Online.Chat;
+
+namespace osu.Game.Online.API.Requests
+{
+    public class MarkChannelAsReadRequest : APIRequest
+    {
+        private readonly Channel channel;
+        private readonly Message message;
+
+        public MarkChannelAsReadRequest(Channel channel, Message message)
+        {
+            this.channel = channel;
+            this.message = message;
+        }
+
+        protected override string Target => @"/chat/channels/{channel}/mark-as-read/{message}";
+    }
+}
diff --git a/osu.Game/Online/Chat/Channel.cs b/osu.Game/Online/Chat/Channel.cs
index 451174a73c..6f67a95f53 100644
--- a/osu.Game/Online/Chat/Channel.cs
+++ b/osu.Game/Online/Chat/Channel.cs
@@ -36,6 +36,11 @@ namespace osu.Game.Online.Chat
         /// </summary>
         public readonly SortedList<Message> Messages = new SortedList<Message>(Comparer<Message>.Default);
 
+        /// <summary>
+        /// Contains all the messages that weren't read by the user.
+        /// </summary>
+        public IEnumerable<Message> UnreadMessages => Messages.Where(m => LastReadId < m.Id);
+
         /// <summary>
         /// Contains all the messages that are still pending for submission to the server.
         /// </summary>
@@ -75,6 +80,9 @@ namespace osu.Game.Online.Chat
         [JsonProperty(@"last_message_id")]
         public long? LastMessageId;
 
+        [JsonProperty(@"last_read_id")]
+        public long? LastReadId;
+
         /// <summary>
         /// Signalles if the current user joined this channel or not. Defaults to false.
         /// </summary>
diff --git a/osu.Game/Online/Chat/ChannelManager.cs b/osu.Game/Online/Chat/ChannelManager.cs
index 1d8c5609d9..e92a4853ff 100644
--- a/osu.Game/Online/Chat/ChannelManager.cs
+++ b/osu.Game/Online/Chat/ChannelManager.cs
@@ -445,6 +445,14 @@ namespace osu.Game.Online.Chat
             return tcs.Task;
         }
 
+        public void MarkChannelAsRead(Message message)
+        {
+            var channel = JoinedChannels.First(c => c.Id == message.ChannelId);
+            var req = new MarkChannelAsReadRequest(channel, message);
+            req.Success += () => channel.LastReadId = message.Id;
+            api.Queue(req);
+        }
+
         [BackgroundDependencyLoader]
         private void load(IAPIProvider api)
         {